Modeling and Simulation of Three-Phase Voltage Source Inverter with Dynamic Phasors

The rapid switching of the high-frequency three-phase voltage source inverter bring the system with the rapid dynamic process, which beyond the application of the traditional phasor model. Furthermore, a large number of power electronic devices make the electromagnetic transient (EMT) model of microgrid involving multiple inverters very complex. In this paper, the dynamic model of three-phase voltage source inverter (VSI) interfacing with micro-source is established using dynamic phasor method under the condition of RL loads. The three-phase VSI model is simplified by keeping important system state variables corresponding to the time-varying Fourier series, which include switching function considering both the DC component and fundamental frequency component, and the DC source considering only the DC component, the AC output considering only the fundamental frequency component. Finally, the dynamic phasor (DP) model of the three-phase VSI and its EMT model was built in Matlab/Simulink. By comparing the DP model and the detailed time domain EMT model of three phase VSI, the simulation results show that the DP model can reflect the main dynamic characteristics, improve the simulation speed and reduce the running time.