基于HHT的船舶综合电力系统故障时间定位新方法

A New Method of Fault Time Location for Ship Integrated Power System Based on HHT

针对强噪声环境下船舶综合电力系统故障时间定位精度不高的问题,提出一种基于Hilbert-Huang变换(HHT)和自适应软阈值法的船舶综合电力系统故障时间定位新方法。首先,电能信号经EMD分解为若干固有模态函数(IMF),对第一个IMF分量进行Hilbert变换得到其瞬时幅值向量。然后,在分析故障波形变化规律的基础上,定义并计算故障信号的瞬时幅值差分向量。最后,设计一种自适应软阈值处理方法,将瞬时幅值差分向量变换为故障时间特征向量,经加权均值后,实现故障时间定位。仿真试验结果表明,该方法能够精确定位不同强度噪声下的故障起止时间,在1 k Hz采样频率下精度为0.88 ms,适用于实际船舶综合电力系统故障的时间定位。

A new method of fault time location for ship integrated power system based on Hilbert-Huang transform （HHT） and adaptive soft threshold method is proposed to solve the problem that the fault time localization accuracy is not high in strong noise environment. First, the power signal is decomposed into several intrinsic modal functions （IMF） by EMD, and the instantaneous amplitude vector is obtained by Hilbert transform of the first IMF component. Then, on the basis of analyzing the variation law of fault waveform, the instantaneous amplitude difference vector of fault signal is defined and calculated. Finally, an adaptive soft threshold processing method is designed to transform the instantaneous amplitude difference vector into the fault time feature vector. After the weighted mean, the fault time is realized. The simulation results show that the method can accurately locate the fault start and stop time under different intensity noise, and the accuracy is 0.88ms at the sampling frequency of lkHz, which is suitable for the time position of the actual ship integrated power system failure.