Research Of The Charging Device Of Lithium Iron DC System In Substation

In the construction project of modern city state grid, the quality of che DC power supply system has an impact on state grid. Reliable or not for DC system of the substation work safety running plays a vital role. As the most important part of the DC power system,the battery is charged efficiently which is to make its long-term operation. Therefore changing equipment is seriously important part of substation in the DC system.In contract to the tradition secondary battery, Lithium ion battery has a high output voltage, large energy density, long shelf life and so on. Although lead-acid batteries used in most substation in our country at present, the utilization of lead-acid is declining gradually so as to the pollution problem. In the long-term, Lithium iron phosphate batterises which have the high performance and non-pollution characteristic is bound to become the most widely used of power supply.Based on the lithium iron phosphate battery as the storage battery of substation, DC power charging module is designed for charging system. Main circuit, control circuit and auxiliary circuit of charging power supply are designed in the system. Application of PID control in TMS32, parameters of the battery is acquired which used to adjust the duty ratio what control the on and off of switch tube. According to lithium iron phosphate battery charging characteristic curve, the high frequency switching power supply output for its efficient charge. At the same time, over-voltage protection, over-current protection and temperature protection is necessary for battery real-time. Finally, the simulation and experiment of the designed circuit, have proved that the results are in conformity with requirements and verified the rationality of the design.