大型电力变压器损耗测量不确定度分析

为指导大型电力变压器损耗测量设备的选用,实现精确损耗测量,分析了造成大型变压器损耗测量不确定度的各种因素,并对这些因素造成的不确定度进行定量计算,最终对单个因素造成的不确定度进行合成,得到整体测量系统的测量不确定度.基于对损耗测量不确定度的分析,确定测量系统的相位测量精度是影响测量不确定度的最主要因素.定量分析和比较了使用不同测量系统进行损耗测量的不确定度,结果表明,使用0.01级的电压和电流互感器配合 Fluke Norma5000型功率分析仪(或性能接近的功率分析仪产品),大型电力变压器损耗测量的不确定度可控制在2%以内,是适合于大型变压器损耗测量的测量系统

Uncertainty Analysis of Loss Measurement for Large-Scale Power Transformer

To guide the selection of measuring devices for loss measurement of large-scale power transformers and implement accurate loss measurement,the factors leading to the uncertainty during the loss measurement of large-scale power transformers are analyzed.Through quantitative calculation of uncertainties due to these factors,the uncertainties caused by single factors are synthesized to attain the measurement uncertainty of the whole measuring system.Based on uncertainty analysis of loss measurement,it is found that the phase measurement accuracy of the measuring system is the upmost factor affecting the measurement uncertainty.The uncertainties of loss measurements by different measuring systems are quantitatively analyzed and compared,and the results show that the measuring system composed of CT and PT with 0.01 accuracy grade and worked in with Fluke Norma 5000 power analyzer(or power analyzers with similar performances) is suitable to loss measurement for large-scale power transformers,and the uncertainty of loss measurement for large-scale power transformers can be controlled to be lower than 2%.