Research On Control Strategy Of Power Conversion System Based On Improved Grey Wolf Optimization Algorithm

Energy storage systems play an important role in power system "peak shaving",electric vehicle charging station construction,microgrid and smart grid construction,both as power generation systems and as load units.In this paper,an improved grey wolf optimization algorithm(IGWO)is used to adjust the control parameters of an energy storage bi-directional converter to optimise its performance.A composite control strategy based on IGWO-PID and improved model prediction is proposed to address the limitations of the traditional linear control strategy.Firstly,to address the shortcomings of the grey wolf optimisation algorithm,which is prone to premature convergence,low convergence accuracy in the face of complex problems and insufficient convergence speed,three improvements are proposed:(1)increasing the diversity of the initial population of the grey wolf optimisation algorithm by using the good point set theory;(2)non-linearising the convergence factor a to coordinate the global search ability and local exploitation ability of the grey wolf optimisation algorithm;(3)addressing the shortcomings of the grey wolf optimisation algorithm in solving complex problems easily fall into local optimality,Gaussian variation and greedy selection strategies are introduced to enhance the search capability of the algorithm and the search accuracy in the late iteration.Secondly,the improved grey wolf optimization algorithm(IGWO)is used to rectify the control parameters of the energy storage bi-directional converter in islanding and grid-connected modes respectively,and the simulation results are compared with the particle swarm algorithm(PSO)and grey wolf optimization algorithm(GWO).Again,for the dynamic characteristics of the hybrid system of the energy storage bidirectional converter,the classical PI control has certain limitations,and the composite control strategy of IGWO-PID and improved model prediction is proposed to improve the performance of the energy storage bidirectional converter system.The simulation results are compared with those of traditional linear control,and it is proved that the composite control strategy has higher accuracy and better dynamic performance.Finally,the simulation model of the energy storage bidirectional converter is built in MATLAB/Simulink,and the simulation verifies the effectiveness of the IGWO algorithm in rectifying the control parameters of the energy storage bidirectional converter;the accuracy of the improved grey wolf optimization algorithm in rectifying the control parameters of the energy storage bidirectional converter is experimentally verified by using a power electronic physical device in x PC mode.