Isolated microgrid voltage regulation using fuzzy-logic based inverter control

Abstract

Modern isolated microgrid requires flexible and intelligent control of inverter to minimize the power mismatch between renewable generators and load. Maintaining the voltage at load connection is one of the critical aspects of voltage regulation in the isolated microgrid. The power generation from renewable generators is not constant as well as load parameters. Also, the power flow control between renewable generators is another major issue in an isolated microgrid. In this study, the intelligent fuzzy-logic based inverter control (FLIC) is used to regulate the voltage at the load connected considered the change in load-parameter and variation in the renewable power generation. The power output from the renewable generators is converted in DC to make the DCbus, which helps to maintain the power flow control between renewable generators and battery storage. The variation in the DC bus voltage is kept within acceptable limit using PI battery controller. The FLIC uses the error in the reference voltage and difference between the line-to-line voltage to generate firing pulses based on if-then rules. PV and renewable wind generator modeled with MPPT control for optimal power generation.