The wide variation of induction motor characteristics with temperature, coupled with unpredictable track and load conditions, make the inclusion of closed loop tractive effort control essential where there exists a requirement for repeatability and predictability of performance. Such a requirement is often necessary on rapid transit systems and multiple unit operations. In particular the variation of rotor resistance (typically 50 % over normal operating conditions) will result in tractive effort variations. Open loop control methods require measurement of individual wheel diameters, so that the inverter frequencies may be compensated to maintain equal output torques. The alternative would be to keep wheel diameters matched. Open loop schemes also suffer the risk of torque pull out.
Torque control of A.C. induction motor traction drives
Die Drehmoment-Regelung von Asynchronmotoren in Elektrolokomotiven
1987
5 Seiten, 6 Bilder, 8 Quellen
Conference paper
English
Induction motor drives for traction application
Tema Archive | 1993
|Torque Ripple Minimization for Induction Motor Drives with Direct Torque Control
Online Contents | 2005
|Characteristics of traction motor drives
Engineering Index Backfile | 1944