Hillcrest Energy Technologies Ltd. has completed the first commercial prototype of its Zero Voltage Switching (ZVS) traction inverter, which the company said is lighter, faster and more efficient than traditional inverters.

“It's been a good year. The commercial prototype is in hand, it's performing exactly as we hoped it would be,” said Don Currie, Hillcrest’s CEO. 

In an electric vehicle (EV), a traction inverter takes the high-voltage direct current (DC) electricity from batteries and converts it into alternating current (AC) electricity for the motor.

Hillcrest’s 800-volt, 250-kilowatt ZVS inverter technology can be applied to batteries, electric motors, generators, fuel cells or any other power source where power conversion is needed.

Two white papers about the inverter show its efficiency exceeds 99.4 per cent at 60 kHz, with improvements in motor efficiency of up to 13 per cent.

It can reduce the size and weight of DC-link capacitors by up to 50 per cent. Capacitors usually make up 20 per cent of an inverter's size and weight.

Founded in 2006 and headquartered in Vancouver, Hillcrest (HEAT-CN) develops control systems and electric power conversion devices for electric vehicles.

The ZVS inverter

In March, SustainableBiz reported on Hillcrest completing the design for the silicon carbide inverter.

Work on the inverter began in the summer of 2021 between Ari Berger, Hillcrest’s CTO, and the company’s partner, Systematec GmbH of Landsberg am Lech, Germany. At the time it was referred to as the high efficiency inverter.

Systematec has over 25 years of experience in drive-train engineering for hybrid and electric vehicles.

“The reason this technology is so exciting is that usually, you would get higher performance (with different inverters), but . . . it would cost more,” Berger told SustainableBiz at the time. “It would be bigger and so on. That’s not the case with this technology.”

While the new technologies are wholly owned by Hillcrest, Systematec has rights to future revenues and commercial properties. Berger credited the company’s involvement in fast-tracking development of the inverter by “several years.”

“The two big streams are traction inverters, and then grid connect,” said James Bolen, Hillcrest’s chief commercialization officer. “So the next steps are enhancing performance, working on more detailed platforms for packaging . . . expanding the scope in order to include other functionality.

"This is the kind of thing that never ends.”

The cost of the traction inverter will depend on the customer, including what model it is being applied to or how many are needed. However, he believes it will be equal to, or slightly less expensive, than currently available inverter technology.

Currie said Hillcrest aims to have a grid inverter proof of concept ready by the end of the Q2 2023. Then it hopes to have a proof of concept for its enhanced power train solution by Q4 2023, and for its multi-level inverter by Q1 2024, all based around its established ZVS technology.

Hillcrest's partnerships

In October, Hillcrest signed a memorandum of understanding (MOU) with Detroit-based Hercules Electric Mobility Inc., as well as a separate MOU with a global automotive designer. Both involve implementing the inverter technology in electric powertrains, on track for Q2 2023.

The patent-pending enhanced power train solution will essentially be a bidirectional powertrain for EVs, capable of taking from the grid and giving back to it. It would remove the need for EVs to have an onboard charger, which could remove charging losses of up to 14 per cent.

Meanwhile, the multilevel system will be focusing on larger energy systems. 

“Because we're a bit ahead of schedule on some of our development stuff towards grid connect, we're probably gonna have some partnerships directed solely for the grid connect market sooner rather than later,” Bolen said.

The plan is for field trials by Q1 2024.

While he wouldn’t reveal specific partnerships, the first test of Hillcrest’s grid-connected inverters will be in connecting solar and wind farms to the grid. The company is to start formal discussions with a European wind company in the first quarter of next year.

Company data shows its wind partnerships will likely be more Canadian-focused and its solar partnerships will largely be U.S.-based.

The same presentation states the global power inverter market will be worth approximately $129.3 billion by 2028, and the global EV inverter market will be worth about $15.6 billion by 2027.

Potential markets in the future

The company is open to partnerships in other industries.

“There's application specific development to do, but marine would be a good example. There's a potentially big market application there. The other one might be island generation like (with a) village,” Bolen said. “We've already had conversations with a number of people about that.

"Those just aren't as close up on our radar as some of the other ones.”

Bolen also discussed the potential of incorporating energy storage, particularly for wind and solar developers, and how Hillcrest’s grid-connected inverters would work with that given the move to higher frequencies and voltages.

“We'd like to think of ourselves a little bit like a really high-end NFL quarterback where, when you throw in a pass to a really fast receiver you don't throw it where he is, you throw it where he's going to be,” Bolen said.

“So we're getting great customer input, and then we're trying to hit where they're going to be.”