Impact of Oustaloup and Matsuda Approximations on Fractional PID Controller of PV Panel

Due to the non-linear relation between current and voltage of the PV modules, DC/DC power electronic converters are used to adapt this non-linearity. Controllers are used to control the DC/DC converters in order that, they can take actions against changes in irradiance input levels, temperature input levels and load values. In this study, a standalone PV system that feeds a DC load is simulated. Integer order controller and fractional order controller are compared considering two scenarios. The first scenario is to change the irradiance levels while maintaining the load at a constant value. In the second scenario, the load value and the input irradiance levels are changed. In the two scenarios, the response is observed while keeping the temperature at a constant value for simplicity. Tuning of controllers is performed using a cost optimization method namely, Particle Swarm method. Oustaloup algorithm and Matsuda algorithm are two techniques are used in this paper individually to approximate the fractional order of Laplace operator. Results show that, better robustness and less error in case of fractional controllers can be observed as compared to the integer controller.