Gan totem column bridgeless boost PFC (single phase) seven PFC duty cycle feedforward

PFC Overview of duty cycle feedforward

Relying solely on the control loop PI The regulator performs control adjustment , The bandwidth of the control loop will be relatively narrow . in addition , Because the adjustment speed is not fast enough , It will also affect the dynamic performance of the whole system . Adopt the digital control technology that the duty cycle feedforward control and feedback control are adjusted at the same time , It reduces the requirements for the parameters of the control loop .

Duty cycle feedforward is added on the basis of average current control (V0-Vin)／V0. Set the duty cycle feedforward control , It can speed up the response speed of the controller , Reduce control overshoot , Increase the stability of the control system .

from Boost APFC The working principle of , The switch on time corresponding to each switching cycle is jointly determined by the input and output voltage , According to the volt second balance of the inductance, the expression of the duty cycle can be obtained as