| Supercapacitor is a novel energy storage device, which has many merits such as high charging speed, high power density, extremely high cycling capability, no memory effect, etc. It has found a wide application in the area of power system, electrical vehicles, uninterruptible power system, the wind-solar hybrid power supply system and industy control area. The usage of a bidirectional DC/DC converter between the super capacitor based power storage system and DC bus can lessen the weight and cost of the system dramatically. So bidirectional DC/DC converter has a significant research value. In this paper, apart from the study of super capacitor property, a novel isalated bi-directional DC/DC converter, which adapts to be applied in high voltage turn ratio occasion, is introduced based on DSP (Digital Signal Processing) control.Firstly, the application, property, voltage balancing method and charging method of super capacitor are studied. Secondly, the topologies of non-isolated and isolated bi-directional DC/DC converter and isolated low voltage-high current rectifiers were compared and analyzed. Based on the pervious two chapters analyze, a bi-directional full-bridge current-doubler converter which is suitable for super capacitor application is introduced. The BUCK and BOOST mode operation procedure of the converter are discussed separately in detail. The control strategy of synchronous rectifying is also explained. In order to lay a solid foundation in closed-loop design, small signal models of BUCK and BOOST mode of the converter are established. The closed-loop stability is discussed and compensation network circuits are given in order to improve the dynamic response of the system.The digital control system is based on TI's DSP chip named TMS320F2812. In this section, the gate drive signal generation methods, driving circuits design, sampling circuits design are discussed in detail. Finally, a 300W bi-directional full-bridge current-doubler prototype is established and optimized by the circuit simulation software SIMetrix/SIMPLIS. The simulation result proves the correctness of the model of the converter. The result of super capacitor charging experiment shows that the converter meets the design requirement.
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