一种实用的电力系统频率实时测量方法  

A practical method of real-time measurement for power system frequency

作　　者：肖朵艳[1] 谭卫斌 张维 

机构地区：[1]西南石油大学,四川成都610500 [2]珠海许继电气有限公司,广东珠海519060

出　　处：《电力系统保护与控制》2014年第21期29-33,共5页Power System Protection and Control

基　　金：国家电网公司科技项目(2012-094)

摘　　要：为解决非同步定频采样系统对电力系统频率测量时存在的运算复杂、实时性不好等问题,提出了一种实用的频率实时测量方法。该方法是基于周期过零点插值原理,通过对A/D采样的离散序列进行FIR带通数字滤波,然后对相邻的同方向过零点进行插值求取频率的估计值。针对电力系统待测信号中不含谐波、含有2-16次谐波以及含有随机噪声的不同情况,分别进行了仿真验证,最后与离散傅里叶变换(DFT)测频算法的结果进行了对比。结果表明该方法抗干扰性和测量精度都要优于DFT测频算法,而且该方法计算量少、实用性强、实时性好、测量精度高,能满足电力系统频率测量要求。To solve the problem of asynchronous frequency-fixed and sampling system’s complex computation and weak real-time for power system frequency measurement, a practical real-time frequency measurement algorithm is proposed. This method is based on the interpolation principle of periodic zero-crossing point, the frequency estimated value is calculated by digital filtering of FIR band-pass for A/D sampling discrete sequence and by interpolating for adjacent zero-crossing point with the same direction. The signal under test in power system is simulated and vertified under three different circumstances： excluding harmonic, including second to sixteenth harmonic and the random noise. The simulation result is compared with that of Discrete Fourier Transform （DFT） method. The result shows that this method is superior to DFT in anti-interference and measurement accuracy, it can satisfy the requirement of frequency measurement for power system due to its simplicity, strong practicability, high instantaneity and measurement accuracy.

关 键 词：电力系统 频率测量 周期过零点 谐波 DFT FIR(数字滤波器) 

分 类 号：TM935[电气工程—电力电子与电力传动]