高电压等级真空断路器研究现状及展望

Research Status and Prospect of High Voltage Vacuum Circuit Breaker

针对绿色电网发展需求,总结对比了现阶段SF6完全替代技术和部分替代技术路线的特点及相关技术,指出真空开断技术是电网绿色低碳发展的有效手段。对比分析现阶段多断口真空断路器的技术特点及研究现状,认为单断口真空断路器在结构及可靠性方面具有显著优势。目前商业化单断口真空灭弧室已经发展到145 kV/40 kA,综述了高电压大电流单断口真空灭弧室内外绝缘技术、电弧形态演变规律及分合闸控制、温升特性和真空灭弧室焊接质量稳定性的研究现状及未来发展趋势。结果表明:真空灭弧室内部真空间隙的均压设计及长真空间隙绝缘“饱和”问题是制约灭弧室电压等提升的关键因素;耐烧蚀触头材料的制备及磁场设计对触头表面阳极斑点的形成过程和真空断路器分合闸速度匹配至关重要;选取低回路电阻的触头结构、优化真空断路器散热结构能够有效提升真空灭弧室额定通流能力;此外,总结了真空灭弧室焊接质量和稳定性的影响因素,指出陶瓷金属化并选取合适的钎焊温度和焊料能够显著提升焊接强度;最后指出真空断路器趋向于大容量、小型化、智能化、低过电压、免维护、专用化和多功能化发展。

In view of the development needs of green power grid,the characteristics of SF6 complete substitution tech-nology and partial substitution technology route and related technologies are summarized and compared,and it is pointed out that vacuum interrupting technology is an effective means for green and low-carbon development of power grid.Comparing and analyzing the technical characteristics and research status of multi-break vacuum circuit breakers at this stage,we believe that single-break vacuum circuit breakers have significant advantages in terms of structure and reliabil-ity.At present,the commercial single-break vacuum interrupter has been developed to 145 kV/40 kA,and the research status and future development trend of high-voltage and high-current single-break vacuum interrupter indoor and outdoor insulation technology,arc morphological evolution law and opening and closing control,temperature rise characteristics and welding quality stability of vacuum interrupter are reviewed.The results show that the pressure equalization design of the vacuum gap inside the vacuum interrupter and the“saturation”of the insulation of the long vacuum gap are the key factors restricting the increase of the voltage of the interrupter;The preparation of the ablation-resistant contact material and the design of the magnetic field are very important for the formation process of anode spots on the contact surface and the matching of the opening and closing speed of the vacuum circuit breaker;Selecting the contact structure with low loop resistances and optimizing the heat dissipation structure of the vacuum circuit breaker can effectively improve the rated current capacity of the vacuum interrupter;In addition,the influencing factors of vacuum interrupter welding quality and stability are summarized,and it is pointed out that the ceramics metallization and selection of appropriate brazing temper-ature and solder can significantly improve the welding strength.Finally,it is pointed out that vacuum circuit breakers tend to develop with characteristics of large-capacity,miniaturization,intelligence,low-overvoltage,maintenance-free,specialization and multi-function。