The FB-ZVZCS-PWM converter is realized by the way of subjoining block-capacitor into the FB-ZVS-PWM converter. At the freewheeling interval, the primary current is attenuated fast to zero and maintained. And then, power device of the static leg becomes a zero-current-switch (ZCS), power device of the shifted leg becomes a zero-voltage-switch(ZVS). Thus, on one hand IGBT (Insulated gate bipolar transistor) with tail current can be easily used in full-bridge soft-switching converter; on the other hand additional circuiting energy is greatly reduced. At the same tune, less duty cycle loss, lower secondary parasitic resonance, wider soft-switching load range can be achieved. Based on the existing component models in the Pspice software package, a combined model of IGBT is established, in which a non-linear capacitor is introduced to replace the parasitic capacitor. Using this model, computerized simulation is conducted for the FB-ZVZCS-PWM soft-switching converter, the switching and energy-transferring char The FB-ZVZCS-PWM converter is realized by the way of subjoining block-capacitor into the FB-ZVS-PWM converter. At the freewheeling interval, the primary current is attenuated fast to zero and maintained. And then, the power device of the static leg on a zero-current-switch (ZCS), power device of the shifted leg becomes a zero-voltage-switch (ZVS). Thus, on one hand IGBT (Insulated gate bipolar transistor) with tail current can be easily used in full -bridge soft-switching converter; on the other hand additional circuiting energy is greatly reduced. At the same tune, less duty cycle loss, lower secondary parasitic resonance, wider soft-switching load range can be achieved. Based on the existing component models in the Pspice software package, a combined model of IGBT is established, in which a non-linear capacitor is introduced to replace the parasitic capacitor. Using this model, computerized simulation is conducted for the FB-ZVZCS-PWM soft-switching converter, the switching and energy -transferring char