Improved Multivariable PPF Controller to Mitigate Damping and Cross Coupling Effects of LCL-Type Filter in PV Islanded Microgrids

Abstract

An improved multi-input multi-output (MIMO) positive position feedback (PPF) controller is designed for LCL-filtered voltage source inverter of solar powered islanded microgrid. The proposed controller is designed based on multi-input multi-output framework and simulated annealing optimization algorithm. This controller provides high performance in terms of damping, closed-loop bandwidth, tracking and cross coupling effects reduction to the LCL-filtered solar powered inverter unit. Moreover, the designed controller is robust against the shift in resonance frequency of LCL-filter due to filter parameters and line inductance variations. Simulation results of open- and closed loop system are presented and the result show that the proposed controller provides high performance for a 102.59 kW solar powered islanded microgrid.