Abstract
As a result of the increasing acceptance of renewable energy conversion technology that gives high reliability, hybrid power systems now represent the preferred choice for electrical power at many remote sites. These systems include the following power elements; photovoltaic panels, storage batteries, wind turbines, public grid and system controls. The system architecture combines the power systems on the DC bus where the load distribution and battery storage is also located. The system controller provides supervisory control of all power system elements as well as protection. Some of the control functions and protections that the system executes are listed as follows. 1) The battery charging sequence is inherently current limited by parallel array resistors as well as the capacity of the power systems components, 2) Voltage is limited for the end of charge current reduction, and 3) The batteries do not require full charge every cycle. The operation of a stand-alone photovoltaic system depends not only on the quality of the individual system components but also on their interaction in the total system. The demands on the operation control, which co-ordinates the interactions, increase with the system complexity The significance of the operation control is due to its influence on the reliability of the energy supply and on the component lifetimes. This paper introduces the design and implementation of the PVBWG hybrid system. A new technique is used to control the battery charging current. A developed control algorithm is created to give hundred percent priorities of the load tasks as well as to manage and protect the system components.