Proportional Resonant Controller for a 27-Level Asymmetric Multilevel STATCOM

Abstract

In this paper a 27-Level Asymmetric Multilevel STATic COMpensator is presented aimed to compensate reactive power. The STATCOM is controlled with a master-slave approach, where the master loop is responsible to regulate the DC voltage using a Proportional-Integral controller, while the inner loop is in charge to track the reference currents through a Proportional-Resonant control block. The presented multilevel topology considers the cascaded connection of single-phase HBridge converters that follow the 9:3:1 voltage ratio in order to generate a staircase waveform with 27 levels. The correctness of the proposal is validated through simulations, where stationary and dynamic tests were performed. Keywords—27-Level Asymmetric Multilevel Converters, PR Control, STATCOM, Reactive Power.