OVER TEMPERATURE PROTECTION DEVICE FOR ELECTRIC MOTORS

摘要

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, based on a frequency fs including frequency information 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, generate an over temperature protection signal Tf for protecting the electric motors from the over temperature, and output the over temperature protection signal Tf to the control device.