Robust Control of Grid-connected Voltage-sourced Converter based on Sliding Mode Control

This paper presents the application of Control of Grid-connected Voltage-sourced Converter (VSC), based on Sliding Mode Control (SMC). This Control Strategy was originally developed for Distributed Energy Resources (DERs), operating as Slave Units in Inverter Based Microgrids with Master-Slave Control Strategy. This paper compares the SMC based Control Strategy of VSC with Classical Control of VSC, in Grid-connected Mode. DC Bus Voltage is observed with normal operation of Main Grid and under Parametric Changes of VSC. Existing work entirely ignores the dynamics of the DC side, only concentrating on power output at AC side of Microgrids. Voltage of DC Bus and Total Harmonic Distortion (THD) of current exchanged with the Main Grid are the basis for comparison. It is observed that the THD of current is significantly less for SMC based Control Strategy for VSC, as compared to VSC with Classical Control. Moreover, the performance of SMC based Controller is unaffected by the disturbance, in the form of change of circuit parameters in Grid-connected VSC. However, the performance of the Classical Controller is adversely affected, when subjected to identical disturbance.