The future of industrial automation is efficiency. If we can improve the efficiency of the electronics powering smart factories, we can make big reductions in carbon emissions, as well as decreasing usage costs. This begs the question: where are the biggest opportunities?
Electric motors, the best bet for power savings
The answer is clear, if not quite as glamorous as electric vehicles or high-tech solar panels: it’s the humble electric motor, and the associated drive systems. According to the IEA, electric motors and motor systems in industrial and infrastructure applications account for 53% of total global electricity consumption, which in 2023 amounted to circa 29,500 TWh.
LOOKING FOR SUPPORT? CONTACT OUR POWER EXPERTS
In fact, electric motors represent the single biggest opportunity for energy savings by improving power electronics efficiency. Studies show that moving from silicon insulated-gate bipolar transistors (IGBTs) to wide bandgap (WBG) semiconductors, such as silicon carbide (SiC), could save more than 120 TWh of electricity per year.
A large part of this amount consists of 103 TWh worth of savings achieved by using SiC in industrial variable speed drives (VSDs). This includes fans, pumps and compressors, which make up around 75% of drives in use worldwide. The 103 TWh figure was calculated by industry body PECTA, and uses an estimate that typical inverters today can achieve around 93% efficiency with silicon, and 98% with SiC – so the difference in efficiency is around 5%.
Hence, the overall energy savings are calculated based on the improvements in efficiency. This calculation only includes electric motors that are sold with a VSD; however, the energy savings could be further increased if the current VSD adoption rate of 30% was increased.
Potential energy savings with WBG semiconductors in different applications (source - IEA 4E)
Motor drives, their needs, and the use of wide bandgap
Using a DC power supply, an electric motor is powered by the conversion of DC to AC by the inverter power devices of a motor drive. Many such drives are variable speed drives (VSDs), which enable the frequency of the AC signal, and hence the speed of the motor, to be electronically controlled. This means the operation of the motor can be matched to the needs of the application, thus saving energy and improving the motor’s effectiveness – for example, to optimise process control, or to provide a smoother start and stop.
The most common technique used in VSDs to create the AC output is pulse width modulation (PWM), where the transistors in the inverter are switched on and off rapidly to generate the required output waveform, with the desired frequency and voltage. For these transistors, motor drives require semiconductor devices that are highly efficient, compact, reliable, and competitive on cost.
To meet these requirements, SiC devices offer some key advantages when compared to Silicon IGBTs. SiC devices have high breakdown voltage, high thermal conductivity, low on-resistance and excellent recovery behaviour. This enables them to operate at high switching frequencies – hence significantly reducing switching losses – and at higher operating temperatures. Their lower losses and good thermal performance reduce heat sink and cooling requirements, enabling smaller systems with improved power density.
One potential challenge is that running at high switching frequencies can cause increased electromagnetic (EMI) issues. This can be avoided by operating SiC-based inverters at frequencies between 10 kHz and 30 kHz.
GaN and IMDs, additional options for industrial automation devices
Another WBG material that shows great promise for electric motor drives is Gallium Nitride (GaN). GaN devices can be switched at ultra-high frequencies in the MHz range, and provide high efficiency in a compact package. However, GaN devices have limited breakdown voltage and low current ratings, which limits where they can be used.
Another approach for engineers looking to use WBG materials in industrial automation applications is to use an integrated motor drive (IMD), where the inverter and its power electronics are housed in the same enclosure as the motor. This is enabled by the high efficiency, compact size and high temperature capability of WBG devices. Additionally, by operating at high frequencies, the size of the required inductors and capacitors can be reduced.
By eliminating the need for cables between the drive and the motor, an IMD can significantly reduce EMI issues, and removes the requirement for an output filter that would otherwise be needed on the cable. Another benefit IMDs bring is their smaller footprint than a traditional, separate drive and motor. Additionally, integrating the motor and drive can reduce the time required for system manufacturing and testing.
Technology
Power: designing solutions with power at the core
We provide you with the right insights and expertise when you need it most, so you can make the right decisions for your product, and your business.
We cover all of the bases for designing, building and getting your industrial application to market. Let us put our experience developing long-life applications to work for you.
SMART INDUSTRYPowering industrial automation together
Using the best semiconductor for power devices, and choosing the right design, can make a significant difference to the energy efficiency of a motor drive and, implicitly, of a smart factory. WBG materials can deliver big power savings, as well as enabling compact, reliable power systems. Whatever your needs, get in touch with our experts to find out how we can guide you in choosing the right solution for your industrial automation applications.
Working on a power project?
Our experts bring insights that extend beyond the datasheet, availability and price. The combined experience contained within our network covers thousands of projects across different customers, markets, regions and technologies. We will pull together the right team from our collective expertise to focus on your application, providing valuable ideas and recommendations to improve your product and accelerate its journey from the initial concept out into the world.
Like what you see?
Follow us on LinkedIn
Follow our dedicated power page on LinkedIn for the latest power updates and news from our team of power experts.