Frequency Adaptive Circle Tracing Observer-Based Control Algorithm for Ride-Through Operation of Grid-Connected SECS

This article deals with a ride-through strategy for a three-phase grid-tied solar photovoltaic array system. Unlike the conventional control algorithms, this control algorithm does not tradeoff with power quality melioration features while permitting ride-through dynamics of the solar energy conversion system (SECS). As per the revised IEEE-1547 standard, the distributed energy resources have to provide a full range of services even under voltage disturbances caused by faults like existing power plants. In this article, the grid-connected solar power generation system follows the grid code even under ride-through operation with the presence of reactive local load, unlike the traditional algorithms. In order to map future challenges, the low-voltage ride-through features of three-phase SECS at symmetrical/asymmetrical faults, are explored here. This control strategy is capable to operate SECS at various modes. To operate the voltage source converter within a safe limit, a constraint is incorporated on the active power of SECS to avoid overcurrent and energy aggregation in the dc-link capacitor, which reduces the life-time of the dc-link capacitor. Simulated results demonstrate the effectiveness of the control strategy for various operating conditions. The comparative performances of the presented control strategy are analyzed to demonstrate the effectiveness under the presence of distorted grid voltages and non-Gaussian noises in sensed measurements. Test results manifest the dynamics of SECS at various operating conditions.