High-speed Railroad Power Cable Partial Discharge Test Research And Application

In China’s newly built high-speed railroads,the proportion of the use of power cables is rising,especially the inter-district power through-line all-cable power supply method has become the norm.Railroad power cables as railroad stations along the line,signals,communications and other railroad integrated power equipment to provide electrical energy important infrastructure,its operational reliability for the stability of the railroad power system,to ensure the safety of train operation plays a vital role.In recent years,with the increase in the number of high-speed railroad power cables in operation,cable failures have also emerged as a growing trend,becoming a prominent issue affecting the safety of high-speed railroad operations.Once a fault occurs in the operation of high-speed railroad power cable,due to its linear distribution structure and the time constraints of the universal night-time skylight operation of high-speed railways,it brings a lot of inconvenience for cable fault finding and disposal.With the current technical means and equipment level of the power supply section of each railroad bureau,there is a lack of effective control over the insulation status of railroad power cables.The detection of partial discharge of the cable,as a characterization parameter and evaluation means of early cable insulation deterioration,has been confirmed its effectiveness at home and abroad.Therefore,it is of great practical significance to find a suitable and effective means of local discharge detection for high-speed railroad power cables to assess the insulation status of the cables and to formulate effective measures.This thesis firstly introduces the structure of high-speed railroad power system and cable operation reliability requirements,summarizes the main causes of railroad power cable faults,analyzes the examples of power cable faults in Daxi high-speed,and proposes the necessity of local discharge testing.The advantages,disadvantages and applicable conditions of the current common cable local discharge detection methods are compared,and the feasibility of oscillatory wave local discharge test for high-speed railroad power cables is demonstrated.Finally,combined with the field application of oscillation wave local discharge test for power cables of Daxi high-speed railroad,effective countermeasures are formulated,and suggestions for operation and maintenance of high-speed railroad power cables and preventive tests are put forward to guide railroad power cable operation and maintenance management.There are 37 figures,6 tables and 64 references in this thesis.