Ferromagnetic Resonance and Transient Response in Capacitive Voltage Transformers - News - Global IC Trade Starts Here.

Probe current voltage pin 420*4450 head diameter 5.0 over current current and voltage pin

Photocoupler

The specific conditions of ferromagnetic resonance and transient response in a capacitive voltage transformer are as follows:

The main components of a capacitive voltage transformer are a capacitive device and an inductive device, and the inductive device is a ferromagnetic nonlinear inductive device. Thus, under the action of the system voltage, ferromagnetic series resonance may occur. In order to suppress the ferromagnetic resonance, a damper is needed. The damper can be a resistive type, a resonant type, a fast saturated type, etc., and the damper parameters can be reasonably designed to effectively suppress the ferromagnetic resonance, but the error is increased and the transient is affected. stable.

Due to the function of the capacitor, when the grid short-circuit fault occurs, the secondary voltage can not immediately reflect the change of the voltage, which affects the correct action of the protection device. This is the transient response problem of the capacitive voltage transformer. In order to improve the transient response characteristics, the parameters of various components such as capacitors, compensating reactors and intermediate transformers should be reasonably matched.

For the ferromagnetic resonance and transient response, the national standard has been restricted.

The damper R and the discharge gap P are used to eliminate the transient overvoltage that may be generated by the secondary circuit short circuit, disconnection and impact, to prevent the insulation damage of the compensation reactor, the intermediate transformer and the voltage dividing capacitor, and also prevent the secondary damage. The relay protection caused by harmonic resonance malfunctions.

The damper is connected to the secondary side of the intermediate transformer, and the discharge gap is connected to the compensating reactor.

The damper parameters are determined by comprehensive considerations such as resonant overvoltage, accuracy level, and carrier communication.

Therefore, the difference between a capacitive voltage transformer and an electromagnetic voltage transformer is:

1) It is connected to the capacitor divider and is capacitive to the power system.

2) In order to improve the accuracy, the compensation reactance is connected, so that the transformer is close to the series resonance.

3) In order to eliminate and limit the saturation of the core during the transient process, a fractional resonance is generated, and then the overvoltage of the compensating reactor and the intermediate transformer is generated, and damping measures are required.