2.4.1 Motor body structure
The structure of the switched reluctance motor is simpler than that of the squirrel cage induction motor. The outstanding advantage is that there is no winding on the rotor, and it is only laminated by ordinary silicon steel sheets. The loss of the whole motor is mostly concentrated on the stator windings, which makes the motor simple to manufacture, good in insulation, easy to cool, and has excellent heat dissipation characteristics. This motor structure can reduce the volume and weight of the motor and can be obtained in a small volume. Larger output power. Because the motor rotor has good mechanical elasticity, the switched reluctance motor can be used for ultra-high speed operation.
2.4.2 Motor drive circuit
The phase current of the switched reluctance motor drive system is unidirectional, and independent of the torque direction, only one main switching device can be used to satisfy the four-quadrant operating state of the motor. The power converter circuit is directly connected in series with the field winding of the motor, and each phase circuit is independently powered. Even if a certain phase winding or controller of the motor fails, it is only necessary to stop the phase, and no greater impact is caused. Therefore, both the motor body and the power converter are safe and reliable, so they are more suitable for harsh environments than asynchronous machines.
2.4.3 Motor system performance aspects
Switched reluctance motors have many control parameters, and it is easy to meet the requirements of four-quadrant operation of electric vehicles through appropriate control strategies and system design, and also maintain excellent braking capability in high-speed operation areas. Switched reluctance motors are not only highly efficient, but also maintain high efficiency over a wide range of speeds, which is hard to match with other types of motor drive systems. This kind of performance is very suitable for the operation of electric vehicles, which is very beneficial to improve the mileage of electric vehicles.
Conclusion
The focus of this paper is to compare the various commonly used drive motor speed control systems, and put forward the advantages of switched reluctance motors as electric motor drive motors, which is a research hotspot in the development of electric vehicles. For this type of special motor, there is still a lot of room for development in practical applications. Researchers need to work harder on theoretical research, and at the same time, it is necessary to combine the needs of the market to promote the application of such motors in practice.
