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Ngoc Thuy Nguyen,Nhat Thong Tran,Tan Phat Phan,Anh Thu Nguyen,My Xuyen T. Nguyen,Nguyen Ngan Nguyen,Young Ho Ko,Dai Hai Nguyen,Tran T.T. Van,DongQuy Hoang 한국공업화학회 2022 Journal of Industrial and Engineering Chemistry Vol.108 No.-
While the efficient usage of biomass waste can significantly help in addressing environmental issues,there are only a few reports that discuss about processing such waste effectively at a low-cost. Such challengearises from the strong association between the components biomass. In this study, an abundantagricultural byproduct, rice husk (RH), was used as the starting resource. A simple biorefining processof alkaline peroxide treatment followed by acid precipitation and ethanol extraction was performed onRH to obtain cellulose, hemicellulose, lignin, and silica. The chemical structures, morphologies, andphysic-chemical properties of the separated components were identified through a wide range of characterizationapproaches. The final products obtained from of this process were (i) bundles of fiber-likecellulose with a fiber width of 6 mm and (ii) small particles of hemicellulose and lignin with nonuniformshapes. The lignocelluloses products had over 90 wt% carbon with 52.28% crystalline ratio. Meanwhile, the other products comprising hemicelluloses, lignin, and silica were amorphous. The outcomeof this study contributes to expanding and developing the simple and efficient conversion processof biomass waste into sustainable value-added materials. It is crucial to reduce the environmental impactby using renewable materials as the new building block resources for synthetic chemicals.
Improving Utilization of GPS Data for Urban Traffic Applications
Nguyen Duc Hai,Nguyen Tan Phuc,Doan Khue,Ta Ho Thai Hai,Pham Tran Vu,Huynh Nam,Le Thanh Van 한국인터넷방송통신학회 2015 International Journal of Internet, Broadcasting an Vol.7 No.1
The use of Intelligent Transportation System (ITS) is promising to bring better solutions for managing and handling the city traffic. This system combines many fields in advanced technology such as Global Positioning System (GPS), Geographic Information System (GIS) and so on. The basement of applications in ITS is the effective collections and data integration tools. The purpose of our research is to propose solutions which involve the use of GPS time series data collected from GPS devices in order to improve the quality of output traffic data. In this study, GPS data is collected from devices attached to vehicles travelling on routes in Ho Chi Minh City (HCMC). Then, GPS data is stored in database system to serve in many transportation applications. The proposed method combines the data usage level and data coverage to improve the quality of traffic data.
The Root Causes of Rural Tourism Development Intentions in Vietnam:A Local Government Perspective
Hoai Than Nguyen,Tan Thanh Nguyen,Thi Thanh Truc Nguyen,Tan Hai Nguyen 영남대학교 박정희새마을연구원 2023 새마을학연구 Vol.8 No.1
Rural tourism has gained popularity in Vietnam, attracting more tourists, particularly foreigners and urban visitors. Despite the attention it receives from the central government, rural tourism development faces challenges, including the perceptions of local civil servants. This study combines the theories of planned behavior and organizational support theory to propose a model predicting the intention of local civil servants to develop rural tourism. A quantitative approach was used, with a questionnaire survey distributed to 405 local civil servants participating in training programs. The findings indicate that factors from both theories positively and significantly influence the intention of rural tourism development. Notably, perceived leader support directly impacts intention and moderates the relationship between perceived government support and intention. Despite its limited practical performance, the study emphasizes the importance of attitude toward rural tourism development. The research provides implications for academics, government, and policymakers to enhance local civil servants' intention for future rural tourism development.
Advanced Pitch Angle Control Based on Fuzzy Logic for Variable-Speed Wind Turbine Systems
Tan Luong Van,Thanh Hai Nguyen,Dong-Choon Lee IEEE 2015 IEEE transactions on energy conversion Vol.30 No.2
<P>In this paper, an advanced pitch angle control strategy based on the fuzzy logic is proposed for the variable-speed wind turbine systems, in which the generator output power and speed are used as control input variables for the fuzzy logic controller (FLC). The pitch angle reference is produced by the FLC, which can compensate for the nonlinear characteristic of the pitch angle to the wind speed. With the control variables of the generator output power and speed, the wind turbine is smoothly controlled to maintain the aerodynamic power and its speed at the rated values without any fluctuation in the output power and speed in the high-wind-speed regions. The effectiveness of the proposed method is verified by simulation results for a 2-MW permanent-magnet synchronous generator (PMSG) wind turbine system, and experimental results for a reduced-scale PMSG wind turbine simulator.</P>
Nguyen, Thanh Hai,Van, Tan Luong,Lee, Dong-Choon,Park, Joo-Hong,Hwang, Joon-Hyeon The Korean Institute of Power Electronics 2011 JOURNAL OF POWER ELECTRONICS Vol.11 No.6
This paper proposes a control mode switching scheme between vector control and constant V/f control for induction machine (IM) drives for maximum torque utilization in a higher speed region. For the constant V/f scheme, a smooth transition method from the linear range of PWM up to the six-step mode is applied, by which the machine flux and torque can be kept constant in a high-speed range. Also, a careful consideration of the initial phase angle of the voltage in the transient state of the control mode change between the vector control and V/f schemes is described. The validity of the proposed strategy is verified by the experiment result for a 3-kW induction motor drives.
Tan Luong Van,Trong Huan Nguyen,Nhut Minh Ho,Xuan Nam Doan,Thanh Hai Nguyen 전력전자학회 2019 ICPE(ISPE)논문집 Vol.2019 No.5
This paper proposes a control strategy of the voltage compensation based on a nine switch converter (NSC) to enhance a low-voltage ride-through (LVRT) capability for a doubly fed induction generator (DFIG) wind turbine system. The nine switch converter connected to a stator-side of the DFIG can enable to compensate the voltage response of the system during the grid faults. For series voltage source converter (VSC), a control algorithm consisting of dual voltage controllers is implemented for the two sequence components in the dq synchronous reference frame. As for shunt voltage source converter (VSC), a control algorithm is carried out in the dq reference frame and incorporates both an inner current control loop and an outer voltage control loop. The effectiveness of the proposed methods is verified by the simulation results for the 2 [MW]-DFIG wind turbine system under unbalanced grid voltage conditions.
Coordinated Control of Reactive Power between STATCOMs and Wind Farms for PCC Voltage Regulation
Nguyen, Thanh Hai,Lee, Dong-Choon,Van, Tan Luong,Kang, Jong-Ho The Korean Institute of Power Electronics 2013 JOURNAL OF POWER ELECTRONICS Vol.13 No.5
This paper proposes a coordinated control of the reactive power between the STATCOMs (static synchronous compensators) and the grid-side converters (GSC) of wind farms equipped with PMSGs (permanent-magnet synchronous generators), by which the voltage fluctuations at the PCC (point of common coupling) are mitigated in the steady state. In addition, the level of voltage sags is reduced during grid faults. To do this, the GSC and the STATCOM supply reactive power to the grid coordinately, where the GSCs are fully utilized to provide the reactive power for the grid prior to the STATCOM operation. For this, the GSC capability of delivering active and reactive power under variable wind speed conditions is analyzed in detail. In addition, the PCC voltage regulation of the power systems integrated with large wind farms are analyzed for short-term and long-term operations. With this coordinated control scheme, the low power capacity of STATCOMs can be used to achieve the low-voltage ride-through (LVRT) capability of the wind farms during grid faults. The effectiveness of the proposed strategy has been verified by PSCAD/EMTDC simulation results.
Flicker Suppression Scheme for Variable-Speed Wind Turbine Systems
Tan Luong Van,Thanh Hai Nguyen,Dong-Choon Lee 전력전자학회 2012 JOURNAL OF POWER ELECTRONICS Vol.12 No.2
This paper proposes a strategy of flicker mitigation for doubly-fed induction generator (DFIG) wind turbine systems. In the weak grid system where the grid impedance ratio is low, the reactive power compensation only cannot suppress the flicker sufficiently due to the limited power capacity of the converters or the DFIG. For the full suppression of flickers, the active power smoothening using the energy storage system (ESS) needs to be utilized together with the reactive power compensation. The effectiveness of the proposed method is verified by PSCAD/EMTDC simulation results for a 2[MW] DFIG wind turbine system and by experimental results for a 3[kW] wind turbine simulator.
Coordinated Control of Reactive Power between STATCOMs and Wind Farms for PCC Voltage Regulation
Thanh Hai Nguyen,Dong-Choon Lee,Tan Luong Van,Jong-Ho Kang 전력전자학회 2013 JOURNAL OF POWER ELECTRONICS Vol.13 No.5
This paper proposes a coordinated control of the reactive power between the STATCOMs (static synchronous compensators) and the grid-side converters (GSC) of wind farms equipped with PMSGs (permanent-magnet synchronous generators), by which the voltage fluctuations at the PCC (point of common coupling) are mitigated in the steady state. In addition, the level of voltage sags is reduced during grid faults. To do this, the GSC and the STATCOM supply reactive power to the grid coordinately, where the GSCs are fully utilized to provide the reactive power for the grid prior to the STATCOM operation. For this, the GSC capability of delivering active and reactive power under variable wind speed conditions is analyzed in detail. In addition, the PCC voltage regulation of the power systems integrated with large wind farms are analyzed for short-term and long-term operations. With this coordinated control scheme, the low power capacity of STATCOMs can be used to achieve the low-voltage ride-through (LVRT) capability of the wind farms during grid faults. The effectiveness of the proposed strategy has been verified by PSCAD/EMTDC simulation results.