Industry

SiC and GaN for more efficient drives

WBG semiconductors not only save energy, they also enable miniaturised drives as are required in robotics.

A crucial twin challenge for industry is to improve energy efficiency and reduce carbon emissions - not just based on growing pressures from society and ever more stringent legal requirements, but also because energy is a major cost factor. Electric drives are a key factor in this context, as they account for around 70% of total electricity consumption in industry. According to the German Commission for Electrical, Electronic and Information Technologies (DKE), electric motors employed in European industry will have converted approximately 1,470 TWh into mechanical energy in 2020.

New ecodesign requirements

The European Commission set out requirements for the environmentally friendly design of electric motors in order to reduce that energy consumption as far back as 2009 in its Regulation (EC) No. 640/2009. Regulation (EU) 2019/1781 laying down ecodesign requirements for electric motors and variable speed drives, which comes into force on July 1, 2021, makes them even more stringent: It stipulates the use of IE3 or IE4 motors for specific applications, and for the first time also includes variable speed drives. It is estimated that the new Regulation will save an additional 10 TWh of electricity per year and reduce greenhouse gas emissions by 3 million tonnes of CO2 equivalent per year by 2030.

Energy saving with frequency-controlled drives

Frequency-controlled drives, in particular, offer great potential for energy saving, among other reasons because they ensure that an electric motor only delivers the power that an application actually needs. According to market research by Global Market Insights, 23 million frequency-controlled drives were installed in 2019 alone. More stringent energy efficiency directives and standards are pushing a steady rise in demand for frequency-controlled drives, with an average annual growth rate of 5 to 6% according to various analysts.

Wide-band gap (WBG) semiconductors can significantly improve the efficiency of frequency converters. They allow operation at much higher voltages and temperatures than conventional silicon. And their switching and conduction losses are lower. Power electronics based on silicon carbide (SiC) and gallium nitride (GaN) enable the design of smaller devices that work faster and offer higher efficiency.

More than just energy saving

WBG components in servo drives reduce power semiconductor losses by as much as 80%. This generally means that no cooling fans are needed - not only saving space, but also cutting operating costs, as the fans themselves would consume energy and require regular maintenance.

The converter itself can also be housed in a small form factor package thanks to the thermal and cyclical capabilities of SiC and GaN. This means that the number of drives or frequency converters in each cabinet can easily be doubled, which is an enormous advantage when production space is limited. Ultimately, the technology even enables the integration of motor and drive electronics, making it possible to miniaturise the entire drive system.

Miniaturised drives for robots

This results in drives that are both compact and powerful, and can be easily integrated directly into a robotic arm, for example, so the dozens of cables between the cabinet and arm can be eliminated. While the drive and power electronics for conventional servo drive systems must be accommodated in a separate cabinet, electronics based on SiC or GaN enable a “cabinet-free” system design.

So drive technology featuring power electronics based on SiC and GaN cuts energy consumption in industry while at the same time enabling more powerful and flexible, mobile and - last but not least - more cost-effective robotics.