70 n STRAP July/August 2026 www.drivesncontrols.com Power semiconductor devices based on silicon carbide materials promise AC drives with improved efficiencies, higher switching frequencies and greater power densities. But are they going to replace regular silicon devices soon? Renee Ju, an analyst with Interact Analysis, examines the current state-of-play. Energy efficiency is a primary driver of innovation in low-voltage AC drives. This has been the case throughout the transition from thyristors to IGBTs, during widespread adoption of vector control, and now in a new phase of innovation centred on higher switching frequencies, power density, and system-level efficiency. Each pivotal breakthrough has been enabled by advancements in underlying power semiconductor devices. Wide-bandgap devices, especially silicon carbide (SiC), are entering the low-voltage AC drive market, which has long been dominated by silicon IGBTs. They offer more than a simple improvement in efficiency; they expand the design envelope. While SiC is unlikely to displace conventional devices in the near term, the technology is unlocking new possibilities for higher switching frequencies, greater power densities, and better optimised system architectures in lowvoltage inverter design. From a technology maturity perspective, SiC is not a new entrant. It has already been adopted widely in photovoltaic inverters and in new energy vehicles. However, its penetration into industrial drive systems remains relatively limited so far. But with ongoing advances in manufacturing processes, continuing cost reductions, alongside the growing demand for higher industrial energy efficiency, SiC devices are now starting to be used in LV AC drives. Conventional silicon-based power devices exhibit increasing switching losses and greater thermal management challenges when they are operated at high carrier frequencies. SiC devices, by contrast, can reduce switching losses significantly under high-frequency conditions, delivering superior performance and providing stronger hardware support for low-harmonic control. In practical applications, SiC components can cut energy losses at the device level. For motors, they can reduce harmonic distortion, helping to extend service lives. At the system level, simplified thermal management enables more compact designs and reduced auxiliary hardware costs, achieving simultaneous improvements in efficiency and power density. Considering performance matching and cost factors, the core value of SiC-based drives is currently most pronounced in niche applications which have demanding requirements, such as high-speed operation, high energy efficiency, and high power density. Such applications represent the most competitive near-term deployment scenarios for this technology. Two approaches There is currently no single standardised technical pathway for the adoption of silicon carbide in LV AC drives. Instead, two distinct engineering approaches have emerged: one is a cost-controlled, incremental approach; while the other is a full-SiC approach, aimed at maximising performance gains. Neither is inherently superior. Rather, they represent different engineering strategies tailored to specific market needs. n Hybrid SiC This refers to a configuration in which IGBTs are retained as the primary switching devices, while traditional silicon diodes are replaced by SiC diodes. Compared to conventional IGBT-based designs, this approach improves operating efficiency and power densities. Its key advantage lies in achieving a well-balanced trade-off between performance and cost. A example of this concept is Inovance Technology’s MD520HS drive, which is targeted primarily at highspeed applications for medium-to-highpower equipment in fluid-related industries. Inovance has adopted the hybrid SiC approach as an entry strategy, with a core rationale of prioritising scalability and commercial viability over peak performance. n Full SiC These drives employ silicon carbide devices both for their switching elements and for their diodes. This reduces losses and increases power density further. However, it also comes at a substantial cost premium. A representative player in this space is the emerging Canadian company SmartD Technologies, which is focusing on developing AC drives based on widebandgap devices such as SiC and gallium nitride (GaN). Its Clean Power variableA comparison of the benefits and drawbacks of various silicon and SiC drive architectures (Source: Interact Analysis) Silicon carbide: the future for LV drives?
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