Study of novel traction substation hybrid power quality compensator

In order to improve the power quality of the traction power supply system, a novel hybrid power quality compensator with new construction and new compensation method is proposed. The hybrid power quality compensator has the following features: (1) a three-phase voltage type converter is used in two-phase circuit of the traction power supply systems. The power quality of traction substation can be regulated integrally because the two feeders are linked indirectly; (2) through a Scott transformer, two banks of passive filters and the three-phase converter are connected in series so that the capacity of the converter is reduced greatly; (3) the compensating object is not one of the feeders but the traction substation itself; and (4) by regulating the active power currents in two feeders, the traction substation will reach a load balance status. So the reactive power, negative-sequence and harmonic currents in two feeders of a traction substation are canceled together. Its feasibility is proven by simulation results.