A simple adaptive scheme for indirect field orientation of an induction motor

✍ Scribed by P. J. Costa Branco

• Publisher: John Wiley and Sons
• Year: 2007
• Tongue: English
• Weight: 580 KB
• Volume: 7
• Category: Article
• ISSN: 1430-144X
• DOI: 10.1002/etep.4450070404

✦ Synopsis

A self-adaptive scheme is described f o r automatically tracking the temperature and saturation-dependent rotor time constant T, in indirect vector control. This method is based on a monitoring signal injected into the process. A cross-correlation function between the monitoring signal and the speed error indicates the T, changes in direction (increase or decrease) and magnitude. The proposed identification algorithm presents unique characteristics: it does not use current or voltage sensors; it is not motor-parameter dependent; the amplitude of the monitoring signal can be reduced but with an increase on the speed-error sensibility to control interference in drive 3 performance and it works either on steady-and dynamic transient-state. It will need some load to operate but this condition is satisfied in all practical cases. Tests were conducted with a 1.2 kW four-quadrant AC drive. The adaptive indirect vector-control was implemented in a microcomputer with the motor supplied by a voltage-source inverter with current control using IGBT. Experimental and simulated results using this adaptive digital scheme for different loads and values of model T, (representing a detuned operation) are presented showing good performances.