Part A:
Three impedances Z1 = 3 + j4Ω, Z2 = 6 + j0Ω and Z3 = 2 + j5 Ω are to be connected to a three-phase, 400V 4-wire supply, with phases A, B and C and neutral connection N as follows:
Z1 between A and N
Z2 between B and N
Z3 between C and N
(a) Sketch a diagram showing how the three loads would be connected to the supply.
(b) Calculate the magnitude of the phase voltage
(c) Calculate the magnitude and phase of all line currents
(d) Calculate the magnitude and phase of the neutral current
(e) Calculate the total active power for the 3-phase load
Part B:
The two impedance Z1 and Z2 given in Part A are now disconnected from the three-phase, 400V- wire supply of Part A, and are reconnected in parallel across a 1-phase, 230V, 50Hz sinusoidal voltage source.
For the resulting single-phase circuit:
a. Calculate the magnitude and phase of the currents in the impedances Z1 and Z2, using the Current Division Rule.
b. Calculate the magnitude and phase of the supply current.