Dual-loop generalized predictive control method for two-phase three-wire railway active power quality controller

Abstract

One of the most challenging topics in electric railway networks (ERNs) is power quality (PQ) problems caused by single-phase feeding of time-varying and high-power locomotives. During previous years, many techniques and compensators have been offered to alleviate these problems. Railway active power quality controller (RAPQC) is considered as one of the most efficient approaches. Due to the time-variant, uncertainty and distorted features of ERNs, the controlling of RAPQCs has always been a substantial concern to experts. This paper presents, a new robust control system for two-phase three-wire RAPQC (ThRAPQC) based on generalized model predictive control integrated with modified instantaneous reactive power theory (GMPC-MIRP). A dual-loop balancing system has been adopted in the proposed control system to equalize the active powers of traction power substation (TPSS) adjacent feeders, compensate reactive powers and suppress harmonic simultaneously. The performance of the proposed method in comparison with the conventional Fryze-Buchholz-Depenbrock (FBD)-based current strategy together with hysteresis current controller (FBD-HCC) has been evaluated through the detailed simulations and Opal-RT 5600-based laboratory setup results. The fast response, high precision, lower fluctuation in reference current tracking and high capability of working in distorted conditions are the outstanding privileges of the proposed method that are confirmed by the output results.