Browsing by Author "Tau, Jen-Hau"

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PFC Control of Electrolytic Capacitor-less PMSM Drives for Home Appliances
(2017-01-01)
Tau, Jen-Hau
;
Tzou, Yin-Yu
;
電控工程研究所
;
Institute of Electrical and Control Engineering
This paper proposes a mixed dq-control scheme for a sensorless PMSM drive to improve input power factor with an electrolytic capacitor-less bridge rectifier. Instead of using bulky traditional electrolytic capacitor, a very small film capacitor is adopted to achieve high input power factor with improved power density and reliability. However, due to large dc-link voltage fluctuations, deterioration of current control capability inevitably causes large torque ripples with twice grid frequency. Therefore, the proposed control scheme is more appropriate for applications with large-inertia load such as fan and pump systems which can reduce influence of torque ripples. Due to the small value of the dc-link capacitance, the grid input current can be controlled as a mixed d-q current with its instantaneous average current to be synchronized with the grid voltage. By using field oriented control (FOC) with field weakening control, a reference current generator is devised to generate the desired d-q current reference commands. Simulation and experimental verification have been carried out to illustrate the effect of power factor correction with a high reduction of dc-link capacitance.
Sensorless PMSM Drive with Large DC-link Voltage Fluctuation
(2017-01-01)
Tau, Jen-Hau
;
Wu, Kao-Chih
;
Tzou, Yin-Yu
;
電控工程研究所
;
Institute of Electrical and Control Engineering
This paper realizes a high power factor, high reliability, and low cost PMSM drive system with small DC-link capacitor. Compared with conventional bulky electrolytic capacitor for the regulation of DC-link voltage, a small-size film capacitor with capacitance reduction to 1% is used to realize a seneorless PMSM drive with high power factor, high reliability, and high compactness. To overcome high DC-link voltage fluctuations due to the small capacitor, the d-q axis current commands are modified according to the measured dc-link voltage and a power factor derived torque control strategy. A dc-link voltage feed-forward compensation scheme is used to minimize speed ripples due to the large voltage fluctuation effect. Simulation results show that design compromise between power factor, dc-link voltage ripple ratio, and speed ripple ratio can be achieved for practical design considerations. Experimental results of a sensorless PMSM drive in rated condition with a measured power factor of 97% with a reduction of dc-link capacitance to 1% have been obtained.