OVERTEMPERATURE PROTECTION DEVICE FOR MOTOR

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 14 configured to control the operation of an inverter device 10 and a protecting device 20 configured to detect, on the basis of a frequency fs including frequency information at the time when the inverter device 10 is applying control for fixing a ratio of a voltage and a frequency to electric motors 12a and 12b and electric currents I1 and I2 of at least one phase flowing to the electronic motors 12a and 12b, an over temperature that could occur in the electric motors 12a and 12b, to generate an over temperature protection signal Tf for protecting the electric motors 12a and 12b from the over temperature, and to output the over temperature protection signal Tf to the control device 14.