  This paper presents a combined power system with a common dc bus that
contains solar power, wind power, battery storage, and a constant dc load
(CDL). In wind system, an AC-DC uncontrolled rectifier is used at the first
stage and the DC-DC converter is controlled by a maximum power point tracker
(MPPT) at second stage. In the solar system, two cascaded boost converters are
controlled through a sliding mode controller (SMC) to regulate the power flow
to the load. A supervisory control strategy is also introduced to maximize the
simultaneous energy harvesting from both renewable sources and balance the
energy between the sources, battery, and the load. According to the level of
power generation available at each renewable energy source, the state of charge
in the battery, and the load requirement, the controller results in four
contingencies. Simulation results show the accurate operation of the
supervisory controller and functionality of the maximum power point tracking
algorithm for solar and for wind power.
