Active power control of autonomous hybrid power system using two degree of freedom PID controller

Abstract

This paper shows an approach of active power control stratagem for an islanded Hybrid Power System (hPS) comprising of dish-stirling engine solar thermal system, wind accumulated turbine generator, diesel supplied generators, aqua electrolyzer with fuel cells and battery unit. Due to the intermittent output of DSTS and WTG as well as the load fluctuations in such a hPS, there is a rising demand for an appropriate control strategy. The Two-Degree-of-Freedom (2DOF) controllers are employed for the considered autonomous hPS so as to contain the frequency fluctuation under varying conditions. The controller gains are tuned by leveraging Flower Pollination Technique (FPA). The system’s dynamic reveal that 2DOF-Proportional–Integral–Derivative controller performs better to reduce fluctuations and stabilized time factor as compared to classical proportional–integral (PI), classical Proportional–Integral–Derivative (PID), and 2DOF-PI controllers. A Sensitivity assessment is performed to check the sturdiness of the optimized controller gains as well. Results show that the proposed active power control scheme addresses intermittent output of renewable generation and operates in a very robust way with very limited oscillations introduced to the system. In this fashion, more renewable generation can be deployed with stability and reliability.