
Associate Professor Thavatchai Tayjasanant, Ph.D.
รศ. ดร.ธวัชชัย เตชัสอนันต์
Education
- Ph.D. (2000-2005) Electrical and Computer Engineering, University of Alberta, Canada.
- M.Sc. (1995-1996) Electric Power Engineering, University of Manchester (formerly UMIST), UK.
- B.Eng. (1990-1994) Electrical Engineering Chulalongkorn University, Thailand.
Email: Thavatchai.T@chula.ac.th
Research Interest
- Power Quality Analysis
- Power Quality Impacts of Distributed Generations and Smart Grid
- Power quality data analytics
- Smart Road Lighting
- Horticultural Lighting
- Human Centric Lighting
- Intelligent lighting control
Research Cluster
Potharajaroen, S; Tangwongchai, S; Tayjasanant, T; Thawitsri, T; Anderson, G; Maes, M
Bright light and oxygen therapies decrease delirium risk in critically ill surgical patients by targeting sleep and acid-base disturbances Journal Article
In: Psychiatry Research, vol. 261, pp. 21-27, 2018, ISSN: 01651781, (cited By 12).
@article{Potharajaroen2018,
title = {Bright light and oxygen therapies decrease delirium risk in critically ill surgical patients by targeting sleep and acid-base disturbances},
author = {S Potharajaroen and S Tangwongchai and T Tayjasanant and T Thawitsri and G Anderson and M Maes},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85038883000&doi=10.1016%2fj.psychres.2017.12.046&partnerID=40&md5=64043f9deda7a63437b2934426d1e81d},
doi = {10.1016/j.psychres.2017.12.046},
issn = {01651781},
year = {2018},
date = {2018-01-01},
journal = {Psychiatry Research},
volume = {261},
pages = {21-27},
publisher = {Elsevier Ireland Ltd},
abstract = {This study examined the effects of bright light therapy (BLT) on the incidence of delirium in post-operative patients admitted to a surgical intensive care unit (SICU) and delineates risk and protective factors. We included 62 patients in a single-blind, randomized controlled study. The intervention group was treated with care as usual plus BLT for three consecutive days. Delirium was diagnosed by DSM-5 criteria with the Confusion Assessment Method-Intensive Care Unit (CAM-ICU). Risk factors for delirium were measured, including the APACHE II score, Insomnia Severity Index (ISI), as well as hematocrit and bicarbonate levels. Results were adjusted for treatment with nasal cannula oxygen and medications. Thirteen patients developed delirium within the three days following surgery. Generalized estimating equations analysis showed a significant preventive effect of BLT on delirium, which was independent of risk or treatment factors. Higher APACHE-II and ISI scores, lower hematocrit and lower bicarbonate levels increased the risk of developing delirium. BLT plus nasal cannula oxygen significantly reduced the likelihood of delirium. BLT significantly lowered ISI scores, while nasal cannula oxygen significantly enhanced bicarbonate levels. The results indicate that BLT and supplementary oxygen therapy may protect against delirium by targeting sleep-wake and deficits in the bicarbonate buffer system. © 2017 Elsevier B.V.},
note = {cited By 12},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Boonnamol, J; Tayjasanant, T
Impacts of distributed generators on voltage sag analysis Journal Article
In: Advanced Materials Research, vol. 732-733, pp. 877-881, 2013, ISSN: 10226680, (cited By 0; Conference of 2013 2nd International Conference on Energy and Environmental Protection, ICEEP 2013 ; Conference Date: 19 April 2013 Through 21 April 2013; Conference Code:99790).
@article{Boonnamol2013,
title = {Impacts of distributed generators on voltage sag analysis},
author = {J Boonnamol and T Tayjasanant},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84884756131&doi=10.4028%2fwww.scientific.net%2fAMR.732-733.877&partnerID=40&md5=577eb783451e9be637dc1502b17bb7d4},
doi = {10.4028/www.scientific.net/AMR.732-733.877},
issn = {10226680},
year = {2013},
date = {2013-01-01},
journal = {Advanced Materials Research},
volume = {732-733},
pages = {877-881},
address = {Guilin},
abstract = {This paper presents impacts of distributed generators (DGs) such as synchronous-based DG and inverter-based DG on voltage sag analysis in distribution systems. Voltage sag analysis is assessed through area of vulnerability (AOV), number of sags frequency (NSF) and voltage sag index (SARFI). Single line-to-ground and three-phase faults are investigated. Size and location of DG are carried out by using Particle Swarm Optimization algorithm (PSO) in order to minimize losses and number of sag frequency. Roy Billinton Test System (RBTS) Bus 2 is used for simulation cases. Results show that the distribution system with DG installed improves voltage sag performance compared with the system without DG installed. © (2013) Trans Tech Publications, Switzerland.},
note = {cited By 0; Conference of 2013 2nd International Conference on Energy and Environmental Protection, ICEEP 2013 ; Conference Date: 19 April 2013 Through 21 April 2013; Conference Code:99790},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Tanthadiloke, C; Tayjasanant, T
Development of a measuring device and software for measurement of electric power quantities based on IEEE standard 1459-2010 Journal Article
In: Advanced Materials Research, vol. 732-733, pp. 830-834, 2013, ISSN: 10226680, (cited By 0; Conference of 2013 2nd International Conference on Energy and Environmental Protection, ICEEP 2013 ; Conference Date: 19 April 2013 Through 21 April 2013; Conference Code:99790).
@article{Tanthadiloke2013,
title = {Development of a measuring device and software for measurement of electric power quantities based on IEEE standard 1459-2010},
author = {C Tanthadiloke and T Tayjasanant},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84884751594&doi=10.4028%2fwww.scientific.net%2fAMR.732-733.830&partnerID=40&md5=20bddc173210a3142db6e371d33a0eba},
doi = {10.4028/www.scientific.net/AMR.732-733.830},
issn = {10226680},
year = {2013},
date = {2013-01-01},
journal = {Advanced Materials Research},
volume = {732-733},
pages = {830-834},
address = {Guilin},
abstract = {This paper presents a development of measuring device and software for 3-phase measurement of electric power quantities according to IEEE Std. 1459-2010. Blackman-Harris windowed FFT algorithm is used for the harmonic analysis to reduce the errors from leakage problems. Result verification with a technical paper has been made. Actual implementation with an adjustable speed drive at a laboratory has been carried out and crosschecked with a commercial power quality meter. © (2013) Trans Tech Publications, Switzerland.},
note = {cited By 0; Conference of 2013 2nd International Conference on Energy and Environmental Protection, ICEEP 2013 ; Conference Date: 19 April 2013 Through 21 April 2013; Conference Code:99790},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Hengsritawat, V; Tayjasanant, T; Nimpitiwan, N
Optimal sizing of photovoltaic distributed generators in a distribution system with consideration of solar radiation and harmonic distortion Journal Article
In: International Journal of Electrical Power and Energy Systems, vol. 39, no. 1, pp. 36-47, 2012, ISSN: 01420615, (cited By 53).
@article{Hengsritawat2012,
title = {Optimal sizing of photovoltaic distributed generators in a distribution system with consideration of solar radiation and harmonic distortion},
author = {V Hengsritawat and T Tayjasanant and N Nimpitiwan},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84858449087&doi=10.1016%2fj.ijepes.2012.01.002&partnerID=40&md5=7738350c527f80f3c46597b0d4934ab9},
doi = {10.1016/j.ijepes.2012.01.002},
issn = {01420615},
year = {2012},
date = {2012-01-01},
journal = {International Journal of Electrical Power and Energy Systems},
volume = {39},
number = {1},
pages = {36-47},
abstract = {This paper presents a probabilistic approach to design an optimal size of photovoltaic distributed generator (PV-DG) in a distribution system. A steady-state voltage stability index is applied to select PV-DG locations. The objective of the proposed technique is to minimize average system active power losses, while considering power quality constraints (i.e., voltage regulation, total harmonic voltage distortion, total demand distortion and harmonic currents). Monte Carlo simulation is applied to acquire solar radiations, ambient temperatures, load demands and substation voltages. The proposed technique is tested on an actual 51-bus medium voltage distribution system in Thailand. From simulations, there is a different solution between selecting the optimal size of PV-DG from with and without considering background harmonics. Also in realistic cases, PV-DGs may improve voltage regulation and decrease losses in distribution systems; however, increase total harmonic voltage distortion values. © 2012 Elsevier Ltd. All rights reserved.},
note = {cited By 53},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Hengsritawat, V; Tayjasanant, T
Impacts of load models and power factor control on optimal sizing of photovoltaic distributed generators in a distribution system Journal Article
In: IEEJ Transactions on Electrical and Electronic Engineering, vol. 7, no. 6, pp. 567-573, 2012, ISSN: 19314973, (cited By 2).
@article{Hengsritawat2012a,
title = {Impacts of load models and power factor control on optimal sizing of photovoltaic distributed generators in a distribution system},
author = {V Hengsritawat and T Tayjasanant},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84867359245&doi=10.1002%2ftee.21774&partnerID=40&md5=8c650d4880bfae32fc7d07557c72952e},
doi = {10.1002/tee.21774},
issn = {19314973},
year = {2012},
date = {2012-01-01},
journal = {IEEJ Transactions on Electrical and Electronic Engineering},
volume = {7},
number = {6},
pages = {567-573},
publisher = {John Wiley and Sons Inc.},
abstract = {This paper studies the impact of optimal sizing of photovoltaic distributed generators (PV-DGs) on a distribution system using different static load models (i.e., constant power, constant current, and constant impedance) and various power factor (PF) operations. A probabilistic approach with Monte Carlo simulation is proposed to obtain the optimal size of PV-DG. Monte Carlo simulation is applied to predict the solar radiation, ambient temperatures, and load demands. The objective is to minimize average system real power losses, with the power quality constraints not exceeding the limits, i.e. voltage and total harmonic voltage distortion (THDv) at the point of common coupling (PCC). A modified Newton method and a classical harmonic flow method are employed to calculate the power flow and THDv values, respectively. An actual 51-bus, medium-voltage distribution system in Thailand is employed as a test case. Results demonstrate that the proposed method performs well to provide the optimal size of PV-DG based on technical constraints. Further, the results show that the three static load models do not affect the optimal PV-DG size but the model has a different impact for various PF operations. PV-DGs may improve the voltage regulation and decrease the losses in distribution systems practically, but the THDv values could increase. © 2012 Institute of Electrical Engineers of Japan.},
note = {cited By 2},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Xu, W; Tayjasanant, T; Zhang, G; Bahry, R
Mitigation of interharmonics using a switched filter scheme Journal Article
In: European Transactions on Electrical Power, vol. 20, no. 1, pp. 83-95, 2010, ISSN: 1430144X, (cited By 6).
@article{Xu2010,
title = {Mitigation of interharmonics using a switched filter scheme},
author = {W Xu and T Tayjasanant and G Zhang and R Bahry},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-76249097056&doi=10.1002%2fetep.361&partnerID=40&md5=c1aa5e8499fc218fb6c8c8246096a8dc},
doi = {10.1002/etep.361},
issn = {1430144X},
year = {2010},
date = {2010-01-01},
journal = {European Transactions on Electrical Power},
volume = {20},
number = {1},
pages = {83-95},
abstract = {This paper presents a real-life case where variable frequency drive is identified as an interharmonic source that causes flickers. Through field measurements and system studies, the mechanism of light flicker production is revealed. After investigating various options to mitigate the problem, a simple switched filter scheme is recommended as the solution. Field measurement results have confirmed the effectiveness of the proposed scheme. Copyright © 2009 John Wiley & Sons, Ltd.},
note = {cited By 6},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Zhu, K; Yong, J; Tayjasanant, T
Quantifying flicker impact of interharmonics Journal Article
In: Zhongguo Dianji Gongcheng Xuebao/Proceedings of the Chinese Society of Electrical Engineering, vol. 28, no. 28, pp. 113-118, 2008, ISSN: 02588013, (cited By 13).
@article{Zhu2008,
title = {Quantifying flicker impact of interharmonics},
author = {K Zhu and J Yong and T Tayjasanant},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-54549117997&partnerID=40&md5=42da33f9c01dd41faba5fd73e0d9fe0a},
issn = {02588013},
year = {2008},
date = {2008-01-01},
journal = {Zhongguo Dianji Gongcheng Xuebao/Proceedings of the Chinese Society of Electrical Engineering},
volume = {28},
number = {28},
pages = {113-118},
publisher = {Chinese Society for Electrical Engineering},
abstract = {A limit for interharmonics by utilizing the published limits on voltage flicker is proposed. The limit is presented as an interharmonic-magnitude versus interhar-monic-frequency curve and is called as interharmonic-flicker curve. The interharmonic-flicker curves based on the root-mean-square (RMS) and peak magnitude fluctuations are both derived, as incandescent and fluorescent lamps react differently to voltage RMS and peak fluctuations. The results reveal that the modulation impact of interharmonics on the RMS value is less significant than that on the peak value at high inter-harmonic frequency.},
note = {cited By 13},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Yong, J; Tayjasanant, T; Xu, W; Sun, C
Characterizing voltage fluctuations caused by a pair of interharmonics Journal Article
In: IEEE Transactions on Power Delivery, vol. 23, no. 1, pp. 319-327, 2008, ISSN: 08858977, (cited By 37).
@article{Yong2008,
title = {Characterizing voltage fluctuations caused by a pair of interharmonics},
author = {J Yong and T Tayjasanant and W Xu and C Sun},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-37749045964&doi=10.1109%2fTPWRD.2007.911129&partnerID=40&md5=390ad1ff2118f85bc761843d7b018395},
doi = {10.1109/TPWRD.2007.911129},
issn = {08858977},
year = {2008},
date = {2008-01-01},
journal = {IEEE Transactions on Power Delivery},
volume = {23},
number = {1},
pages = {319-327},
abstract = {Voltage fluctuations and interharmonics have an inherent relationship. The magnitude of voltage waveform can fluctuate if it contains interharmonics. Although the impact of voltage fluctuation caused by a single interharmonic has been understood due to recent research activities, little knowledge is available on the impact of a pair of interharmonics. In reality interharmonics often appear in pairs. The objective of this paper is to investigate voltage fluctuations caused by a pair of interharmonics. Using rms and peak values as indices, the amount of voltage fluctuations caused by a pair of interharmonics is determined. Analytical formulas to estimate the impact are developed. One of the interesting findings of this work is that the voltage fluctuation impact of a pair of interharmonics can be equivalenced into that produced by one interharmonic component. This paper also presents potential applications of the findings. © 2007 IEEE.},
note = {cited By 37},
keywords = {},
pubstate = {published},
tppubtype = {article}
}