LCL Filter Grid Connected Inverter with Harmonics Modeling Flexibility

Abstract

In the last decades, distributed generation (DG) has experienced ever high growth. Most of the energy sources used in DG, notably solar and wind power, are dependent on electronic converters for integration with the main grid. The development of converters and their control structures usually applies computational simulations, which allow for fast analysis of the prototypes. However, the performance of those simulations is dependent on the model used. Grid-connected converters, like LCL-type inverters, tend to need high-order models to correctly represent most of its dynamics, which may lead to time-consuming analysis and simulations. In the literature, many works present simplified models of grid-tied inverters, being some of those unable to deal with frequency components other than the fundamental. This paper proposes a new model for an LCL filter-based grid-tied inverter with harmonics modeling flexibility, which allows the complexity to be adjusted to some extent. The considered system and its respective control scheme are firstly presented. Then, the contribution of this work is discussed for the considered study case. The main goal of this work is an approach suitable for a wide range of applications and analyses with various degrees of complexity in the field of LCL-type inverter studies. Simulation results applying the proposed model are presented and compared with results obtained via real-time domain emulations (RTDE).