All GaN-based multidevice interleaved boost converter structure for hybrid electric vehicles

Greenhouse gas emissions reduction requires an ongoing approach to decreasing the use of fossil fuels in global transportation. Due to their environmental friendliness, efficiency, quietness, and potential for long-term sustainability, electric vehicles (EVs) are a viable alternative to those powered by internal combustion engines (ICE). Despite the rising popularity of EVs, they still need significant advancements in areas such as cost, capacity, driving range, energy losses, and powertrain technologies in order to successfully compete with conventional vehicles. Therefore, advancements in power transmission in terms of architecture and effectiveness have been in the foreground of the scientific community for decades. Direct current to direct current (DC/DC) converters are one example of circuit components that can be optimized to reduce power consumption, thereby enhancing energy efficiency, decreasing size, and thus providing compactness. Miniaturization of circuitry, together with proper component selection and the use of lightweight structural materials, might result in cheaper, more responsive systems with improved reliability. Passive components such as inductors and capacitors play a crucial role in converter topologies that aim to smooth out input current and output voltage ripples, respectively. However, they are so large that they occupy the majority of the space reserved for the converter. Therefore, any effort to reduce the number of passive components used and their miniaturization represents a significant advancement for converter technology. Gallium nitride (GaN) and silicon carbide (SiC) are two examples of wide band gap semiconductor materials that are suited for designing state-of-the-art efficient power converter devices. These semiconductors' features, such as their large bandgap, high critical breakdown electric field, high thermal conductivity and higher electron velocity allow a considerable reduction in the size of passive components, shrinking the heatsink and an increase in the converter's power density. In this thesis, the 2010 Toyota Prius Si-IGBT-based boost converter topology was investigated and simulated with the help of PSpice simulation software. After that, this converter structure was reconstructed with a multidevice interleaved boost converter (MDIBC) topology with implementing SiC and GaN semiconductors, respectively. Two prominent case studies with varying switching frequencies were utilized to analyze the performance of the SiC-based and GaN-based MDIBC topologies in terms of power loss, efficiency, the size of the passive components, as well as the current and voltage ripples. In both cases, it was achieved lower values of the passive components despite the relatively reduced current and voltage ripples. In contrast to the higher efficiency results achieved with GaN-based MDIBC at all switching frequencies, SiC-based MDIBC resulted in lower values at 80 and 100 kHz compared to the benchmark converter. Proposed GaN-based MDIBC achieved higher efficiency than the benchmark converter by lowering ripple by 93.4% for current and 40% for voltage in the first case, and by 88.5% for inductor value and 97.92% for capacitor value at 100 kHz switching frequency in the second case. Keywords: current and voltage ripples, efficiency, hybrid electric vehicles, multidevice interleaved boost converter, SiC and GaN semiconductors