基于快速CEEMD和Prony算法的井下变频系统漏电检测方法研究

Study on Leakage Protection of Underground Frequency Conversion System Based on Fast CEEMD and Prony Algorithm

阐述在井下变频系统中,变频器产生的大量高次谐波在对地分布电容上产生零序电流,对变频系统漏电保护造成了干扰,使其出现误动。因此,需要通过信号处理提取漏电信号特征再加以判别。然而,传统频域方法无法很好地处理低频漏电信号。针对这一问题,设计一种基于快速完全集合经验模态分解(Fast Complete Ensemble Empirical Mode Decomposition,FCEEMD)和Prony算法的漏电检测方法,通过FCEEMD分解信号,去除噪声模态分量并由剩余模态数量确定Prony算法阶数,再通过Prony算法进行检测。所设计方法兼顾了检测的精度和漏电保护实时性的要求。最后,通过仿真验证了所设计方法的有效性和快速性。

In the underground frequency conversion system, zero-sequence current is generated by a large number of high-order harmonics from inverter on the distributed capacitance to the ground,which interferes with the leakage protection of the frequency conversion system and causes it to misoperation. Therefore, it is necessary to extract the characteristics of the leakage signal through signal processing, and then make a judgment. Traditional frequency-domain methods cannot handle low-frequency leakage signals well. Aiming at this problem, this work designs a leakage detection method based on fast complete ensemble empirical mode decomposition(FCEEMD) and Prony algorithm. This method decomposes the signal through FCEEMD, removes the noise mode component,and determines the order of Prony algorithm from the number of remaining modes. And lastly denoising signal is detected by Prony method. This method takes into account the detection accuracy and real-time leakage protection requirements. Simulations results show the effectiveness and rapidity of the proposed method.