The Research On The Charge-Discharge Control System Of Large-Capacity Lithium Battery

The lithium battery charge and discharge control system, as the system that first move and the subsystem that supplying initial energy and control power, is an important part of the lithium-powered electric power system. The impact of its performance on the whole system is very critical.In order to improve the performance of the system, this paper focuses on the research and investigation of the maintenance in charging and discharging the lithium battery, the choice of the power circuit, the design of control panel and the application of control strategy, etc. particularly, as for selecting the power circuit, in order to significantly improve the system reliability and reduce the current stress and thermal stress of power semiconductor devices as well as to inhibit the output of current ripple and reduce the capacity of the output filter, this paper developed three-phase parallel Buck/Boost bi-directional power converter for the system. By using the average of the state space method, I analyzed and mathematical modeled the PWM type DC/DC conversion circuit and proposed the dual closed-loop PID control scheme based on the current and voltage. Meanwhile, I took advantage of advanced technology staggered, by means of mathematical analysis and simulation tests and so on, verified the advantages of interleaving technology.This result makes the management of charge and discharge of Large-capacity lithium battery become truth, and the final result also shows that the design performance of the system is able to meet the requirements of the entire system.In addition, as for strongly nonlinear, delay and parameter drift of the DC/DC converter, this paper has also optimized the lithium battery charge and discharge control algorithm on the basis of the dual-loop PI algorithm and has proposed the Fuzzy-PI control algorithm based on the voltage control, which can greatly improve the control accuracy of the control system and can also enhance the dynamic performance and the adaptive capacity of converter systems for nonlinear perturbations. As a result, I verified the feasibility of this control strategy by computer simulation.