Design and Control of a Bidirectional Dual Active Bridge DC-DC Converter to Interface Solar, Battery Storage, and Grid-Tied Inverters

In order to further reduce the size of today’s power converters, wide bandgap semiconductor technologies are being explored. These devices, such as silicon carbide (SiC), have been shown to outperform their silicon counterparts when used in high frequency switching, high temperature, and high voltage applications. These properties make them highly desirable in the bidirectional dual active bridge power converter. Being an isolated converter topology, the dual active bridge employs a transformer to provide step-up/step-down functionality and galvanic isolation for the converter. Transformers, as well as other passive components such as inductors and capacitors may be reduced in size when higher switching frequencies are employed. SiC devices used in this application can in turn provide a means to shrink overall system size and increase the power density of the converter, proving further the viability of power electronic systems in applications that require compactness and high efficiency. The aim of this thesis is to demonstrate the performance benefits of SiC MOSFETs in the dual active bridge topology. A justification for the choice of topology is included in this work, along with all of the appropriate design considerations and analysis, leading to the design of a 2kW dual active bridge converter. Modern modeling techniques are also explored and used to develop an enhanced digital controller, implemented in a DSP, for steady state reference tracking and load disturbance rejection. A demonstration of the designed converter verifies the analysis techniques explained therein