How to Calculate the MVA Rating of a Shunt Reactor for a Transmission Line?
Understanding MVA Rating Calculation for a Shunt Reactor
To determine the MVA rating of a shunt reactor needed to maintain 275 kV at the receiving-end of a no-load transmission line, we need to calculate the reactive power compensation required.
Line Parameters Conversion:
Given the line parameters of resistance, inductance, and capacitance per phase, we convert them to per-unit values using the line length of 400 km.
Voltage Drop Calculation:
We calculate the voltage drop due to the line's reactance using the per-unit values and the line voltage of 275 kV.
Reactive Power Compensation Formula:
By using the formula Q = V^2 / X, where Q is the reactive power, V is the line voltage, and X is the reactance, we can determine the reactive power compensation required.
Final Calculation:
Substituting the values into the formula, we get Q = (275 kV)^2 / (1 mH/km x 400 km) = 190625 kVAR, which corresponds to an MVA rating of 190.625 MVA for the shunt reactor.