Application Of Partial Discharge Location For 10kV Power Cable Under Oscillating Wave Voltage

Cross-linked polyethylene cable is widely used in power distribution network at home and abroad,its safety and reliability has a close relationship with operation reliability of power grid terminal equipment.Cable insulation has long been affected by electrical,thermal,chemical,and other factors,which will lead to local electric field concentration and trigger partial discharge.Partial discharge signal contains abundant cable insulation status information,it is the main characteristics of the cable insulation state.As an effective diagnosis method for partial discharge test,the oscillation wave voltage method has been taken by power grid operation management department in recent years.The study of oscillation voltage was limited to defect detection and location currently,by developing the research of partial discharge characteristics and pattern recognition under the oscillation wave voltage,it has an important significance of defining the features of cable insulation defect and taking appropriate measures.The main contents of this article are shown as follows:(1)Structures of power cable and the middle connector between two power cables were addressed the Chapter 2 firstly.Faults trends and reasons of the power cables were statistically analyzed.The typical defects in power cable are simulated by ANSYS,and based on the principle of traveling wave fault location calculation source,realize the function of positioning the partial discharge through the accumulated energy curve method.(2)Based on the RLC circuit,the paper studies the oscillation wave compression system deeply,and studies the two cases of the under damped and over damped according to the oscillation wave voltage generating circuit.Characteristics of Rogwski coil sensor involving amplitude-frequency and phase-frequency response were calculated by the MATLAB,based on analysis of the principle of Rogwski coil.(3)Power cable PD defect model was manufactured and the experimental setup was built in the laboratory.Oscillation wave PD detection steps of power cable were designed in this chapter.PD detection and location was researched in the laboratory.Finally,the system was used to PD detection and location for filed fault power cable.Experimental results showed that the oscillation wave PD detection system waseffective to detect and locate PD signals of power cable,which is significant to engineering practice.