Dynamic performance of PWM DC-DC boost converter with input voltage feedforward control

Small-signal characteristics are studied for a pulsewidth modulated (PWM) b oost converter with input voltage feedforward control. The characteristics are valid for the continuous conduction mode (CCM). A small-signal circuit model is used to derive the input-to-output voltage transfer function (audi o-susceptibility), the input impedance, and the output impedance, A respons e of the output voltage to a step change in the input voltage is also compu ted. The measured Bode plots of the input-to-output voltage transfer functi on agreed with that predicted theoretically. It is shown that the feedforwa rd control may reduce the magnitude of the input-to-output voltage transfer function by 40 dB, The input resistance of the converter with feedforward control is negative at low frequencies. The output impedance is not affecte d by feedforward control.