Grid‐connected operation and control of single‐phase asymmetrical multilevel inverter for distributed power generation

Abstract

Abstract In recent times, multilevel inverters (MLIs) are gaining popularity for grid integration of distributed power generation sources. In this paper, a proportional‐resonant (PR) controller based on current control logic is proposed for a single‐phase eleven‐level inverter topology, enabling the integration of distributed power generation sources into the grid. The presented topology utilizes eight two‐quadrant switches and three dc sources to produce an eleven‐level output voltage. The level‐shifted pulse width modulation (LS‐PWM) scheme is used for providing switching signals to the inverter under grid‐connected operation. Simulation and real‐time results are presented for the eleven‐level inverter to validate the presented current control logic under the grid‐connected mode of operation. The hardware‐in‐loop emulator (Typhoon HIL‐402) is used for taking real‐time results of the presented grid‐connected topology. The total harmonic distortion (THD) of the eleven‐level inverter voltage and grid current is 12.10% and 0.46%, respectively. The efficiency of the inverter while supplying 2 kW active power to the grid is 98.4%.

Keywords

• Power electronics, supply and supervisory circuits
• Current control
• Control of electric power systems
• Distributed power generation
• Power supply quality and harmonics
• Power convertors and power supplies to apparatus