Near unity power factor single phase trapezoidal AC power supply with minimum DC bus capacitor

Conventional power factor correction circuits use a boost stage between rectifier and inverter. This paper proposes a topology that does not require either a boost stage or a large DC bus capacitor; it uses a voltage-controlled inverter in the output stage, in which the PWM modulating function is synchronized with the DC capacitor voltage ripple. A number of feedforward voltage controlled PWM pattern generator options are presented. They are used to produce the trapezoidal waveforms required to power hybrid fiber/coax cable systems. Theoretical and design considerations are validated on an experimental unit