改进基波相位分离法在介损角测量中的应用  

Application of Modified Fundamental Harmonic Separation Algorithm in Dielectric Loss Angle Measurement

作　　者：徐志钮[1] 律方成[1] 姚辉[2] 李和明[1] 

机构地区：[1]华北电力大学电力工程系,保定071003 [2]安徽省淮南供电公司,淮南232007

出　　处：《高电压技术》2007年第5期29-31,49,共4页High Voltage Engineering

基　　金：华北电力大学重大项目预研基金。~~

摘　　要：为有效减少基波相位分离法在非同步采样时给介损角测量带来的误差,提出了加汉宁窗插值的改进基波相位分离法。介绍了该算法的原理,给出了非同步采样情况下该算法的计算公式。因矩形插值积分公式将小积分区间的被积函数看成常量容易导致算法误差增加,所以采用梯形插值积分公式,给出了相应的计算公式,并分析了原因,它可以提高非同步采样时该算法测量所得介损角的准确性;针对该算法需要获得信号频率、且使用硬件方法获得频率时增加系统硬件环节的问题,使用了加汉宁插值谐波分析法快速、高精度获得基波相位分离法需要的信号频率,该算法在获得较高介损角精确度的同时减少了硬件环节。仿真结果显示结合加汉宁窗插值的改进基波相位分离法使非同步情况下的介损角测量精度有所提高,最大误差从4.04×10-4rad下降到了5.52×10-5rad,算法精度在49.5～50.5Hz频率范围内更加稳定,且无需外部条件获得信号频率,是介损角测量的一种有效算法。To decrease errors of fundamental harmonic separation algorithm in dielectric loss angle measurement in asynchronous sampling, a modified fundamental harmonic separation algorithm based on Hanning-windowed interpolation was proposed. Principle of the algorithm was introduced, calculation formulae of the algorithm in asynchronous sampling were given. Taking the integrand in a small integral interval as a constant, the Rectangular interpolation integral formula would cause increase of error. It was pointed out that accuracy of dielectric loss angle measured by the algorithm in asynchronous sampling could be improved by trapezoidal interpolation integral formula, calculation formulas were given and the reason was analyzed. For solving the problem of how to get signal frequency, and signal frequency gotten by hardware mode had the problem of more complex hardware composition. Hanning-windowed interpolation harmonic analysis method was used to acquire signal frequency for fundamental harmonic separation algorithm, and the algorithm was high-speed and high accurate. Accuracy of dielectric loss angle calculated by the proposal algorithmimproved, and the hardware part was lessened. Simulation result indicates that accuracy of dielectric loss angle is improved by modified fundamental harmonic separation algorithm based on Hanning-windowed interpolation, and the largest error decreases from 4.04×10^4 rad to 5.52 ×10^-5 tad, the stability of dielectric loss angle calculation result increases, and the signal frequency is unnecessary to be gotten by external means. The result indicates that the proposal algorithm is effective for dielectric loss angle measurement.

关 键 词：介损角 汉宁窗 基波相位分离法 梯形插值积分 非同步采样 频率 

分 类 号：TM934.3[电气工程—电力电子与电力传动]