Average modeling of a three-phase inverter for integration in a microgrid

This paper proposes average inverter model operating in two complementary modes suitable for microgrid simulation applications. Three phase voltage source inverter (VSI) connects to the microgrid through an LCL low pass filter and operates either in current controlled (CC) or voltage controlled (VC) mode. Models presented here take into account the nonlinear behavior of the switches, delays in the control loops, and the practical constraints. Models can simulate active and reactive power controls of the inverter in two different ways and also to estimate the low order harmonics of the output current. The performance of developed average models was verified by comparison of the simulation results between these models and detailed switching model of a 125 kW inverter.