Modelling and Control of Active Clamp Forward Converter with Centre Tap Transformer

ABSTRACT

This paper presents the small-signal model, controller design, open-loop, and closed-loop analyses of an active clamp forward converter with centre tap transformer (ACFCC). The centre tap transformer provides full-wave rectification at the secondary side of transformer to form a quasi-integrated topology. A clamp circuit comprises an auxiliary switch and a capacitor is used to recycle the energy stored in the transformer magnetizing inductor. However, due to the presence of the clamp circuit and the centre tap transformer, the active clamp forward converter exhibits a fourth-order power-stage dynamics. The circuit averaging technique is applied to extract the small-signal model of the power stage. Based on this model, frequency domain approach is used for stability analysis. The distinctive power-stage dynamics of the ACFCC is addressed and a feedback controller is designed accordingly. The small-signal model and experimental results with voltage-mode control applied to ACFCC are presented.

Keywords:

• Active clamp
• Forward converter
• Small-signal modelling
• Circuit average modelling
• Voltage mode control
• Compensator design

Additional information

Notes on contributors

Vijaya Sanjay Rajguru

Vijaya. S. Rajguru received the BE degree in power and electronics from Government College of Engineering Amravati and ME degree in electrical control system from College of Engineering Pune in the year 1989 and 1996, respectively. Since 2000 she is working as an associate professor in the Department of Electrical Engineering, Collage of Engineering, Pune. Her areas of interest include power electronics, control system, design, analysis and controller design of switching mode power converters and power factor correctors.

Bhalchandra Nemichand Chaudhari

B. N. Chaudhari received his BE and ME degrees in electrical engineering from Dr. B. A. Marathwada University at Aurangabad, in 1987 and 1991, respectively. He completed his PhD in 2001 from Indian Institute of Technology, Bombay. He joined Government College of Engineering Aurangabad in March 1990. Presently, he is a professor in electrical engineering at College of Engineering, Pune, India. His areas of interest are permanent magnet machines, power electronics, power quality and control of electrical drives.