Abstract：The magnitude and composition of transformers no-load current harmonics can be used to examine the saturation degree and detect the inter-turn faults. Generally, a large capacity of industrial-frequency (IF) power supply is used to measure the no-load current harmonics content in transformer factory test. In order to reduce the capacity of testing power supply, this paper proposed a method using low frequency power supply to replace IF power supply to measure no-load current harmonics of transformers. Two low-frequency voltages were first applied to obtain the eddy current and no-load current harmonics. The converted current harmonics content and total harmonics distortion (THDi) under IF were then calculated based on eddy current compensation. In addition, the experiments and simulations were conducted on a single-phase power transformer. Compared with the conversion results of 15Hz, the errors of harmonics content and THDi directly measured under IF are both below 1%. It is shown that this method has high conversion accuracy and can significantly reduce the capacity of testing power supply.
姚陈果, 刘鑫, 胡迪, 万佳伦, 王俊凯. 变压器空载电流谐波低频测量方法[J]. 电工技术学报, 2017, 32(22): 115-21.
Yao Chenguo, Liu Xin, Hu Di, Wan Jialun, Wang Junkai. No-Load Current Harmonics Measurement of Transformers Using Low-Frequency Method. Transactions of China Electrotechnical Society, 2017, 32(22): 115-21.
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