高压断路器中C_(4)F_(7)N/CO_(2)混合气体的开断性能  

Interruption Performance of C_(4)F_(7)N/CO_(2) Gas in High-voltage Circuit Breaker

作　　者：宋宇 林莘[1] 徐建源[1] 张佳[1] SONG Yu;LIN Xin;XU Jianyuan;ZHANG Jia(School of Electric Engineering,Shenyang University of Technology,Shenyang 110870,China)

机构地区：[1]沈阳工业大学电气工程学院,沈阳110870

出　　处：《高电压技术》2023年第3期971-981,共11页High Voltage Engineering

基　　金：国家自然科学基金(51637006,51777130)。

摘　　要：C_(4)F_(7)N/CO_(2)混合气体是一种潜在的SF_(6)替代气体,开展其在高压断路器中开断性能的研究,对推动环保输电方式发展、支撑双碳目标实现具有重要的工程意义。基于磁流体动力学(magnetohydrodynamics,MHD)理论,仿真计算了充有0.6 MPa 5%C_(4)F_(7)N/CO_(2)、10%C_(4)F_(7)N/CO_(2)、15%C_(4)F_(7)N/CO_(2)混合气体和纯SF_(6)的40.5 kV断路器20 kA短路电流开断过程,分析C_(4)F_(7)N混合比例对电弧温度特性、灭弧室气压与喷口气流特性的影响规律,并与纯SF_(6)进行比较。研究结果表明:与混合气体相比,SF_(6)气体电弧具有更高的弧芯温度和更小的电弧半径,随着C_(4)F_(7)N比例的增加,混合气体弧芯温度升高、电弧半径减小。断路器短路开断过程中,SF_(6)气体建立起更高的吹弧气压,气吹速度明显高于混合气体,可以形成更好的气吹效果来冷却电弧。最后,基于Mary电弧数学模型计算得到电流零区不同气体的电弧时间常数与电弧功率耗散系数,并以临界恢复电压上升率(rate of rise of TRV,RRRV)定量评判气体开断性能,0.6 MPa的5%C_(4)F_(7)N/CO_(2)、10%C_(4)F_(7)N/CO_(2)、15%C_(4)F_(7)N/CO_(2)混合气体临界RRRV分别为1.54、2.22和2.28 kV/μs,远低于SF_(6)的4.98 kV/μs。The C_(4)F_(7)N/CO_(2) mixed gas is a potential alternative gas for SF_(6).It is of great significance to further study its interruption performance in high-voltage circuit breaker for the development of new environmentally friendly power transmission methods and realization of the carbon peaking and carbon neutrality goals.Based on the magnetohydrodynamics theory,the 20 kA short-circuit current interrupting process of 40.5 kV circuit breaker filled with 0.6 MPa 5%C_(4)F_(7)N/CO_(2),10%C_(4)F_(7)N/CO_(2),15%C_(4)F_(7)N/CO_(2) and pure SF_(6) was calculated.The influences of C_(4)F_(7)N content on the arc temperature,arc chamber pressure and nozzle airflow characteristics were analyzed,and compared with pure SF_(6).The research results show that,compared with mixed gas,SF_(6) gas arc has higher arc core temperature and smaller arc radius.With the increase of C_(4)F_(7)N content,the mixed gas arc core temperature increases and the arc radius decreases.During the short-circuit interrupting process of the circuit breaker,the SF_(6) gas establishes a higher gas pressure,and the airflow velocity is significantly higher than that of the mixed gas,which can form a better blowing effect to cool the arc.Finally,the arc time constant and arc power loss coefficient of different gases were calculated based on the Mary arc mathematical model,and the gas interrupting performance was quantitatively evaluated by the rate of rise of TRV(RRRV).The critical RRRV of 5%C_(4)F_(7)N/CO_(2),10%C_(4)F_(7)N/CO_(2) and 15%C_(4)F_(7)N/CO_(2) at 0.6 MPa are 1.54 kV/μs,2.22 kV/μs and 2.28 kV/μs,respectively,which are much lower than 4.98 kV/μs of SF_(6).

关 键 词：高压断路器 SF6替代气体 C_(4)F_(7)N/CO_(2) 电弧温度 气压特性 气吹速度 开断性能 

分 类 号：TM561[电气工程—电器]