Modelling, simulation and optimisation of robust PV based micro grid for mitigation of reactive power and voltage instability

• Small signal modelling and simulation of microgrid with PV–Wind–Diesel system has been done.
• Robust H∞H∞ and μμ synthesis based STATCOM is designed to enhance system stability and reactive power.
• GA and PSO are used to optimise the parameters of the robust controller.
• Robustness of controller is verified with different operating conditions.

This paper proposes a robust H-infinity STATCOM controller for compensating reactive power in stand-alone micro grid consisting of a PV–Wind–Diesel hybrid system. In order to carry out MATLAB based simulation, a small signal linear model of the stand-alone hybrid power system is considered, comprising of a photo voltaic cell, a DFIG based wind turbine and a diesel generator. Synchronous generator based DG acts as a backup for the hybrid system. Generally these standalone systems experience frequent variation of loads, wind power input and solar radiation, which affect the vital system parameters like reactive power, terminal voltage and frequency to a great extent. These variations of system parameters with variation of load inputs are studied and its impact on overall system stability and reactive power compensation is properly monitored. Furthermore the system performance is improved and the robustness of the controller is enhanced with the incorporation of GA and PSO.