300kHz600WZVT--PWM boost converter

Using the power stage circuit as shown in the figure, a switching regulated power supply with a switching frequency of 300kHz, an output power of 600W, and an output voltage of 300V can be designed using the ZVT--PWM boost converter. Its input voltage is 150~200V. Ls is a saturable reactor, used to eliminate the ringing between Lr and VT1 output capacitor, using Toshiba spike killer (Toshiba spike killer) SAl0×6×4.5 magnetic core, wound with 5 turns. Use fast recovery diode VD2 to prevent the VTl body diode from conducting. Without the diode, some current would be conducted to provide resonance between the Lr and VTl output capacitors. In this way, when VTl is turned off, it will suffer the reverse recovery problem. It should be noted that the auxiliary switch is chosen for a much smaller current rating than the main switch. The auxiliary switch here uses IRF730 (400V, 5.5A, 75W), and the main switch uses IRFP350 (400V, 16A, 150W). The circuit operates in zero-voltage switching within the input voltage and load ranges, with a maximum efficiency of 97% at full load and the highest input voltage, and the noise is very low, and the experimental waveform is consistent with the theoretical waveform.