Linear Extended State Observer Based Current Sensorless Control for DAB Converters to Improve Bus Voltage Transient Response

Abstract

In the operation of DC microgrid, the switching of resistive load will cause disturbance-type fluctuations of DC bus voltage. When DAB converters are used to stabilize the DC bus voltage, the transient response of traditional PI control is relatively slow. The load current feedforward technology can effectively suppress the disturbance caused by resistive load switching and improve the bus voltage transient response, but it relies on expensive high-bandwidth isolated current sensors. Therefore, this paper proposes a current sensorless control method based on linear extended state observer, which regards the resistive load switching as a kind of external disturbance to estimate and perform the feedforward compensation. The method used has a better voltage transient response than PI control without using a current sensor.