基于逆变电源的中低压配电网谐波阻抗测量研究

基于谐波注入的阻抗测量方法具有谐波幅值可控的优势,在阻抗测量中得到了广泛的应用。文中介绍了一种基于逆变电源的中低压配电网谐波阻抗测量方法,针对不同电压等级的配电网设计了不同的测试拓扑,分析了通过逆变电源产生的谐波电压测量中低压配电网谐波阻抗的原理;同时,建立了不同控制方式逆变电源的戴维南模型,并分析了不同控制逆变电源等效电路的特性;为了提高测量精度,同时满足测试时的电网谐波要求,文中也提出了一种谐波注入准测。最后通过Simulink仿真证明,基于逆变电源的配电网谐波阻抗测量方法可以准确测量出配电网阻抗参数。

Research on medium and low voltage distribution network harmonic impedance measurement based on inverter power supply

The impedance measurement method based on harmonic injection has the advantage of harmonic control,and it has been widely used in impedance measurement.In this paper,a method for measuring harmonic impedance of medium and low voltage distribution network based on inverter power supply is introduced,and different test topologies are designed for distribution networks with different voltage levels.The principle of measuring harmonic impedance of low voltage distribution network by harmonic voltage is analyzed,meanwhile,the Thevenin model of inverter power supply with different control methods is established,and the characteristics of the equivalent circuit under different control modes are analyzed.In order to improve the measurement accuracy and meet the grid harmonic requirements during the test,a criterion of harmonic injection is proposed in this paper.Finally,the simulation proves that the harmonic impedance measurement method based on the inverter power supply can accurately measure the impedance parameters of the distribution network.