A novel compensation method for impedance measurement when long feeders are involved

Abstract

Abstract Black‐box modelling for the electrical equipment requires accurate admittance/impedance frequency‐sweep measurements. In some cases, long test leads are required because of the large size of the electrical equipment under test. It would induce unacceptable measurement errors in high frequency band. In order to solve this problem, first, the measurement principle of the impedance analyzer is studied, based on which the factors affecting the measurement accuracy are fully discussed. Second, a novel compensation method for measuring the wide‐band impedance of the large electrical equipment is proposed, in which the long test leads effect and the non‐standard characteristics caused by the extra leads connected to the open/short/50Ω‐load compensation terminals can both be eliminated. Finally, this method is validated by some experiments with 30 m‐long test leads in a frequency band ranging from 40 Hz to 10 MHz.

Keywords

• Measurement and error theory
• Electrical instruments and techniques
• Measurement theory
• Impedance and admittance measurement
• Microwave measurement techniques