Design and Development of 48V, 50A VRLA Battery Charger Using DSP TMS320F2811

Abstract

Uninterruptible power supply (UPS) is integral part of any industry. Continuous availability of secured power supply is key factor for smooth plant operation. Due to higher load demands, the reliability of supply utility is a vital problem for continuous process industry as well as some critical applications. The battery charger is one of the most important parts of the UPS system. Where we require continuous supply of power irrespective of any situation; batteries are used as a back up. Battery charging is a complex electro chemical process, in which discharged electrical energy is only replenished by the chemical process. Chargers are used to charge the batteries by providing a regulated DC supply and controlled charging current as per the require- ment. The main aim of this thesis is to develop different possible solution for battery charger. Then by simulating all the available options, find out best suitable system, which can meet the industrial requirement. The main aim of the study is to become a compact battery charger, which is possible by increasing switching frequency. Due to this compactness, its installation and transportation becomes more comfortable. This thesis demonstrates the different lead acid battery charging methods and amongst them the best suitable method for lead acid battery charging. An approxi- mate battery model is developed to get the exact charging behavior in the simulation. The report contains the simulation of phase shifted isolated full bridge converter for dc-to-dc power conversion is done with PSIM software. The whole circuit is simu- lated with the help of DLL block, which will help while preparing algorithm for DSP. Then for hardware implementation, necessary pulse patterns are generated with DSP TMS320F2811. After that design of necessary high frequency transformer is included. First hardware implementation of full-bridge converter is carried out. Trouble shoot- ing with the hardware setup is done by modifying hardware and also software. At the end hardware implementation of battery charger is done. Thesis also includes necessary hardware results and images of battery charger setup.