Abstract-The paper proposes a direct torque control (DTC) algorithm suitable for low-variable-frequency operation of the brushless doubly fed reluctance machine (BDFRM) and considers aspects of its practical implementation. The simulation and experimental results show that a small BDFRM prototype can successfully operate down to zero supply frequency of the inverterfed (secondary) winding, unlike cage induction or many other alternating current machines with DTC. This BDFRM advantage is a consequence of using a flux estimation technique not relying on the secondary voltage integration and therefore avoiding the well-known problems at low secondary frequencies, being typical for the BDFRM normal operation. The developed algorithm also offers the prospect for optimizing the machine performance in a manner similar to conventional vector controllers but with control actions executed in a stationary reference frame as usual for all traditional DTC methods. The maximum torque per inverter ampere control strategy has been chosen as a case study. Index Terms-Brushless doubly fed reluctance machines (BDFRMs), direct torque control (DTC).
Another related approach is used for direct torque control of brushless reluctance machines REF .
Encoderless direct torque controller for limited speed range applications of brushless doubly fed reluctance motors
IEEE Transactions on Industry Applications
IEEE Transactions on Industry Applications
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