Demand for miniaturization in power electronics systems has increased substantially. This trend is driven by applications such as electronic devices from consumer devices to electric vehicles that require smaller and lighter systems to improve their performance. However, efficiently reducing the size of power electronics systems is very challenging because of the limitations of today’s technologies. My research aims to develop power electronics systems that are miniaturized and efficient, and then apply these systems to a wide range of applications such as electric vehicles, robotics, medical devices, plasma generation and renewable energy systems. Furthermore, I extend the systems to provide wireless power transfer (WPT) to eliminate manual intervention during battery charging. An innovative contribution of my work is the use of wideband gap (WBG) devices such as silicon carbide (SiC) MOSFETs or enhancement mode gallium nitride (eGaN) FETs to reduce the size and weight of the entire WPT system and improve system performance.