摘要
根据热平衡方程建立了以温升为变量的动态过载保护数学模型,确定了被保护对象的负载电流变化时的温升变化过程。与常用反时限保护特性相比较,此保护模型更符合负载的实际运行规律及保护要求。针对全周傅里叶算法不能滤除衰减直流分量与频率特性较差的问题,提出减法滤波器加全周Morlet复小波幅值算法,计算了配电线路的基波的幅值。
A mathematical model for the dynamic over-load protection was established,based on the heat balance equation,to determine how temperature increased with the change of the protection object＇s current.Compared with the common inverse time characteristic,this model conformed to the load actual operating law and the protection request.And to solve the problem of the full-wave Fourier algorithm which was disable to filter decaying DC component and had worse frequency characteristic,an algorithm depending on the combination of subtraction filter and full-wave Morlet complex wavelet amplitude algorithm was presented to get out the amplitude value of fundamental wave in the distribution line.
出处
《低压电器》
北大核心
2010年第13期8-11,共4页
Low Voltage Apparatus
基金
天津市科技支撑计划重点项目资助(07ZCKFGX00600)
关键词
过载保护
热积累
等效电流
MORLET小波
减法滤波器
over-load protection
heat accumulation
equivalent current
Morlet wavelet
subtraction filter
