Research Of Bi-drectional DC/DC Converter For Energy Exchange

With the development of switching power towards high-power density, high-efficiency and high-frequency, bi-directional DC/DC converters are widely applied in storage battery charging and discharging, electric vehicle power, aviation power and DC uninterruptible power systems. As the new type of DC/DC converters, it would have grate applications in industry area. Nowadays, digital signal processor becomes a popular technology, and it has been used in DC/DC converter and gradually takes place of traditional analogy controller.This dissertation presents the investigation and designing of a digital controlled bi-directional DC/DC converter, which is used for the activation processing of electrochemistry substance.Some DC/DC topologies applied for the energy transfer are discussed and compared. Based on the analyes, a bi-directional buck-boost type topology is selected for the study. The working process of this circuit is described in detail. All of the main circuit parameters are designed.Moreover, defferent control modes of the bi-directional converter are tested. According to the demand of storage charging and discharging, the average-current control is implemented by using DSP2812 as the controller.Based on the theoretical analyze, a topology is realized. The main circuit, contol circuit, drive and measure circuit and CAN bus interface are all designed. At the same time, the design of schematic and PCB are completed, and then PCB is made into a circuit board.The main characteristic is that a bi-directional DC/DC converter is applied in the the activation processing of storage.The energy exchange inside the DC networks will greatly reduce the feedback current flowing from regenerative inverter to AC line when discharging battery groups. It is significant to reduce the harmonic pollution coursed by the active inverting, and it also improves the active power.