基于双积分滑模控制的光伏电压平衡器研究

Research on a photovoltaic voltage balancer based on double integral sliding mode control

文章采用三电平Boost电压平衡器将光伏电源接入双极性直流微电网。针对变换器正、负极输出电压不平衡问题,设计了一种基于PWM技术的双积分滑模控制器对电压平衡进行控制。与传统的PI控制器相比,该方法能提高系统的动态响应速度和增强鲁棒性。仿真结果表明,相比PI控制,该方法将电压平衡器的动态调节时间缩短42%以上,电压差峰值减小33%以上。同时,系统采取的控制策略能确保电压平衡的控制对光伏最大功率点追踪的控制影响极小。

A three-level boost voltage balancer is applied to connect photovoltaic power with bipolar DC microgrid.For the problem of neutral-point voltage balancing of the TL-Boost converter,a double integral sliding mode controller based on PWM technology is designed to control voltage balancing.Compared with the traditional PI controller,the proposed method can improve the dynamic response speed and enhance the robustness.Simulation results show that,compared with PI control,the proposed control shortens the dynamic adjustment time of voltage balancer by more than 42%,and the peak value of voltage difference is reduced by more than 33%.Meanwhile,the control strategy adopted by the system ensures the control of voltage balance almost without affecting the control of photovoltaic maximum power point tracking.