摘要
塑壳断路器瞬动校验试验需要进行选相合闸,针对其中周期信号的初始相位与频率这两个关键待测参数的测量,提出了一种改进的计算方法。首先利用中值滤波与改进小波去噪对信号进行复合去噪,再进行加窗处理用以抑制Hilbert数字化实现所产生的频谱泄露问题,最后进行Hilbert运算求取信号的初始相位以及频率,仿真表明,较之传统的快速傅里叶法,采用Hilbert法可以克服频率波动对测量结果的影响,改进后的方法在典型噪声下仍具有很高的测量精度,现场选相试验也进一步表明该方法的实用性。
Phase selection is necessary for the instantaneous validation test of a molded case circuit breaker. To the mea- sure of the two key testing parameters of initial phase and frequency of periodic signal, an improved calculation method is proposed in this paper： First, the compound method of median filter and improved wavelet denoising are adopted to complete signal denoising. Then, with window-addition treatment, the spectrum leakage problem caused by Hilbert digitalization is restrained. Finally, Hilbert computation is performed to obtain the initial phase and frequency of the signal. Simulation shows that compared with the traditional fast Fourier transformation method, the use of Hilbert method can overcome the impact of frequency fluctuations on the measured result. Moreover, the improved method has high measurement accuracy even under typical noises. The phase selection experiment in situ further validated the practicability of this method.
出处
《电力系统及其自动化学报》
CSCD
北大核心
2017年第11期67-74,共8页
Proceedings of the CSU-EPSA
基金
天津市科技支撑重点资助项目(12ZCZDGX014000)
河北省教育厅资助科研项目(ZD2016108)
河北工业大学博士科研启动费资助项目
关键词
选相合闸
瞬动校验
HILBERT
中值滤波
小波去噪
窗函数
phase selection
instantaneous validation
Hilbert
median filter
wavelet denoising
window function
