Fuzzy self tuning PI controller based inverter control for voltage regulation in off-grid hybrid power system

The management of reactive power has become an important aspect of the off-grid power system as voltage control is a key parameter in the quality of supply. This paper presents voltage profile control through VAR support by PV inverter in off-grid hybrid power system. PV (Photovoltaic system) inverter when oversized its reactive power capacity increases while injecting full active power and can provide necessary reactive power support to the system to maintain the voltage profile flat. The system considered for study consists of wind power generation by Induction Generator, Photovoltaic system with inverter and Synchronous Generator based diesel engine. The intelligent control based on Fuzzy with classical PI control strategy is presented in this paper to control reactive power of PV inverter to regulate load bus voltage and system model with developed intelligent control is simulated in SIMULINK/MATLAB, under the step load change and step change in input wind power and the results, obtained separately from PI controller and proposed Fuzzy self tuned PI controller are compared to validate the advantages of the proposed intelligent control algorithm.