Ultra-low frequency insulating medium loss calculation method based on Nyquist theorem

• Main Authors: ZHENG ZHONGNAN, HUANG YOUCONG, LIAN HONGSONG, LIN TIANJIN, XU JUN, WANG XIAOJIE, HAN TAO, FANG CHAOYING, CHAN SIU-HONG, FU CHIH-WEI, ZHANG YING, PENG LIQIANG, LI WENHAO, WANG QIONG, LIN ZIYIN
• Format: Patent
• Language: Chinese; English
• Published: 22.03.2024
• Subjects: MEASURING; MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES; PHYSICS; TESTING

The invention relates to an ultralow-frequency insulating medium loss calculation method based on the Nyquist theorem, and the method specifically comprises the steps: applying a voltage to a cable through an ultralow-frequency power supply, carrying out the synchronous sampling of the voltage and current in a sampling period through a data collection terminal, and obtaining a sampling signal; filtering other frequencies except the specified frequency in the sampled signal by using a fast Fourier transform algorithm to obtain a filtered signal; all frequency components higher than the Nyquist frequency in the filtered signal are filtered out, and a filtered frequency domain signal is obtained; and converting the filtered frequency domain signal into a time domain signal by using inverse Fourier transform, determining a phase angle difference between voltage and current under the time domain signal, and calculating a dielectric loss value by using the phase angle difference. 本发明涉及一种基于奈奎斯特定理的超低频绝缘介质损耗计算方法，具体步骤包