三相电即三相交流电，是电能的一种输送形式。三相交流电源，是由三个频率相同、振幅相等、相位依次互差120°的交流电势组成的电源。“三相电”的概念是
：线圈在磁场中旋转时，导线切割磁力线会产生感应电动势，它的变化规律可用正弦曲线表示。
扩展资料：
以下是一个理想的三相交流电压的数学式：
V1
=
Asin(2πft)=Asin(wt）
V2
=
Asin(2πft
-
2π/3)=Asin(wt-2π/3)
V3
=
Asin(2πft
+
2π/3)=Asin(wt+2π/3)
其中A是电压的峰值，f则是交流电压的频率。
相与相之间的电压称为线电压，任两相之间的电压都是380V。相与中性点之间的电压称为相电压，任一相对中性点的电压都是220V。（三相交流电因用途不同还有660V和6000V供电等）。
能产生幅值相等、频率相等、相位互差120°电势的发电机称为三相发电机。以三相发电机作为电源，称为三相电源；以三相电源供电的电路，称为三相电路。
三相电的接法：分为三角形接法(符号△)和星形接法(又称Y形接法，符号Y)。
三角形接法的负载引线为三条火线和一条地线，三条火线之间的电压为380V，任一火线对地线的电压为220V；
Y形接法的负载引线为三条火线、一条零线和一条地线，三条火线之间的电压为380V，任一火线对零线或对地线的电压为220V。Y型接法的示例如图，六个灯泡全打开，三相平衡时，零线的电流为零，不平衡时，零线维持0电势，上面会有电流。
三相电源与单相电源的区别：单相是220V,是相线对零线间的电压。三相的是A.B.C之间380V的相间电压，用电器是三相电380V的电机或设备。发电机发出的电源都是三相的，三相电源的每一相与其中性点都可以构成一个单相回路为用户提供电力能源。注意在这里交流回路中不能称做正极或负极，应该叫相线（民用电中称火线）和中性线（民用电中称零线）。
参考资料：三相电-搜狗百科
因选择空气断路器的额定电流应是计算电流的1.1～1.5倍，In=1.2~1.5Ijs，Ijs=In/1.1~1.5
取1.2，Ijs=63/1.2＝52A
带三相负荷：P=IU√3cosφ=52×380×1.732×0.8=27379.5W
63A的3极漏电断路器能带27.4KW。
用js如下:// 主调用函数是 setday(this,[object])和setday(this)，[object]是控件输出的控件名，举两个例子：
// 一、<input name=txt><input type=button value=setday onclick="setday(this,document.all.txt)">
// 二、<input onfocus="setday(this)">
var bMoveable=true
var strFrame
document.writeln('<iframe id=endDateLayer frameborder=0 width=162 height=187 style="position: absolute z-index: 9998display: none"></iframe>')
strFrame='<style>'
strFrame+='INPUT.button{BORDER-RIGHT: #63A3E9 1px solidBORDER-TOP: #63A3E9 1px solidBORDER-LEFT: #63A3E9 1px solid'
strFrame+='BORDER-BOTTOM: #63A3E9 1px solidBACKGROUND-COLOR: #63A3E9font-family:宋体}'
strFrame+='TD{FONT-SIZE: 9ptfont-family:宋体}'
strFrame+='</style>'
strFrame+='<scr' + 'ipt>'
strFrame+='var datelayerx,datelayery'
strFrame+='var bDrag'
strFrame+='function document.onmousemove()'
strFrame+='{if(bDrag &&window.event.button==1)'
strFrame+=' {var DateLayer=parent.document.all.endDateLayer.style'
strFrame+=' DateLayer.posLeft += window.event.clientX-datelayerx'
strFrame+=' DateLayer.posTop += window.event.clientY-datelayery}}'
strFrame+='function DragStart()'
strFrame+='{var DateLayer=parent.document.all.endDateLayer.style'
strFrame+=' datelayerx=window.event.clientX'
strFrame+=' datelayery=window.event.clientY'
strFrame+=' bDrag=true}'
strFrame+='function DragEnd(){'
strFrame+=' bDrag=false}'
strFrame+='</scr' + 'ipt>'
strFrame+='<div style="z-index:9999position: absoluteleft:0top:0" onselectstart="return false">'
strFrame+='<span id=tmpSelectYearLayer style="z-index: 9999position: absolutetop: 3left: 19display: none"></span>'
strFrame+='<span id=tmpSelectMonthLayer style="z-index: 9999position: absolutetop: 3left: 78display: none"></span>'
strFrame+='<table border=1 cellspacing=0 cellpadding=0 width=142 height=160 bordercolor=#63A3E9 bgcolor=#63A3E9 >'
strFrame+='<tr><td width=142 height=23 bgcolor=#FFFFFF>'
strFrame+='<table border=0 cellspacing=1 cellpadding=0 width=158 height=23>'
strFrame+='<tr align=center >'
strFrame+='<td width=16 align=center bgcolor=#63A3E9 style="font-size:12pxcursor: handcolor: #ffffff" '
strFrame+='onclick="parent.meizzPrevM()" title="向前翻 1 月" ><b ><</b></td>'
strFrame+=' <td width=60 align="center" bgcolor="#63A3E9" style="font-size:12pxcursor:hand" '
strFrame+=' onmouseover="style.backgroundColor=\'#aaccf3\'"'
strFrame+='onmouseout="style.backgroundColor=\'#63A3E9\'" '
strFrame+='onclick="parent.tmpSelectYearInnerHTML(this.innerText.substring(0,4))" '
strFrame+='title="点击这里选择年份"><span id=meizzYearHead></span></td>'
strFrame+=' <td width=48 align="center" style="font-size:12pxfont-color: #ffffffcursor:hand" '
strFrame+='bgcolor="#63A3E9" onmouseover="style.backgroundColor=\'#aaccf3\'" '
strFrame+='onmouseout="style.backgroundColor=\'#63A3E9\'" '
strFrame+='onclick="parent.tmpSelectMonthInnerHTML(this.innerText.length==3?this.innerText.substring(0,1):this.innerText.substring(0,2))"'
strFrame+='title="点击这里选择月份"><span id=meizzMonthHead ></span></td>'
strFrame+=' <td width=16 bgcolor=#63A3E9 align=center style="font-size:12pxcursor: handcolor: #ffffff" '
strFrame+='onclick="parent.meizzNextM()" title="向后翻 1 月" ><b >></b></td>'
strFrame+=' </tr>'
strFrame+=' </table></td></tr>'
strFrame+='<tr><td width=142 height=18 >'
strFrame+=' <table border=0 cellspacing=0 cellpadding=2 bgcolor=#63A3E9 ' + (bMoveable? 'onmousedown="DragStart()" onmouseup="DragEnd()"':'')
strFrame+='BORDERCOLORLIGHT=#63A3E9 BORDERCOLORDARK=#FFFFFF width=140 height=20 style="cursor:' + (bMoveable ? 'move':'default') + '">'
strFrame+='<tr><td style="font-size:12pxcolor:#ffffff" width=20> 日</td>'
strFrame+='<td style="font-size:12pxcolor:#FFFFFF" > 一</td><td style="font-size:12pxcolor:#FFFFFF"> 二</td>'
strFrame+='<td style="font-size:12pxcolor:#FFFFFF" > 三</td><td style="font-size:12pxcolor:#FFFFFF" > 四</td>'
strFrame+='<td style="font-size:12pxcolor:#FFFFFF" > 五</td><td style="font-size:12pxcolor:#FFFFFF" > 六</td></tr>'
strFrame+='</table></td></tr>'
strFrame+=' <tr ><td width=142 height=120 >'
strFrame+='<table border=1 cellspacing=2 cellpadding=2 BORDERCOLORLIGHT=#63A3E9 BORDERCOLORDARK=#FFFFFF bgcolor=#fff8ec width=140 height=120 >'
var n=0for (j=0j<5j++){ strFrame+= ' <tr align=center >'for (i=0i<7i++){
strFrame+='<td width=20 height=20 id=meizzDay'+n+' style="font-size:12px" onclick=parent.meizzDayClick(this.innerText,0)></td>'n++}
strFrame+='</tr>'}
strFrame+=' <tr align=center >'
for (i=35i<37i++)strFrame+='<td width=20 height=20 id=meizzDay'+i+' style="font-size:12px" onclick="parent.meizzDayClick(this.innerText,0)"></td>'
strFrame+='<td colspan=5 align=right style="color:#1478eb"><span onclick="parent.setNull()" style="font-size:12pxcursor: hand"'
strFrame+=' onmouseover="style.color=\'#ff0000\'" onmouseout="style.color=\'#1478eb\'" title="将日期置空">置空</span> <span onclick="parent.meizzToday()" style="font-size:12pxcursor: hand"'
strFrame+=' onmouseover="style.color=\'#ff0000\'" onmouseout="style.color=\'#1478eb\'" title="当前日期">当前</span> <span style="cursor:hand" id=evaAllOK onmouseover="style.color=\'#ff0000\'" onmouseout="style.color=\'#1478eb\'" onclick="parent.closeLayer()" title="关闭日历">关闭 </span></td></tr>'
strFrame+='</table></td></tr></table></div>'
window.frames.endDateLayer.document.writeln(strFrame)
window.frames.endDateLayer.document.close() //解决ie进度条不结束的问题
//==================================================== WEB 页面显示部分 ======================================================
var outObject //输出对象
var outButton //点击的按钮
var outDate="" //存放对象的日期
var odatelayer=window.frames.endDateLayer.document.all //存放日历对象
var odatelayer=window.endDateLayer.document.all
//bt响应按钮，obj输出对象
function setday(bt,obj) //主调函数
{
if (arguments.length >2){alert("对不起！传入时间选择控件的参数太多！")return}
if (arguments.length == 0){alert("对不起！没有传回时间选择控件任何参数！")return}
var dads = document.all.endDateLayer.style
var th = bt
outObject = (arguments.length == 1) ? bt : obj //设定输出结果对象
outButton = (arguments.length == 1) ? null : bt//设定外部点击的按钮
var ttop = outObject.offsetTop//bt控件的定位点高
var thei = outObject.clientHeight//bt控件本身的高
var tleft = outObject.offsetLeft//bt控件的定位点宽
var ttyp = outObject.type//bt控件的类型
while (bt = bt.offsetParent){ttop+=bt.offsetToptleft+=bt.offsetLeft}
dads.top = (ttyp=="image") ? ttop+thei : ttop+thei+6
dads.left = tleft
//根据当前输入框的日期显示日历的年月
var reg = /^(\d+)-(\d{1,2})-(\d{1,2})/ //不含时间
var r = outObject.value.match(reg)
if(r!=null){
r[2]=r[2]-1
var d=new Date(r[1],r[2],r[3])
if(d.getFullYear()==r[1] &&d.getMonth()==r[2] &&d.getDate()==r[3])
{
outDate=d
parent.meizzTheYear = r[1]
parent.meizzTheMonth = r[2]
parent.meizzTheDate = r[3]
}
else
{
outDate=""
}
meizzSetDay(r[1],r[2]+1)
}
else
{
outDate=""
meizzSetDay(new Date().getFullYear(), new Date().getMonth() + 1)
}
dads.display = ''
meizzWriteHead(meizzTheYear,meizzTheMonth)
try
{
event.returnValue=false
}
catch (e)
{
//此处排除错误，错误原因暂未找到。
}
}
var MonHead = new Array(12)//定义阳历中每个月的最大天数
MonHead[0] = 31MonHead[1] = 28MonHead[2] = 31MonHead[3] = 30MonHead[4] = 31MonHead[5] = 30
MonHead[6] = 31MonHead[7] = 31MonHead[8] = 30MonHead[9] = 31MonHead[10] = 30MonHead[11] = 31
var meizzTheYear=new Date().getFullYear()//定义年的变量的初始值
var meizzTheMonth=new Date().getMonth()+1//定义月的变量的初始值
var meizzTheDate=new Date().getDate()//定义日的变量的初始值
var meizzWDay=new Array(37)//定义写日期的数组
function document.onclick() //任意点击时关闭该控件 //ie6的情况可以由下面的切换焦点处理代替
{
with(window.event)
{
if (srcElement != outObject &&srcElement != outButton)
closeLayer()
}
}
function document.onkeyup() //按Esc键关闭，切换焦点关闭
{
if (window.event.keyCode==27){
if(outObject)outObject.blur()
closeLayer()
}
else if(document.activeElement)
{
if(document.activeElement != outObject &&document.activeElement != outButton)
{
closeLayer()
}
}
}
function meizzWriteHead(yy,mm) //往 head 中写入当前的年与月
{
odatelayer.meizzYearHead.innerText = yy + " 年"
odatelayer.meizzMonthHead.innerText = format(mm) + " 月"
}
function tmpSelectYearInnerHTML(strYear) //年份的下拉框
{
if (strYear.match(/\D/)!=null){alert("年份输入参数不是数字！")return}
var m = (strYear) ? strYear : new Date().getFullYear()
if (m <1000 || m >9999) {alert("年份值不在 1000 到 9999 之间！")return}
var n = m - 50
if (n <1000) n = 1000
if (n + 101 >9999) n = 9974
var s = " <select name=tmpSelectYear style='font-size: 12px' "
s += "onblur='document.all.tmpSelectYearLayer.style.display=\"none\"' "
s += "onchange='document.all.tmpSelectYearLayer.style.display=\"none\""
s += "parent.meizzTheYear = this.valueparent.meizzSetDay(parent.meizzTheYear,parent.meizzTheMonth)'>\r\n"
var selectInnerHTML = s
for (var i = ni <n + 101i++)
{
if (i == m) { selectInnerHTML += "<option value='" + i + "' selected>" + i + "年" + "</option>\r\n"}
else { selectInnerHTML += "<option value='" + i + "'>" + i + "年" + "</option>\r\n"}
}
selectInnerHTML += "</select>"
odatelayer.tmpSelectYearLayer.style.display=""
odatelayer.tmpSelectYearLayer.innerHTML = selectInnerHTML
odatelayer.tmpSelectYear.focus()
}
function tmpSelectMonthInnerHTML(strMonth) //月份的下拉框
{
if (strMonth.match(/\D/)!=null){alert("月份输入参数不是数字！")return}
var m = (strMonth) ? strMonth : new Date().getMonth() + 1
var s = " <select name=tmpSelectMonth style='font-size: 12px' "
s += "onblur='document.all.tmpSelectMonthLayer.style.display=\"none\"' "
s += "onchange='document.all.tmpSelectMonthLayer.style.display=\"none\""
s += "parent.meizzTheMonth = this.valueparent.meizzSetDay(parent.meizzTheYear,parent.meizzTheMonth)'>\r\n"
var selectInnerHTML = s
for (var i = 1i <13i++)
{
if (i == m) { selectInnerHTML += "<option value='"+i+"' selected>"+i+"月"+"</option>\r\n"}
else { selectInnerHTML += "<option value='"+i+"'>"+i+"月"+"</option>\r\n"}
}
selectInnerHTML += "</select>"
odatelayer.tmpSelectMonthLayer.style.display=""
odatelayer.tmpSelectMonthLayer.innerHTML = selectInnerHTML
odatelayer.tmpSelectMonth.focus()
}
function closeLayer() //这个层的关闭
{
var o = document.getElementById("endDateLayer")
if (o != null)
{
o.style.display="none"
}
}
function showLayer() //这个层的关闭
{
document.all.endDateLayer.style.display=""
}
function IsPinYear(year) //判断是否闰平年
{
if (0==year%4&&((year%100!=0)||(year%400==0))) return trueelse return false
}
function GetMonthCount(year,month) //闰年二月为29天
{
var c=MonHead[month-1]if((month==2)&&IsPinYear(year)) c++return c
}
function GetDOW(day,month,year) //求某天的星期几
{
var dt=new Date(year,month-1,day).getDay()/7return dt
}
function meizzPrevY() //往前翻 Year
{
if(meizzTheYear >999 &&meizzTheYear <10000){meizzTheYear--}
else{alert("年份超出范围（1000-9999）！")}
meizzSetDay(meizzTheYear,meizzTheMonth)
}
function meizzNextY() //往后翻 Year
{
if(meizzTheYear >999 &&meizzTheYear <10000){meizzTheYear++}
else{alert("年份超出范围（1000-9999）！")}
meizzSetDay(meizzTheYear,meizzTheMonth)
}
function setNull()
{
outObject.value = ''
closeLayer()
}
function meizzToday() //Today Button
{
parent.meizzTheYear = new Date().getFullYear()
parent.meizzTheMonth = new Date().getMonth()+1
parent.meizzTheDate = new Date().getDate()
if (meizzTheMonth<10 &&meizzTheMonth.length<2) //格式化成两位数字
{
parent.meizzTheMonth="0"+parent.meizzTheMonth
}
if (parent.meizzTheDate<10 &&parent.meizzTheDate.length<2) //格式化成两位数字
{
parent.meizzTheDate="0"+parent.meizzTheDate
}
//meizzSetDay(meizzTheYear,meizzTheMonth)
if(outObject)
{
outObject.value= parent.meizzTheYear + "-" + format( parent.meizzTheMonth) + "-" +
format(parent.meizzTheDate)//注：在这里你可以输出改成你想要的格式
}
closeLayer()
}
function meizzPrevM() //往前翻月份
{
if(meizzTheMonth>1){meizzTheMonth--}else{meizzTheYear--meizzTheMonth=12}
meizzSetDay(meizzTheYear,meizzTheMonth)
}
function meizzNextM() //往后翻月份
{
if(meizzTheMonth==12){meizzTheYear++meizzTheMonth=1}else{meizzTheMonth++}
meizzSetDay(meizzTheYear,meizzTheMonth)
}
// TODO: 整理代码
function meizzSetDay(yy,mm) //主要的写程序**********
{
meizzWriteHead(yy,mm)
//设置当前年月的公共变量为传入值
meizzTheYear=yy
meizzTheMonth=mm
for (var i = 0i <37i++){meizzWDay[i]=""}//将显示框的内容全部清空
var day1 = 1,day2=1,firstday = new Date(yy,mm-1,1).getDay()//某月第一天的星期几
for (i=0i<firstdayi++)meizzWDay[i]=GetMonthCount(mm==1?yy-1:yy,mm==1?12:mm-1)-firstday+i+1 //上个月的最后几天
for (i = firstdayday1 <GetMonthCount(yy,mm)+1i++) { meizzWDay[i]=day1day1++}
for (i=firstday+GetMonthCount(yy,mm)i<37i++) { meizzWDay[i]=day2day2++}
for (i = 0i <37i++)
{
var da = eval("odatelayer.meizzDay"+i) //书写新的一个月的日期星期排列
if (meizzWDay[i]!="")
{
//初始化边框
da.borderColorLight="#63A3E9"
da.borderColorDark="#63A3E9"
da.style.color="#1478eb"
if(i<firstday) //上个月的部分
{
da.innerHTML="<b><font color=#BCBABC>" + meizzWDay[i] + "</font></b>"
da.title=(mm==1?12:mm-1) +"月" + meizzWDay[i] + "日"
da.onclick=Function("meizzDayClick(this.innerText,-1)")
if(!outDate)
da.style.backgroundColor = ((mm==1?yy-1:yy) == new Date().getFullYear() &&
(mm==1?12:mm-1) == new Date().getMonth()+1 &&meizzWDay[i] == new Date().getDate()) ?
"#5CEFA0":"#f5f5f5"
else
{
da.style.backgroundColor =((mm==1?yy-1:yy)==outDate.getFullYear() &&(mm==1?12:mm-1)== outDate.getMonth() + 1 &&
meizzWDay[i]==outDate.getDate())? "#84C1FF" :
(((mm==1?yy-1:yy) == new Date().getFullYear() &&(mm==1?12:mm-1) == new Date().getMonth()+1 &&
meizzWDay[i] == new Date().getDate()) ? "#5CEFA0":"#f5f5f5")
//将选中的日期显示为凹下去
if((mm==1?yy-1:yy)==outDate.getFullYear() &&(mm==1?12:mm-1)== outDate.getMonth() + 1 &&
meizzWDay[i]==outDate.getDate())
{
da.borderColorLight="#FFFFFF"
da.borderColorDark="#63A3E9"
}
}
}
else if (i>=firstday+GetMonthCount(yy,mm)) //下个月的部分
{
da.innerHTML="<b><font color=#BCBABC>" + meizzWDay[i] + "</font></b>"
da.title=(mm==12?1:mm+1) +"月" + meizzWDay[i] + "日"
da.onclick=Function("meizzDayClick(this.innerText,1)")
if(!outDate)
da.style.backgroundColor = ((mm==12?yy+1:yy) == new Date().getFullYear() &&
(mm==12?1:mm+1) == new Date().getMonth()+1 &&meizzWDay[i] == new Date().getDate()) ?
"#5CEFA0":"#f5f5f5"
else
{
da.style.backgroundColor =((mm==12?yy+1:yy)==outDate.getFullYear() &&(mm==12?1:mm+1)== outDate.getMonth() + 1 &&
meizzWDay[i]==outDate.getDate())? "#84C1FF" :
(((mm==12?yy+1:yy) == new Date().getFullYear() &&(mm==12?1:mm+1) == new Date().getMonth()+1 &&
meizzWDay[i] == new Date().getDate()) ? "#5CEFA0":"#f5f5f5")
//将选中的日期显示为凹下去
if((mm==12?yy+1:yy)==outDate.getFullYear() &&(mm==12?1:mm+1)== outDate.getMonth() + 1 &&
meizzWDay[i]==outDate.getDate())
{
da.borderColorLight="#FFFFFF"
da.borderColorDark="#63A3E9"
}
}
}
else //本月的部分
{
da.innerHTML="<b>" + meizzWDay[i] + "</b>"
da.title=mm +"月" + meizzWDay[i] + "日"
da.onclick=Function("meizzDayClick(this.innerText,0)") //给td赋予onclick事件的处理
//如果是当前选择的日期，则显示亮蓝色的背景；如果是当前日期，则显示暗黄色背景
if(!outDate)
da.style.backgroundColor = (yy == new Date().getFullYear() &&mm == new Date().getMonth()+1 &&meizzWDay[i] == new Date().getDate())?
"#5CEFA0":"#f5f5f5"
else
{
da.style.backgroundColor =(yy==outDate.getFullYear() &&mm== outDate.getMonth() + 1 &&meizzWDay[i]==outDate.getDate())?
"#84C1FF":((yy == new Date().getFullYear() &&mm == new Date().getMonth()+1 &&meizzWDay[i] == new Date().getDate())?
"#5CEFA0":"#f5f5f5")
//将选中的日期显示为凹下去
if(yy==outDate.getFullYear() &&mm== outDate.getMonth() + 1 &&meizzWDay[i]==outDate.getDate())
{
da.borderColorLight="#FFFFFF"
da.borderColorDark="#63A3E9"
}
}
}
da.style.cursor="hand"
}
else { da.innerHTML=""da.style.backgroundColor=""da.style.cursor="default"}
}
}
function meizzDayClick(n,ex) //点击显示框选取日期，主输入函数*************
{
parent.meizzTheDate=n
var yy=meizzTheYear
var mm = parseInt(meizzTheMonth)+ex//ex表示偏移量，用于选择上个月份和下个月份的日期
//判断月份，并进行对应的处理
if(mm<1){
yy--
mm=12+mm
}
else if(mm>12){
yy++
mm=mm-12
}
if (mm <10) {mm = "0" + mm}
if (outObject)
{
if (!n) { //outObject.value=""
return}
if ( n <10){n = "0" + n}
WriteDateTo(yy,mm,n)
closeLayer()
}
else {closeLayer()alert("您所要输出的控件对象并不存在！")}
}
function format(n) //格式化数字为两位字符表示
{
var m=new String()
var tmp=new String(n)
if (n<10 &&tmp.length<2)
{
m="0"+n
}
else
{
m=n
}
return m
}
function evaSetTimeNothing() //设置时间控件为空
{
WriteDateTo(meizzTheYear,meizzTheMonth,meizzTheDate)
}
function evaSetTimeNow() //设置时间控件为当前日期
{
WriteDateTo(meizzTheYear,meizzTheMonth,meizzTheDate)
}
function WriteDateTo(yy,mm,dd)
{
outObject.value= yy + "-" + format(mm) + "-" + format(dd)//注：在这里你可以输出改成你想要的格式
}
设置TextBox
<asp:TextBox ID="txtStartDate" runat="server" onfocus="setday(this)" ToolTip="只能输入日期" MaxLength="10"></asp:TextBox>
你需要把上面的代码封装到js文件里就可以用了.
用calender控件不好做!
