Development of a 3MVA/6kV Advance Power Quality Controller for Substations

An advance power quality controller combined with thyristor controlled reactor (TCR) and hybrid active power filter (HAPF) is proposed in this paper for substations in power system. The TCR and the passive filter part of the HAPF makes a static Var compensator (SVC), which acts as a classic reactive power compensator for load balancing and power factor correction. The small rating active filter of the HAPF is used to improve filtering characteristics of the passive filter in SVC and suppress possible resonance between the system impedance and the passive filter. The HAPF topology presented in the paper is different from the conventional HAPF. The basic of the new HAPF topology is to add a small inductor in parallel with the active power filter (APF) controlled as a current source, in order to force the fundamental current flow through the additional inductor instead of the APF. By this way, it can reduce the VA rating of the APF greatly. The paper introduces the main circuit structure, analyzes the operation principle and control method. The practical 30MVA/6kV advance power quality controller has been developed and installed in LieShan 35kV/6kV Substation, Anhui province, China. The running results verify the effectiveness and advantage of the comprehensive power quality controller for substations in power system.