Optimized Robust Controller Design Based on CPSOGSA Optimization Algorithm andH₂/H_∞Weights Distribution Method for Load Frequency Control of Micro-Grid

Abstract

In this paper, a mixed $H_{2}/H_{\infty }$ robust control strategy that considers the weights of the $H_{2}$ and $H_{\infty }$ norm in the optimization process is proposed, and it is used to solve the load frequency control (LFC) problem of the micro-grid (MG). The MG load frequency model established in this paper includes battery energy storage system (BESS), fuel cell (FC), wind turbine (WT), photo-voltaic (PV), and diesel engine generator (DEG). The optimal mixed $H_{2}/H_{\infty }$ robust controller takes the minimum square integral of the system’s frequency fluctuation as the goal of control optimization by integrating the robust performance expressed by the $H_{2}/H_{\infty }$ two norms. The hybrid particle swarm optimization and gravitational search algorithm with chaotic map algorithm (CPSOGSA) is used to optimize the weight value reflecting the $H_{2}$ and $H_{\infty }$ performance of the system and the evaluation function’s weighting matrix of the output performance so that the controller can reach the optimum under the constraints. Simulation experiments show that the robust controller designed by the proposed method has better dynamic performance when compared with $H_{\infty }$ robust controller, $H_{2}$ robust controller, and traditional $H_{2}/H_{\infty }$ robust controller, and the results are very satisfactory.