抑制电网电压扰动的输出阻抗增强型控制环路优化设计研究

Control-loop Optimizations Based on Output-impedance Enhancement for Disturbance Suppression of Grid Voltage

为抑制电网背景谐波对并网电流的影响,该文从输出阻抗重塑角度出发,提出基于输出阻抗增强的控制环路拓扑推演与拆分优化方法。在此基础上以LCL型电容电流、并网电流双闭环为例,研究基于阻抗增强的谐波抑制控制环路拓扑,提出一种电容电压和并网电流回馈控制环路拓扑结构,这种结构消去了电容电流内环,简化了控制回路,同时具有抑制谐振尖峰的效果。最后通过仿真及实验验证该方法的有效性和正确性。

To suppress the current distortion effected by harmonics in grid voltage,from the point of view of reshaping the output impedance,the method of deduction and split optimization of control-loop topologies based on the output impedance enhancement was proposed.Using the LCL dual-closed loop control with capacitor current and grid current feedback,different kinds of control loop topologies based on the concept of infinite output impedance were explored.A novel control loop with capacitor voltage and grid current was proposed.This control loop can remove the inner capacitor current loop and simplify the control.Finally the effectiveness of the proposed control method was verified by simulators and experiments.