Comparison of Deadzone and Vanderpol Oscillator Controlled Voltage Source Inverters in Islanded Microgrid

Abstract

This paper presents two types of nonlinear oscillator-based controllers termed virtual oscillator control (VOC). VOC is a time-domain control method unlike droop and virtual synchronous machine (VSM). In this method, each voltage source inverter (VSI) is tuned to mimic the dynamics of the nonlinearly coupled oscillators. Because VSIs are electrically coupled, they synchronize their output voltages and distribute the load in proportion to their ratings. Here, the authors presented two types of VOCs; one is nonlinear deadzone based VOC (NDZVOC) and the other is nonlinear vanderpol based VOC (NVPVOC). The design and implementation of the two control methods are presented in this work. The simulation study is conducted on the single- phase parallel VSIs system with the above-mentioned control methods during startup and load disturbance. Equal and unequal power-sharing is also presented in this study. The simulation results validate the proposed control methods