摘要
我国中低压配电网多采用中性点非有效接地方式,在暂态过程的激发下,电磁式电压互感器(PT)容易饱和,引起铁磁谐振。结合小波分析与FFT变换的优点,提出一种新的铁磁谐振信号的检测方法:将MALLAT算法与快速傅里叶变换结合,通过MALLAT算法确定激发铁磁谐振的激励与铁磁谐振发生的时刻;运用FFT分析谐振信号频谱,为铁磁谐振的辨识提供更精确的数据。论文应用EMTP与Matlab建模仿真,仿真结果表明基于小波分析与FFT变换的铁磁谐振信号检测方法能够准确、有效提取与分析谐振信号,提高选线装置的动作可靠性,满足实用要求。
Neutral Ineffectively Earthed Power Systems widely exist in the low and medium voltage distribution net- works in China. With transient excitation, electromagnetic volt- age transformer is easily saturated to cause ferromagnetic reso- nance. Combined with the advantages of wavelet analysis and FFT transform, a novel method for detecting the ferromagnetic resonance signal is proposed in this thesis. The above method combined the MABLAB algorithm with fast Fourier transform. The MATLAB algorithm was used to ensure the excitation and the start time of ferromagnetic resonance, and FFT algorithm was used to ensure the fi＇equency of the ferromagnetic resonance signal for ferromagnetic resonance identification. EMTP and MATLAB simulation results showed that this method can ex- tract and analyze the ferromagnetic resonance signal accurately and effectively which can improve the reliability and practicabil- ity and it possesses great significance.
出处
《电力学报》
2014年第2期124-126,132,共4页
Journal of Electric Power
