3 phase calculation?

In a 3 phase, 4 wire symmetrical supply system, loads of 2 ohms, (2+j) ohms and (1-j) ohms are connected in star in L1,L2 and L3 phases. The voltages are 380/220 volts. If the neutral conductor NN’ is open-circuit, find a) the load currents before the open-circuit b) the potential of the load star-point with... 顯示更多 In a 3 phase, 4 wire symmetrical supply system, loads of 2 ohms, (2+j) ohms and (1-j) ohms are connected in star in L1,L2 and L3 phases. The voltages are 380/220 volts. If the neutral conductor NN’ is open-circuit, find
a) the load currents before the open-circuit
b) the potential of the load star-point with respect to earth
c) the new voltages across the loads
d) the new load currents in the three phases

我只有部份答案,有人識過程嗎?
b)V(NN')= -85.6+j8.4 V
c)
V(L1N')=305.6-j8.4 V
V(L2N')=-24.4-j198.9 V
V(L3N')=-24.4+j182.1 V
d)
I(L1')=152.8-j4.2A
I(L2')=-49.5-j74.7A
I(L3')=-103.3+j78.9A