某750 kV变电站SVG光纤断路故障分析及处理

Analysis and Handling of SVG Fiber Optic Circuit Breakage Fault in a 750 kV Substation

以某750 kV变电站2号静止无功发生器(static var generator,SVG)为背景,针对其在并网投运过程中发生光纤断路故障为研究对象,提出避免该类故障的处理措施。首先对故障过程进行解读,在分析取能电源拓扑结构的同时,将模块取能电源进行解体试验,得到其故障原因为单模块的取能电源中输入电容的引脚受损处于虚接状态,进而造成50 V转400 V电路板处于低压输入工作状态,最后匝间短路烧坏,致使光纤断路以至于2号SVG并网失败。再结合该装置从投运以来故障频发的器件类型,确认这类故障具有共性原因,均为取能电源里的精细元件经过长途运输颠簸、振动等原因发生断裂或接触不良等问题,进而造成跳闸等故障。最后提出对精细元件点胶加固、采取抗震性能高的包装箱等处理措施来预防此类故障的发生。

Based on the background of the No.2 static var generator(SVG)in a 750 kV substation,this paper proposes measures to avoid fiber optic open circuit faults that occur during its grid connection and operation.Firstly,the fault process is interpreted.While analyzing the topology of the energy harvesting power supply,a disassembly test is conducted on the module energy harvesting power supply.It is found that the cause of the fault is that the pin of the input capacitor in the single module energy harvesting power supply is damaged and in a virtual connection state,causing the 50V to 400V circuit board to be in a low—voltage input working state.Finally,the turn to turn short circuit burns out,causing the fiber optic to break and leading to the failure of grid connection of No.2 SVG.Combined with the types of devices that have experienced frequent failures since the device was put into operation,it is confirmed that these types of failures have common causes,all of which are caused by fine components in the energy harvesting power supply breaking or poor contact due to long—distance transportation bumps,vibrations,and other reasons,leading to tripping and other faults.Finally,measures such as reinforcing fine components with glue and adopting packaging boxes with high seismic performance are proposed to prevent such failures from occurring.