Power Electronic Based Emulation of Synchronous Generator with Improved Accuracy

Abstract

Existing methods of synchronous generator emulation utilize simplified synchronous machine models which neglect the effects of stator transients for calculating the terminal voltage. These models are suitable when the load current consists of only a fundamental frequency positive sequence component. Unbalanced and non-linear loads draw currents having negative sequence and other low-order harmonic contents as well. This paper details a method which takes into account the stator transients for emulating a synchronous machine. The performances of the emulated synchronous machines using the proposed and conventional methods are compared with that of an actual generator through simulations. The voltage and current waveforms of the actual generator are found to be much closer to those of the proposed emulator as compared to those of the conventional emulator. The experimental waveforms of the two emulators are observed to be similar to the simulated ones.