Design And Application Of Half-Bridge Soft Switching AC/DC Charging Power Supply

In recent years, with the rapid development of new energy sources, energy storage segment receives more and more attention. Lead-acid batteries which is known as a simple, inexpensive, and reliable power supply has been widely used. The performance of the charging power supply has a direct impact on the life and charging efficiency of the battery. With the diversification of the energy storage device, charging power supply moves towards the direction of high efficiency, high power density and intelligence.The power supply charge is designed base on the half-bridge LLC resonant soft-switching in this paper, which has APFC + LLC two stage structures. The former stage circuit has the main function of achievement of power factor correction.The class half-bridge LLC resonant circuit DC/DC converter are adopted in the latter stage circuit.The management and protection with MCU is used in the whole process of charging the battery pack.The critical mode BOOST circuit is adopted in the former stage of power factor correction circuit.In, this paper, the characteristics, working principle and mode of the circuit are deeply analyzed, The complete parameters are designed. the high power factor of power supply design can be achieved, which meets the specifications.LLC resonant half-bridge circuit is used in the latter stage of DC/DC converter.The mathematical models are developed based on fundamental analysis. The main resonance parameter Q, the value of k and n values effect on the performance of the converter are analyzed based on the model. The failure problem of LLC resonant soft-switching circuit is also analyzed, A limit of power law and the division limiting method avoiding soft switch failure are proposed. The resonant parameters of a half-bridge LLC are designed. The main circuit parameters are simulated based on Saber software.The magnetic element is an important part of the switching power supply.The technology of magnetic component integration is used in the design of the leakage inductance and magnetizing inductance of the transformer is used as a resonant inductor. The design directly affects the results of soft switches. The difference between theoretical derivation ideal transformer and practical transformer is analyzed in this paper. The associated transformer is designed.The modules of charging power supply mainly comprise the microcontroller and its peripheral circuits, including the module of given voltage and current, leveling module, sampling module. Three-stage charging process is used in the whole process of the charging process, namely the constant current stage, constant stage, floating stage.Charging power supply modules mainly by the microcontroller and its peripheral circuits, including voltage and current for a given module, leveling module, sampling module, the entire process using the charging process using three-stage charging process, namely the constant current stage, constant stage, floating stage.Finally a charging power of 150 W, the input AC voltage is 90 V ~ 265 V, output 42 V ~ 59 V, rated output current of 3A is designed. The prototype is completed, which is tested under a variety of operating conditions. Th testing waveforms are analyzed and summarized, which verify the consistency of the experimental and theoretical analysis.