An Enhanced Converter-based Diesel Generator Emulator for Voltage and Frequency Control Studies in Laboratory-Scale Microgrids

Abstract

Diesel generator emulators (DGEs) are commonly used instead of real diesel generator units in laboratory-scale studies for their lower noise, more flexible parameters design and lower environmental pollution. This study presents a new control system in αβ framework for a DGE based on power electronic converter. The proposed control system has two parallel control paths including the frequency path and the voltage path. The voltage path consists of a PI controller that generates the amplitude of the modulation reference waveform. The frequency path consists of a transfer function in series with a droop curve to generate the angle of the modulation reference waveform. Finally, the angle and amplitude are applied to an especial space vector modulation unit for generation of the inverter gate pulses. The presented algorithm can be simply implemented in αβ framework with no need to PLL system and park transformation. It employs just one PI controller which can be easily implemented and tuned on the microcontroller. The experimental and simulation results verify the accuracy and performance of the proposed method.