The unique properties of SiC devices enable substantial improvement of existing power conversion systems. SiC devices offer lower conduction and switching losses which increases converter efficiency. With high switching speed ability, employing SiC is expected to reduce weight and cost of conversion systems. This paper investigates the potential impact of SiC devices on renewable energy applications. 1. Introduction Renewable energy system designers have been striving to achieve higher efficiency and lower cost systems. These gains will translate directly into higher adoption of renewable energy sources. SiC devices offer, compared to silicon, a higher voltage devices with lower on-state resistance and faster switching speed. This boosts converter efficiency by reducing conduction and switching losses. For example, photovoltaic inverters can achieve smaller size, lighter weight, and more cost-effective designs utilizing SiC. For example, inverter based on SiC JFET and Schottky diode has achieved efficiency up to 99% [1]. With such developments, solar energy price can be brought to comparative price level with conventional energy source. The high efficiency and cost effective SiC-based solution also benefits other applications including wind power and hybrid vehicle. Along with SiC, GaN is another wide band-gap material that gained a lot of research interest in the last decade. GaN-based MOSFETs with extremely low on-resistance are already reported [2, 3]. These developments in wide band-gap transistors are expected to dominate the ever-growing renewable energy production systems in the near future. 2. SiC Technology and State-of-the-Art 2.1. Introduction Due to the high critical electrical field for breakdown, SiC devices feature higher breakdown voltage. This high critical electric filed (ten times higher than silicon) allows for thinner devices and thus lower on-resistance. Moreover, SiC has the capability of high-temperature operation without sacrificing the switching speed or significantly increasing conduction loss, all of which make them very potential in the high-power, high-voltage, high-frequency, and high-density applications. This fits the requirements of renewable energy applications. However, methods of driving some of these devices, for example, JFET, are different from the conventional Si-MOSFET or BJT. Therefore, the acceptance of this type of devices depends on the understanding of its switching behaviour and the ability to design a proper driving circuit. 2.2. SiC Devices Several SiC devices were demonstrated. Unipolar devices combine
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