特高压直流线路带电融冰系统研制及工程应用

Development and Project Application of Live Ice-melting System for UHVDC Transmission Lines

为避免覆冰引起线路跳闸事故,且在融冰时不影响线路运行,论文研发了特高压线路地线和光纤复合架空地线(OPGW)的带电融冰系统,包含融冰电源、融冰装置、过电压保护系统、OPGW与地线回路。开展了OPGW/地线融冰参数校核、融冰装置参数校核,换流变压器、平波电抗器、桥臂过电压保护器选型,融冰线路绝缘化改造和绝缘配合设计,研发了特高压线路OPGW带电融冰系统。现场实测表明,融冰回路双端开路时,OPGW/地线感应电压可达13.7 kV,融冰回路单端接地时,感应电压降低至0.6 kV。计算表明,带电融冰装置选定额定参数10 kV/10 MW,可满足现场融冰要求。OPGW/地线表面覆冰为非规则形态,冰凌长度、直径、厚度的增长为非线性变化过程。现场实测表明,融冰装置输出260 A直流电流75 min后,OPGW最高温度升至20.7℃,安全地完成了特高压线路带电融冰。论文研制的特高压线路OPGW的带电融冰系统,为特高压直流线路在雨雪冰冻天气间安全运行提供了保障。

In order to avoid tripping of line due to ice coating and not affect operation of line in the ice melting,the live ice melting system for ultra-high voltage line ground wire and optical fiber composite overhead ground wire(OPGW),including ice melting power supply,ice melting device,over-voltage protection system,OPGW and ground wire circuit,is developed.The check of OPGW/ground wire melting parameter and melting device parame-ter,type selection of transformers,smoothing reactors,bridge arm over-voltage protectors and design of the insula-tion transformation and insulation coordination of melting ice lines are performed,and an OPGW live melting ice system for ultra-high voltage lines is developed.The actual measurement at site shows that,in case the both ends of the ice melting circuit are open,the induced voltage of OPGW/ground wire can reach 13.7 kV.When the single end of the ice melting circuit is grounded,the induced voltage decreases to 0.6 kV.The calculation shows that the select-ed rated parameters of 10 kV/10 MW for the live ice melting device can meet the ice melting requirements at site.The surface icing of OPGW/ground wire is irregular,and the growth of ice length,diameter,and thickness is a non-linear process.The actual measurement at site shows that after the ice melting device outputs a 260 A DC current for 75 minutes,the maximum temperature of OPGW rises to 20.7℃,completing safely the live ice melting of ultra-high voltage lines.The live ice melting system for OPGW of ultra-high voltage transmission lines developed in the paper provides a guarantee for safe operation of ultra-high voltage DC lines in rainy,snowy,and freezing weather.