Abstract: An over temperature protection device for electric motors applicable to a railway vehicle driving system that operates a plurality of electric motors in parallel using one or a plurality of inverter devices includes a control device configured to control the operation of an inverter device and a protecting device configured to detect, on the basis of a frequency fs including frequency information at the time when the inverter device is applying control for fixing a ratio of a voltage and a frequency to electric motors and electric currents of at least one phase flowing to the electronic motors, an over temperature that could occur in the electric motors, to generate an over temperature protection signal Tf for protecting the electric motors from the over temperature, and to output the over temperature protection signal Tf to the control device.

Abstract: A rotator coil is provided that includes a coil conductor and a mica tape wound a plurality of times around an outer periphery of the coil conductor. The mica tape includes mica paper and a reinforcing member, and has an adhesive resin layer containing an acryloyl-based component and a cyanate ester-based component between the mica paper and the reinforcing members. The reinforcing member, the mica paper, or both, are impregnated with a thermosetting resin composition, and hardened.

Abstract: An over temperature protection device for electric motors applicable to a railway vehicle driving system that operates a plurality of electric motors in parallel using one or a plurality of inverter devices includes a control device configured to control the operation of an inverter device and a protecting device configured to detect, on the basis of a frequency fs including frequency information at the time when the inverter device is applying control for fixing a ratio of a voltage and a frequency to electric motors and electric currents of at least one phase flowing to the electronic motors, an over temperature that could occur in the electric motors, to generate an over temperature protection signal Tf for protecting the electric motors from the over temperature, and to output the over temperature protection signal Tf to the control device.

Abstract: A rotator coil is provided that includes a coil conductor and a mica tape wound a plurality of times around an outer periphery of the coil conductor. The mica tape includes mica paper and a reinforcing member, and has an adhesive resin layer containing an acryloyl-based component and a cyanate ester-based component between the mica paper and the reinforcing members. The reinforcing member, the mica paper, or both, are impregnated with a thermosetting resin composition, and hardened.