Research On Control Strategy Of Battery Charge And Discharge In Wind Solar Hybrid System

With the development of social economy, the environmental problems is becoming more and more outstanding and drawing people’s extensive concern. In this case, the development and utilization of new energy has become an irresistible trend, of which the wind and solar power is the most potential. The hybrid system based on the complement of the two kinds of this energy is a economic and reasonable power supply mode. It can not only play a positive role in solving environmental problems, but also solve the problems of the remote region’s power supply. But because of the randomicity and intermittence of the two kinds of energy, the battery storage is the key link in the system. The research object of this article is the battery storage system.First, this paper compared the performance of different batteries, based on the feature of the wind solar hybrid system choose the LiFePO4battery as the storage unit. Combined with the characteristics of the battery, choose and develop the batteries’charge and discharge circuit and control strategy, it can maintain the stability of system, when the DC bus fluctuated obvisously because of the power unbalanced, at the same time it can ensure the safety and effectiveness of the batteris.Secondly, aimed at the battery imbalance phenomenon when the batteries are charging, this article compared and analysed the inductance topology and flyback converter topology equalization system, and completed energy equalization of the LiFePO4battery module with the two methods in the Matlab/Simulink, drew the conclusion that flyback converter topology equalization system is faster and more effective than the inductance topology equalization system.At last, the experimental platform battery management system is built. The charge and discharge experiment is done on this platform, and combined with the20kVA bi-directional inverter.