同步相量测量不确定度估计

摘要

同步相量测量不确定度估计可用于检测相量测量中的坏数据,监测同步相量测量单元(PMU)工作状态,并为PMU相关应用提供上报数据的测量精度信息,具有重要应用价值.文中提出基于同步录波数据和同步相量测量结果进行不确定度估计.由相量测量序列重构基波,并与录波数据相减得到残差信号,通过计算残差信号基波带内和带外分量相对重构基波的功率比,得到参数ρi和ρo.文章理论分析表明,通过基波带宽合理选取,ρi为同步相量测量不确定度近似无偏估计,-20lg (ρo)可准确估计电网采样信号信噪比(dB值).仿真和实测实验验证了算法的有效性,展示了算法的实用功能和应用效果.%The uncertainty estimation of synchrophasor measurements processes many valuable potential applications, such as detecting bad measurement data, monitoring the status of PMU setup, and providing measurement accuracy information for PMU applications.In this paper, we propose an uncertainty estimation method based on the synchronous sampled data and the synchrophasor measurements.The fundamental wave is reconstructed with the synchrophasor measurements, and the residual signal is computed as the difference between the synchronous sampled data and the reconstructed fundamental wave.Two variables, i.e.ρi and ρo, are calculated respectively representing the power ratios of the components of the residual signal inside and outside of fundamental frequency band to the reconstructed fundamental.Theoretical analysis has proven that with reasonable selection of fundamental frequency band, ρi is an approximately unbiased estimate of the measurement uncertainty, and-20lg(ρo) is an accurate estimate of signal to noise ratio of the sampled grid signal in decibel.Experiments with simulated data and PMU recorded data have verified the effectiveness and practical capacities of the algorithm.