Stand-Alone Operation of Distributed Generation Systems With Improved Harmonic Elimination Scheme

Improvement in the efficiency of distributed generation (DG) inverters is a concern and challenge for researchers across the globe. To address the concern, an inverter control technique is developed. Inverters have issues with voltage regulation and harmonics when operating in the grid-connected (GC) and stand-alone (SA) mode. This article proposes a control strategy capable of operating DGs in both SA and GC environments. The GC operation of the inverter is achieved by the current control mode, and the SA control features a voltage control loop capable of overcoming the drawbacks due to load shedding or load switching. Besides, the harmonics due to various conditions of transition and load switching are eliminated by adapting a harmonic elimination pulse width modulation (PWM) scheme. To enhance the performance of the inverter and eliminate the problem of flexibility associated with conventional and offline switching angle calculations in the PWM technique, a bioinspired intelligent algorithm is adapted. The developed system is verified for various reduced total harmonic distortions (THDs) by performing simulations and experiments. The results depict that the output voltage is regulated for varying load conditions, and the THD is observed to be 2.4% under varying load conditions.