Rapid parameter determination for high performance induction motor drives

The paper describes the implementation of a rapid on line parameter determination method for three phase induction motors without the need to connect a mechanical load or drive to the machine´s output shaft. The technique is based on data sampling during a normal run up to speed test. The method has been refined such that even the normal locked rotor and synchronous speed data are measured during the run up to speed test. Furthermore the technique takes into account rotor parameter variations with frequency due to skin effect (mainly due to double-cage or deep-bar rotor), and other non linear imperfections such as heating and main flux path saturation. Moreover the system can be used for condition monitoring of any electrical drive system and can be permanently or temporarily connected to such a system for diagnosis.