Full-Bridge Converter

In the previous chapter, we examined power converters with two controllable power devices, and thereby introduced the concept of coordinated switching of controllable devices. Subsequently, we introduced the single converter leg comprising of two controllable devices and their associated anti-parallel diodes, and examined how such a converter leg can be used a fundamental building block for other power converters. We used simple permutations and combinations to examine the different switching combinations possible, and also were able to conclude that it would not be permitted to turn ON both controllable devices in the leg to avoid short-circuiting the dc bus. Using the examples of buck, boost, buck-boost and the half-bridge converter, we examined different conduction modes of the converters and devised PWM strategies in all cases.