Intelligent Power Converter Controllers for Photovoltaic Systems

Photovoltaic inverters (PV-VSI) are deployed as the main technology in integrating PV systems to the grid. The operation of the PV-VSI is of paramount importance under all system operating conditions. Despite the current provision of deterministic and heuristic approaches in optimal-tuning of PV-VSI controller parameters, there is still a likelihood of less satisfactory controller performance during unknown system dynamics and short-term transients. This study presents an additional layer of intelligence added to the control structure of a PV-VSI, through harnessing the capabilities of a bio-inspired algorithm, i.e. artificial immune system (AIS). AIS-based control comprises of two subsystems: first, innate immunity (robustness) to typical system perturbations is accomplished offline utilizing a fast-converging heuristic optimization algorithm e.g. particle swarm optimization (PSO). For random and unknown perturbations, online modification of controller parameters occur, hence offering the control system with adaptive immunity. A prominent feature of the proposed controller is its applicability to available PV-VSI control systems, irrespective to its controller specific conventional and smart functionalities. The effectiveness of the proposed AIS-based adaptive controllers for PV systems is investigated through simulations in a real-time simulator i.e. RTDS.