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.