Industrial motor drives power everything from collaborative robots and automated guided vehicles to pumps, compressors and factory automation equipment. Expected to operate continuously under demanding conditions for twenty years or more, these systems must balance efficiency, reliability, power density and increasingly sophisticated control requirements. Their operating profiles vary enormously, but designers face many of the same challenges. Wide-bandgap (WBG) technologies such as silicon carbide (SiC) and gallium nitride (GaN) provide new ways to address them.
Just as industrial applications encompass an extremely broad range of automation and robotics use cases, industrial motor drives cannot be grouped into a single application category. Operating profiles may range from sustained high-torque, low-speed operation to applications demanding high switching frequencies and rapid dynamic response. System requirements also differ dramatically between, for example, a compact servo drive operating at a few hundred watts and a multi-kilowatt industrial drive expected to run continuously for years.
Device selection therefore depends on where losses occur, and which system constraints matter most. Voltage rating, thermal management, switching strategy, control bandwidth and packaging all play a part. There is no single WBG solution for every design, but there are common strategies for exploiting the lower losses and faster switching capabilities of WBG devices.
Benefits of higher-performance motor drives
Higher-performance motor drives can deliver significant improvements in energy efficiency, process control and equipment productivity. By matching motor speed and torque more precisely to the actual load, advanced drives reduce unnecessary energy consumption, particularly in variable-load applications such as pumps, fans, compressors and conveyors. Improved control also enables smoother acceleration and deceleration, more accurate speed regulation and faster dynamic response, allowing processes to operate closer to their optimum conditions. The improved switching characteristics of WBG power semiconductor devices can be exploited in two main ways.
The first is to maintain the existing switching frequency while reducing inverter losses. This can be particularly important for high-voltage, low-power motors, where semiconductor losses may represent a substantial proportion of the total drive losses. In conventional IGBT-based drives, both switching losses and conduction losses associated with the collector-emitter saturation voltage VCE(sat) can make significant contributions. Reducing these losses directly improves drive efficiency and can also lower the thermal-management requirements of the inverter.
Alternatively, the improved switching performance can be used to increase the switching frequency instead. Unlike in power-supply design, where higher frequencies typically shrink magnetic components such as transformers and inductors, the relevant magnetic component in a motor drive is the winding itself. Higher frequency switching does indeed enable use of motors with lower-inductance windings, but generally motor selection is not a design variable for the drive designer. So, the benefit shows up as reduced current ripple and torque ripple rather than smaller magnetic components. Reduction of capacitance on the DC link may be possible due to the reduced ripple.
Balancing competing requirements
For high-power industrial drives operating at 600 V / S kW and above, sustained load operation often means conduction tosses dominate, particularly under high-torque condit ions. Regenerative braking can also int roduce significant voltage stress into the DC bus, while continuous operation places demanding requirements on thermal management and long-term reliability. In these applications, SiC MOSFETs offer a strong combination of voltage capability, stable RDS(on) performance over temperature and thermal
robustness.
At the other end of the spectrum, compact servo and motion-control systems place greater emphasis on switching performance. This is particularly true in low- and medium-voltage motor drives used in robotics, autonomous systems and emerging physical Al applications, where efficiency, power density and dynamic response are critical. Here, GaN FETs are well suited to designs using very high PWM frequencies for fast, precise control and compact system implementation. For higher voltage and power levels, SiC also offers an attractive balance between switching and conduction performance.
Packaging provides a further optimization lever. Through-hole TO-247-4 packages suit designs requiring direct heatsink mounting, generous creepage and clearance, and high RMS phase-current capability. For compact servo drives and integrated motor modules, D2PAK-7 SiC MOSFETs support automated surface-mount assembly and effective thermal management with metal-core or heavy copper PCBs. Where power density is the priority, X.PAK and QDPAK top-side-cooled packages can reduce thermal coupling to control electronics and support higher current density in confined enclosures.
Powering Industry 4.0 for the long haul
Wide-bandgap technology therefore gives motor-drive designers more options rather than a single universal solution. GaN can unlock very high switching frequencies where compact size and dynamic control are priorities, while SiC addresses the efficiency, voltage and thermal demands of higher-power industrial systems.
The opportunity is to use those characteristics selectively, matching the device technology and package to the motor, operating profile and control strategy. As industrial drives become more efficient, compact and sophisticated, that flexibility will become increasingly valuable, helping accelerate the Industry 4.0 revolution through more capable motor drives, robotics and industrial automation.
For more on Nexperia’s WBG portfolio, check out our Wide-bandgap semiconductors Technology Hub.