Two-stage isolated AC/DC converter and its compound control strategy.

Area of Science:

• Electrical Engineering
• Power Electronics
• Control Systems

Background:

• Two-stage isolated AC/DC converters are crucial for new energy vehicles due to their simple topology and control.
• The front-stage Buck power factor correction (PFC) converter and rear-stage full-bridge converter are widely employed.

Purpose of the Study:

• To investigate and propose an enhanced control strategy for two-stage isolated AC/DC converters.
• To compare the performance of a novel compound control strategy against conventional PI control.

Main Methods:

• Detailed circuit analysis and component selection for the Buck PFC and full-bridge converters.
• Implementation of PI control for the front stage and parameter-adaptive terminal sliding mode control for the rear stage.
• Simulation analysis and experimental validation using a low-power prototype.

Main Results:

• The compound control strategy ensures optimal system regulation under various operating conditions.
• Experimental results demonstrate that parameter-adaptive terminal sliding mode control provides faster dynamic response and enhanced robustness.
• The proposed control strategy outperforms conventional PI control under identical load switching conditions.

Conclusions:

• The developed compound control strategy is effective for two-stage isolated AC/DC converters.
• Parameter-adaptive terminal sliding mode control offers significant advantages in dynamic performance and robustness.
• The study provides a valuable reference for engineering applications in the new energy vehicle sector.