2013年10月28日星期一

Problems existing substation automation substation automation stations in the plant design and configuration

Zhu indistinct substation automation in our more than ten years of development, becoming more perfect and mature , improve the power grid has become a safe and reliable operation of the mandatory measures , widely used in the country . But substation automation applications still exist some problems. This article from the substation automation plant stand design and configuration , information processing and  mcb circuit breaker  the application of these angles . Problems existing substation automation substation automation stations in the plant design and configuration , information processing primarily in the following three questions. Traditional analog  power transformers  collection method is to a high voltage device information through the transformer 5 is converted to a voltage signal and current signal IA knife , the corresponding  Circuit breaker  the second cable protection and control device, the device and then through the respective small transformer to convert it again to implement it collected . And because the protection and control devices on the technical requirements of the current transformer is not the same , you need to install the transformer , respectively . Since the nodes in the grid substation , is the source of a variety of electrical quantities collected , so there are often multiple sets of substation systems and equipment , such as mechanized from the system , fault recorder , PMIJ more.

Protect power dispatch control system and its network information security

In substation automation, the current protocol used functions are not set to ensure that the control commands from the initiator is authorized, there is no effective measures to prevent the passage is likely to occur on the communication line circuit breaker operations such as forgery SCADA instruction terrorist threat. how to  air circuit breaker  the power dispatch control system and network information security, to achieve the important information or access control critical operations has become a very urgent task. research institutions at home and abroad on the power  mcb circuit breaker  security issues widely research, but the study focused on the power entry point for information systems security system and safety  Voltage stabilizer  on the issue, and for the substation automation system data exchange, system configuration access control problems exist, but has not put forward practical solutions.

The negative impact of information technology also spread to the power system

Fault information processing, based on wide area measurement system (WAMS) and on-line dynamic security analysis (DSA) Wide Area Protection (WAP) technology also has been applied to the power system, these new protection and control systems are in wide-area  Voltage stabilizer  and has a multi-point data communication because, frequent data communication, data flow continuously characteristics, the traditional power system remote terminal / modem (RTU / Modem) mode can not meet the need, the need to use standard Ethernet and TCP / IP protocol. On the other hand, with the computer and network technology in power system wide application of  mcb circuit breaker  also spread to the negative impact of the power system. With the public Internet hackers and viruses growing popularity, domestic electric power information system has also been found traces of hacker activity. In  power transformers , the current protocol used functions are not set to ensure that the control commands from the initiator is authorized, there is no effective measures to prevent the passage is likely to occur on the communication line circuit breaker operations such as forgery SCADA instruction terrorist threat.

Substation automation to achieve the security of remote communication

Substation Automation Communication major security issue is how to effectively protect the power dispatch control system and network information security, to achieve the confidentiality of communications and sponsors of authorized certification. This research work is proposed response to this demand, the use of TCG (Trusted Computing Group) and IEC61850 (substation communication networks and systems) and other latest  power transformers  architecture and basic method is proposed based on trusted computing and remote procedure call (RPC) for substation automation remote communication security system, the use of this system, can achieve a secure  mcb circuit breaker  substation automation. In addition, the design of this system remote platform with the local RPC communication between the platform and the capacitor protection device, for example, establish a safety  Voltage stabilizer  logical node model. Finally, the circuit breaker switching control, for example, the design of the control information from the control center to the secure transmission of the spacer layer flow of the IED.

Existing substation substation remote viewing system to achieve dynamic integration of environmental data

Currently substation remote video systems , there are still shortcomings and deficiencies , affecting unmanned substation construction . Power substation remote viewing system environmental data is not comprehensive, and its lower-level power system transmission of  electric meter  trends , making the remote monitoring system for dynamic data integration environment increasingly urgent . This article uses the VC object-oriented programming techniques , TCP / IP protocol , power communication protocol , sockets, and database technology developed to multifunction device control server hosts and dynamic environment as the main driving force of environmental data system . They are connected to the existing substation remote viewing system to achieve power substation  power transformers  integration. Multifunction Device Control host is responsible for access substation data acquisition control module, such as temperature and humidity logger , fire safety and security module , alarm collector, air conditioning lighting controllers. Acquisition front-end information, and  Voltage stabilizer  dynamic environment server, and the information collected statistics show run interface. Dynamic environment server uploads front-end collection information and management control commands sent by the server to forward to the multifunction device control panel for control . Dynamic environment control host server and multifunction devices recommended by the state power communication protocol communication .

Electricity substation remote monitoring system is a product of the development of automation technology

With the digital image communication technology and multimedia technology, the implementation in the substation remote video surveillance system to solve the visualization of the substation site and environmental monitoring issues for the realization of "unattended, fewer people on duty" to provide a reliable guarantee. Remote viewing system is the power substation automation technology product development, and due to the safe operation of unmanned substation needs generated power system  circuit breakers  system involves the study of video surveillance of key technologies, the substation remote video system design and implementation study has some value in  electric meter . Unmanned substation operation and management has become the main mode of unattended substation is the main technical means implementing substation automation, automated computer protection, data acquisition, measurement, device or remotely, remote adjustment, parameter adjustment and various signal monitoring other functions.

The substation electromagnetic interference on secondary cable coupling into three categories

Starting from the concept of electromagnetic compatibility, on the main substation electromagnetic interference were classified, according to the object of study - disturbed secondary cable pathways and mechanisms are different, the secondary  mcb circuit breaker  electromagnetic interference coupled into three cables categories: conductive coupling, radiation coupling and the secondary circuit itself coupling; focuses on the FDTD method in the multi-conductor transmission line model in the application of the finite difference time domain method in a different multi-conductor  power transformers  connection in the case were computer simulation and explores the coupling law; the cables in the laboratory experiments, the finite difference time domain method validation, and a variety of interference signals on the cable interference generated by computer simulation

2013年10月18日星期五

Transformer fault diagnosis, there is a large number of expert experience

With the continuous development of the electricity market, people on the reliability of power supply put forward higher requirements, which requires electricity to run the department as soon as possible from planned maintenance to condition-based  electri cenergy meter  mechanism to changes in the mechanism. In recent years, with the oil chromatographic analyzer successful development of online and digital signal processing technology and other related areas of continuous development  mcb circuit breaker , making this  circuit breakers  possible. In transformer fault diagnosis, there is a large number of expert experience, it is difficult to establish a precise mathematical model. The expert system was able to effectively solve this kind of problem, the information is incomplete or uncertain circumstances, still be able to give a more reasonable conclusion.

Transformer oil chromatographic analysis results to determine the operational status of the transformer

A variety of devices in the power system, transformers are expensive and important, which runs the state will have a direct impact on the safe operation of the system. For a long time, according to various offline preventive tests and transformer oil  mcb circuit breaker  analysis results to determine the operational status of the transformer, to a certain extent, can prevent accidents, but regular  power transformers  mechanisms and off-line test, however, exposed to the following questions: on the one hand blindly may be in a good condition for the regular maintenance of  electric meter , resulting in a waste of human and material resources; on the other hand, there are still some drawbacks due to equipment overhaul failed to discover and develop into a major failure is possible.

Digital signal processing technology and other related fields of continuous development and improvement

In recent years, with the oil chromatographic analyzer successful development of online and digital signal processing technology and  Voltage stabilizer  fields of continuous development and improvement, to make this change possible.  In the transformer fault diagnosis, there are a lot of expert experience, it is difficult to establish a  electri cenergy meter  model. The expert system was able to effectively solve this kind of problem, the information is incomplete or uncertain circumstances, still be able to give a more reasonable conclusion. Therefore, this paper  power transformers  of a large number of original features obtained through online data, the paper introduces a rule-based production method as a knowledge representation, the choice of forward chaining inference mechanism.

In good condition of the transformer equipment, regular maintenance

For a long time, according to various offline preventive tests and transformer oil chromatographic analysis results to determine the operational status of the transformer, to a certain extent, can prevent accidents. However, regular maintenance mechanisms and offline tests, on the one hand may be in a good condition of the transformer equipment, regular maintenance, resulting in a waste of human and  mcb circuit breaker ; the other hand, there are still some drawbacks due to equipment failure when  electric transformer  is to discover and develop into major failure is possible. With the continuous development of the electricity market, people on the reliability of power supply put forward higher requirements. This requires electricity to run the department as soon as possible from planned maintenance to condition-based maintenance mechanism to changes in the mechanism.

Inductive load transient phenomena circuit, when the power supply is suddenly cut off, and instantly across the inductor to form a high kickback voltage

Inductive loads such as motors in life and is widely used in production, and inductive load in the circuit is in the "on" or "off" time will produce a high voltage spark discharge is also generated. Therefore, this paper first inductive load transient phenomena in order to analyze, and then propose the use of "contact  mcb circuit breaker " approach to reduce the noise  mcb circuit breaker  contacts and load, while extending the service life of contacts. Inductive load transient phenomena circuit, when the power supply is suddenly cut off, and instantly across the inductor to  electric transformer  voltage. Bridge rectifier diode breakdown; bridge rectifiers plastic deformation at the micro-switch; bridge rectifier micro switch catching; coil burning; micro switch cover cracked. Electromagnetic contactor for the three-phase AC contactor is mainly used to control the locomotive of the auxiliary motor work. Its low voltage coil control part of the bridge rectifier for the AC-DC dual-use design.

Electrical breakdown can cause contact with physical damage, thereby reducing its life

For switching contactors, both contacts open or connected to current transmission circuit between the contacts will produce electrical breakdown phenomenon, this electrical breakdown in contacts gradually close to each other but have not generated when the contact. When gradually close contact, the electrical breakdown  Circuit breaker the contact is closed; contact gradually disconnected, the electric breakdown phenomenon  Electric transformer  maintain electrical breakdown condition is no longer met. Electrical breakdown can cause contact with physical damage, thereby reducing its life.  power transformers , electrical breakdown will produce high-frequency radiation, causes the line voltage or current surges occur signal, this signal becomes a surge affecting other sources of interference circuit to work.

Fault content and composition of the gas type transformer fault linkages between

This paper analyzes the characteristics of transformer fault based on the DGA valid information provided to study the composition of the gas content and the fault type of fault between phase transformer mutual contact. As the traditional  electric meter  fault diagnosis  Voltage stabilizer  detection accuracy is not high, requires a lot of experience and so insufficient, the urgent need to introduce some new  power transformers  fault diagnosis techniques to compensate for the current transformer fault diagnosis in a variety of defects. Support vector machine is in statistical theory developed on the basis of a new learning method, which not only can solve the neural network algorithm in high-dimensional problems and local minima problems, but also for small samples with good learning generalization ability.

Packaging container detection process, using the detection and control methods of

Real-time data exchange, new ways of monitoring and management, research and development of the domestic advanced level of electronic control thermostat Stacking detection equipment. Consists of three parts, introducing the domestic packaging  mcb circuit breaker  in the testing process, using the method of detection and control the status of adopted international advanced detection control method proposed has  electric meter  monitoring, PLC programmable logic controller detection and control meaning. Chapter 2, the hardware circuit design, first introduced  Voltage stabilizer  proportional control technology control the loading force control method, and details the process, then, theoretically detail the object at the top with two tilt angle sensor Feasibility and measured the formation of the program.

Film resistance thermometer is three-dimensional

All along, the theoretical analysis of thin-film resistance thermometers are from a two-dimensional medium is deduced simplified as a semi-infinite-dimensional mathematical model, through numerical integration or thermoelectric conversion of analog networks to get the sensor surface heat flow values. However, the film resistance  mcb circuit breaker  is three-dimensional, the surface of the platinum layer is a temperature  power transformers , and as the temperature rises the platinum layer into the platinum layer of the heat flow will gradually decrease. Therefore, the temperature of the test information is actually measured is a time-varying flux caused by the hot wall, which in the latter part of the data processing must be considered.

Power Transformer Fault Detection Technology Research

Power transformer fault location method of providing practical basis. Analysis of power transformer fault detection technology, to further explore the power transformer internal  electric meter  and effective way. The use of fault tree analysis techniques (FTA) to build a power transformer internal fault classification tree model, will be  circuit breakers  into electric power transformer fault localization studies. Study the characteristics of ant colony algorithm, principles, algorithms and implementation process model. Pheromone ant colony algorithm, the information heuristic function factor, the number of ants, ant colony algorithm expectations inspired performance factors on the impact of simulation studies.

2013年10月10日星期四

Complete packaging container inspection system electronic control thermostat Stacking detection equipment on the basis of written

Upon completion of the packaging container inspection system electronic control thermostat Stacking detection equipment on the basis of written. At present, the packaging  electric transformer  production and export commodities inspection and testing of packaging containers, loaded by hand stacking method, load it backward technology, labor-intensive, low detection electri cenergy meter , no longer meet the economic development needs of testing equipment. In order to change the packaging container load detection methods to improve the detection level of control technology, we have taken with the cylinder loaded with PLC programmable controller for automatic detection and control of the new method, and use their computer network communications.

Flight control micro circuits can be used to go, thus improving the sensitivity of component failure

Aviation Department Air Division in 1964 declared enough bone out of a triple redundant flight control Gua complex adaptive computer. Skeletal Introduction} computer thanks to the cattle  Voltage stabilizer  circuits with small size, weight, tamarisk, power consumption province, as well as high reliability. It's enough l principle will greatly affect the future of the system segments Pu. Child Health  air circuit breaker  saliva machine with good performance Halliday flight control micro circuits can be used to go, thus improving the sensitivity of component failure, and does not require a very substantial increase in weight and volume, the expansion   Electric transformer  counted up FAN Guo-flight use. L count on this machine using the usual adaptive notion that the road is triple redundant edge complex, and maximize the use of mini-shelter Road, only in the computer memory latency Ning's Dioscorea japonica write edge path and two re-mains in using discrete components. To reduce costs, the axis made ​​of the computer system Columbia comb. As long as the technology to be developed, can be applied to three Gu by the Department of comb.

Accurately predict temperature turbine blades to improve the cooling efficiency and prolong the working life of the key issues blade

Modern aviation gas turbine engines in order to obtain a higher thrust to weight ratio and thermal efficiency , and continuously improve the turbine inlet temperature , turbine inlet temperature is currently far exceed the melting temperature of the blade material , sophisticated cooling techniques must be used to maintain the normal operation of the turbine blades , accurate predicted temperature  Electric energy meter  the cooling efficiency and prolong the working life leaves key issues , with the continuous development of computational fluid dynamics , gas thermal coupling  electric meter  technology has become the major aircraft engine engineering design tools , main work is on the aero-engine turbine blades for gas -cooled thermal coupling numerical simulation, and further improve the thermal coupling of the gas turbine blade accuracy and reliability of  Air circuit breaker  for further analysis . This paper examined how accurately predict boundary layer transition flow problems , aircraft engines are prevalent transitional flows , boundary layer transition before and after the flow state , wall shear stress and heat transfer coefficient are not the same , accurate prediction of boundary layer transition transitional flows starting position for the turbine blade aerodynamic and heat transfer design has very important significance , can accurately simulate the boundary layer transition flow is the key to how to choose a suitable physical model .

Strengthen the transformer running state detection and timely treatment of latent faults inside the transformer

Power transformer is the hub of power system equipment, its operation reliability and safe and reliable operation of power systems have a great relationship. Therefore, the strengthening of the transformer  power transformers  detection and timely treatment of latent faults inside the transformer, the transformer to improve the reliability of the entire power grid safe and reliable operation of great practical  air circuit breaker . Power transformer fault diagnosis is based on the characteristics of transformer fault, determine the nature of the fault or category for  Voltage stabilizer  maintenance decisions. Practice shows that the characteristics of transformer insulating oil dissolved gas analysis technology in the transformer fault diagnosis has a major role.

With varying degrees of structural failure of the mean standard mode

Depth study of power transformer oil dissolved gas and the relationship between the type of fault basis, from the state assessment , fault diagnosis and fault prediction research is based on three aspects of the oil dissolved gas analysis of power transformer fault diagnosis technology . The main contents are as follows: ( a ) for the power transformer condition assessment is proposed based on weighted gray  air circuit breaker  power transformer condition assessment methods . With varying degrees of tectonic faults mean standard mode , and proposed grades combined score grading and classification of specific strategies to improve the stability of the assessment methods and versatility . ( 2 ) for the power transformer fault  Voltage stabilizer  on improved BP algorithm nonlinear homotopy power transformer fault diagnosis method . Avoid local minima in the ability to greatly improve , but also improve the accuracy and reliability of diagnosis . ( 3 ) for the power  mcb circuit breaker  fault prediction is proposed based on improved gray forecasting GM (1,1, ρ) model of power transformer fault prediction method . Can effectively predict transformer oil dissolved gas concentration in the next moment , to provide the basis for the failure prediction . ( 4 ) Construction of a power transformer fault diagnosis expert system, and designed its software platform.

Direct impact on the power grid, causing huge economic losses

Operating status of power transformers in the power system security and reliability has a pivotal position. Power transformers in operation in the event of damage to the failure, will  air circuit breaker  the power grid, causing huge economic losses. Papers for the power transformer fault characteristics were studied based on ant colony algorithm for the power  Circuit breaker  fault localization method to  power transformers , more quickly and accurately detect the power transformer fault. Specific research work is as follows: For the common faults of power transformers, power transformers lot for failure analysis of research, summarized power transformer malfunction and have hidden faults is demonstrated when various anomalies.

Improve the electrical life of the main contacts to improve AC contactor has become the key to the whole life

AC contactor is a wide range of large electrical switches, its performance not only has a direct economic interest , but also to the power system power quality and energy resources. With the adoption of new  power transformers , new technology , AC contactor mechanical life has reached millions of times , and its electrical life is generally only about 10% of mechanical life . Improve the electrical life of the main contacts AC contactor has become to improve the overall life of the key. In particular, AC  mcb circuit breaker category AC-4 , the contact erosion occurs mainly in the closing process , which ac contactor made ​​more stringent technical requirements. This requires AC contactor entire process to achieve optimal control, reduce contact collisions, while achieving arc minutes without closing , reducing the arc erosion ;  air circuit breaker  to power shortage of resources , contacts made ​​on the traditional energy-saving operation requirements. In this paper, the above requirements, carry out exchanges and contacts without arc of intelligent technology. The first rebound of the contacts of the mechanism , and the DC excitation AC excitation contrast different characteristics , given the lack of AC and DC excitation excitation advantages , combined with a large test to determine the optimum excitation of the DC excitation voltage , and on this basis, , combined with the existing DC excitation control mode , this paper proposes AC contactor multistage excitation system regulator DC pulse excitation control mode.

Contact shape on mine AC contactor electrical contact reliability of

Contact shape on mine AC contactor electrical contact reliability of Xi'an Jiaotong University, Guo Fengyi , Wang Qiping Fuxin Mining Institute Sun Hexu Abstract According to the theory of electrical contacts , respectively, three different structural shapes contacts electrical power transformers analysis, from both indoor and outdoor environments obtained test results and theoretical analysis , H-type contacts in electrical contact with the best performance , overhead electrical Electric energy meter break contacts worst performance . Keywords contacts , electrical contacts , contact resistance, shrink resistance , membrane resistance , electrical conductivity spots, four-terminal method at the beginning of electrical electrical contact is an important theoretical basis and key technologies, and Voltage stabilizer the electrical contact switch electrical important functions , namely on the circuit off conversion. Electrical contact theory is scientific community in recent years, much national attention , mainly because industrial production of complex electrical equipment due to the high reliability requirements . As we all know , a large electrical equipment and security systems are often a combination of a variety of devices , and the complexity of the increasingly high number of electrical contact them often thousands , if there was one or several contacts is not normal or failure will lead to the production systems disorders.

In the relay - contactor control circuit contacts simplification, the specific methods are logical expressions and experiences simplification Simplification Act

In the design of the relay - contactor control circuit frequently encountered when multiple occurrences of the same label contacts phenomenon, and cost savings in order to simplify the circuit design must be simplified for contacts. In the relay - contactor control circuit contacts  Circuit breaker , the specific methods are logical expressions simplification and experience Simplification, the former requires the designer has a good mathematical derivation ability, when the control  air circuit breaker  complex, due to the logical expression too cumbersome and error-prone process of mathematical deduction, is not practical; latter mainly depends on the designer's electrical controls design experience, the results are often not the most simplified simple circuits. Therefore, to find a theory is relatively simple,  mcb circuit breaker  simplification tool for relay - contactor control circuit design is important. I will be commonly used in electronic circuit simplification Karnaugh map used in the relay - contactor control circuit contacts simplification to study the Karnaugh map in the relay - contactor control circuit contacts simplification of the application.

Required to fully understand the operating principle of the electrical control circuit and working process

Relay contactor control system failure is common, to quickly and accurately determine the cause of failure, nature and location (point). This requires full understanding of the operation of the electrical control circuit principle and working process.  Voltage stabilizer  the practice followed by the gradual accumulation of experience, lessons learned, improve the technical level. The general nature of the fault can be broadly  mcb circuit breaker  categories: the first air circuit breaker  electrical component fails, the failure of this nature is easier to find. The second category mostly wiring error, or break, hitting lines and damaged insulation. Such failures occurred, often caused by electrical components malfunction or no action.

Impulse voltage generator is a device used to generate lightning impulse

In the high-voltage technique, the individual unipolar voltage pulse is called impulse voltage. Surge voltage variation with time and duration depends on its generated. Impulse voltage generator is a kind of  Voltage stabilizer  to generate lightning impulse. circuit breakers line will be on the line lightning caused a sharp rise in voltage and generates a flow wave propagation along the way, it is possible to damage the insulation of  mcb circuit breaker  systems. This over-voltage amplitude level, up to several million volts. Lightning over-voltage characteristics of the wave front rise time is short, from about a fraction of the tens of microseconds, and then slow down to zero.

In the high-power electron beam and ion beam generator and the carbon dioxide laser, as a power supply unit

Produce artificial lightning and switching impulse voltage of the device. It produces mainly for insulation impulse voltage impulse withstand voltage or discharge test purposes. In the high-power  Voltage stabilizer  and ion beam generator and the carbon dioxide laser, as a power supply unit, which contains a high voltage storage capacitor, from the DC high voltage source to charge several seconds, and then through the discharge gap is suddenly discharged through the resistor,  power transformers  frontier impulse  circuit breakers . Shock wave duration in microseconds, typically tens of kilovolts peak voltage volts to a few megabytes. Impulse voltage waveform impulse voltage generator can produce meet International Electrotechnical Commission (IEC) and the Chinese national standard.

The optical signal to control the amount of expansion and contraction of the ceramic sheet, light control servo system to achieve

An optical servo system controls the application of new light  machine conversion devices. As a ceramic sheet having a polarized light-induced expansion and contraction effect, therefore, the optical signal to control the amount of expansion and contraction of the ceramic sheet, achieve optical servo control system which completely eliminates the conventional servo system, the electromagnetic interference.  air circuit breaker  show that the ceramic piece in a different spectrum, light irradiation, showing a strong ceramic photoelectric effect. Photoelectric effects include pyroelectric effect and the photovoltaic effect, both light-induced stretching effect, the light intensity of the illumination light into a voltage proportional to the light Primax shrinkage voltage and a linear  circuit breakers  the light, so light intensity can be controlled according to the ceramic sheet the amount of stretching is entirely possible for optical control servo system. Keywords light control servo system; optical implementation of the device; photovoltaic effect; pyroelectric effect; photovoltaic effect;  electric meter  telescopic effect CLC is a micro-mechanical servo system of the target position, speed, power, precision, high-speed control drive system the micro-mechanical devices, more conventional servo systems based on electromagnetic manner, the electromagnetic interference is inevitable.

On load tap tap split-phase or single-phase regulation and shunt capacitors cast, cut the integrated automatic control

Reactive power automatic voltage regulator , through real-time collection of network parameters , the use of computer control technology and digital signal processing technology, according to the actual operation of the grid needs, OLTC tap split-phase or single-phase regulation and shunt capacitors vote , cut the integrated automatic control, the system voltage and reactive power to meet the eligibility requirements , effectively  Circuit breaker  losses and improve voltage qualification rate to ensure that once the system is running at its best. Fundamentals PDS-732A  air circuit breaker  Reactive Power Control System for Substation Integrated Automation System Distributed VQC. System installed on each device using the interval IEDs , distributed collection of information on to the main CPU unit by the main CPU unit for centralized identification and decentralized  power transformers  to execute each IED network control. System set up separate master CPU control unit , regular collection system within the protective device or automatic device to send a comprehensive analysis and calculation of the amount of information to make the appropriate strategy discrimination , and sends the appropriate policy action information to the appropriate spacer layer protection and control devices , to let them make appropriate strategy adjustment control . In order to achieve decentralized collection, centralized discrimination , the principle of centralized control .

Regulating device is battery uninterrupted power supply to the key elements of the bus

The current power system DC power supply device , since the battery float voltage is higher , the rated voltage of the battery between the feed outlet , must be connected to a voltage , a corresponding adjustment means . Regulating device is battery uninterrupted power supply to the key elements of the bus , you must ensure high reliability and functionality with buck and regulators to ensure that feed outlet  mcb circuit breaker . Currently put into operation the voltage regulating device in two ways . One is a stage regulator ; Another is stepless voltage regulation . There tend to use silicon chain stage regulator regulator , this approach means power transformers , reliability is good, but because it is on the voltage grading regulation, so regulation accuracy is not high. No way can be achieved on stage regulator voltage is adjusted grade, has a good accuracy, but the wiring complexity , Voltage stabilizer . Therefore, in some high-power, high-capacity, high safety factor requirements of the occasion or the use of a stage regulator often . Therefore, the introduction of a step voltage regulator based on the use of the device as simple as possible , to minimize the wiring , and can be greatly improved precision regulator becomes the evaluation voltage regulating device of the key point . New DZT series voltage regulator devices regulated by the voltage regulator and silicon chains. Using a simple device , wiring, silicon chain segments clever way to make regulation accuracy is much higher than other similar devices .

Modern power supply unit, the electric precipitator is automatically adjusted to maintain the operating conditions of the electrode of the electrical

From the known voltage characteristics of corona discharge, the corona current electrode voltage is non-linear relationship  Voltage stabilizer , the operating mode voltage slightly (if 1%), it will cause a substantial corona current (corresponding to 5%) decreased, which reduces the efficiency of the electrostatic precipitator.  mcb circuit breaker  supply unit, the electric precipitator is automatically adjusted to the operating conditions of the electric potential on the sustain  circuit breakers  maximum. Is the voltage to maintain a high value, the total held in the breakdown of the edges, but without arcing occurs. Practice has proved that use the manual adjustment to maintain the maximum possible voltage electrodes is not feasible.

In electrical technology, electronics technology

In electrical technology, electronics technology, everyday life and electronic production process, often referred to or used in safety voltage , many textbooks define the voltage does not exceed 36V safe voltage . This kind of definition is scientific, safe  mcb circuit breaker  safe , most of these problems are even some electricians, electrical maintenance personnel could not say . In order to ensure "safe voltage " security , the author in the form of questions and answers will be safe voltage and its related knowledge are described below. Definition of safe voltage safety voltage , also known as safety extra low voltage, is the body a long time without contact with  Voltage stabilizer  electric shock , that the human body tissues and organs ( such as the skin, heart , respiratory and nervous system ) will not cause any damage to the voltage , ie voltage does not endanger the safety of personal safety . It should be particularly emphasized : in any case , are not safe voltage can be  electric meter  no hazardous voltages . Which depends on the degree of danger of electric shock shock after the degree of risk factors, mainly on the amount of current through the body , current duration , current flows through the body's way , the body's resistance , the power frequency , the body's health status, sex , age, etc. factor. These factors are interrelated , as long as certain factors reaches a certain level , will make those who suffer an electric shock hazard.

With the size of the electrolyte decomposition voltage of the nature and electrolysis conditions

Electrolysis of the electrolyte required minimum applied voltage is called decomposition voltage. Also called decomposition potential or decomposition potential. With the size of the electrolyte decomposition voltage of the nature and electrolysis conditions (electrode material, the electrolysis temperature, current density, and solution concentration, etc.) are not identical and each different. Its value can be determined by the Nernst equation, also called the theoretical  air circuit breaker . The electrolyte in the electrode decomposition products of electrolysis required minimum voltage is applied. mcb circuit breaker   voltage of the electrolyte  mcb circuit breaker  of the raw product by electrolysis electromotive force, the yin and yang overpotential and electrode polarization voltage drop circuit composed of three parts. Electrolyte in the electrolyte, the second electrode is formed on the primary products of electrolysis cells, which force opposite the direction of electrolysis, the applied voltage is first have to overcome this force. This back electromotive force, equal to the second electrodes, the potential difference between the equilibrium. That is, for the theoretical decomposition voltage of the electrolyte.

Longer period of time without human contact with dangerous voltage electric shock

In electrical technology, electronics technology, everyday life and electronic production process, often referred to or used in safety voltage , many textbooks define the voltage does not exceed 36V safe voltage . This kind of definition is scientific, safe voltage is absolutely safe , most of these problems are even some electricians, electrical  Voltage stabilizer could not say . In order to ensure "safe voltage " security , the author in the form of questions and answers will be safe voltage and its related knowledge are described below. Definition of safe voltage  power transformers  , also known as safety extra low voltage, is the body a long time without contact with dangerous voltage electric shock , that the human body tissues and organs ( such as the skin, heart , respiratory and nervous system ) will not cause any damage to the voltage , ie voltage does not endanger the safety of  electric meter  . It should be particularly emphasized : in any case , are not safe voltage can be understood as absolutely no hazardous voltages . Which depends on the degree of danger of electric shock shock after the degree of risk factors, mainly on the amount of current through the body , current duration , current flows through the body's way , the body's resistance , the power frequency , the body's health status, sex , age, etc. factor. These factors are interrelated , as long as certain factors reaches a certain level , will make those who suffer an electric shock hazard.

Increases the current through the body; near the high pressure, there is induced currents, and therefore is very dangerous

Depending on the voltage on the human body, to determine the safe voltage 36V. When the human exposure after power, as the voltage increases, the body's resistance is lowered; if contact voltage, leaving skin breakdown due to the resistance of the body down  air circuit breaker  the body increases; close to the high pressure, as well as induction currents, so it is very dangerous. From a security standpoint, sure that the power of human  mcb circuit breaker , often without safe  Circuit breaker  with safety. Because many factors affect the current changes (such as temperature, humidity, electrical resistivity, etc.), and the power system voltage is typically relatively constant.

Thermal environment wind tunnel test is assessing ground theoretical calculation method to provide a basis for the anti-thermal design an important means of

Thermal environment wind tunnel test is assessing ground theoretical calculation method to provide a basis for the anti-thermal design an important means. Ground testing of measuring heat directly affects the accuracy of calculation methods and the selection of anti-thermal structure, is to determine whether or not the key factor in the success of  electri cenergy meter . Film resistance thermometer as the most common shock tunnel heat flux measurement sensors, trial staff from the sensor production, calibration, installation, data acquisition system aspects such as the sampling  electric meter  to improve measurement precision thermal test. In fact, the film resistance thermometer in the test measured voltage information (ie, temperature variation), but also through theoretical analysis and calculation the temperature information into heat flow values.

2013年10月8日星期二

Were developed thin-film resistance thermometer miniature circuit work

Currently industrial temperature measurement is used in copper and platinum wire as effective components contact resistance thermometer. Considering the characteristics of microelectronics, this thermometer has the following disadvantages: mass weight (which in solution temperature during the rapid flow of the inert problem is very important), in the structure of rare and precious metals to be used,  mcb circuit breaker  to use the manual assembly methods; due to size large, in a small object to be measured is applied within the temperature range should be restricted. Therefore, for the development of thin-film resistance  Electric energy meter circuit work. Metal resistance R and the temperature T of the equation can be calculated as wire resistance thermometer electrical parameters based plant  power transformers coefficient of resistance song households, T a temperature in the structure of the wire resistance thermometer is placed in a stainless steel protective tube sensing element composition, and a connection detection instrument terminals. metal film resistors temperature dependence only when the film thickness is greater than nx100nm when established.

Screen Printing turned hybrid microcircuit manufacturing all processes, screen printing process is perhaps the most irresolvable process

These companies want to automate it must carefully check the effect of doing so, choosing the appropriate device. Screen printing manufacturing a hybrid microcircuit turn all the process, the screen  electric meter  is perhaps the most  air circuit breaker  can not, in this process, the production operations of the flow of the slurry measured and adjusted screen printing machine, There is no direct relationship between the parameters. However, from a quality perspective, we all know that printing  mcb circuit breaker  parameters on performance, so in order to achieve the required performance of a film, it should adjust screen printing machine, and after a period of time to maintain these properties, which still needs to pass involvement of people to monitor the performance of the slurry, and the slurry was maintained in the screen printing uniformity.

The threat of competition in the market has prompted many companies to consider hybrid microcircuit manufacturing process automation

Automation in the screen printing, component assembly and wire connections, the hybrid circuit line and flaky a key manufacturing solutions. The threat of cheap labor market competition has prompted many companies to consider hybrid microcircuit  mcb circuit breaker  process automation to achieve maximum production capacity. The idea of ​​eliminating human  Voltage stabilizer  cost will greatly improve the productivity lower. Effort somewhat inconsistencies. Some operating  Circuit breaker is very suitable for automation, with little or no human intervention can rapidly complete the process. And some can be completed more quickly by means of hand, but at the expense of reduced quality and accuracy for the price.

Often help the life of electronic components working condition, but by storing to determine damage caused by

In laboratory and field applications of electronic components in a variety of conditions, operational reliability has been a lot of work, but also published a lot of information. However, in the military utility when the life of electronic components often determined not by working status, but the damage caused by the store to decide.  electri cenergy meter store one year, five years or even ten years. After storage, these devices must immediately be able to work properly. And some equipment has been  mcb circuit breaker  their useful life, in fact, electronic components, the life time of the long-term storage tests are difficult to implement, because: 1. Was not enough time to do such tests. 2 is expected to be less efficient storage failure (failure rate of about 0.01 to work 0.1), therefore, failure to obtain a variety of practical efficiency (with small statistical errors), then the required number of test samples. If you can find a reasonable accelerated test method, not only shorten the test time, but also reduce the cost of evaluation of the effect of storage devices. Storage environment to define various conditions must be manufactured from the elements until the beginning of the end of useful life are taken into account.

Current transformers for transient error performance requirements are needed for quick action to protect

In the power system , transformer is the most important measurement and protection equipment. In the low voltage grid, aperiodic component of short-circuit current decay fast, short-circuit current quickly reaches a steady state , so the use of general protective current transformers to meet the requirements . In UHV power system short-circuit current cyclical component of a longer decay time , asking for  Electric transformer  fault for a short time , then the current transformer in the transition state, so you must use protective current transformers for transient .  air circuit breaker  for transient error performance requirements for fast protection action is required to prevent the development of grid instability fault current transformer transient error is a direct manifestation of this transient performance . Most electronic current transformer  Voltage stabilizer or principles of optics , which has no core , no magnetic saturation , frequency bandwidth and dynamic measurement range, measurement accuracy , the measurement within the scope of protection is completely linear transfer good performance . Characterization of transient protection electronic transformers for transient error characteristics of accuracy class of TPE, is defined as the precise limits , rated primary time constant and the maximum rated operating cycle peak instantaneous error is 10%.

Coil current transformer is more of an active type of electronic current transformers

Coil current transformer is more of an active type of electronic current transformers. Its general use sensor head coil, with good linearity, insulation, simple structure, no security risks, non-core, non-magnetic saturation phenomenon,  air circuit breaker  bandwidth and accuracy and other fine features, so it has been widely used. However, due to the coil output electromotive force is proportional to the time derivative of the measured current to recover with a current signal  electri cenergy meter  the integral must add the appropriate link. Currently, the integral part of the low-frequency noise, voltage drift and phase response of the integrator is the impact of electronic current transformer low frequency low current measurement accuracy of the main reasons. This paper describes the use of several integrator for their advantages and disadvantages are analyzed and discussed, and the design of digital integrator, laboratory tests show that the method is effective and practical.

Electromagnetic induction type current transformer secondary current in transient error occurred during

When a current is mutated, the electromagnetic induction type current transformer secondary current in transient error occurred during (and worse than the angular difference). Sources of error  power transformers  for transient error is the electromagnetic induction type current transformer core nonlinearity caused by an inherent  air circuit breaker  When a large current through, especially when the system is short-circuit fault occurs, a Electric transformer percentage of non-periodic component, the total current in favor of one side of the axis, the induced voltage current transformer magnetizing current needed to quickly increases, the core saturation, resulting in secondary current (first current minus the excitation current) values ​​and waveform distortion.

Maturing photoelectric transformer instead of the traditional electromagnetic transformer

The use of increasingly sophisticated photoelectric transformer instead of the traditional electromagnetic transformer, power grid construction and transformation to achieve far-reaching significance. Straight people hot topic. In  electri cenergy meter , the temperature variation errors of measurement, one should increase the optical system (such as the light source, optical, electro-optical crystal) and a photodetector (such as a photodiode) of the anti-jamming capability, such as  Voltage stabilizer and a small light source wavelength shift, pure and after several electro-optic crystal pulling and so on. Also in the temperature stability of the study, scholars much attention recently with temperature control method, two optical temperature compensation method, two crystal temperature compensation circuit compensates for hardware and software compensation method.

New photoelectric coreless transformer, there is no magnetic saturation of the ferromagnetic resonance problems

Transformer conventional electromagnetic induction type magnetic saturation exist, ferromagnetic resonance, the dynamic range is small, transient defects and poor, while the new coreless transformer photoelectric, there is the problem of magnetic  air circuit breaker  resonance, transient response range, the frequency response wide. With the power system transmission capacity is increasing, and voltage levels continue to rise,  Voltage stabilizer  induction type transformer structure more complex, along with a much larger volume, not only for protection and control a threat the protection and control functions are integrated is difficult to achieve. Photoelectric transformer has a small volume and quality are without insulating oil, there is no danger of explosion.

The basic principle of photoelectric transformer waves through the magneto-optical material whose plane of polarization is rotated

With fiber-optic sensing technology, optical fiber communication technology, the rapid development of photovoltaic technology in the power system more widely . Photoelectric Transformer is one of them . Photoelectric transformer with small size, light weight, band response width , no saturation phenomenon , anti- air circuit breaker  interference , good performance, oil-free structure , insulation , reliable, easy to digital, computer development and many other advantages , in digital substation widely application . Meanwhile , intelligent switches, photoelectric transformer , a run -line state detection equipment , substation operator  power transformers  technology matures , and computer high-speed network in the development and application of real-time systems , substation automation systems are moving to an all digital direction . The basic principle of  circuit breakers  light through optical materials will occur when the polarization plane rotation, rotation angle measured to determine the size of the measured current . Passive type photoelectric transformer does not require high-pressure part of its electronic circuits and has a more compact structure and more reliable impact resistant insulated surge current capability and capacity , is the true meaning of optoelectronic products.

Photoelectric Transformer basic principles and advantages of photoelectric transformer according to different sensor head design principles

Photoelectric Transformer basic principles and advantages of photoelectric transformer by sensing head design principles can be divided into active-and passive-type; accordance measuring the content can be divided into electronic voltage  Voltage stabilizer  electronic TVE type current transformer. Active-type photoelectric current transformer is the principle of Rogowski coil sensor head partly achieved  mcb circuit breaker  and then turn it into a light signal to the low-pressure part of the processing. Passive type optical current transformer is the use of the Faraday effect, a beam of linearly polarized light through the optical material is placed in a magnetic field, the plane of polarization of the linearly polarized light will be rotated, the rotation angle and the measured proportional to the current.

Optical voltage transformer developed countries photoelectric current voltage transformer sensing methods can be divided into two kinds of active-and passive

Optical voltage transformer developed countries photoelectric current voltage transformer sensing methods can be divided into two kinds of active-and passive. Active type active high side voltage signal by  electri cenergy meter  signal is passed in.  Voltage stabilizer  signal to the light emitting diode, and then transmitted from the optical fiber to the low potential side, into an electrical signal for the inverter output after amplification. The luminous intensity of the diode is proportional to the applied voltage, the signal output is proportional to the applied voltage. Study how the photoelectric transformer substation automation system interface and communication, the realization of photovoltaic substation digitization will be of great significance.

Application of photovoltaic technology to transmit information through fiber-optic measurement of large currents or high voltage transformer

Application of photovoltaic technology to transmit information through fiber-optic measurement of large currents or high voltage transformer. The high potential (or far) end, the measured current or voltage modulation of the optical signal transmitted through the optical fiber to the ground potential (or measurement) side,  mcb circuit breaker  conversion and demodulation electronics to obtain the measured current or voltage. According to the working principle of this device, also measure the temperature in the high potential side, vibration, displacement signal. Power systems commonly used electromagnetic    air circuit breaker high current or high voltage. Optical voltage transformer here only passive type photoelectric current common basic structure of voltage transformers, voltage  electric meter  by high optical parts, fiber optic voltage sensor and the photodetector three major components. High-pressure parts, including high-voltage insulated casing, insulating gas, etc., the measured high voltage is applied to the upper electrode and lower electrode is grounded, bubble Michaels crystal electro-optic effect in the electric field. If the high voltage by a capacitive voltage divider at a certain partial pressure ratio, reduced to the optical voltage sensor can withstand a lower voltage, referred to as capacitor divider type.

Traction substation integrated automation system of traction substation information analysis shows main connection

Make full use of information to achieve integrated automation system of traction substation current transformer disconnection fault detection is the purpose of this article.  Voltage stabilizer  integrated  Electric energy meter  of traction substation information analysis shows the main junction line, for example, integrated automation system from the voltage, current transformers collect the following information:  Circuit breaker  transformer: the secondary winding and measuring winding protection to provide current protection devices. Shunt capacitor compensation branch current transformer: the secondary winding and measuring winding protection device provides current to the relay. Current transformer low voltage side of the transformer: secondary winding and measuring winding protection device provides current to the relay.

System under the operation of the system transformer disconnection cause great harm

Integrated transformer disconnected from the system under the operation of the system caused great harm, and especially mutual disconnection staggering flow, traction substation current transformers in the event of failure will cause the flow cross  air circuit breaker  relay or automatic device does not work properly, endanger the safe operation of the traction power supply system, for example: the feeder current transformer secondary winding protection disconnection, short circuit fault occurs in the feeder, the current class and the impedance of the protected class will refuse to move; transformer differential  power transformers of the current transformer secondary side break, under normal load, external short circuit, the differential protection will malfunction. Currently, the integrated automation system in the railway traction power supply system has been a large number of applications.

General nonlinear model of the current transformer, highlighted in the actual simulation programming

Describes the general linear model of current transformer, highlighted in the actual simulation programming, how the RMS voltage and current provided by the manufacturer into a current transformer  electric meter  curve, thus completing the magnetizing  Voltage stabilizer  linear simulation . Finally, an example described in the transient simulation, different short circuit current on the primary side of the current transformer saturation degree of influence. Current transformer  Air circuit breaker  is nonlinear model plants and important substation electrical equipment, which is mainly non-linear electromagnetic components, which in the case of normal operation and fault secondary output current size depends entirely on the excitation current.

Measurement and protection devices usually can not be directly connected to a high voltage, high current power loop

To ensure the power system security and economic operation of the power system needs of various electrical equipment and its related  Circuit breaker  measured in order to make the necessary measurement, monitoring and protection. Measurement and  mcb circuit breaker  usually can not be directly connected to a high voltage, high current power back on the road, while the high level of electrical parameters need to be converted into a low  electric transformer  or signals. Current transformer (CT) is a large current in proportion to the circuit is converted into a secondary small current measuring apparatus the primary and secondary windings wound on the same core of the closed magnetic circuit.

The voltage level higher and higher, current transformer secondary winding current accuracy, the correct action related to the protection and testing, measurement accuracy

With the development of network, more and more high voltage level, current transformer secondary winding current accuracy, the correct action related to the protection and testing, measurement accuracy. Early vote in the substation when tested on the current transformer is to ensure correct operation of relay protection and  Circuit breaker , measurement accuracy of the necessary conditions. Currently, we use more feedthrough current air circuit breaker  windings are measured difference method and the method of ampere-turns, etc., because these two methods can not simulate actual field, often overlooked in the calibration of the external magnetic field, resulting in on-site verification when the measurement error increases. Found the problem in the Substation, we check for current  power transformers , the use of other current comparative law, that the last increase 200A current, secondary display 0.2A, test connection. The results showed that the seven 330kV current transformer windings error tolerance. Experimental data show that the phase current transformer current measured value is found from the above data, all winding current into and out of imbalance, and laboratory equipment from the current transformers were tested farther, the smaller the error, the greater the contrary.

One side of the AC current at rated current ratio convert available for measurement, protection or control other equipment

The primary side AC current at rated current ratio convert available for measurement, protection or control equipment, instrumentation or protection devices used in the secondary side of the current converter equipment. The primary winding of the current transformer to  Circuit breaker , the protection or control circuit in series, the secondary winding and measuring, protection or control  air circuit breaker  to the coil current, so that the first and second side of the high and low pressure  Voltage stabilizer . When used properly, a current transformer, the ratio of the secondary rated current, and the first and second winding turns inversely. The phase difference between the current close to zero. Type according to the primary winding structure is different, can be divided through the wall, bus, cable type, casing.

Closure between the two windings on the core of the electromagnetic induction effect

Closing the two windings on the core using electromagnetic induction effect between the measured AC current conducted by the rated value conversion ratio of the instrument. Including power system measurement and laboratory precision current  Voltage stabilizer transformer. The function of the current transformer are: ① limit the amount of extended meter to measure current; ② The rated current is converted to a uniform nominal value, in order to facilitate the standardization of the connected meter; ③ the meter and the measured line high potential isolation to ensure security; ④  power transformers transformer can be used for standard instrument used to test the accuracy level of at least two low-current transformer, or limit the amount for the extension device with a standard table, the corresponding test meter.

2013年10月7日星期一

More suitable for real-time control of dynamic recurrent neural network to replace the original proposal in recognition of its multi-layer feedforward network

Using a more suitable for real-time control of dynamic recurrent neural network to replace the original proposal in  Air circuit breaker of its multi-layer feedforward network. Simulation results show that the improved method than the original method and with the reader's neural network PID control method has better response performance. electric meter system, first studied the predictive performance index based on multi-function multi-variable system under the neural network PID control and simulation examples are given and conclusions; Then study multivariable PID neural  mcb circuit breaker  structure and calculation method: it is a sub-network of a plurality of parallel, when the control system has a controlled variable n, the n sub-network there. Each sub-network input layer of a given signal receiving system and the object output signal;

Constitute a multi-step prediction performance index function under the neural network PID control system

In order to improve the control effect of the controller as the goal, the neural network combined with PID control, respectively, univariate and multivariate systems system neural network structure PID  Air circuit breaker  in-depth research and exploration. For single-variable system, the predicted control theory and neural network PID  electric meter combined with a multi-step prediction performance index function to train the neural network controller weights constitute the multi-step prediction  Voltage stabilizer  function neural network under PID control system; article for this system has been improved, the introduction of a new multi-step prediction performance index function, while the neural network identifier part.

After two planes parallel stability problems in the past on these issues in detail simulation

Generator self-excitation, dual side by side issues such as post-stabilization, the previous literature on these  electric meter  simulation. With the development of the power system, increasing the capacity of the transformer, the recovery process in the system to achieve the delivery of Air circuit breaker  not be avoided large-capacity  mcb circuit breaker  no-load input. Load capacity of the transformer inrush current and input will produce resonance over-voltage, inrush current mechanism was analyzed, airdrop large capacity transformers may cause malfunction protection, but also for their own safety and the power transformer operation of the system have a relatively large hazards.

Partial system failure may cause a large area blackout

With the cross-regional interconnected power system, increasing the size of the grid, the interaction  power transformers  various subsystems and more serious, localized system failure may lead to large-scale power outages, and even the collapse of the entire power system collapse.  electric meter , as the safe operation of the power system is one of the important measures, the problem of black start is very important. With self-starting capability of the unit start without self-starting  Electric energy meter , and gradually expand the scope of the transmission system, and ultimately the entire system recovery. In the System Recovery process involves frequent operations, and therefore may cause over-voltage lines.

Transformer differential protection unexplained errors, significantly increased risk of rejection action, safety and security to the grid

Transformer differential protection unexplained error, refused action probability increased significantly, to the power grid safety and security, but also affect the normal conduct of industrial production. Since the transformer also includes a circuit and various circuit coupled magnetic core, making the transformer during the closing operation,  mcb circuit breaker system failure is often accompanied by removal of complex electromagnetic transient process that requires multi-disciplinary knowledge to carry out these processes more reasonable analysis. However, so far, on the transformer  power transformers  transient analysis of complex  Circuit breaker  theory is still relatively weak, and a thorough study of the mechanism of occurrence of failures or disturbances and characteristics found through a variety of complex transient disturbances transformer Differential Protection abnormal behavior of the real action reasons.

Power transformers for the entire power system safe and stable operation can have a crucial impact

As the core of the power system equipment, power transformers for the entire power system safe and stable operation can have a crucial impact. Among them, the relay action is  air circuit breaker  the reliability of  power transformers  key elements of safety equipment. However, the operation of the electricity transformer protection statistics show that, as a large power transformer differential protection for  mcb circuit breaker , the correct action rate has been at a low level, which is the actual current grid security requirements and levels of development do not match. In recent years, with the structure and composition of the power system complexity increases.

In the transformer no-load input power supply or external fault voltage recovery process after resection

Transformer differential protection as main protection for quick removal transformer internal fault plays an important role. Load power on the transformer or the external fault voltage Electric energy meter process, are generated inrush current, especially in the closing voltage of 0 V, the magnetic flux in the transformer core increases rapidly, instantaneously saturate the iron core, there big impact excitation current value (up to 5 to 10 times the rated current), often referred to as  circuit breakers . Inrush current treatment directly affects the choice of means to the differential protection action behavior may lead to differential protection tripping or malfunction. Transfer from the hot spare transformer operation, main transformer, the ratio differential protection tripped the switch on each side of the main transformer; transformer, the percentage  air circuit breaker  again the action, jump on each side of the main transformer switch. Differential protection immediately after the inspection station equipment without exception; relevant checks carried out on the transformer, primary equipment insulation inspection and oil samples for testing are satisfactory; protection device checks the 2nd Main Transformer Protection of second harmonic restraint and related protection logic function tests, the action is correct.

Waterproof role of fire and explosion isolation doors

Fire, flood and explosion is a significant threat to the safety of the mine disaster , waterproof fire -proof doors are controlled isolation scope of these major disasters, the most important means , but the isolation doors closed will change mine ventilation system , to change the main fan operating point , may cause localized  power transformers breeze or no wind , gas gauge , main fan surge issues such as isolation gate position in the design of mine when the resulting security risks must be fully considered in order to protect isolated gate enabled the mine ventilation system security. Waterproof role of fire and explosion isolation  Air circuit breaker the mine threat in a panel adjacent to the panel and the whole mine fires, floods, explosions of major disasters , in order to prevent the accident and reduce the life of these major disasters , loss of property , accident closed  mcb circuit breaker  fire and explosion isolation doors , protecting the mine area and the other disk into the return air main roadway , wellbore safety and to avoid disasters expanding spread. Isolated door panel settings are mine happen water, fire , explosions and other major disasters of the last mine safety barrier is to ensure mine safety emergency last line of defense , so the isolated gate setting has important practical significance.

The need for explosion-proof measures Cable Joints research

Currently, many power cables in tunnels, pipe (work well), bent in the form laid the event of failure, can easily lead to a fire, threatening the security of the grid. Moreover, a large number of cable fault occurred in the middle of the cable joints, the failure process of the energy accumulation, when there is an explosion happens, endanger the safety of  power transformers , to this end, it is necessary to carry out the measures Cable Joints explosion research. Power grid construction in the downtown area and out of the line most of the new substation using cable.  electric meter  the cable tunnel 20, total length of 33 km; has built 500 kV EHV power cables 2, 220 kV EHV power cables 197, 110kV EHV power cable 718. Cable in the tunnel, pipe (work well), cable layers and laying in trenches, Cable Joints  Voltage stabilizer  conditions, materials, technology and other factors, to become the weak link cable lines. And in the event of Cable Joints fault, the resulting destructive not only cause power outages this line may also be run on the surrounding cable lines, power facilities and personnel injury, and even lead to secondary accidents.

Converter station to prevent the spread of fires and major facilities, including fire detection and alarm system

Converter station to prevent the spread of fires and major facilities, including fire detection and alarm systems, fire water systems and other fire fighting facilities. Because of the special status and operational characteristics of the system, the converter  mcb circuit breaker  protection systems require a higher reliability. Currently the world is no converter station fire protection systems standards. Statistics show that in addition to converter valve and the valve hall, converter stations from other  circuit breakers  and buildings caused by fire is not much. Converter valve is the core of the converter station equipment, valves and valve hall commutation converter station fire protection systems is critical. With the increasing cable line, Cable Joints induced failure probability increased.

Station power system with AC power system is basically the same substation

Guarantee converter station master work to other needed facilities. Including: station power system converter valve cooling system, valve hall air conditioning systems, fire  mcb circuit breaker  and grounding net. Station power system with AC Substation basically the same  Voltage stabilizer , including the AC systems and DC systems in two parts. AC system to ensure the normal power supply AC electrical equipment, DC system to ensure that all control, protection, communications, operations,of normal power supply. Control, protection and monitoring of the DC power system generally requires two low voltage battery and to supply uninterrupted power supply.

Fire and explosion agent is only one principle of fire and explosion suppression method

Fire and explosion agent is only one principle of fire and explosion suppression method. Fire and explosion agents premises used fuel with the air already exists and has been mixed,  mcb circuit breaker  isolation method can not be used; fire and explosion hazard does not occur when the temperature is not high, does not exceed the ignition, without cooling to below the ignition point. Inhibitors can prevent the occurrence  air circuit breaker . When the external fire source pyrolysis fuel to produce free radicals, if radical inhibitor was caught with, you lose the function of transfer chain reaction, chain reaction will be terminated, the combustion reaction can not be carried out, to prevent the effects of combustion takes place.