Method, system and equipment for evaluating minimum input time of closing resistor of circuit breaker

Abstract

The invention relates to the technical field of excitation inrush current suppression, and discloses a method, a system and equipment for evaluating the minimum input time of a closing resistor of a circuit breaker. According to the method, the steady-state magnetic flux of the transformer corresponding to the circuit breaker and the closing angle when the auxiliary contact in the circuit breaker is closed are determined, and then the minimum discontinuity angle of the excitation inrush current is calculated according to the steady-state magnetic flux and the closing angle. And finally, evaluating the minimum input time of a closing resistor of the circuit breaker according to the minimum discontinuity angle and the closing angle. The minimum input time of the closing resistor is determined according to the minimum discontinuity angle of the magnetizing inrush current and the closing angle of the auxiliary contact, and compared with the mode that the minimum input time of the closing resistor is set according to empirical parameters in the prior art, the magnetizing inrush current can be restrained more effectively.

Description

technical field [0001] The invention relates to the field of excitation inrush current suppression technology, in particular to a method, system and device for evaluating the minimum input time of a circuit breaker closing resistance. Background technique [0002] Magnetizing inrush current refers to the inrush current generated in the coil when the no-load transformer is put into operation, due to the nonlinear saturation characteristics of the transformer core and the influence of the residual magnetic flux in the iron core before the transformer is put into operation. The magnitude of this inrush current is more than 20 times the no-load current, which may cause damage to the AC filter and transformer, resulting in AC voltage and current distortion, seriously endangering the safe operation of the system. [0003] At present, circuit breakers with closing resistance are mainly used to weaken the excitation inrush current generated when the no-load transformer is put into o...

AI Technical Summary

Problems solved by technology

[0005] The invention provides a method, system and equipment for evaluating the minimum input time of the closing resistance of a circuit breaker, and solves the technical problem that the current method for determining the minimum input time of the closing resistance makes it impossible to effectively suppress the excitation inrush current after the closing resistance is switched on

Images