H3X launches HPDM-30 high power density electric motor
Targeting urban air mobility markets and featuring an additively manufactured synergistic cooling jacket

H3X, a company building the lightest electric propulsion systems for aviation and the urban air mobility market, officially released its latest product, the HPDM-30. This is a 33kW integrated motor drive that weighs only 4.1 kg and features a 3D printed synergistic cooling jacket, optimized for weight reduction via DfAM. The HPDM-30 motor has already been built and tested up to 33kW continuously on the company’s in-house dyno and the first articles are now being shipped out to customers in the aerospace and defense markets.
The HPDM-30 is a high power density integrated motor drive with a continuous power rating of 33 kW and a mass of only 4.1 kg. The motor utilizes the same core technology as the previous HPDM-250, combined with a new discrete SiC FET inverter running an in-house developed self-sensing rotor position algorithm.
The HPDM-30 has a peak-specific power greater than 10 kW/kg and can be used as a motor or generator. Finally, the unit can be stacked axially to form 66kW and 99kW machines. There are a number of key enabling core technologies that made this unit possible, including the additively manufactured synergistic cooling jacket and extremely tight integration between the motor and inverter. The cooling jacket is one of the most critical cooling components for e-motors on the market today.
H3X came out of stealth in April 2021 rasing $3.8M in seed funding led by Metaplanet, with participation from Soma Capital, Liquid2 Ventures, Psion Capital, Infinite Capital, Pegasus Tech Ventures, Lombardstreet Ventures, Tamar Capital, Zillionize, Asymmetry Ventures, and notable angels. This cam shortly after an investment from Y Combinator as part of the Winter 21 batch.
The company is building the lightest electric propulsion systems in the world for aviation and the urban air mobility market. This is a key enabling technology for long-range electric flights that are currently not possible. The company believes that we are on the cusp of a revolution in the aviation industry, with short-haul flights soon to be dominated by electric airplanes, which not only enable zero-emission air travel, but also reduce fuel and maintenance costs by up to 75%.
However, for electric aircraft to be commercially feasible, substantial improvements need to be made to electric propulsion system technology. Today, best-in-class motors and inverters have a combined power density of 3-4 kW/kg. ARPA-E has determined that for a Boeing 737 to complete a typical five-hour flight, the propulsion system must be >12 kW/kg continuous.
At 12 kW/kg continuous, H3X’s HPDM exceeds ARPA-E’s requirements and is at least 3X better than current systems. It is a step change in electric propulsion technology and removes one of the main barriers blocking widespread commercialization of electric aircraft. The HPDM products can be used to power any mass-sensitive, packaging-constrained, or high-performance application.
HPDM-250 applications include eVTOL urban air mobility, military aircraft and vessels, electric boats, e-racing, power generation. A new, more powerful motor, the HPDM-3000 will be targeted at large commercial electrified aircraft, electric ships and ferries, as well as power generation.

H3X unveiled the HPDM-3000 concept prototype in late 2022 at the Interferry Conference in Seattle, Washington. This is a full-scale concept prototype that was built to capture the imagination of the marine and aviation industry and show them what is possible with H3X scalable and advanced core technology.
The HPDM-3000 is an ultra-high power density MW-class Integrated Modular Motor Drive (IMMD) for primary propulsor applications on large electric aircraft and ships. Based on the same core technology as the H3X HPDM-250, this EPU has a continuous specific power of >12 kW/kg and features the highest level of fault tolerance and reliability with its 12 independent drive sectors. While the power density of the “high-tech” HPDM-3000 is substantially better (10x-100x) than current marine motor/drive solutions, it is actually quite cost-competitive due to its diminutive size and lower raw material costs.
H3X is now targeting to have HPDM-3000 prototypes available for initial testing in Q1 2024. The company is seeking customers in the marine and aviation space to partner with to develop this unit.