序号机械名称单位数量设备功率Pr(KW)总功率(KW)PeKxCOSфPjstgфQjs1塔吊台3501502塔吊大灯台91.210.83现场照明台61.27.24木工电锯台53155钢筋切断机台3396钢筋调直机台37.522.57木工圆盘锯台53154钢筋弯曲机台3399项目部办公室间305.516510厨房台24811插入式振动器台101.515150.10.451.51.988.2512交流电焊机台52311513电渣压力焊机台149.449.414闪光对焊机台1100100合计690.9318.13285.02Pjs294.3Q补Qjs263.6Qjs补Sjs279.0tgф前1.2tgф后0.4832S280.2ΔS8.11#号箱变负荷计算Pe值PrPjs=(0.9~0.95)∑P210.9Q补=Pjs(tgф前-tgф后)0.450.70.7552.71Qjs补=Qjs-Q补Qjs=(0.9~0.95)∑QSjs=(Pjs2+Qjs补2)1/2补偿后功率因数cosф=0.9S=Sjs+ΔSΔP=0.01PjsΔQ=0.05PjsΔS=(ΔP2+ΔQ2)1/2施工总负荷S为217KW,考虑开盘展厅及展示区用电负荷约为为200KW,1#箱变容量利用500KVA。160.822.255.5173264.40.30.750.50.70.60.680.4548.240.562527.75121.1118.981.9848.245.5522.255.36145.42表中:Pr为设备额定功率,Sr为电焊机额定功率,Pe为设备功率,Kx为需要系数,KΣP和KΣq为有功功率和无功功率同时系数,COSф为功率因素,εr为设备额定负载持续率(电机一般40%,焊机一般60%),Pjs为计算有功功率,Qjs为计算无功功率,Sjs为计算视在功率。Δs为变压器的损耗PrPrPr1.020.881.331.08