Two-level 24-pulse double-way voltage source converter-based STATCOM

Abstract

This paper presents a two-level 24-pulse double-way voltage source converters (VSCs) configuration for the static synchronous compensator (STATCOM). It uses four identical six-pulse double-way VSC sets to form a 24-pulse VSC configuration of STATCOM. Each six-pulse double-way VSC set consists of two sets of two-level three-phase six-pulse gate turn off thyristor (GTO) VSCs. The phase angle difference between the fundamental ac voltages of two three-phase six-pulse GTO VSCs is varied for the reactive power control. The STATCOM is operated at a constant dc link voltage which results in better utilisation of the converter compared to the operation of the STATCOM with variable dc link voltage. The STATCOM is designed for ±100 MVAR and connected to a 33 kV/60 Hz ac system to evaluate its performance by varying the reference reactive power. The model of proposed STATCOM is developed using MATLAB along with Simulink, sim-power system (SPS) toolboxes and simulation results demonstrate its satisfactory steady state and dynamic performances.