Northvolt partners with two Swedish municipalities for European Li-ion gigafactory
ICCT study finds GHGs from shipping on the rise

Visedo introducing new SRPM motor design for buses; 10% increase in power, better cooling

Finnish manufacturer Visedo is unveiling a new electric motor design at BusWorld 2017 that is optimized for the bus market and ready for mass manufacture. With the new S-model PowerDRUM, Visedo has achieved a 10% increase in power output as well as better cooling. Visedo says that the upgrades enable it to offer the highest efficiency in the market across the RPM range, with the Visedo system being 31% more efficient than average.

The new S-model is part of a design upgrade across the entire PowerDRUM line. The upgraded range includes motors in 4 different sizes: XS-short, XS, XSe and S, ranging from 50 to 343 kW. The whole range will benefit from better cooling and a 10% increase in power output.

Visedo’s drivetrains are based on synchronous reluctance assisted permanent magnet technology (SRPM). They are liquid-cooled and designed to work as traction motors in harsh operating environments.

SRPM technology combines the benefits of PM and synchronous reluctance technology, and features increased torque capability over a wide speed range and the ability to produce torque to higher speeds. Machine efficiency at lower speeds is also good.

The supply current to the machine stator windings create a rotating magnetic field, which in turn rotates the rotor containing permanent magnets. In the synchronous permanent magnet machine, the rotation of the rotor (shaft) is synchronized with the frequency of the power supply current. The reluctance technology maximizes the pull­out torque of the machine.

Compared to conventional technologies such as induction machines (IM) or standard permanent magnet motors (PM), Visedo SRPM motors offer smaller dimensions, lighter weight and higher efficiency.

PowerDRUM S Click to enlarge.

The new design allows Visedo to deliver several key benefits to its customers in the electric bus market:

  • The compact and robust design saves space while ensuring high vibration and shock tolerance.

  • The high efficiency will increase battery life while shortening recharge cycles.

  • The new PowerDRUM S-model also improves hill-climbing ability.

The new design is also optimized for high volume manufacture using Visedo’s facilities in both Finland and Taiwan. This will allow the company to meet growing customer demand in Europe and Asia. Earlier this year, Visedo signed a production and cooperation agreement with TECO, Asia’s largest electric motor producer. (Earlier post.)

The company has PowerDRUM projects underway with Linkker in Finland (powering Helsinki’s first all-electric buses) and Hybricon Bus Systems in Sweden. Visedo recently started a project with Ledgent Technology in Taiwan, and further announcement in the Chinese, Asian and South-East Asian markets are expected in coming months.



This seems like a win-win e-motor to increase range of electrified vehicles operating in harsh environment.

Asian EVs manufacturers will certainly make good use of it and produce it locally at lower cost?

How does it compare with other e-motors in the same field?


Electric motors operate with efficiencies of over 90% over a large part of the map, so the claim of "31% more efficient than average" is suspect. If one were to significantly understate the efficiency to 75%, a 31% improvement would yield 98.25%, yet another implausibility.


Very curious. And along with that 31% it gives 10% more power - than what? an air cooled motor? a low(er) power density machine?

You make the point that efficiency does vary across operating speeds and power.

One way to justify these number would be to say 31% decrease in losses.

Then if losses are av 10%, a 31% 'improvement' is a 3.5% efficiency increase.

I'm constantly amazed at these sort of claims that just don't sound plausible only to find that on a closer reading the claims can be justified.

At the same time we find high public acceptance of language being distorted to the extent that it describes the opposite of its definition
No wonder we get confused.


90% is peak efficiency, they can be 30% during high current loads at take off, pulling loads or climbing grades.


Assuming that these improved e-motors can transfer 10% more mechanical power than the current best e-motors, range would be extended by about equivalent percentage.

Being lighter and liquid cooled it could supply free heat for the passenger cabin. This could further increase range between recharges.

This could be a winner, specially if mass produced at low cost in China and/or Mexico?


"..PM and synchronous reluctance.."
This is unique, but if they use rare earth element magnets, supply could be an issue.

The comments to this entry are closed.