Design Methodology and Control Strategy of Phaseshifted LLC Resonant Converter Based SiCMosfet for Battery Charger of High Speed Train

As an important part of DC power supply system of High Speed Train, Battery Charger requires higher efficiency and economy. LLC resonant converter has become one of the popular topology of power supply because of its advantages of wide load range, soft switching, low electromagnetic interference. SiCMosfet can be adapted at higher switching frequency as a new generation semiconductor device. According to the application requirements of Battery Charger, the topology of PWM rectifier and LLC resonant converter is adopted in this paper, while the Sicmosfet is introduced into LLC converter. Taking a 25 kW Battery Charger as an example, the design steps of phase-shifted LLC resonant converter are described in detail with the principle of high efficiency. and the two-level composite control method are introduced to achieve unit power factor and low ripple of output voltage. Finally, the working waveform of 25 kW Battery Charger is used to verify the effectiveness.