Hybrid PI-ANN Controller Design and Analysis for DC Bus Regulation in PV–Wind Microgrids

Abstract

Hybrid renewable energy systems are increasingly used to power applications that are not connected to the main electrical grid, particularly in off-grid environments, where access to the grid is limited or not available. While these systems offer a practical alternative to conventional power sources, maintaining a stable DC bus voltage is one of their main challenges. This is due to the variable and intermittent nature of renewable energy sources such as photovoltaic (PV) and wind. To regulate the DC bus voltage, each source is connected via a boost converter whose performance depends on the control strategy used. In this work, a classic PI controller is first implemented for its simplicity and common usage. However, it has limited performance in fast and unpredictable input variations. In this regard, a PI controller is integrated with an ANN, resulting in a hybrid PI-ANN control structure. Each of the control approaches is applied to the boost converter interfacing either the PV or wind source, and the resulting DC bus response is compared. The most effective configuration uses PI control on the photovoltaic converter and PI-ANN control on the wind converter. This indicates that an appropriate choice of a control strategy at each energy source can result in better performance, especially in a hybrid system where more than one source operates simultaneously and is connected to the same DC bus.