Simulation Study On Fault Diagnosis Of Marine Power Cable

Since marine power cables often lay in complex environment,its working environment is harsher.The cable is more prone to various types of fault,for which it needs regular fault diagnosis.Based on the limitations of the existing method time domain reflectometry(TDR),this paper draws on and absorbs the advanced theory and experience at home and abroad,and it takes the Ethylene Propylene Rubber(EPR)insulated low-voltage marine power cable as the research object,then the frequency domain reflectometry(FDR)and Time Frequency Domain reflectometry(TFDR)are proposed to apply to the power cable.The paper does a series of simulation experiments to verify new methods' feasibility in the application of power cable,so as to provide a new method for the marine power cable.The new method will have more accurate fault diagnosis and is able to diagnose more fault type,and the fault measurement distance can be more extensive.And the detection method is expected to have a good prospect in practical engineering application.The research work of this paper is as follows:(1)Equivalent mathematical model of marine power cables.Based on the actual physical structure of the Ethylene Propylene Rubber(EPR)insulated power cable,the mathematical model is established,and the primary parameters and secondary parameters of the cable are calculated respectively.The operation rules of the electromagnetic wave in the cable are analyzed and explained.(2)The fault diagnosis principle of cable.FDR and TFDR method is presented to diagnose the fault of marine power cable for the first time.FDR method uses standing wave reflectometry method to be as the fault diagnosis principle.The sine sweep signal is output to the test cable.The fault location is based on the frequency difference.TFDR method uses Gaussian envelope chirp signal as the incident signal,and uses Wigner-Ville distribution(WVD)and cross correlation detection technology to deal with the incident and reflected signals,so that the testing cable is diagnosed.(3)Simulation experiments study on fault diagnosis of marine power cable.The simulation model of marine power cable is established by PSPice and Matlab software.In order to prove the high efficient performance of novel methods(FDR and TFDR method),the different category fault(high resistance,low resistance and open circuit)and fault distance is set.Moreover,the traditional TDR method is investigated as a comparison.Experiment results show that FDR and TFDR method is able to overcome the disadvantages of TDR method which cannot measure the high resistance fault and have unmeasurable area.FDR and TFDR method has high efficient performance,and it is very accurate in comparison to TDR method.Moreover,multiple faults is easy to be recognized by TFDR method,and power cable fault of short distance is accurately measured.