Browsing by Author "Huang, HS"

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A three-phase PWM AC-DC converter with low switching frequency and high power factor using DSP-based repetitive control technique
(1998)
Jung, SL
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Huang, HS
;
Tzou, YY
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電控工程研究所
;
Institute of Electrical and Control Engineering
This paper presents a novel digital control scheme for PWM AC-DC converters with low switching frequency used in high-power applications. The proposed scheme incorporates an inner current loop with an outer voltage loop to improve input power factor and regulate the output de-link voltage. The inner current loop consists of a predictive controller and a repetitive controller. The outer voltage loop is composed of a digital IPI controller and a load current compensator. A PWM AC-DC converter employing DSP control has been constructed to verify the proposed control scheme. A nearly unit input power factor can be achieved even with a low switching frequency. Experimental results confirm the feasibility and features of the proposed repetitive control scheme for unit power factor regulation.
Design and implementation of an FPGA-based control IC for the single-phase PWM inverter used in an UPS
(1997)
Jung, SL
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Chang, MY
;
Jyang, JY
;
Huang, HS
;
Yeh, LC
This paper presents an FPGA-based multiple-loop control scheme for the regulation of the PWM inverters used in UPS. The proposed control scheme incorporates an inner current loop with an outer voltage loop to regulate the output voltage of the PWM inverter, which is expected to be sinusoidal. The corresponding control gains are designed through deadbeat theory so that the inverter can achieve fast dynamic response. An output voltage decoupling mechanism and a load disturbance compensation scheme have been proposed to improve the stiffness of the controlled PWM inverter. The developed digital controller has been realized by a RAM-based FPGA XC4010 to verify its effectiveness. The simulation and experimental results show that the output voltage of the controlled PWM inverter has good transient response and little distortion under rough load conditions.
DSP-based multiple-loop control strategy for single-phase inverters used in AC power sources
(1997)
Jung, SL
;
Huang, HS
;
Chang, MY
;
Tzou, YY
;
交大名義發表
This paper presents a fully digital multiple-loop control scheme for the regulation of the PWM inverters used in AC power sources. The proposed digital control scheme incorporates an inner current loop with an outer voltage loop to regulate the output voltage of the PWM inverter. The digital controller is designed through deadbeat theory so that the inverter can achieve fast dynamic response. To enhance the robustness of the PWM inverter concerned, an output voltage decoupling mechanism Is added to improve the performance of the inner current loop. Besides, a load disturbance compensation scheme Is also developed to remedy voltage distortion caused by load variation. Both the frequency domain end time-dom in behavior of the proposed control scheme have been examined in this paper. A PWM inverter control system based on DSP TMS320C14 was constructed to verify the control law. The results show that the output voltage of the controlled PWM inverter has little even under rough load conditions.
Luminescence of selective area growth of epitaxial ZnO nanowires and random-growth-oriented nanobelts
(2006-03-14)
Hsu, HC
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Cheng, HM
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Wu, CY
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Huang, HS
;
Lee, YC
Epitaxial ZnO nanowires and random-growth-oriented nanobelts were grown on c-plane sapphire with and without a pre-coated ZnO epilayer film. On the pre-coated ZnO epilayer, ZnO nanowires are vertically aligned with good in-plane alignment as a result of homoepitaxy, whereas on the bare c-plane sapphire, besides a few nanowires vertically aligned with [0001]znO parallel to [0001](Al2O3), the nanowires were properly aligned with three-fold rotation symmetry. The ZnO nanowires are well-defined hexagonal crystals with diameters of 70-500 nm and lengths of up to several micrometres. In the junction regions between the pre-coated epilayer and the bare sapphire surface, however, ZnO nanobelts (nanoribbons) were found. Cathodoluminescence measurements revealed that the emission at 3.26 eV is correlated with free-exciton recombination and the broad green emission at 2.48 eV is attributed to surface defects. The stronger green emission implies that more surface defects exist on the side walls of nanowires and nanobelts. In Raman scattering, the E1 (LO) mode is sensitive to the orientation of nanostructure that is consistent with the cathodoluminescence results.
Self-tuning discrete sliding mode control of a closed-loop regulated PWM inverter with optimal sliding surface
(1996)
Jung, SL
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Huang, HS
;
Tzou, YY
;
電控工程研究所
;
Institute of Electrical and Control Engineering