Protection of 1000kV fixed series compensation against lightning

UHV fixed series compensation (FSC, shortly) can greatly increase transmission capacity of UHV system. Safe operation of UHV FSC is important to ensure stability of the UHV system. FSC has complicated structure and high cost. It needs reliable protection against lightning. Its lightning protection includes direct stroke lightning protection and lightning intruded wave protection. The direct stroke lightning protection can adopt lightning rod and ground wire. Height of FSC platform was 12 m, and the max height of FSC installations was 21.7 m. Configuration of lightning rod and ground wire should be studied. Protection against lightning intruded wave mainly adopts lead-in line protection section and metal oxide arrester (MOA, shortly). Lead-in line protection sections of FSC stations were protected by 3 ground wires, which could provide effective protection. So, layout of MOA in FSC station was mainly studied in this paper. Protection layouts against direct stroke lightning and lightning intruded wave were calculated and checked. Appropriate adjustments were made. Results indicated that, for direct stroke lightning, FSC should be protected by both lightning rod on architecture and independent lightning rod, because only lightning rod on architecture could not provide effective protection. For lightning intruded wave, MOA should be installed on the circuit of FSC, in addition to MOAs in transformer circuit, on bus bars and beside high voltage reactors. On such MOA layout, safe operation annuals of installations were more than 1500 meeting requirements of UHV standards, whether FSC operated or not.