基于滑模控制的并联DC/DC变换器均流控制策略

Sharing Control Strategy of Parallel DC/DC Converters Based on Sliding Mode Control

在大功率直流供电系统中,一般采用分布式并联系统运行来提高输出功率以及可靠性,而在实际中分布式并联系统运行的电源模块间会产生环流,采用传统线性控制方法会造成均流精度低、抗干扰能力低、稳定性差等问题。为此,提出了一种基于积分滑模电压控制的分布式均流的方法。对分布式并联系统建立状态空间平均模型,在保留双闭环的基础上设计了积分滑模控制器,分析积分滑模的稳定性并对参数进行选取;其次,将分布式并联系统转化为多智能体协同控制问题,通过相邻模块之间通信,消除误差并补偿母线电压;最后,通过仿真验证了所提算法能提高均流精度和鲁棒性,且在负载跳变下,仍获得良好的动态均流特性。

In the high-power DC power supply system,the distributed parallel system improves output power and reliability.In practice,there will be circulating currents between the power modules running in a distributed parallel system.Using the traditional linear control method will cause problems such as low current sharing accuracy,low anti-interference ability,and poor stability.Therefore,a distributed current sharing method is proposed-based on integral sliding mode voltage control.The state-space average model is established for the distributed parallel system,the integral sliding mode controller is designed based on retaining the double closedloop,the stability of the integral sliding mode is analyzed and the parameters are selected.Secondly,the distributed parallel system is transformed into a multi-agent cooperative control problem,and the error is eliminated and the bus voltage is compensated through communication between adjacent modules.Finally,it is verified by simulation that the proposed algorithm improves the accuracy and robustness of the equalization,and obtains good dynamic equalization characteristics even under the load jump.