A novel three‐phase buck‐boost inverter controlled by an open‐loop assisted closed‐loop hybrid control method

Abstract

Summary A novel general purpose three‐phase buck‐boost inverter without need of additional filtering units is presented in this study. The proposed inverter topology is built with moderate numbers of elements in terms of the operation advantages and qualities. The buck‐boost converter‐based structure provides obtaining wide‐range output voltage amplitudes lower or higher than the input voltages. A novel hybrid control method that is open‐loop assisted closed‐loop control is proposed for the inverter operation to improve the response performance on various input and output operation conditions. The wye‐connected modular structure of the proposed inverter topology also enables unbalanced three‐phase operation and single‐phase operation for each phase with independent phase voltages and frequencies. An experimental laboratory setup is built for the proposed three‐phase inverter for 0–50 Hz, 0–100 Vp, and 1.5 kW operation values for real‐time application tests. Simulation tests are also applied for the inverter. The obtained results for both the simulation and the experimental tests show that the presented inverter with the proposed hybrid control method is capable of operating in balanced/unbalanced three‐phase and independent single‐phase modes while producing close to sine wave output voltages under 5% THD levels with wide range desired amplitudes and frequencies on different operating points.