Permanent Magnet
Synchronous Motor

Toshiba started developing the PMSM system in the early 1990s. Utilising data accumulated through R&D and field tests, Toshiba established the PMSM main circuit system technologies for railway cars.


The most strong point of PMSM system is High efficiency. There is no secondary copper loss, decreased primary copper loss, iron loss and others. Overall loss, drastically reduced to less than 50% compared to induction motor.


Key Features

  • Energy

  • Reliability
  • Low

  • Easy





High Efficiency

* 1The motor efficiencies were calculated with loss measurement based on IEC
60349-2 at the temperature below 40oC from 8/25/2009 to 9/25/2009 for PMSM.

Energy Savings

** This graph compares the energy consumption measurement result on the following condition.

Trains used:

  • C151 PMSM train:

    EMU131/132 of SMRT fleet which equips PMSM propulsion system

  • C151 Existing train:

    EMU 109/110 of SMRT fleet which equips DC motor propulsion system

  • Duration:

    7th Dec 2015 to 11th Dec 2015 (Total 5 weekdays)

  • Running pattern:

    These 2 trains were used in commercial operation and they run in a series as possible as diagram allows.

Service Uptime

C151 PMSM Train Running Mileage

Since the introduction of C151 PMSM prototype train (2 train-sets) in July 2015, C151 PMSM trains (total 6 train-sets) keep to run with no service disputation disruption.

Easy Maintenance

Toshiba has developed a totally-enclosed structure to make maintenance operations smarter compared to our conventional Induction Motor (IM) in terms of cost and time. We have succesfully eliminated potential internal contamination, which makes cleaning no longer required through the PMSM’s service life. We have also engineered a structure allowing the bearing unit to be replaced without disassembly of the entire motor.