Abstract:

Renewable energy has attracted significant attention in recent years due to its abundance in nature and almost non-polluting. Hybrid systems combine two or more energy sources and are widely regarded as one of the most feasible and dependable solutions. Grid-connected renewable energy systems are wind-solar hybrid systems that have achieved widespread interest worldwide as a means of overcoming the depletion of non-renewable energy sources. DFIG is considered one of the most suitable generators for the nature of the variable wind speed due to its different composition from the rest of the generators. By implementing a system of BESS and PV array together and connecting them to the DC-link voltage of DFIG, this design produces active energy to compensate the shortfall in the power delivered to the grid at low wind speeds and also when the wind speed is zero, thus maintaining a constant active power under conditions of changing wind speed. This paper presents an intelligent methodology for optimal power management using combining PV and BESS to adjust a 1.5 MW DFIG performance under wind variations conditions. Where PV and BESS are connected into the DC-link of the back-to-back convert. The MFO optimization technique is used to optimize FLC scaling factors for both RSC and GSC. In addition, it is implemented an MFO-FLC technique-based MPPT algorithm to extract maximum power from PV with a DC-DC converter system. BESS is designed to be a vital component in improving the dynamic behavior of DFIG under a fluctuating wind speed by smoothing the output power injected into the grid. The batteries are charged from the PV that has been designed with MPPT based on MFO-FLC control method. Furthermore, the batteries are discharged to maintain the constant DC-link voltage, and also the keep active power delivered to the grid as stable as possible, and thus the stability of the system is maintained. The proposed enhanced methodology utilizes an optimal FLC technique for the control of WECS based on DFIG modification which used BESS and PV into a back-to-back converter DC-link. This methodology's main aim is to maintain a constant DC-link voltage without affecting variation in wind speed, keeping the stator and rotor currents stable and smooth under changing conditions, and maintaining stabilization of active power with slight fluctuations compared to the overshoot of active power under conventional control. The proposed system is operated under varying wind speed and solar radiation conditions to evaluate DFIG behavior during the transition from low to high gusts. Finally, a comparison is made between the proposed system and a system without PV and BESS that uses a PI controller. It is noticed from the results that the proposed modified DFIG exhibits excellent behavior under variable solar radiation and wind speed conditions. <

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