School of Mechanical, Electronic & Information Engineering, China University of Mining and Technology (Beijing), Beijing 100083, China.
College of Electrical Engineering and Automation, Shandong University of Science and Technology, Qingdao 266590, China.
Sensors (Basel). 2023 Apr 25;23(9):4273. doi: 10.3390/s23094273.
The dielectric loss angle can better reflect the overall insulation level of mining cables, so it is necessary to implement reliable and effective online monitoring of the dielectric loss angle of mining cables. In order to improve the monitoring accuracy of the dielectric loss angle tan of mining cables, a low-frequency dielectric loss angle online monitoring method combining signal injection method and double-end synchronous measurement method is proposed in this paper. Firstly, the superiority of the low-frequency signal in improving the detection accuracy of dielectric loss angle is explained, and the feasibility of the low-frequency signal injection method is analyzed. Secondly, the cable leakage is calculated using the double-terminal synchronous measurement method to measure the core current at the first and last ends of the cable, and the phase sum of the voltage at the first and last ends is selected as the reference phase quantity to realize the effective calculation of the dielectric loss angle tan of the cable. Then, the simulation model for online monitoring of dielectric loss angle of mining cable is built, and the feasibility of the online monitoring method proposed in this paper is verified by combining the simulation results. Finally, the theoretical and simulation analysis of the monitoring error of dielectric loss angle of mining cable is carried out.
介电损耗角能更好地反映矿用电缆的整体绝缘水平，因此有必要对矿用电缆的介电损耗角进行可靠有效的在线监测。为了提高矿用电缆介电损耗角 tanδ 的监测精度，本文提出了一种结合信号注入法和双端同步测量法的低频介电损耗角在线监测方法。首先，解释了低频信号在提高介电损耗角检测精度方面的优势，并分析了低频信号注入法的可行性。其次，利用双端同步测量法计算电缆泄漏电流，测量电缆首端和末端的芯线电流，选择首端和末端电压的相量和作为参考相位量，实现电缆介电损耗角 tanδ 的有效计算。然后，建立矿用电缆介电损耗角在线监测的仿真模型，结合仿真结果验证了本文所提在线监测方法的可行性。最后，对矿用电缆介电损耗角监测误差进行了理论和仿真分析。
