Coordinated Control Strategy for Hybrid off-Grid System Based on Variable Speed Diesel Generator

In this article, the control of hybrid off -grid configuration based on a variable-speed diesel generator and solar photovoltaic array, is implemented. To ensure a stable operation with the ac voltages and system frequency regulation, back-to-back connected converters are controlled using vector-based control, and stator flux-oriented frame-based control. To adjust the speed of diesel engine according to specific fuel consumption, an effective control strategy is developed. In addition, to compensate for the slow dynamics of variable speed operation and to balance the power in the system the dc-link voltage and battery current are controlled using a double-loop control strategy. Furthermore, the dynamic model of the dc–dc boost converter is integrated with the perturbation and observation method for obtaining smooth and efficient maximum power point tracking (MPPT). To prevent overshoots during the sudden transition, all proportional-integral controllers are reinforced with a back-calculation antiwindup scheme. The performance is obtained using MATLAB/Simulink and validated on real-time hardware to demonstrate the effectiveness of coordinated control under variations of loading and weather conditions.