Multiple Reference Frame Theory in the Synchronous Generator Model Considering Harmonic Distortions Caused by Nonuniform Pole Shoe Saturation

The paper describes a synchronous generator model developed based on the multiple reference frame theory. The main physical phenomena included in the model are the machine armature non-sinusoidal voltage waveform and the influence of armature current in load conditions on the armature voltage waveform higher harmonic components. The modified multiple reference frame theory model is proposed. In this modified theory model the field and armature currents are the cause of the non-sinusoidal airgap spatial field distribution. The influence of this airgap spatial field distribution is also investigated. The resulting nonuniform saturation of the pole shoe affects the machine voltage waveform in load conditions. Simulation and measurements of the machine performance in steady and transient states are conducted in order to validate the model.