Investigation of Internal Fault Modeling of Power former

This paper describes a model of a 75MVA and 150kV synchronous machine (powerformer), which can be used to simulate internal fault waveforms for power system protection studies. The method employs a direct phase representation considering the cable capacitance. A method to calculate the inductance and its magnetic axis location of the faulty path is outlined. The machine equations are then solved using a suitable numerical technique. Comparisons are made between the simulated waveforms and recorded waveforms to verify the accuracy of the model.