Research And Design Of Battery Charging And Discharging Based On Bi-directional DC/DC Converter

With the continuous development of the information society, the demand for high quality power supply is increasing, digital control power supply has become one of the new hot spots.The bi-directional DC/DC converter as a digital control power supply, not only can be used to meet the requirements of the converter output voltage, but also to reverse the output of the absorption of excess energy, to achieve two-way transmission of energy. Is widely used in AC and DC power supply system, photovoltaic power system, electric vehicle system and battery charging and discharging system. The bi-directional DC/DC converter is more and more widely used in industry. In this paper, based on the charging and discharging system of the battery, the charging and discharging of the battery is carried out by using the voltage dropping and charging of the bi-directional DC/DC converter. The input end is connected with the DC bus, and the output end is connected with the battery energy storage device system, and the bi-directional DC/DC converter is used as the bridge hub of the whole system,and the charging and discharging motor system of the whole system is coordinated.The present widely used BUCK/BOOST type bi-directional DC/DC converter as the main topology, using the most popular arm micro controller for digital control, and the feedback signal acquisition, signal control design is realized through the design of the software. ARM micro controller is used to generate complementary adjustable PWM pulse waveform, by adjusting the duty cycle, so that the input square wave power supply and output square wave power supply to achieve the match.The BUCK and BOOST mode of the two were detailed theoretical analysis, through hardware and software two bi-directional DC/DC converter in the prototype design, gives the main circuit, auxiliary power circuit, isolation drive circuit, sampling circuit, and can communication circuit design process. Simulation experiment using MATLAB software for bi-directional DC/DC converter positive and negative direction of the work mode. The experimental results show the stability of the output waveform verify the feasibility of the bi-directional DC / DC converter.