Research on application of TCR+FC typed SVC in power quality integrated management for power traction system

With characteristics such as impact, asymmetric and nonlinear, the electromotive in electrified railway is a typical kind of single-phase load. Electrified railway connected to power grid will bring a lot of power quality problems. To solve harmonic problems and three-phase voltage unbalance caused by the negative sequence, this paper proposes an integrated management of power quality problems based on the three-phase static var compensator (SVC). In this management, SVC is composed of fixed capacitors (FC) and thyristor controlled reactor (TCR). This SVC management is accessed to the high-voltage side of traction substation by a dedicated transformer, which focuses on compensating the negative sequence and the reactive power. Based on the analysis of this TCR+FC typed SVC, a composite control system is used in this paper, which consists of a open-loop control system and a closed-loop control system. By modelling and simulating the actual situation of a traction station in PSCAD/EMTDC software, the feasibility of the comprehensive power quality controlling device is verified and we conclude results that this TCR+FC typed SVC management can effectively control three-phase unbalance and harmonic power quality problems.