Hyong-Yeol Yang

Acoustic Noise/Vibration Reduction of a Single-Phase SRM Using Skewed Stator and Rotor

This paper presents a single-phase switched reluctance motor (SRM) with skewed stator and rotor so that the acoustic noise and vibration have been significantly reduced. The motor has the same skew angle for both stator and rotor laminations. The main source of acoustic noise and vibration is the rapid change of radial magnetic force along the air gap between the stator and rotor poles. Since the radial force (RF) is most intensified on the stator yoke near the salient poles, the abrupt change of the RF can be mitigated by skewing the stator and/or rotor laminations. Therefore, the RF can be more distributed throughout the stator core, and in turn, the peak value of the RF is reduced. In this paper, the distribution of the RF with respect to the skew angles is analyzed through the finite-element method simulation to design a single-phase SRM with the significantly reduced vibration and noise. Based on the simulation results, prototype motors with three different skew angles (0°, 30°, and 64°) have been constructed and tested, validating that the proposed design is effective in mitigating acoustic noise and vibration.

Speed control method for switched reluctance motor drive using self-tuning of switching angle

In this paper, a determination method of turn-off angle is realized by using a self-tuning control method. During the sampling time, a number of pulses from the encoder are checked by using a single-chip microprocessor and then compared with a pre-checked number of pulses. After calculating the difference between the two data, the turn-off angle moves forward or backward by the self-tuning method. By repeating such a process, the optimal turn-off angle is determined and the maximum torque is maintained. Though experiments, it is observed that motor speed is almost maintained if the turn-off angle is adjusted automatically by a self-tuning method when turn-on angle is changed.

Harmonic Intensity Reduction Technique for Single Phase Switched Reluctance Motor Drives Using a New Random PWM Scheme

This paper proposes a new random switching strategy using a DSP TMS320F2812 to reduce the harmonics spectra of single phase switched reluctance motors. The proposed method combines the random turn-on/off angle technique and the random pulse width modulation technique. A harmonic spread factor (HSF) is used to evaluate the random modulation scheme. In order to confirm the effectiveness of the proposed method an experiment was conducted. The experimental results show that the harmonic intensity of the output voltage for the proposed method is better than that for conventional methods.

Rotor position detection method of a single phase switched reluctance motor using back EMF

This paper presents the position estimation and driving method of single phase switched reluctance motor (SRM) using back EMF. To drive SRM, the information about position of a rotor must be fully needed. Generally, a rotorpsilas position sensor is used to detect the rotor position. However, most of position sensors are complex and increase the constructing cost of the system. Moreover, these sensors tend to decrease reliability of driving system. Therefore, a detecting method of a rotorpsilas specific position using back EMF is supposed to solve those problems mentioned above. When a rotor pole and a stator pole are overlapped, a variation occurs in the back EMF waveform and the instant of the overlap can be detected. Therefore the rotor position and speed can be calculated and the SRM is driven by appropriate switching. The validity of presented method is verified through simulation and experiment.

Detection of Rotor Position at Standstill for a TSRM Using Neural Network

In this paper, detection of rotor position at standstill of toroidal switched reluctance motor(TSRM) with built-in search coils using neural network is proposed. When search coils are used as a position sensor, it has many advantages like low cost, decrease in the volume, high robust characteristics and wide applications. However, the initial rotor position detection is very difficult because the search coil`s EMF doesn`t exist at standstill. In this paper, detection of initial rotor position of TSRM with built-in search coils using neural network is suggested. The experiment for the proposed method are presented. As a result of that, the accuracy and validity of the proposed method is verified.