摘要
传统基于傅里叶变换、小波变换等信号时频变换的电力系统功率测量方法大多没有考虑非整数次谐波(间谐波)的影响,采用一段时间窗的整体计算,不能得到电力系统具体时刻的瞬时功率,无法评估电力系统中的瞬态现象,如衰减谐波、冲击脉冲等。另外,传统方法的测量精度较低,受到采样数据的限制。本文提出了一种基于Prony算法和改进Budeanu理论的电力系统功率测量方法。借鉴Fryze理论和Shepherd&Zakikhani理论对经典频域功率理论Budeanu理论进行改进,将Budeanu理论推广到非整数次谐波情况。使用Prony算法可以将电压和电流分解为指数函数的线性组合,精确得到频率、振幅、初相和衰减因子等特征,进而可以计算电力系统的瞬时有功功率和无功功率。提出的方法充分考虑了电力系统中的间谐波功率以及衰减谐波、冲击脉冲等瞬态现象,可以计算得到电力系统的瞬时功率,同时具有动态性能好,测试精度高等优点。最后通过算例进行了仿真验证。本文提出的功率测量方法为电力系统非正弦复杂情况下的功率测量、瞬态现象研究及谐波治理提供了一种有效的思路和方法。
Generally, the traditional power measurement method based on the Fourier transform, wavelet transform or other time-frequency method can＇ t consider the influence of non-integer harmonics （ Inter harmonics ）. The overall calculation using a time window can＇ t get instantaneous power at special time, and unable to assess the power system＇ s transient phenomena such as harmonic attenuation, shock pulse and so on. In addition, the measurement accuracy of the conventional method is low, which is limited by the sampled data. This paper proposes a method based on Prony algorithm and improved Budeanu theory. Fryze theory and Shepherd ＆ Zakikhani theory are used to improve the Budeanu theory to the case of non-integer harmonics. And Prony algorithm is used to decompose voltage and current into a linear combination of exponential function, the frequency, the amplitude, the initial phase and the attenuation factor are obtained accurately, and then the instantaneous active power and reactive power can be obtained. The proposed method takes into account the inter harmonics, harmonic attenuation, impulse and other transient phenomena, and can calculate the instantaneous power, meanwhile it has good dynamic performance and high test precision. Finally, a simulation example is used to verify the method. The proposed power measurement method provides an effective way of thinking and method to study the power measurement, transient phenomena and harmonic control study of non-sinusoidal complex power system.
出处
《电子测量与仪器学报》
CSCD
北大核心
2016年第10期1582-1590,共9页
Journal of Electronic Measurement and Instrumentation
