PWM effect on MPPT for hybrid PV solar and wind turbine generating systems at various loading conditions

Abstract

Hybrid systems employing different kinds of renewable energy sources, like wind and solar energy conversion systems, are used to reduce generation costs and the pollution of traditional fossil fuel-based electrical generation methods. The current paper presents the design of an off-grid hybrid connection of an 852 W photovoltaic (PV) panel with a 1 kW small-scale wind turbine. This work is based on a study of the effect of the changes in the pulse width modulation (PWM) of a DC/DC converter that was connected to each renewable energy source at various loads. The pulse width can be varied by changing its duty cycle value (D). In this paper, the D value is changed manually for each renewable energy source and automatically using an incremental conductance (IC) and Perturb and Observe (P&O) maximum power point tracking (MPPT) algorithms. The IC algorithm is used for the PV system whereas the P&O algorithm with a smaller step size is used for the PMSG wind turbine.  The hybrid system is exposed to different environmental conditions to test the validity of the MPPT algorithm for both renewable energy sources. The results of manual and automatic changes of D values are compared for different loads. The AC output voltage is regulated to obtain a constant RMS voltage at different loads. The hybrid system is tested and simulated using MATLAB SIMULINK R2017a software.