基于非同步电能质量监测系统的谐波状态估计

Harmonic State Estimation Based on Asynchronous Power Quality Monitoring System

谐波状态估计是电能质量管理的重要手段,当前方法多基于理想化实时同步谐波数据开展,未考虑非实时、非同步等现实困难,致使其准确性在应用中难以得到保证。针对我国现有电能质量监测平台数据特点,该文提出一种基于非同步数据的谐波状态估计法。在建立的谐波状态估计模型中,以相角误差补偿的方式将非同步问题同步化,并以信赖域算法求解模型。同时,针对所提谐波状态估计模型特点,提出适用于该文模型的可观性分析方法,保证状态估计的可实施性。最后,运用IEEE 30节点数据与某地区实际测量数据对所提方法进行了验证,结果显示该文算法可较好地解决非同步问题,且在谐波波动较小时具有更高的准确性。另外,通过与其他非线性求解算法对比证实信赖域算法的优越性。

Harmonic state estimation is of great importance for power quality management. Most of existing methods assume the harmonic phasors at different locations are available, which do not consider the practical challenges such as the synchronization and the real-time data transmission. As a result, these methods can hardly be used in practice. In view of this, this paper proposed a new harmonic state estimation algorithm that suits for asynchronous power quality monitoring system in China. In the proposed method, the nonsynchronization issue was addressed through phase angle error compensation, and the trust region algorithm was applied to solve the nonlinear least-square problem. In addition, a new observability analysis method was proposed to ensure the applicability of the method in practice. Finally, the performance of the proposed model was verified by simulation studies using IEEE 30 node system and the real-life field measured data. The result indicates that the proposed method can deal with the asynchronous harmonic measurements and its performance is better when the load fluctuation is small. Furthermore, the trust region algorithm is proved to be effective through the comparison with other nonlinear least square algorithms.