Research on Balance and Control Strategy of Lithium Battery Pack for Distributed Photovoltaic Power Generation
For distributed photovoltaic energy storage systems,their battery balancing system needs to meet the advantages of high reliability,simple topology structure,and high balancing efficiency.Aiming at the problems of low energy conversion rate and slow balancing speed in the existing series lithium battery balancing process,a series lithium battery pack power balancing and control strategy is proposed based on multiple intersecting staggered balancing circuits.This strategy adopts the idea of game theory to establish a Nash equilibrium model with independent equalizers as participants,switch conduction time as strategy,and battery SOC change as profit.The improved particle swarm optimization algorithm is used to solve the Nash equilibrium and obtain the optimal control scheme of the equilibrium circuit.Finally,a simulation model for series balancing of 6 batteries was built on the PSIM platform and tested under idle and discharge conditions.The results indicate that the design avoids repeated charging of the battery during the balancing process and greatly shortens the SOC balancing time of the battery,verifying the effectiveness of the proposed strategy and improving the performance of the balancing system.
battery equilibriumstate of chargegame theoryNash equilibriumparticle swarm optimization algorithm
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