基于LCL滤波器的并网逆变器控制策略研究

Control strategy for grid-connected inverter with LCL filter

针对基于LCL滤波器的三相并网逆变系统,首先给出了三相并网逆变器的数学模型,同时分析了LCL滤波器参数设计的限制条件以及步骤,然后在分析传统电容电流反馈有源阻尼法的基础上,以进一步减少系统传感器为目的,提出了一种并网电流反馈及电网电压前馈的控制策略。最后,为了验证提出的控制策略的有效性和可行性,搭建了基于Matlab/Simulink的仿真模型并进行仿真,仿真结果表明:该控制策略不仅可以使系统获得高质量的并网电流,并且能减少传感器的数量,节约了系统成本。

Aiming at the three-phase grid-connected inverter with LCL filter, the mathematic model of the three-phase grid-connected inverter was firstly presented, and the limiting condition and the step of the parameters design for LCL filter were analyzed. Then, based on the analysis of the traditional active damping method with capacitor current feedback, for reducing system sensors, a control strategy with grid-connected current feedback and network voltage feedforward was proposed. In order to validate the effectiveness and feasibility of the proposed strategy, the inverter system was modeled and emulated via Matlab/Simulink simulation. Simulation results indicate that grid-connected current is high-quality and the sensors are reduced which makes the system cost reduced.