Adaptive Extended State Observer for the Dual Active Bridge Converters.

Area of Science:

• Electrical Engineering
• Control Systems
• Power Electronics

Background:

• DC-DC dual active bridge (DAB) converters are crucial for bidirectional energy transfer and integrating renewable energy sources.
• Extended state observers (ESO) enable output voltage regulation in DAB converters without current sensors, reducing system costs.
• High observer bandwidth in ESO improves tracking but degrades disturbance suppression, while low bandwidth offers the opposite.

Purpose of the Study:

• To propose an adaptive extended state observer (AESO) that optimizes the trade-off between tracking performance and disturbance suppression for DAB converters.
• To enhance the control of DAB converters by dynamically adjusting observer bandwidth based on system error.

Main Methods:

• Development of an adaptive extended state observer (AESO) for DAB converter voltage regulation.
• Dynamic adjustment of observer bandwidth: increasing for high voltage errors to boost tracking, decreasing for disturbance rejection.
• Comparative analysis using simulations and experimental validation against fixed-bandwidth ESO and improved model-based phase-shift control (MPSC).

Main Results:

• The proposed AESO demonstrates a superior compromise between tracking accuracy and disturbance suppression compared to fixed-bandwidth ESO.
• AESO effectively manages system dynamics under varying operating conditions and disturbances.
• Validation through simulations and experiments confirms the effectiveness of the AESO method.

Conclusions:

• The adaptive extended state observer (AESO) offers an effective solution for enhancing the control performance of DC-DC dual active bridge (DAB) converters.
• This sensorless control strategy reduces system complexity and cost while maintaining robust performance.
• The proposed method provides a valuable advancement for renewable energy integration and power management systems.