Motor network frequency conversion refers to the standard conditions, with 100% extra load within 10% ~ 100% extra speed after operation, the temperature does not exceed the motor calibration of the permissible value. Motor can be realized by the driving of the frequency converter different rotational speed and torque, so as to adapt to the demand of load change. The general frequency conversion motor, is derived from the traditional squirrel-cage motor. Generally use the traditional motor fan cooling fan to independence, and advances the motor winding insulation of corona resistant function. How to maintain good frequency conversion motor frequency converter. 1, the differential maintenance to ensure internal fault sensitive differential maintenance action, together to avoid external failure and the motor starting transient unbalance current caused by misoperation, join the frequency conversion motor maintenance device, including differential maintenance frequency and frequency conversion backup maintenance, and then gives the frequency conversion motor running perfect maintenance. 2, backup maintenance for variable frequency operation, have corresponding backup maintenance reflect the various abnormal operating condition of the motor, the setting of demand has a quick break over current, over current and negative sequence maintenance maintenance function, used to detect the locked-rotor and turn-to-turn fault of the machine. Backup maintenance real-time detection frequency conversion motor operating frequency, and calculating the corresponding current RMS, discriminant condition of motor. When electric mechanic frequency startup, the corresponding maintenance function exits, original heald now consider to choose motor protection device to complete the backup maintenance. When the motor frequency conversion operation, if the attack turn-to-turn fault, fault fault current level and the attack time frequency, the size of the negative sequence current maintenance in order to progress to the sensitivity of turn-to-turn fault, set how much period of fixed value, detection of turn-to-turn fault under different frequency.
