An improved control method of Buck converter to reject input-disturbance

An improved voltage-mode control method is presented for Buck converter. The input voltage is modulated by triangular carrier, which is taken as the feed-forward input. Combining with the end-point prediction, the influence of RC compensation network is bypassed, which makes the input disturbance and reference variation directly reflect to the variation of duty cycle. The quantitative analysis of the presented method demonstrates that the variation of duty cycle depends on both input disturbance and reference variation, while the output variation is just determined by reference variation. The closed loop gain of the system is provided, which shows that the system stability analysis is independent of input voltage. The simulation and experimental results demonstrate that Buck converter with the presented method can reject the input disturbance naturally. When the reference voltage is constant, the stability of output voltage is better than the other methods and the output voltage has no transient overshoot.