Design and Implementation of a Simple Diesel Generator Emulator for Frequency Analysis of Laboratory-Scale Microgrids

Diesel generators play an important role in the frequency variation of microgrids. In laboratory-scale microgrids, researchers usually prefer to use diesel generator emulator instead of real diesel generator due to its flexibility. In this paper, a simple diesel generator emulator is presented for frequency analysis in laboratory-scale microgrids. So the approximated behavior of diesel generator is emulated by an inverter equipped with voltage and current control loops in d-q frame. A proposed transfer function and a P-f droop curve are used to generate the reference frequency for virtual PLL of the inverter considering transfer functions of prim-mover, governor and synchronous machine. The experimental results demonstrate the appropriate performance of the proposed emulator.