چكيده به لاتين
Today, in many applications where the electricity is not directly accessible, Energy storage elements such as batteries are used. Batteries are made to supply the amount of needed energy from the merging of multiple cells in series and parallel. One of the applications where batteries are desperately needed, is in satellites. Satellites generally receive the required power through solar cells. There is one eclipse period per 24 hours with the maximum period of 72 minutes for GEO satellites. That's why the satellites should be powered by batteries during this session. for optimal performance batteries require a management system to enable optimal performance for the satellite during the mission. A battery management system (BMS) can be applied for monitoring, protecting the battery cells, battery state estimation, to maximize battery performance and to provide communication with external devices. In lithium – ion batteries, observation, measurement, balance and protection, are important parameters. Balancing the cell is the most important factor in this type of the batteries. In this thesis, a balanced converter for a module consisting of 6 battery cells connected in series, is designed. The system is designed based on the Transformers DC-DC, active bridge (SAB). This Is because the full-bridge converter is full budgetary control and has high throughput rates. This helps balancing speed to be high because the balance current is high as much as possible. In this circuit, the power circulation is single directional so it prevents the core to be saturated through the small loop between the adjacent cells. Also the circulation is completely out of control. Since if a single cell is unbalanced, more current is drawn or if the imbalance between the cells is low, the frequency switching decreases. For optimal performance of a hysteresis frequency controller and the frequency limit has been designed to put the circuit in an acceptable range.
Key words: Balancer; battery cell; equalization; snubber circuit; flyback convertor
