Question

Use MATLAB:

A three-phase Y-A transformer is rated 225-kV:24-kV, 400 MVA and has a series reactance of 6.08 Ohms as referred to its high-voltage terminals. The transformer is supplying a load of 375 MVA, with 0.89 power factor lagging at a voltage of 24 kV (line-to-line) on its low-voltage side. It is supplied from a feeder whose impedance is 0.17 + j 2.2 Ohms connected to its high-voltage terminals. The total load in the system remains constant at 375 MVA.

A) Plot the line-to-line voltage which must be applied to the sending end of the feeder to maintain the load voltage at 24 kV line-to-line for load power factors in range from 0.3 lagging to unity to 0.3 leading.

B) Plot the sending-end voltage as a function of power factor angle.

Answer 1