Direct Instantaneous Torque Controlled Switched Reluctance Motor Drive for Fan Type Load and Constant Torque Load

Abstract

Switched reluctance motor (SRM) drives can be a good competitor to conventional induction and permanent magnet motors in variable speed applications because of advantages, such as simple construction, no rotor windings, high torque to inertia ratio, adaptability to hostile conditions, etc. Due to its high nonlinearity, the torque ripple is high in switched reluctance motor. The sophisticated direct instantaneous torque control (DITC) can maintain the torque developed by the motor within hysteresis band by suitably selecting the switching states of the converter. Hence, DITC controller minimizes the torque ripples and also provides fast response to the torque changes. The performance of DITC controlled SRM drive is analyzed through simulations during acceleration and also in steady state for two types of load torques namely fan type and constant torque. The variation of the switching frequency of the converter is analyzed by changing the torque hysteresis band. It has been observed that as the hysteresis band decreases, the switching frequency increases. So, the hysteresis band cannot be increased beyond a certain limit so as to ensure that the switching frequency of the device cannot increase beyond its operating limit.

Hybrid intelligent controller based torque ripple minimization in switched reluctance motor drive

“…A controller with lyapunov function is used to minimise the ripples in the torque of SRM drives [31]. The DTC reduced the ripples in the motor torque by regulating the motor torque within the hysteresis band [32]. In this proposed technique the actual flux and the torque are estimated from the stator voltage and the resistance.…”

Sizing and Control of a Typical 6/4 Switching Reluctance Motor

“…The optimal voltage vectors are selected to limit the torque errors and stator flux inside the hysteresis band and then applied to the inverter to reduce the torque and flux errors efficiently and rapidly. The optimal voltage vectors are provided in the form of a switching table [11][12]…”

“…To control the electromagnetic torque and the stator flux, the hysteresis controllers are generally used allowing the choice of the suitable sequence. To control the variation of the motor flux, one of the six voltage vectors is selected by the controller from the voltage source inverter [11][12].…”

“…Amri et al [10] proposed the application of a neural network as an intelligent software sensor control. Moreover, Pratapgiri et al [11] applied the direct torque control (DTC) approach and Birame et al [12] added the use of a DTC with 12 sectors. This DTC was based on PWM vector and the fuzzy PI (tuning Rs).…”

“…Several research efforts have been done to increase the performance of DTC [11][12][13]. The fractional order control has been effectively applied in various industrial control applications [14][15].…”