Boost PFC Constant Voltage Control with Constant Power Load

The power factor correction (PFC) can be realized by the input-output linearization method for boost converter, The advantage is that the duty cycle of MOS transistor can be calculated directly without control parameter setting, but when the converter is connected to constant power load (CPL), because the duty cycle formula includes the ratio of output voltage to current, the load of Buck CPL has no current flow during the toff period, so the normal calculation results cannot be given. In order to solve the problem that the output duty cycle cannot be calculated, this paper starts from the relationship of equal input and output power, and merges resistance into the output terminal. At the same time, in order to reduce the power loss, the capacitor is connected to the original circuit to provide continuous current to correct the current discontinuity, and then the output voltage is precisely adjusted to realize the fast constant voltage control of Boost PFC converter under CPL.