总功率:6+7+8=21(KW)各相电流总电流(以阻性负载计算):Ia=6/0.22≈27.3(A)Ib=7/0.22≈31.8(A)Ic=8/0.22≈36.4(A)总电流就是每相平均电流:I=P/1.732/U=21/1.732/0.38≈31.9(A)或:I=(27.3+31.8+36.4)/3≈31.83(A)