DC Link Voltage Balancing for Enhanced Performance in Multilevel Inverter-based Distribution Static Synchronous Compensator

Abstract

This article describes the use of a sliding mode controller (SMC) in conjunction with an integral (PI) controller for a MLI based DSTATCOM to balance dc side voltage, control a cascaded H-bridge inverter, and compensate for power quality issues related to current harmonics. Several benefits come with using SMC for DSTATCOMDC link voltage regulation, including a decrease in switching ripple in the DC side voltage and a steady DC side capacitor voltage under dynamic conditions. A DSTATCOM based CHBMLI supplying three phase loads is used to implement the SMC algorithm. When using the suggested dc link voltage balancing method, the DSTATCOM characteristics perform satisfactorily in terms of voltage balancing and the removal of power quality issues such current harmonics. Additionally, the DSTATCOM's improved voltage balancing (IVB) scheme is used to compare the performance of the PI controller with the SMC's improved voltage balancing method. The real-time investigation validates the performance characteristics, and the enhanced voltage balancing scheme of SMC results in better transient and steady state response.