Single‐Phase Single‐Stage Integrated Ćuk Inverter Operating in Discontinuous Conduction Mode for Autonomous Operation

ABSTRACT DC microgrids are required to supply energy to AC local loads in many applications. To address this need, integrated inverters have been rising as an excellent solution for interfacing AC loads with the microgrid due to their good conversion efficiency, lower costs, and enhanced reliability. Thus, this paper explores and analyzes the single‐phase single‐stage integrated Ćuk inverter (ICI). The ICI is designed to operate in discontinuous conduction mode with an improved switching strategy. The inverter's output voltage is regulated by a single‐loop control system employing a proportional integral multiresonant controller. This paper presents a comprehensive qualitative and quantitative mathematical analysis of the ICI, such as the main system equations, component sizing, and the converter modeling using the state‐space technique associated with the small‐signal analysis. The ICI distinguishes itself by (i) reduced number of electrical/electrical components; (ii) operation with a single high‐frequency switch, while the remaining bridge switches operate at low frequency; and (iii) ability to step up the input voltage while supplying an AC voltage in its output. The feasibility and functionality of the ICI are demonstrated from computational simulation and experimental results. The ICI provides an AC output voltage with low harmonic distortion and presents an efficiency greater than 96%.