基于谐波状态空间的逆变器滤波电路状态评估方法研究

逆变器已经成为现代电网不可或缺的部分,广泛应用于电网与可再生能源和各种负荷之间。逆变器末端的滤波电路属于重要的部件之一,其参数状态决定于逆变器的品质及可靠性。首先通过建立谐波状态空间数学模型,获得输入量与输出量之间的耦合关系,然后注入扰动电压到逆变器输入端,通过检测输出电流的信号,利用输出量与输入量之间的耦合关系来判断逆变器滤波电路的状态情况,并将仿真所得到的输出电流的谐波含量与滤波电路元器件参数的改变关系拟合成线性关系图。最后通过实验样机验证了方法的有效性。

Research on State Evaluation Method of Inverter Filter Circuit Based on Harmonic State Space

Inverters have become an integral part of modern power grids and are widely used between the grid and renewable energy sources and various loads. The filter circuit at the end of the inverter is one of the important components whose parameter states determine the quality and reliability of the inverter. First of all, the study establishes a harmonic state space mathematical model to obtain the coupling relationship between the input and output quantities, then injects the disturbance voltage into the input of the inverter, and uses the coupling relationship between the output and input quantities to judge the state of the filter circuit of the inverter by detecting the signal of the output current, and fits the harmonic content of the output current obtained from the simulation to the change of the filter circuit components parameters. The harmonic content of the output current obtained from the simulation is plotted against the change of the filter circuit components. Finally, the validity of the method is verified by the experimental prototype.