Measurement Technology of Impedance Characteristics of Multi-node Ports in Power Network

With the increase of the proportion of new energy connected to the grid, power system oscillation accidents caused by power electronic equipment occur frequently. Because the performance of grid-connected converters is closely related to the impedance characteristics of the power grid, accurate impedance measurement technology is the key to achieve high-performance adaptive control of grid-connected converters in weak power networks. Existing techniques can only analyze the impedance characteristics of specific nodes in the grid. In order to improve the efficiency and economy of network impedance measurement, this paper presents a technique for measuring the impedance characteristics of multi-node ports in power network. The impedance characteristics of multiple nodes are calculated by injecting disturbance into one node and collecting signals from multiple nodes. In this paper, the simulation model of power grid impedance measurement system is built by Simulink, the realizability of power grid impedance measurement is studied, and the experimental platform of power grid multi-node port impedance measurement is set up. The experimental results show that the measurement system has high efficiency and accuracy.