供电质量的指标释义及标准.doc

文档介绍：供电质量的指标释义及标准
of rural drinking water sources, protection of drinking water sources in rural areas by the end ofs
of rural drinking water sources, protection of drinking water sources in rural areas by the end of the delimitation of the scope of protection, complete with warning signs, isolating network protection facilities
式中Un--第n次谐波电压有效值，V
　　U1--基波电压有效值，V
公用电网谐波电压限值见表1。
(4)负序电压系数：
负序电压系数K2u表示三相电压不平衡的程度。通常以三相基波负序电压有效值与额定电压有效值之比的百分数表示。即： [FS:Page]
式中Ue--额定电压有效值，V
　　K2〔1〕--基波负序电压有效值，V
三相电压允许不平衡度见表1。
(5)频率偏差：
供电电源频率缓慢变化的现象，常以实际频率与额定频率之差或其差值Δf与额定值之比的百分数Δf％表示，即：
Δf=f－fe
Δf％=(f－fe)/fe×100％
式中f--实际供电频率值，Hz
　　fe--供电网额定频率值，Hz
电力系统频率允许偏差见表1。
表1　电能质量国家标准摘要
标准
标准名称
允许限值
说明
GB12325-90
供电电压允许偏差
%
±7%
+7%～-10%
衡量点为供用电产权分界处或电能计量点
GB12326-90
电压允许波动和闪变
电压波动：
1．％
2．35～110kV ％
3．％
闪变△U10：
1．％(推荐值)
2．％(推荐值)
衡量点为公共连接点，取实测95%概率值
of rural drinking water sources, protection of drinking water sources in rural areas by the end of the delimitation of the scope of protection, complete with warning signs, isolating network protection facilities
of rural drinking water sources, protection of drinking water sources in rural areas by the end of the delimitation of the scope of protection, complete with warning signs, isolating network protection f