Fast and Precise Output Voltage Control of the Buck Converter Without Increasing the System's Order

This article presents a controller for a dc/dc buck converter. The controller has four distinguishing features: 1) does not increase the order of the control system; 2) regulates its output voltage without a steady-state offset; 3) can have highly fast dynamics; and 4) has wide stability margins. Moreover, it can prevent and limit the transient over-current of the converter switch and protect it against possible short-circuit transient faults. The controller is based on leveraging and employing the converter's natural dynamics to address the control objectives. A similar process has been done in some recent publications. However, the proposed method of this article succeeds in completely removing any possible steady-state errors that some highly accurate applications may demand. The theoretical analysis, a clear step-by-step design algorithm for the controller parameters, and a detailed study of the proposed controller's performance using simulations and laboratory experimental results are presented in the article to illustrate its properties.