Research On Digital Control Of Indirect Rotor Position Sensing For Switched Reluctance Motor

The switched reluctance motor drive system (SRD) is a novel mechanical -electrical device with the virtue of simple structure and high efficient. The rotor position information in SRD is essential in detaining the switching instants for proper control of speed, torque and further optimizing the motor operation performance. So rotor-position estimation is a necessary factor of a SRD to run properly. As the drawbacks of the traditional direct rotor-position detecting schemes, which are liable to be influenced by the environmental factors, the indirect rotor-position estimation techniques, applying some of SRD's electrical parameters to work out rotor position information, are so that created and developed rapidly.This paper presented a novel position estimation technique for Switched Reluctance Motors (SRM). The technique combines two different methods to deliver high resolution position information over the wide speed range. At zero and low speeds, a voltage pulse injection method is used to estimate the rotor position. For higher speeds, a sliding mode observer (SMO) based algorithm is used and combined to work with the low speed algorithm. The design of the new sensorless drive system for SRM is based on the Texas Instruments TMS320F240 DSP.Firstly, this paper summarized the development and application of SRM, analyzed the indirect rotor position sensing methods of sensorless SRD.Secondly, this paper summarized the running mechanism of SRD and analyzed how to control this system, and also compared all control methods.Thirdly, this paper described the principle of rotor position sensing and commutation logic of SRM with the presence of position sensor, and then presented a novel direct rotor position sensing technique which combined a voltage pulse injection method at zero and low speeds to a sliding mode observer algorithm at higher speeds. The technique was simulated in MATLAB.Finally, this paper designed a sensorless drive system based on TMS320F240 DSP. In this chapter, the hardware design and the software design were all listed clearly. Experiments had been done on this practical system. The experimental results demonstrate the effectiveness of this new combined technique.