Driving system

A drive system for generating propulsive force of a railway vehicle, the drive system comprising:

• a synchronous reluctance motor to rotate in response to feeding of electric power and thereby generate the propulsive force of the railway vehicle;
• power converting circuitry comprising switching elements and freewheeling diodes each connected in parallel to a corresponding one of the switching elements, the power converting circuitry being connected directly to the synchronous reluctance motor and configured to convert electric power fed from an overhead wire or third rail into electric power to be fed to the synchronous reluctance motor and feed the converted electric power to the synchronous reluctance motor;
• and
• controlling circuitry to control the switching elements included in the power converting circuitry, wherein
• at least either of the switching elements or the freewheeling diodes comprise wide-gap semiconductors,
• the power converting circuitry is connected to the synchronous reluctance motor, without a switching circuit therebetween, by direct connection that is a connection via a conductor only or a connection via a conductor and a passive element, and
• wherein the controlling circuitry generates gate signals for the switching elements, on a basis of comparison between modulated waves and a carrier wave, the modulated waves being associated with voltage command values for achieving a target torque of the synchronous reluctance motor, the carrier wave having a frequency increasing in accordance with acceleration of a rotational speed of the synchronous reluctance motor.