一、计算数据主要电气参数S"∽10.05518.180.4800.8000.0340.6450.561S0.1400.38071500.9710.844主要电气参数S"∽0.630.04514.000.3020.5040.0130.4700.450S0.1020.38071500.9690.93电动机启动计算系统容量视为无穷大，变压器为630KVA油浸变压器，上级母线距车间母线采用2根185电缆连接（150米），电动机距车间母线50米。系统示意图1-11、电动机频繁启动(1)选用电机为75KW三相鼠笼异步电机SrTxTSkmQfhSfhXlSqMSqIrMUrMkquqmuqM(2)选用电机为55KW三相鼠笼异步电机SrTxTSkmQfhSfhXlSqMSqIrMUrMkquqmuqM主要电气参数S"∽0.630.04514.000.3020.5040.0131.1291.022S0.2450.38071500.9330.84主要电气参数S"∽0.630.04514.000.3020.5040.0140.9400.862S0.2040.38071200.9430.86二、计算过程02、电动机不频繁启动(1)选用电机为132KW三相鼠笼异步电机SrTxTSkmQfhSfhXlSqMSqIrMUrMkquqmuqM(2)选用电机为110KW三相鼠笼异步电机SrTxTSkmQfhSfhXlSqMSqIrMUrMkquqmuqM1、电动机不频繁启动Skm=SrT/(xT+SrT/S")=14(MVA)(1)选用电机为75KW三相鼠笼异步电机(SqM=0.645MVA)。Xl=(0.07+6.3/185)*0.5*0.15+(0.07+6.3/70)*0.05=0.031+0.008=0.039Sq=1/(1/SqM+Xl/U2m)=0.549Qfh=0.302uqm=(Skm+Qfh)/(Skm+Qfh+Sq)=14.302/14.851=0.963uqM=0.963*Sq/SqM=0.963*0.549/0.645=0.82(2)选用电机为55KW三相鼠笼异步电机(SqM=0.470MVA)。Xl=(0.07+6.3/185)*0.5*0.15+(0.07+6.3/50)*0.05=0.031+0.010=0.041Sq=1/(1/SqM+Xl/U2m)=0.295Qfh=0.302uqm=(Skm+Qfh)/(Skm+Qfh+Sq)=14.302/14.718=0.972uqM=0.972*Sq/SqM=0.972*0.416/0.472=0.86故电机功率为55KW三相鼠笼异步电机可直接启动。2、电动机频繁启动Skm=SrT/(xT+SrT/S")=14(MVA)(1)选用电机为37KW三相鼠笼异步电机(SqM=0.322MVA)。Xl=(0.07+6.3/185)*0.5*0.15+(0.07+6.3/25)*0.05=0.031+0.016=0.047Sq=1/(1/SqM+Xl/U2m)=0.292Qfh=0.302uqm=(Skm+Qfh)/(Skm+Qfh+Sq)=14.302/14.594=0.980uqM=0.98*Sq/SqM=0.98*0.292/0.322=0.89(2)选用电机为30KW三相鼠笼异步电机(SqM=0.263MVA)。Xl=(0.07+6.3/185)*0.5*0.15+(0.07+6.3/16)*0.05=0.031+0.023=0.054Qfh=0.302Sq=1/(1/SqM+Xl/U2m)=0.239uqm=(Skm+Qfh)/(Skm+Qfh+Sq)=14.302/14.541=0.984uqM=0.984*Sq/SqM=0.984*0.239/0.263=0.90故电机功率为30KW三相鼠笼异步电机可直接启动。工厂配电设计手册150页表6-16，钢铁手册下册193页表23-4主要电气参数S"Skm∽0.630.04514.000.3020.5040.0390.6450...
