静止形逆相電流補償装置

抄録

When a single-phase load is applied to a three phase power system, negative-phase-sequence current flows in the circuit. The negative-phase-sequence current brings about local heating on the surface of generator rotor, which connected to the circuit. In the single-phase AC railroad system, Scott-connected transformers are used in order to reduce the power unbalance among three phases and also negative-phase-sequence current.
Recently, regenerative braking system has come to be applied to electric rolling-stocks. But in this system, when one phase in the Scott-connected transformer feeds power, and another phase in the Scott-connected transformer receives power from regenerative braking system, power unbalance among three phases increases and negative-phase-sequence current also increases.
This paper describes a newly developed static negative-phase-sequence current compensator which is applied to rotary frequency converters (50/60Hz) feeding 60Hz electric power to the Tokaido Shinkansen in 50Hz power system area.
Basic principle of compensation of negative-phase-sequence current is generating negative-phase-sequence current in reverse phase to the negative-phase-sequence current to be compensated using a fixed capacitor and a thyristor controlled reactor.
In this paper, the principle of negative-phase-sequence current compensation, characteristics of the compensation circuit and digital simulation study are described.