15-10-2010, 09:08 AM
SRM,prprstn.doc (Size: 125.5 KB / Downloads: 83)
This article is presented by:
L.Revathi
K.Jaseema Banu
Dept of Electrical & Electronics Engg
NATIONAL COLLEGE OF ENGINEERING
Maruthakulam
Tirunelveli
SPEED CONTROL OF THE SWITCHED RELUCTANCE MOTOR DRIVE
ABSTRACT – This paper deals with the Speed Control of the Switched Reluctance Motor Drive. The SRM is a singly excited and doubly salient machine. This means that it has salient poles on both the stator and rotor but only stator is excited. The SRM can also be called Electronically Switched Motor. The position information is the essential one for the operation of the motor. The speed is sensed from the motor terminal and it is compared with the Ref speed and error signal is generated using the error detector. The error signal is processed using Speed Controller and it produces Current Reference. Current Reference is compared with the actual currents and error current is generated. The current error is processed using Hysteresis Current Controller. The Classical Converter switches current in to the windings. The simultaneous switching of currents in to the winding will provide continuous rotation.
INTRODUCTION
The SRM is a doubly-salient, singly-excited machine with independent windings of the stator. Its stator structure is same as PM motor, but the rotor is simpler having no permanent magnet on it.
Stator windings on diametrically opposite poles are connected in series or parallel to form one phase of the motor. Several combinations of stator and rotor poles are possible, such as 6/4 (6 stator poles and 4 rotor poles), 8/6, 10/6, 12/6 etc. The configurations with higher number of stator/rotor pole combinations have less torque ripple.
The torque is developed by the tendency of the magnetic circuit to adopt a configuration of minimum reluctance. The excitation currents are unidirectional and discontinuous in nature. The stator phases are sequentially excited to obtain continuous rotation. Besides, the SR motor operates well into saturation.
The simplicity in both motor construction and power converter requirement made the switched reluctance motor (SRM) an attractive alternative to the induction motor and the PM motors in adjustable speed drive applications.