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Abstract
Batteries are essential means for storing energy and open the way for greater mobility in our day-today lives. from portable cell phones to high-tech space equipment, batteries find numerous applications. There are two main categories of batteries, Primary batteries for single use and secondary batteries, (rechargeable).
There are several conventional types of electronic circuitry used within battery chargers such as ferro-resonant and linear chargers. Recently, switched mode power supplies are utilized as switch mode battery charger. Advantages of the switch mode battery charger include the reduction in size and efficiency enhancement compared to the other conventional charger topologies. SMBC are classified into two groups: isolated type and non isolated type. The
thesis presents a study of different topologies suited for the application of SMBC. Some are based on a Buck DC/DC converter while the other is a full bridge isolated DC/DC converter.
The proposed control techniques of the SMBC are responsible to regulate the charging voltage without exceeding the
rated current of the battery. In order to achieve these targets, the structure of the controller should comprise two loops. The first loop regulates the voltage across the battery using a simple PI controller while the second loop is dedicated to limit the charging
current and it is based on Hysteresis Current Control (HCC) technique. HCC offers a fast dynamics and high bandwidth among other current controllers.
A modified thevinen equivalent battery model is used to represent the battery characteristics. This model is essential to evaluate the performance of the proposed control techniques for
the switch mode chargers. With this model, the depth of discharge (DOD) of the battery is calculated which help in monitoring the battery status. EMTDC/PSCAD simulation package is used to represent the proposed systems. The simulation results show the dynamic performance of each of the proposed switch mode charger and validate the accuracy of the proposed control technique. The advantages of the voltage and current controllers are clearly obvious in the results. The efficiency of the SMBC is increased by using boost Power Factor Correction which increase the power factor and reach to nearly unity.