Non-Ideal Modeling and Bayesian Correction of Systematic Errors in GIS Loop Resistance Field Testing
摘要
To address poor repeatability and limited accuracy in field measurements of loop resistance within GIS (Gas-Insulated Switchgear), this study conducts controlled experiments and discovers that using a earthing switch-gear as the voltage lead terminal introduces significant contact resistance deviations. These deviations do not align with predictions from the ideal four-wire (Kelvin) method, indicating non-ideal behavior in the actual testing system. A non-ideal physical model is then established, incorporating equivalent parasitic resistance and the instrument’s effective internal resistance. An in-situ calibration framework based on Bayesian Markov Chain Monte Carlo (MCMC) is proposed. This framework, combined with measurements of a set of standard resistors, simultaneously identifies unknown resistances under test. Simulations show that with a R_target of 44.5μΩ, the mean measurement error can be reduced from 4.96 μΩ to 0.12 μΩ, representing an 81.8% decrease in error.