直流电压测量装置中绝缘气体瞬态流动影响研究

Study on the influence of transient flow of insulating gas in DC voltage measurement device

直流电压测量装置是重要的一次测量设备,在特殊工况下对其进行SF6带电补气作业时,应保证在充气瞬态过程中不会因SF6压强突变而发生直流系统告警或闭锁。对此,建立了直流电压测量装置密封气路等效模型,通过有限元方法对在不同阀口位置充气时SF6瞬态流动特性进行仿真计算和对比分析,发现管状气路末端充气时SF6气压监测表计压强变化较大,易导致直流系统发生告警或闭锁。通过在不同阀口位置进行充气试验,验证了压强变化与仿真结果基本一致。基于不同阀口充气时SF6瞬态流动压强变化的研究,对于直流电压测量装置带电补气操作具有工程指导意义。

The DC voltage measurement device is an important primary measurement equipment.In case of live refilling of SF6 under special operating conditions,it should be ensured that no DC system alarm or lockout will occur during the transient refilling due to sudden change of SF6 pressure.In this regard,an equivalent model of sealed gas paths of DC voltage measurement device is established.The transient flow characteristics of SF6 are simulated and comparatively analyzed by finite element method when the gas is refilled at different valve ports.It is found that the gauge pressure of SF6 varies greatly when refilled at the end of the tubular gas path,which easily leads to alarm or lockout in the DC system.By refilling tests at different valve port positions,it is verified that the pressure change is on the whole consistent with the simulation results.The study of transient flow pressure changes of SF6 during refilling at different valve ports is of significance to engineering guidance for the live refilling of the DC voltage measurement device.