Emerging electronics applications require electric motor designs that squeeze higher performance from ever more compact platforms. Designers are hard-pressed to meet the new requirements with motor driver circuits based on traditional silicon MOSFETs and IGBTs. As silicon technology reaches theoretical limits for power density, breakdown voltage, and switching frequency, it gets tougher for designers to contain power losses. The main effects of these limitations are sub-optimal efficiency and additional performance problems at high operating temperatures and high switching rates.

The development of gallium nitride technology has ushered in a new age for power electronics. The greater bandgap, critical field, and electron mobility are the three factors that affect GaN technology the most. To concentrate on expanding motor drive applications based on GaN technology in the e-mobility, robotics, drone, and industrial automation areas, EPC has opened a new design application center close to Turin, Italy.

In an interview, Marco Palma, director of motor drive systems and applications at EPC, discussed the importance of helping EPC customers worldwide to design new generations of motor systems that can take advantage of GaN technology.

“The mission is to reduce power waste in every motor application,” Palma said. “We decided to install the lab in Turin due to the historical industrial reputation in the automation world, and we immediately started our collaboration with the Power Electronics Innovation Center [PEIC] at the Politecnico di Torino. The PEIC is an inter-departmental center and can offer all types of know-how that is required today to design a modern automotive or industrial system. We started with motors in e-mobility and in drones, and we will expand more into integrated circuit design to enhance our portfolio to further extend the application coverage. Unpredictable disruptive solutions come out whenever a new technology gets adopted.”

The experts at EPC are assisting clients in shortening their design cycles and using GaN for more effective, more compact, and less expensive solutions. Additionally, the center is looking at how to use the potential of EPC’s GaN technology in motor drive applications to allow a significant improvement in the motor’s efficiency, leading to higher-power–density designs than what has previously been achieved with MOSFET-based designs.

“The motor control market is multi-disciplinary, so it will require more and more electric, electronics, and firmware engineers,” said Palma. “GaN technology is also inherently an integrated-circuit technology, so micro-electronic engineers will also be required. Wherever size, dimensions, and efficiency matter, GaN will be an important technology. I am thinking about all battery-operated machines that have batteries in the range between 36 V and 96 V: They can immediately [benefit from moving] to GaN technology.”

New design for motor control

GaN technology is a part of the power electronics industry’s wide-bandgap semiconductor revolution. According to Palma, most of the power electronics currently based on silicon in the electric vehicle will transition to GaN technology. “This is thanks to the inherent integration capability that GaN offers because it is a lateral technology,” said Palma. “You can always integrate part of the control with the GaN power switches, while you cannot do it with other technologies.”

GaN FETs outperform traditional silicon-based power devices in several aspects, including the following:

• GaN’s breakdown field is over 10× higher than silicon (3.3 MV/cm versus 0.3 MV/cm), allowing GaN-based power devices to support voltage 10× higher before being damaged.

• Operating at the same voltage values, GaN devices exhibit lower temperatures and develop less heat. As a result, they can operate at higher temperatures than silicon, which is limited by its lower junction temperature (150°C to 175°C).

• Due to its intrinsic structure, GaN can switch at higher frequencies than silicon, has a low RDS(on), and has an excellent reverse recovery. That, in turn, results in high efficiency with reduced switching and power losses.

• Being a high-electron–mobility transistor, GaN devices have a higher electric-field strength than silicon devices, allowing for smaller die size and reduced footprint.

By: DocMemory
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