Adaptive digital proportional–integral–derivative controller for power converters

Abstract

An adaptive digital proportional–integral–derivative (AD-PID) controller scheme is presented in this study to improve the dynamic performance of power converters. The controller adaptively adjusts the integral constant (Ki) and the proportional constant (Kp) following a new control law. The control law is a function of the magnitude change in the error signal and its peak value during dynamic transients. The proposed AD-PID controller adaptively detects the peak value of the error signal, which is a function of the transient nature and magnitude and utilises it in the control law such that no oscillations are generated as a result of the adaptive operation. As a result, the dynamic output voltage deviation and the settling time of the output voltage are reduced. The concept and architecture of the proposed AD-PID are presented and its proposed control law is discussed and verified by experimental results obtained from a single-phase DC–DC buck converter with input voltage range of 8–10 V, nominal output voltage of 1.5 V and a maximum load current of 7 A.