Browsing by Author "Fang, Chih-Hsing"

Now showing 1 - 2 of 2

Inductance Measurement and Estimation Method Utilizing LC Circuit Analysis Techniques under Dynamic Operation for Switched Reluctance (SR) Machines
(2004)
Huang, Wen-Nan
;
Teng, Ching-Cheng
;
Fang, Chih-Hsing
;
Chen, Chih-Hsin
;
電控工程研究所
The method for the inductance measurement applying the LC circuit concept, which means circuit with inductance and capacitor effect, for analysis of switched reluctance (SR) motors in operation status is proposed in this paper. The inductance profile is an important parameter hearing on the performance of a SR motor. The main strategy of the presented methodology is to combine the standard circuit topology analysis results and machine's equivalent model to find B dynamic measurement method for the inductance related magnetization characteristics. The capacitors in series or parallel connection to the SR machine phase inductance are the key components to construct the applicable LC circuit analysis model. Besides, this method owns the capability that being easy to be extended to estimate the incremental inductance for further performance prediction. The measurement results of two SR motors taken into verification both demonstrate the effectiveness of this method under dynamic operation condition while comparing to the conventionally off-line static measurement.
Speed control of the 12-step sensorless drive for a brushless dc motor
(2008-04-01)
Fang, Chih-Hsing
;
Lin, Shir-Kuan
;
Wu, Yu-Jheng
;
Lo, Chen-Kuo
;
電控工程研究所
The 12-step sensorless drive scheme requires an interval to detect the zero crossing of the back emf. The voltage regulating pulse-width modulation (PWM) is commonly used for the speed control of a motor. However, it induces the fluctuation of the back emf and makes the zero-crossing detection difficult. This paper proposes two digital approaches to the zero-crossing detection for the presence of the PWM. One approach is to vary the zero-crossing detecting period linearly with respect to the speed of the motor. The other is to detect the back emf only on the positive pulses of the PWM in order to avoid the fluctuation of the back emf. A digital filter is also incorporated in order to eliminate the noise generated by the PWM. Experiments show that both approaches have good performance for the speed control of the brushless dc motor. (C) 2008 American Institute of Physics.