摘要
推导了煤矿井下低压电网不同位置发生单相漏电时的零序电流计算公式,用电流相量的实部和虚部比较了各零序电流的幅值关系与相位关系,并提出了一种新的选择性漏电保护方案。通过Matlab仿真与快速傅里叶变换(FFT,Fast Fourier Transform)对该方案进行了验证。结果表明,此方法不仅可以实现漏电保护的横向、纵向选择性,而且无需采集零序电压,既提高了漏电保护的可靠性,又降低了硬件成本。
Deduced zero-sequence current formulae when single-phase earth leakage happened in underground low voltage distribution networks＇ different places,compared zero-sequence current amplitude relationships and phase relationships with current phasor＇s real part and imaginary part,and proposed a new selective earth leakage protection scheme.The scheme was verified by simulation via Matlab and calculation via Fast Fourier Transform.The results indicate that this method achieves lateral and longitudinal selectivity,avoids zero-sequence voltage＇s collection,enhances protection reliability,and cuts hardware＇s cost.
出处
《煤炭学报》
EI
CAS
CSCD
北大核心
2010年第3期515-519,共5页
Journal of China Coal Society
关键词
零序电流
群体比幅比相
漏电保护
低压电网
快速傅里叶变换(FFT)
zero-sequence current
amplitude and phase comparison
earth leakage protection
low voltage distribution networks
Fast Fourier Transform（FFT）
