Static Voltage Fluctuation Compensator for Electric Railway using Self-commutated Converters

Abstract

In this paper, authors describe a basic figure of static voltage compensator for electric railway, named RPC (Railway Static Power Conditioner), its compensating philosophy and successful result of its test using a small model of RPC.
An AC electric railway is placed under a load single phase, rapidly changing. To avoid voltage fluctuations under single phase loads, electric power is received from a larger source. And at a feeding substation, 3-phase electric power is transferred to paired directional single-phase feeding electric power.
Authors already proposed a static voltage compensator for AC electric railway, called “RPC”. The RPC links a pair of feeding circuits using 2 self-commutated inverters.
At the substation, the RPC accommodate_??_ an active power of the directional pair of feeding circuits to balance 3-phase power and compensate a reactive power to regulate a 3-phase voltage fluctuation. At a sectioning post, it can compensate for voltage drop using a reactive power. Also it can act as an active filter to compensate higher-harmonics.
Authors have made a small model (220V, 20kVA) of RPC. And we report on the results of tests using this small model under various conditions. The results indicate that RPC can accommodate single phase loads such as transformers and thyristors, can handle an exciting rush current of transformer, can compensate higher-harmonics and so on.