基于矢量作用时间的双向DC-DC变换器预测电流控制方法

Predictive Current Control Method for Bidirectional DC-DC Converter Based on Optimal Operating Time of Vector

在含有分布式电源的直流微网系统中,分布式电源输出波动以及负荷投切等因素会造成直流母线电压产生波动。为了改善系统的输出性能,进一步提高系统的快速性,该文提出一种基于矢量作用时间的双向DC-DC变换器预测电流控制策略。采用预测电流控制器取代传统的电流环PI控制器及调制环节,可以有效地提高系统的快速性。针对传统预测电流控制方法因开关频率不固定导致的电流纹波较大问题,提出改进的控制算法,根据在线计算得到矢量作用时间,设计新的目标函数从而实现定频控制。仿真和实验结果表明,在独立光伏储能直流系统中,基于矢量作用时间的双向DC-DC变换器预测电流控制策略能够有效地改善蓄电池电流纹波,抑制直流母线电压波动,增强系统的抗干扰能力。

In a DC microgrid system with distributed power,factors such as distributed power output fluctuations and load mutations will cause fluctuations in the DC bus voltage.In order to improve the output performance of the system and further improve the rapidity of the system,the predictive current control method for bidirectional DC-DC converter based on optimal operating time of vector is proposed in this paper.The predictive current controller is used to replace the traditional current loop PI controller and modulation part,which improves the rapidity of the system effectively.In order to solve the problem of large current ripple caused by the inconstant switching frequency in the traditional predictive current control method,an improved control method is proposed.A new objective function is designed to achieve constant frequency control based on the vector action time calculated online.The simulation and experimental results show that the battery current ripples and the DC bus voltage fluctuations are suppressed effectively by the predictive current control method of photovoltaic energy storage bidirectional DC-DC converter based on optimal operating time of vector,and the disturbance rejection capability of the system can be enhanced by the method proposed in this paper.