Hillcrest Energy Technologies, a clean technology company developing transformative power conversion technologies and control system solutions for next-generation electrical systems, has completed initial internal testing of its high-efficiency inverter with an electric motor and will release the results in an upcoming whitepaper.
Internal tests announced previously have already confirmed the ability of the Hillcrest inverter technology to achieve efficiencies exceeding 99% at switching frequencies up to 60 kHz.
New tests were performed using the 10 kW Hillcrest high-efficiency inverter proof of concept on an 80 kW electric motor currently used in EV powertrain applications. After running efficiency tests on the motor to establish a performance baseline at the 10 kHz switching frequency, the same tests were run at 20 kHz, 40 kHz, and 60 kHz. Results showed motor efficiency improvements at each increased switching frequency level, confirming the ability of the Hillcrest technology to leverage higher switching frequencies without generating additional losses/heat, thereby enabling the electric motor to operate at higher efficiency levels.
“Currently, electric motors used in electric vehicle powertrains operate within a switching frequency range of 8 kHz to 16 kHz due to the historic trade-off between the best possible switching behavior and acceptable thermal losses,” said Harald Hengstenberger, managing director and founder of Systematec GmbH, a strategic partner to Hillcrest and current power electronics design house to the German automotive industry. “The ability of the Hillcrest high-efficiency inverter to operate at much higher switching frequencies without generating additional losses will now allow motor manufacturers to take advantage of new motor concepts not previously available to them.”
Leveraging the Hillcrest traction inverter to improve motor efficiency in an electric vehicle powertrain has the potential to reduce the motor size and cooling requirements and increase power density. In an electric vehicle, this can result in more power, more payload capability, and increased range.
“We are thrilled to see these initial tests not only validate but exceed our expectations in demonstrating the ability of the Hillcrest traction inverter to increase the efficiency in electric vehicle and motor applications,” said Hillcrest Energy Technologies CTO Ari Berger. “Combined with our existing test results confirming inverter efficiency exceeding 99% at switching frequencies up to 60 kHz, we are one step closer to demonstrating the ability of our technology to anchor the next generation of highly efficient, high-performance powertrain systems.”
The successful tests completed thus far with the Hillcrest proof of concept are the first steps in the commercialization testing protocol. Testing of the Hillcrest 250 kW 800 V commercial prototype inverter will commence in the coming months with the delivery of a working prototype expected this fall.
While this specific testing demonstrates Hillcrest’s efficiency targets in the EV powertrain application, the results indicate a similar potential for other target applications, such as grid-tied renewables, charging and storage systems, and other high voltage/high power applications. As the world moves towards clean energy and electrification in a variety of sectors, these systems must be as efficient as possible. Future testing will be tailored to these additional applications.
