中文摘要：

分布式发电系统将各种不同的能源形式转换为电能加以利用．是分布式能源最有效的利用方式之一。全钒液流电池（VRB）是大型电力存储系统，在分布式电源中有许多潜在的应用。介绍了一种微电网的系统结构，阐述了储能电池的作用。基于VRB的放电特性，将推挽电路应用于微电网中VRB的放电回路，运用小信号模型分析法建立了VRB放电回路的双环控制结构图，并运用状态空间平均法建立了电池放电时双环控制系统的数学模型，然后利用数字控制系统参数优化的方法，设计了推挽电路电流内环和电压外环的数字控制器参数，最后通过Matlab仿真和2kW VRB放电回路的实验。验证了设计的正确性。

英文摘要：

Microgrid which takes a part together with the power grid, is the most effective way to make use of the distributed power supply.Vanadium redox flow battery（VRB） is a large stationary electricity storage system with many potential applications in a deregulated and decentralized network.The structure of microgrid system is introduced and the role of the storage battery is explained.Based on the characteristics of the VRB, push-pull circuit into the discharging circuit of VRB is applied.Small-signal model is used to establish the dual-loop controller structure of VRB discharging circuit, and then the state space averaging method is used to establish the mathematical model of the dual-loop controller of push-pull circuit.After that, the parameter optimizating method of digital control system is used to design the controller parameter of the current loop and voltage loop of push-pull circuit.Finally, Matlab simulation and 2 kW VRB discharging cireuit experiment are used to verify the correctness of the design.