Research On The Adaptive Reclosing Control Technology And Device Of Cables And Overhead Mixed Lines

With the widespread of the cable-overhead hybrid lines and vigorous construction on the smart grid in China,electric hybrid lines utilizing adaptive reclosing for solving instantaneous fault have excluded the line fault fast and accurately after a failure happened and finally achieving the purpose of restoring power supply as quickly as possible which has more actual economic significance.Researches shows that the power lines prossess the highest probability to occur a single-phase grounding fault of transient fault properties under the such case of line insulation damage or a thunder strike.Nevertheless the traditional reclosing device can't distinguish transient fault from permanent fault correctly,the reclosing operation could be implemented uniformly.As to the cable fault of hybrid lines belongs to the permanent fault,it's easily to cause a secondary high-voltage shock to electrical lines and equipments through switching circuit breaker blindly.Thus the secondary high-voltage shock will influence insulation performance of lines and destroy the power network,thence causing a unpredictable serious consequence.To solve this problem,the paper focuses on an adaptive reclosing control device applied in the mixed line,which based on the theory of the transient voltage traveling wave aiming at accomplish the appliance of the mixed line adaptive reclosing device.First,this paper analyzed the propagation properties and the catadioptric process of the fault,wave,putting forward the methods to map the fault,to distinguish the fault section and to realize the adaptive reclosing.Using transient wave signal and polarity,which collected through the specific sensor,it could determined the type of the fault line exploiting section identification and FLA,controlling the close or break of the outlet pressure plate of the reclosing device,thus realizing the adaptive reclosing control.This paper designed both the software and the hardware of the adaptive reclosing device for the mixed line based on the transient wave.The hardware part consists of PCB fault detection module,GPS clock wave recording module,precise fault positioning module,optical fiber communication module and adaptive reclosing control module.The software part includes the upper computer software,the communication protocol,and presents main interface function of the upper computer operating system.The installation of the device is presented in the end of the paper.The device has been installed in the field and put into a trial operation.By analyzing the data collected from the upper computer,it could be realized the fault location of lines and achieved the adaptive reclosing control and its location error is less than 100 meters.In short,the feasibility of this device meets the need of the smart grid.