采用数据拟合算法在线监测介损角

摘要

On-line monitoring of dielectric loss is an important means of measuring capacitive equipments' insulation condition. For the error of traditional algorithm in the online monitoring of dielectric loss, this paper presents a data fitting algorithm to optimize the amplitude of DC component, fundamental frequency, amplitude and initial phase angle of fundamental and harmonic components, using mathematical models to fit the current and voltage sample data. Wavelet analysis is used to reduce the signal noise, remove random noise component and amend power frequency using Fourier frequency measurement to measure actual frequency, so fitting precision is improved. Simulation results show that the measurement precision for dielectric loss's of the proposed method can be achieved to . In case of power grid frequency fluctuations, compared with traditional harmonic analysis method, it has good feasibility and superiority.%在线监测介质损耗角(简称介损)是评估电容型设备绝缘状况的重要手段.针对介损在线监测传统算法的误差,提出了一种数据拟合算法,以直流分量幅值、基波频率、基波和谐波分量幅值以及初相角为优化对象,用数学模型来拟合电流、电压的采样数据.利用小波分析对信号进行降噪处理,去除随机噪声分量,并采用傅里叶测频修正电网实际频率,以此提高拟合精度.仿真结果显示,该方法的介损测量误差精度可达到,在电网频率波动情况下,与传统的谐波分析法相比,具有较好的可行性和优越性.