Sensitivity‐guided PSO‐based PI controller tuning for grid‐connected PV–wind hybrid energy systems

Abstract Systems photovoltaic–wind hybrid energy systems that are grid-connected to the grid need to have a successful system of multi-loop converter control to balance the direct current (DC)-link stability, acceptable quality of grid-current and robust operation under variable renewable generation and fluctuating grid conditions. Even though proportional-integral (PI) controllers are still popular due to their simplicity of structure and the practical consideration of their usage, they are very sensitive to tuning of the gain. The use of conventional particle swarm optimisation (PSO) to search PI corresponding to desired dynamic performance has been commonplace; although the effects of different controller gains on the dynamics are different, all gains are treated equally when searching. This paper suggests a sensitivity-guided based PSO (SG-PSO) approach to the tuning of PI controllers of a grid-connected PV–wind hybrid energy system. The allowed method combines Morris-based global sensitivity screening and PSO to fit the most significant controller gains and biases the optimisation process to concentrate on the predominant parameter aspects. In MATLAB/Simulink, a simulation-based model of the hybrid system, such as the PV subsystem, permanent magnet synchronous generator-based wind subsystem, DC-link, grid-side inverter and the weak-grid representation is developed. The tuning target, at the same time, reduces the DC-link voltage overshoot, settling time, and the total harmonic distortion of grid-currents. The finding is that the influence that prevails is mostly on the grid-side current controller and the DC-link voltage controller, confirming the necessity of parameter-priority-based optimisation. The proposed SG-PSO framework is shown to rapidly converge, be more stable during tuning, and have lower run-to-run variation compared to the ordinary constrained PSO-based tuning. The tuned controller can also be operated with stable operation over co-generation dynamics, fault ride through conditions and with weak grid scenarios with varying short circuit ratios. Such results show that SG-PSO is a practical and efficient offline tuning framework of a hybrid system consisting of multi-loops, PI-controlled invertor-dominated renewable energy systems.