# Output voltage control of DAB converters based on uncertainty and disturbance estimation

## TL;DR

This paper introduces a new control method for DAB converters to improve voltage regulation by estimating and reducing disturbances.

## Contribution

A novel robust control scheme using uncertainty and disturbance estimation is proposed for DAB converters.

## Key findings

- A small-signal model of DAB converters simplifies controller design.
- The UDE method effectively reduces output voltage errors caused by disturbances.
- Experimental results show the UDE-based control outperforms existing methods in disturbance suppression.

## Abstract

The dual active bridge (DAB) converter is a power electronic device commonly used for DC voltage regulation and stabilization. However, during its control process, external disturbances, load variations, input voltage variations, switching tube voltage drops, dead time, etc. lead to errors in the control output, thus reducing the control accuracy of the system. Therefore, this article propose a robust control scheme for the output voltage based on uncertainty and disturbance estimator. In this article, an average small-signal model of the dual active bridge converter was established in terms of the basic principles and operation mechanisms, simplifying the controller’s design. Then, the basic principles of the uncertainty and disturbance estimator (UDE) are introduced. The small-signal model of the dual active bridge (DAB) converter is applied to the UDE to minimize output voltage error by enabling the controller to directly regulate the shift ratio. Finally, this article discusses the application and effectiveness of the uncertainty and disturbance estimator (UDE) in the simulation and control of dual active bridge (DAB) converters. A series of experimental comparative studies are conducted, demonstrating that this scheme offers significant advantages in suppressing system uncertainties and disturbances.