差分升压逆变器半周期调制及单电流环并网控制

Half cycle modulation and single grid-current loop control of differential Boost inverter

当差分升压逆变器并网运行时,需要保证交直流侧的电能质量,同时兼顾较高的控制性能及控制效率。在对差分升压逆变器并网运行工作原理进行分析后,提出了一种基于半周期调制的单电流环并网控制策略。通过将高频和工频控制相结合的调制方法,减少了处于高频工作状态的开关管数量,降低了功率开关管所承受的开关电压、电流应力和开关损耗。同时,通过对比并网电流信号得到误差信号,随后通过控制器调节来实现闭环控制,使控制结构和控制参数设计得以简化。仿真和实验结果表明所提策略具有提高并网电流质量、快速动态响应、控制结构简单等优点。

When DBI(Differential Boost Inverter)achieves grid-connected operation,it not only needs to improve the power quality of both AC side and DC side,but also needs to satisfy rapid dynamic response and high efficiency.After analyzing the working principle of DBI connected to grid,a single grid-current control loop based on half cycle modulation strategy is proposed.Through the modulation method of combining high frequency and power frequency control,the number of switches in high-frequency working state is reduced,meanwhile the switching voltage and current stresses and switching loss of power switches are reduced.At the same time,the error signal is obtained by comparing the grid current signal,and then the closed-loop control is realized by adjusting the controller,which simplifies the design of control structure and parameters.Simulative and experimental results show that the proposed strategy has the advantages of improving grid current quality,fast dynamic response and simple control structure.