Sensorless Control of Dual-Active-Bridge Converter with Reduced-Order Proportional-Integral Observer

Abstract

When controlling a Dual-Active-Bridge (DAB) DC/DC converter, the high frequency terminal current is usually measured for use in the current feedback controller. In order to measure that current, a wide bandwidth sensor accompanied with high-speed amplifiers are required. Furthermore, a high Analog-to-Digital sampling rate is also necessary for sampling and processing the measured data. To avoid those expensive requirements, this paper proposes an alternative control method for the DAB converter. In the proposed method, the terminal current is estimated by a reduced-order proportional integral observer. A technique is also proposed to reduce the phase drift effect when the voltages at two terminals are not matched. Afterwards, a combined current feedforward-voltage feedback control system is developed to enhance the system dynamics and to regulate the output voltage. This control system needs only the information of the terminal voltages and no current sensor is required. Experimental results show that the observer can estimate the terminal current very quickly with the accuracy of more than 98%. In addition, the output voltage is well regulated with a fluctuation of less than ±2.6% and a settling time of less than 6.5 ms in the presence of a 30% load change.

Overview and Comparison of Modulation and Control Strategies for a Nonresonant Single-Phase Dual-Active-Bridge DC–DC Converter

“…Block diagram of CSC with estimated load-current feedforward [106]. some current sensorless control (CSC) strategies can also be used to solve this problem [105], [106]. A CSC with estimated load-current feedforward is proposed to improve the dynamic responses for the NSDAB dc-dc converter under the input voltage and load disturbances [106], and the core principle of this method can be expressed as follows:…”

Systematic analysis of control techniques for the dual active bridge converter in photovoltaic applications

“…The work reports the fuzzy rules for different perturbation types, which provide a robust performance to those perturbations. The same year, a control strategy based on state observers for avoiding sensor was proposed in Nguyen et al 51 In that work, a linear quadratic regulator (LQR) was designed to control the leakage inductor current and a PI controller for regulating V out . The article was focused on the efficiency of the observer in comparison with hardware measurements, where an error of 5.2 % was achieved in the experimental platform.…”

“…The article was focused on the efficiency of the observer in comparison with hardware measurements, where an error of 5.2 % was achieved in the experimental platform. Nguyen et al 52 proposed a LQR for regulating i LK and a PI controller to regulate V out , where those solutions were experimentally tested and contrasted with the previous work reported in Nguyen et al 51 In 2018, an optimal controller for a DAB converter on aerospace applications was reported in Lei et al 53 Such a controller was designed to control i LK , and it was implemented using a MATLAB toolbox and tested using an experimental platform obtaining higher efficiency compared with traditional solutions.…”

An improved closed loop hybrid phase shift controller for dual active bridge converter

“…Sort of an electrical device, it will be accustomed step down or step up a DC voltage supply. Control strategy is one of the important research directions for DAB-isolated bidirectional full bridge DC-DC converter (IBDC) [13]. The control strategies for dual active bridge (DAB) converters are introduced and analyzed in this section, and they are presented next:…”