Grid-Connected VSI With Filter—Models and Comparison

There are several ways to model three-phase grid-connected voltage-source inverters (VSIs) with an LCL filter. Such models often use simplifications like constant dc-link voltage or averaging over a switching period. These simplifications remove transistor switching and dc-link capacitor dynamics from the model. In this paper, a comprehensive modeling of a three-phase VSI, including an LCL filter, is described and compared to models using one or more of the aforementioned simplifications. Advantages and disadvantages of different models are discussed. All simulations are verified by comparing with experimental results.