Hillcrest Energy Technologies completed proof of concept testing that demonstrates the elimination of switching losses with its traction inverter. A comparison of losses between soft-switching and hard-switching was calculated by Hillcrest. The system was tested with 470V DC-link voltage under 5A load with 20kHz switching frequency.

The Hillcrest inverter achieved an average of more than 90% fewer switching losses and a roughly 90% reduction in dV/dt compared to the conventional, hard-switched inverters found in many EVs. The company includes details of the soft-switching testing and results in an update of its previously released technical whitepaper available for download at the Hillcrest website. While previous testing had confirmed the efficiency of total inverter losses, the new tests looked specifically at the efficiencies gained via Hillcrest's mastery of soft-switching.

Electric motors currently used in EV powertrains operate within a switching frequency range of 8kHz to 16kHz, due to the historic trade-off between the best possible switching behavior and acceptable thermal losses. The ability of the Hillcrest high-efficiency inverter to soft-switch at much higher frequencies without generating additional losses will allow motor manufacturers to take advantage of new motor concepts not previously available to them. Leveraging the Hillcrest traction inverter in an EV powertrain is intended to improve overall system-level performance.

A system with higher power density, lower cost and weight, and better power quality and performance could play an integral part in delivering a vehicle with more power, more payload capability and increased range.