Generalized PWM generator with transformer flux balancing for dual active bridge converter

For Dual Active Bridge (DAB) converters a large number of modulation schemes exist, which allow to operate the converter in a wide voltage/power range at a very high efficiency. However, the implementation of these modulation schemes and the transition between the schemes during transient conditions is relatively complicated. Therefore, a simple and flexible concept for generating the PWM signals of the eight switches for all possible modulation schemes and also transient conditions is presented in this paper. The concept is validated by Simulink/Plecs co-simulations for a single module of interleaved DC-DC converter system designed as a battery interface for high power drive systems.