CONTROL AND MANAGEMENT OF A SOLAR-WIND HYBRID SYSTEM FOR POWER QUALITY IMPROVEMENT

The main aim of this paper is to present a modified Maximum Power Point Tracking (MPPT) control strategy of a solar-wind hybrid power system, which allows producing a maximum of energy while enhancing the produced power quality by reducing its fluctuation rate. Indeed, the Photovoltaic System (PVS) is based on a PV field of panels connected to the grid through a DC-DC and DCAC PWM converters and the Wind Energy Conversion System (WECS) is based on a stator field oriented Doubly Fed Induction Generator (DFIG) which its rotor is connected to the network via a back to back AC-DC-AC PWM converter. The proposed control strategy ensures a conventional Maximum Power Point Tracking (MPPT) for the WECS. Furthermore, it guarantees a smooth power injected in the grid by applying a modified MPPT technique applied to the PV system. This strategy uses a part of the PVS available power to compensate the WECS power fluctuations due to wind gusts and generates simultaneously the maximum of smoothed power from the residual part. The simulations results obtained in the case of the proposed control strategy have been compared to those of a conventional MPPT technique and of a Guaranteed Minimum Available Power (GMAP) control strategy. It is obvious that the proposed modified MPPT keeps a good compromise between the quantity and the quality of the total hybrid system produced power.