Simulation And Processing Of Stray Current Signal Based On Independent Component Analysis

Cities,industrial bases,underground infrastructure,all of these areas have a lot of complex electrical structures that are affected by stray currents for a long time.In modern times,various aspects of stray current have been studied for decades.However,due to its irregular distribution and the influence of many factors,it is difficult to realize digital simulation in a strict sense,and field detection and reprocessing is the main means to deal with stray current.As the electrical system and underground pipeline network become more and more dense,the stray current interference from one place is likely to come from several different sources.Up to now,there are many methods to process signals,among which Independent Component Analysis plays an important role in medical treatment,remote sensing,denoising and communication due to its advantages of no prior information.Stray current leaks in the ground,and the measured signal is equivalent to the weighted mixture of the source current signal.The work of electrical appliances producing stray current is not related to each other,which conforms to the statistical independence requirement of the algorithm.Firstly,the Monte-carlo method is used to randomly sample the load generating stray current and calculate the probability distribution of the stray current's effective value,so as to provide a reference for recovering the actual leakage of the stray current source through the waveform.Then,three typical independent component analysis methods-Fast ICA,Informax and JADE-were used for blind source separation.JADE's algorithm shows superior performance according to the separation effect.Finally,several typical stray current simulation models are constructed in MATLAB/simulink: ac stray current,photovoltaic parasitic capacitor leakage current and dc traction system stray current.In case of the target only has the characteristics of the separated waveform,the simulation simplifies the electrical facilities that generate stray current.At last,ICA method was effective for non-sinusoidal waveform separation,but not for ac stray current.