A railway-vehicles scalable tractive power system, integrated into all-wheel steering and braking systems to leverage synergies between plurality of differently designed electric traction-motors, electric steering motors and electric brake calipers; configured with plurality of sensors to eliminate wheel-dragging at virtually 100% dynamic efficiency. A fully automated electronic clutch-system attached to selected electric traction motors configured to perform above 90% traction efficiency by coupling to wheels selected electric traction-motors in their high efficiency range of operation, or de-coupling and replacing electric traction-motors with another electric traction-motors while the vehicle is changing speed or when it requires higher or lower tractive-power, from forward-motion start to top-rated speed. A holistic controller is configured with multi-objective optimization design (MOOD) procedures; measures complex variable parameters and values, finds the required trade-off among design objectives, and improves pertinence of solutions. Plurality of electronic-couplers is monitoring changing distance between wagons, whereas the controller is maintaining optimal ‘free-slack’ between wagons to prevent ‘run-in’ and ‘run-out’ scenarios with precise maneuverability between electric traction-motors actuation and electric brake-calipers actuation.

In a motion guiding device including a track body, and a moving body provided to be movable along the track body, the track body includes a groove formed along a longitudinal direction of the track body and a plurality of rolling surfaces formed inside and outside the groove. The moving body includes a plurality of rotating bodies that roll on the plurality of rolling surfaces, and adopts a configuration in which respective contacts in which the plurality of rotating bodies are in contact with the plurality of rolling surfaces are disposed on the same straight-line in a cross-section orthogonal to the longitudinal direction of the track body.

This semiconductor device according to an embodiment includes: a silicon carbide layer; a gate electrode; a silicon oxide layer between the silicon carbide layer and the gate electrode; and a region between the silicon carbide layer and the silicon oxide layer and having a nitrogen concentration not less than 1×10.sup.21cm.sup.−3. A nitrogen concentration distribution in the silicon carbide layer, the silicon oxide layer, and the region has its peak in the region, and a state density Z.sub.1/2 in a portion is not more than 1×10.sup.11cm.sup.−3. The portion is within 100 nm from the silicon oxide layer toward the silicon carbide layer. A nitrogen concentration and a carbon concentration in a position 1 nm from the peak toward the silicon oxide layer is not more than 1×10.sup.18cm.sup.−3, and a nitrogen concentration in a position 1 nm from the peak toward the silicon carbide layer is not more than 1×10.sup.18cm.sup.−3.

A drive system for a rail vehicle includes a plurality of drive motors. The drive motors include at least one permanent magnet motor and at least one asynchronous motor and/or at least one reluctance motor. A rail vehicle having wheelsets, each of which includes two oppositely disposed wheels and which are driven at least partially by the drive system, is also provided.

A drive system for a rail vehicle includes a plurality of drive motors. The drive motors include at least one permanent magnet motor and at least one asynchronous motor and/or at least one reluctance motor. A rail vehicle having wheelsets, each of which includes two oppositely disposed wheels and which are driven at least partially by the drive system, is also provided.

A first bearing box has, in one end face perpendicular to a direction along a rotor shaft and farther from a fan, an air outlet for air taken in through an air inlet to exit. A flow channel is defined between an outer peripheral surface of a cylindrical portion of the first bearing box continuous with the end face and a frame. A value obtained by dividing a distance between an outer periphery of blades in the fan and the air outlet by an outer radius of the blades is greater than or equal to a threshold.

A first bearing box has, in one end face perpendicular to a direction along a rotor shaft and farther from a fan, an air outlet for air taken in through an air inlet to exit. A flow channel is defined between an outer peripheral surface of a cylindrical portion of the first bearing box continuous with the end face and a frame. A value obtained by dividing a distance between an outer periphery of blades in the fan and the air outlet by an outer radius of the blades is greater than or equal to a threshold.

A method for monitoring the on-board battery of a rail vehicle. The state of charge of the on-board battery is regularly ascertained in an automated manner and is compared with a desired state of charge value. In case the ascertained state of charge value drops below the desired state of charge value, a message is generated for initiating measures for charging the on-board battery.

A method for monitoring the on-board battery of a rail vehicle. The state of charge of the on-board battery is regularly ascertained in an automated manner and is compared with a desired state of charge value. In case the ascertained state of charge value drops below the desired state of charge value, a message is generated for initiating measures for charging the on-board battery.

A vehicle control device includes a power converter that converts supplied direct current power and supplies the converted direct current power to a load device. A first voltage detector detects a first voltage that is a voltage of the power supply line. A second voltage detector detects a second voltage that is a voltage of the power converter on a side where a power supply source is provided. When a first contactor is closed and brought into a state allowing current to flow through the first contactor, if a decreasing amount of the first voltage from a first time ago to a present time is greater than or equal to a first threshold and a decreasing amount of the second voltage from a second time ago to the present time is greater than or equal to a second threshold, a contactor controller opens the first contactor.