Measurement Method of Inverter Output Impedance Based on Voltage Disturbance Source
Zhong Peijun1, Sun Jianjun1, Si Xuezhen2, Cao Zhihuang3, Pan Jing3
1. School of Electrical Engineering and Automation Wuhan University Wuhan 430072 China; 2. State Grid Electric Power Research Institute of Henan Electric Power CompanyZhengzhou 450000 China; 3. State Grid Anhui Electric Power Co. Ltd Hefei 230061 China
Abstract：The output impedance of a grid-connected inverter is an important parameter to determine the stability of its operation in the grid. It is usually measured by the harmonic current injection method. However, the background harmonics of the inverter may affect the accuracy of measurement results. The non-integer harmonics current injection method can effectively avoid this problem. Since the actual grid operating frequency fluctuates within a certain range, it is difficult to synchronize when using a harmonic current source to inject a non-integer harmonic current, and the method may cause measurement errors. Aiming at the above problems, this paper uses the equivalence of voltage disturbance and current disturbance, and proposes a method to measure the impedance of inverters by a voltage disturbance source. The voltage disturbance source can generate the fundamental frequency and non-integer harmonic voltage to measure the impedance of the inverter, and hence the accuracy of the impedance measurement is improved. The full-band impedance of the inverter is obtained by interpolation. The proposed measurement method is verified by the real-time digital simulation.
钟佩军, 孙建军, 司学振, 曹志煌, 潘静. 基于电压扰动源的并网逆变器输出阻抗测量方法[J]. 电工技术学报, 2019, 34(22): 4739-4750.
Zhong Peijun, Sun Jianjun, Si Xuezhen, Cao Zhihuang, Pan Jing. Measurement Method of Inverter Output Impedance Based on Voltage Disturbance Source. Transactions of China Electrotechnical Society, 2019, 34(22): 4739-4750.
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2019, Vol. 34 
