基于SF_(6)气体温度迟滞模型的密度监测失效判定策略

SF_(6)Gas Temperature Hysteresis Model Based Density Monitoring Failure Judgement Criterion

气体绝缘开关(gas insulated switchgear,GIS)设备SF_(6)气体密度监测失效可能会导致泄漏状态误判断,威胁电网安全运行。为此,针对数字式SF_(6)气体密度监测装置特点,构建并优化了基于热力学的SF_(6)气体温度迟滞模型。通过温度迟滞实验,获取了模型中未知参数。模拟实验表明,SF_(6)气体温度迟滞模型温度补偿偏差为±0.6℃,基于补偿后温度的计算压力与压力传感器检测压力偏差为±0.002 MPa。设计基于计算压力与检测压力相互验证的密度监测失效判定策略,结合某220 kV变电站中试点设备数据进行验证,经SF_(6)气体温度迟滞模型温度补偿并归算至20℃下的压力与实际值均不超过0.002 MPa,验证了该模型的准确度以及SF_(6)气体密度监测失效判定策略现场应用的可行性。

The malfunctioning of SF_(6)gas density monitoring in GIS equipment could erroneously indicate a leakage,potentially compromising the electrical grid's safe operation.In response,a thermodynamics-based temperature hysteresis model for SF_(6)gas was developed and refined,tailored for digital gas density monitoring apparatus.The model's unknown parameters were deduced from temperature hysteresis experiments.The simulations highlighted a temperature compensation deviation in the SF_(6)gas temperature hysteresis model of±0.6℃,with a pressure calculation discrepancy,corrected for temperature,showing only±0.002 MPa against sensor-detected pressures.A strategic approach for identifying density monitoring failures was devised,which relies on the corroboration between calculated and sensor-detected pressures.This approach was put to the test using data from a pilot device in a 220 kV substation.After applying temperature adjustments through the SF_(6)gas temperature hysteresis model and recalibrating the pressure to standard conditions at 20℃,the results remained within a tight margin of 0.002 MPa,attesting to the model's precision and the practicality of the proposed SF_(6)gas density monitoring failure detection strategy in operational environments.