Browsing by Author "Chang, Yen-Chuan"

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A new sensorless starting method for brushless DC motors without reversing rotation
(2007)
Chang, Yen-Chuan
;
Tzou, Ying-Yu
;
電控工程研究所
;
Institute of Electrical and Control Engineering
This paper presents a new sensorless starting method for brushless DC motors without reversing rotation for unidirectional applications. The method can detect the rotor position at standstill and a specific start-up method is then used to accelerate the motor up to a middle-speed where conventional sensorless control algorithms based on the back-EMF can work properly. The proposed scheme employs only one current sensor at DC-link side of the inverter, and can be applied to a motor without knowing its parameters and additional position sensors. As compared with previous approaches, the presented technique can simplify the sensorless position detection procedure and lower the cost. The proposed initial rotor position detection technique has a resolution of 30 electrical degrees, and does not cause any rotor vibration during the detection process. The sensorless starting scheme has been implemented on a single-chip DSP controller (TMS320LF2407A) and experimental results reveal that the starting procedure can work smoothly without temporarily reversing rotation.
Design of a digital servo control IC for permanent magnet synchronous motors with linear hall sensors
(2007)
Chang, Yen-Chuan
;
Tzou, Ying-Yu
;
電控工程研究所
;
Institute of Electrical and Control Engineering
This paper presents the design and architecture implementation of a digital position control IC for permanent magnet synchronous motors (PMSMs) with sinusoidal flux distribution using linear Hall sensors for low-cost motion control applications. The absolute rotor position is calculated from the measured Hall sensor signals and a speed estimator is devised to generate speed feedback for the servo loop compensator. The developed digital servo control IC for PMSM motors with linear Hall sensors consists of three major control blocks: a servo loop controller, a position and speed estimator, and a field-oriented torque controller. The accuracy of positioning control resolution can be improved by a position error compensation table via external position calibration. All the control blocks are realized by using digital circuitry with configurable and reusable intellecture property (IP) blocks. Experiment results are presented to verify the performance and feasibility of the proposed IC.
Single-chip FPGA implementation of a sensorless speed control IC for permanent magnet synchronous motors
(2007)
Chang, Yen-Chuan
;
Tzou, Ying-Yu
;
電控工程研究所
;
Institute of Electrical and Control Engineering
This paper presents a single-chip FPGA implementation of a speed sensorless control IC with flux-linkage estimation algorithm for permanent-magnet synchronous motors (PMSM) with sinusoidal flux distribution. By using hierarchical and modular realization strategy, each functional block for the digital sensorless IC is designed as a reusable IP with FPGA implementation. The digital sensorless IC is configurable with its modular blocks and is programmable with its control registers via a serial interface to fit various applications without complicated software programming as realized by using conventional DSP or microcontrollers. The sensorless algorithm implemented uses the incremental values of flux linkage, the normalized back-EMF voltage, and the estimated peak back-EMF value to estimate the incremental rotor position. An internal closed-loop correction mechanism within this algorithm can automatically correct the rotor position estimation drift, which could be resulted by the quantization error, circuit nonlinearities, and sampling noises. An initial rotor position detection scheme with ramping speed control has been developed for startup control. Experimental verification has been carried out on a sensorless spindle motor drive system for DVD applications.