Experimental Research of Dynamic Capacity Based on Conductor Temperature-rise Characteristic of HV Single-core Cable

Increasing transmission current capacity of existing power cable transmission lines is of great significance to the implementation of smart grid.In order to add transmission current capacity of operation cable dynamically,by analyzing the necessity of increasing cable transmission capacity,we put forward a way of increasing cable transmission capacity,designed a temperature rising test for step current of 110 kV XLPE under simulated cable tunnel,including normal load,full load,and over load,and analyzed the experimental data.The results show that,the value of conductor temperature rising-time from the experimental data is consistent with that calculated by theoretical model;if increased cable capacity is within the rated load,according to power supply demand,cable current capacity can be increased and operated dynamically for a long time;when cable capacity is increased from normal load to full load,within conductor temperature rising-time range,under steady condition,the max conductor temperature is 87% of rated operating temperature,so cable current capacity can also be added and operated dynamically for a long time;when cable capacity is increased from normal load to over load,if cable capacity is overloaded 20% of rated load,after 50% of conductor temperature rising-time,conductor temperature reaches rated operating temperature,that is,the operating time of over load is about 50% of conductor temperature rising-time cable.Therefore,making use of cable conductor temperature rising-time,we can increase the capacity of cable transmission lines dynamically,even may make cable to run in status of full load or over load.The results can give a reference value for optimal load of cable lines,power cable operation and management,and related engineering practice.