Measurement and modeling methods for broadband impedance characteristics of large-scale electrical equipment

Abstract

In order to build the broadband model of electrical equipment, it is necessary to measure the broadband impedance characteristics of the equipment. However, the large size of high-voltage electrical equipment requires long measurement leads to measure the broadband impedance characteristics. At present, there is a lack of effective and universal compensation measures, which leads to unacceptable measurement errors in high frequency band. In order to solve this problem, a method for measuring broadband impedance characteristics of large-scale electrical equipment is proposed. In this method, impedance analyzer is used as measuring equipment, and the coupling calculation model of the long leads over the earth is established by using the partial element equivalent circuit (PEEC). The two-port network parameters of the long leads measurement loop are obtained, and the network parameter matrix is used to compensate the influence of the measurement results by the long leads. A measurement experiment is carried out in the laboratory, and the accuracy of the measurement method is proved by comparing the results measured directly by short leads with those measured by compensated long leads. The measurement method can accurately measure the broadband impedance characteristics of large-scale electrical equipment in the range of megahertz.