有源配电网阻抗特性分析与测量

Characteristics Analysis and Measurement of Active Distribution Network Impedance

并网逆变器的接入改变了配电网的阻抗特性,以含L型和LCL型并网逆变器的有源配电网为研究对象,研究含并网逆变器的有源配电网阻抗特性。通过逆变器的小信号控制框图分别建立L型并网逆变器和LCL型并网逆变器的诺顿等效模型,并通过电路变换得到含有多种逆变器的有源配电网的戴维南等效模型。在此基础上,分析不同逆变器的主电路参数和控制参数对有源配电网等效阻抗幅值和相角的影响。为便于工程实际中获取有源配电网阻抗及验证模型的正确性,采用一种基于串联谐波电压源扰动的方法进行有源配电网阻抗进行了测量。最后基于MATLAB/Simulink搭建了仿真模型。仿真结果验证了有源配电网阻抗模型的正确性。

Grid connected inverter could deeply change the impedance characteristics of the distribution network impedance.In order to understand this problem,the impedance characteristics of active distribution network with L-type and LCL-type grid connected inverters were studied.The Norton equivalent models of L-type grid-connected inverter and LCL-type grid-connected inverter were established by the small-signal control block diagram of inverters,and then the Thevenin equivalent model of active distribution network containing multiple inverters can be obtained by using circuit transformation.After that,the effects of main circuit parameters and the control parameters of different inverters on the amplitude and phase of active distribution network impedance were analyzed.To obtain the impedance of active distribution network and verify the correctness of the model,a method based on series harmonic voltage source disturbance was used to measure the impedance of active distribution network.Finally,the simulation model was built based on MATLAB/Simulink,and the correctness of the impedance model of active distribution network has been verified by simulation results.