SVM-based Control Strategy for Three-Phase Inverter-based Diesel Generator Emulator

In this paper an inverter-based prototype of a simple diesel generator emulator is presented for frequency control studies in laboratory-scale microgrids. The behavior of a real diesel generator is emulated by an inverter with voltage control loop using a modified space vector modulation (SVM) technique to generate the PWM switching pulses. The proposed control system consists of two separated paths including voltage and frequency control loops to generate amplitude and phase of the reference voltage for SVM, respectively. The voltage control path contains only one PI controller in alpha beta frame. Also in frequency path, a proposed transfer function and a P-f droop curve are used to generate the reference frequency for SVM considering transfer functions of prim-mover, governor and synchronous machine. The simplicity of implementation is the main advantage of this method. The proposed diesel generator emulator is simulated in MATLAB/SIMULINK software to verify the performance of the proposed method.