This paper presents a modeling and control strategies of a grid connected Wind-Photo voltaic hybrid system. This proposed system consists of two renewable energy sources in order to increase the system efficiency. The Maximum Power Point Tracking (MP PT) algorithm is applied to the P V system and the wind system to obtain the maximum power for any given external weather conditions. The Field Oriented Control (F O C) controls the generator side converter, moreover this approach is used to control independently the flux and the torque by applying the d- and q-components of the current motor. The Voltage Oriented Control (V O C) strategy controls the utility grid side converter which is adopted to adjust the DC-link at the desired voltage. The simulation results using mat lab software environment prove the good performance of these used techniques so as to generate sinusoidal current wave forms. This current synchronizes with the grid voltage, Moreover, the DC bus voltage is perfectly constant because only the active power is injected into the grid. Simulations are carried out to validate the effectiveness of the proposed system methods.
Fig. l.The proposed P V -wind hybrid system
EXPECTED SIMULATION RESULTS
Fig. 2 Solar i r radiance changes
Fig. 3 The variation of PY arrays current
Fig. 4 The P Y arrays voltage
Fig. 5 The P Y arrays power and reference
Fig. 6 Duty cycle
Fig. 7 Wind speed profile
Fig. 8 Electrical angular speed of the SC I G and its reference
Fig. 9 The active power injected into the grid
Fig. 10 The Reactive power injected into the grid
Fig. 11 The wave forms of the current
Fig. 12 The three phase current and voltage wave forms
Fig. 13. DC link voltage.
This paper investigated the Wind-Photo voltaic hybrid system control which included an MP PT method. Different solar irradiation and wind speed environments has been simulated in order to maximize the output power of the proposed system . Two control techniques improved the hybrid system usefulness. The Field Oriented Control (F O C) controlled the controlled rectifier connected to the squirrel-cage induction generator (SCI G) to reach the optimal rotational speed. The Voltage Oriented Control (V O C) method controlled the grid-side invert er in order to keep the dc-link voltage at the desired value. Mat lab / Sim u link software implemented the hybrid system simulation and its performances proved when the solar i r radiance change or the wind speed occurs.