Now showing 1 - 10 of 32
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    Design and application of daylight-based lighting controller on LED luminaire
    (2020-05-01)
    Bunjongjit, Sulee
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    Patcharoen, Theerasak
    This paper proposes a control circuit for Light Emitting Diode (LED) luminaire based on the amount of daylight. This system uses both natural daylight and artificial light from a luminaire to reach the desired illuminance on a working plane. The control circuit operates by receiving an illuminance value from a light sensor and comparing it with a set value in the microcontroller before limiting the light intensity of LED by sending a control Pulse Width Modulation (PWM) signal to the LED driver. In the experimental setup, the controller and a physical model of a working space were built in order to field test the LED daylight control circuit. Electrical characteristics such as voltage, current, and power were measured with a power meter. Illumination characteristics in terms of illuminance on a working plane were determined using a lux meter. The results from actual field tests revealed that this LED control circuit was able to reduce the power consumption of the lighting system while keeping the illuminance on the working plane at the standard value. Both simulation results and the actual experiment of the control circuit proved that it could be used to improve the energy efficiency of both newly installed and retrofitted lighting systems.
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    An Evaluation Study on Electric Appliance Characteristics and Load Patterns in Residential Buildings
    (2026-01-01)
    Thongsuk, Surakit
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    Songsukthawan, Panapong
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    Sottiyaphai, Chayanut
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    Energy usage in residential buildings has been constantly increasing as work-from-home trends continue to maintain popularity. To improve energy efficiency, the load profile and electric appliances in households need to be established and analyzed. This study aims to evaluate the characteristics of electric appliances that are commonly used in residential buildings under various operating conditions. An experimental setup with household electric appliances was built, and power quality meters were installed to assess the patterns under various operating conditions. In addition, the usage patterns were used to construct the daily load profile and analyze the energy consumption in residential buildings. The results demonstrate that load patterns constructed from actual measurements can achieve an accurate depiction of energy usage in residential buildings. The obtained load profile can be used in load control to improve energy efficiency and the application of renewable energy in demand reduction.
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    Transient Analysis to Distinguish Mechanically Switched Capacitors Using Discrete Wavelet Transform and Artificial Intelligence
    (2026-01-01)
    Thongsuk, Surakit
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    Bunjongjit, Sulee
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    ; ;
    Capacitor banks are widely used in modern power systems for reactive power compensation and voltage regulation. However, switching operations of mechanically switched capacitors (MSCs) can generate transient phenomena, such as inrush currents, which may resemble fault currents and lead to misoperation of protection systems. Therefore, accurate detection and classification of transient events are essential for reliable system operation. This study proposes a hybrid approach for transient signal analysis and classification by integrating the discrete wavelet transform (DWT) with artificial intelligence (AI) techniques, including probabilistic neural networks and fuzzy inference systems (FIS). The DWT performs time–frequency analysis to extract multi-scale wavelet features from three-phase current signals. The proposed method enables both discrimination between inrush and fault currents and multi-class classification of transient events among six capacitor switching conditions, namely base case, pre-insertion resistor, pre-insertion inductor, current limiting reactor, 6% reactor, and synchronous closing. The methodology is validated using PSCAD/EMTDC simulations under isolated and back-to-back capacitor switching scenarios. The results demonstrate that the proposed DWT–AI approach achieves high classification accuracy exceeding 95%, outperforming conventional methods based on DWT alone and DWT combined with FIS. Furthermore, the proposed method improves protection system performance by reducing false tripping caused by transient inrush currents, while maintaining reliable fault detection capability. The findings confirm that integrating time–frequency signal processing with AI-based classification provides an effective and practical solution for transient event discrimination in MSC capacitor bank systems.
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    Development of micro-mobility based on piezoelectric energy harvesting for smart city applications
    (2020-04-01) ;
    Songsukthawan, Panapong
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    This study investigates the use of an alternative energy source in the production of electric energy to meet the increasing energy requirements, encourage the use of clean energy, and thus reduce the effects of global warming. The alternative energy source used is a mechanical energy by piezoelectric material, which can convert mechanical energy into electrical energy, that can convert mechanical energy from pressure forces and vibrations during activities such as walking and traveling into electrical energy. Herein, a pilot device is designed, involving the modification of a bicycle into a stationary exercise bike with a piezoelectric generator, to study energy conversion and storage generated from using the bike. Secondly, the piezoelectric energy harvesting system is used on bicycles as a micro-mobility, light electric utility vehicle with smart operation, providing a novel approach to smart city design. The results show that the energy harvested from the piezoelectric devices can be stored in a 3200 mAh, 5 V battery and power sensors on the bicycle. Moreover, 13.6 mW power can be generated at regular cycling speed, outputting 11.5 V and 1.2 mA. Therefore, the piezoelectric energy harvesting system has sufficient potential for application as a renewable energy source that can be used with low power equipment.
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    The conducted emission attenuation of micro-inverters for nanogrid systems
    Road lighting systems require a significant amount of electric energy. To compensate for the utilized energy, the concept of a nanogrid road lighting system is presented. A solar panel is installed on the top of a lighting pole to generate electric power. In this research, a photovoltaic simulator (PV simulator), which is used to simulate solar behavior such as current, voltage, and power based on temperature and solar irradiance levels, is employed to replace a solar panel. In the nanogrid system, grid-connected and stand-alone micro-inverters are employed to convert the electric power. The inverters comprise switching devices that can generate electromagnetic interference (EMI) when operating, which is harmful to the grid system and the electrical equipment. In general, EMI has been studied and reduced in electrical appliances, which only receive electric power. However, for the nanogrid system, which supplies electricity to the grid system, there is less study on the EMI topic because the usage is still not widespread. In the future, the nanogrid system will be widely used delivering high power directly into the electrical grid system. Therefore, the study and attenuation of EMI in the nanogrid system are very promising. Conducted emission (CE) is one form of EMI that flows through a cable connecting several appliances in the frequency range of 150 kHz to 30 MHz. CE of grid-connected and stand-alone micro-inverters have high levels in the low-frequency range between 150 kHz-5 MHz and then decreases steadily. CE attenuation is important for this inverter in a solar power system. This research studies the effect of CE mitigation on the nanogrid system. The result is compared with the Comite International Special des Perturbations Radio (CISPR) 14-1 standard. Finally, the passive EMI filter can reduce CE and meets the CISPR 14-1 standard.
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    Design of a Personal Mobility Device for Elderly Users
    (2021-01-01)
    Phannil, Natthanon
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    The ageing society has resulted in imbalances in the population age ratio. The ratio of working-age people was less than that of elderly people resulting in a shortage of elderly caregivers and increased healthcare costs. Although the lifestyle the elderly remains the same, their physical abilities are reduced, requiring them to rely on special equipment when traveling in order to gain more control and safety. Therefore, the Elderly Personal Mobility Device (EPMD) is developed using Internet of Things (IoT) technology to reduce the burden of caregivers, provide freedom and safety for elderly travelers, assess air pollution risks, and alert the occurrence of emergency events. The EPMD is designed in terms of structure, electrical equipment, and sensor systems. First, the shapes, sizes, and thicknesses of the carbon steel used for construction of the EPMD structure are calculated by using SolidWorks software. Next, the electric equipment is carefully selected to meet the requirements of actual use. Finally, the sensor system is designed to monitor the EPMD status and air quality using IoT devices to create a data interface and big data for elderly health service development, as well as an air quality map with distributed measuring stations and a charging station detection system for future use.
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    Item type:Publication,
    Distributed Temperature Sensing and Real Time Thermal Rating for Underground Power Cable Monitoring
    (2025-01-01)
    Tangtheerajaroonwong, Wiroj
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    Tanapornchinpong, Phiphat
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    Kiatjaroonlert, Boonsak
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    Khan-Ngern, Werachet
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    Sangracha, Chanintorn
    This paper presents the distributed temperature sensing (DTS) technology and its application mainly on underground power cables. The main measuring principle is detecting the back-scattering light via Raman scattering that varies and depends on temperature at each point of optical fiber. In this paper, the authors present the monitoring results that the load current is applied for 50% of the rated current of the 69 kV and 115 kV transmission cables, and the DTS detects temperature increasing 0.5°C from the ambient temperature. This paper also shows real time thermal rating for calculations of conductor temperature.
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    Design and Simulation of Removable Pavement Edge Climbing Electric Wheelchair for Elderly and Disabled Users
    (2023-06-01)
    Phannil, Natthanon
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    In the urban areas of Thailand, those who travel in wheelchairs face a major hurdle owing to infrastructure construction that is not conducive to the use of wheelchairs. Specifically, such construction has a non-conducive design for practical use and long distances; it exposes wheelchair users to the burden of neglect. Furthermore, it is difficult to adjust finished buildings to satisfy the needs of wheelchair users, because this process is time consuming and costly. Therefore, numerous studies have proposed the development of wheelchairs that can be used in various environments as an alternative approach. However, most wheelchair users already have their personal wheelchairs, thus making it difficult to consider purchasing a new special wheelchair. Considering such problems and limitations, this study focuses on the design concept of an accessory (a track-based wheel) for retrofitting a standard wheelchair to enable the pavement edge-climbing function. The combination of a standard wheelchair and an accessory is termed as a removable pavement edge-climbing electric wheelchair. This development involved the design of the track-based wheel structure, static simulations, and dynamic simulations. Moreover, the effects of changing the seat angle, payload, motor speed, and step height on the power and torque of the drive motor, movement speed, angle of the track-based wheel, and linear actuator force were studied to determine the suitable specifications of the motors and linear actuators for the future track-based wheel prototype.
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    An Approach for Voltage Drop Improvement in Distribution Line Using High-Voltage Capacitor Bank
    (2025-01-01)
    Songsukthawan, Panapong
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    Thongsuk, Surakit
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    Phannil, Natthanon
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    Bunjongjit, Sulee
    Distribution line voltage drops cause power losses and a general decline in the efficiency of the electrical power system. In this study, PSCAD software is used to evaluate the elements that impact the voltage drop in the distribution line, including distribution line length, electric load power factor, and electric load capacity, both with and without capacitor bank installation. The 22-kV overhead distribution line in Thailand served as the basis for the simulation model’s creation. It has been suggested to install capacitor bank-based techniques to increase voltage on distribution lines. The findings show that the voltage drop is significantly influenced by the distribution line distance, electric load power factor, and electric load capacity. The voltage drop can be minimized to the greatest extent by properly arranging capacitor banks.
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    Exploration of Sign Language Recognition Methods Based on Improved YOLOv5s
    (2025-03-01)
    Li, Xiaohua
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    Chiradeja, Pathomthat
    Gesture is a natural and intuitive means of interpersonal communication. Sign language recognition has become a hot topic in scientific research, holding significant importance and research value in fields such as deep learning, human–computer interaction, and pattern recognition. The sign language recognition process needs to ensure real-time performance and ease of deployment. Based on these two requirements, this paper proposes an improved YOLOv5s-based sign language recognition algorithm. Firstly, the lightweight concept from ShuffleNetV2 was applied to achieve lightweight characteristics and improve the model’s deployability. The specific improvements are as follows: The algorithm achieved model size reduction by removing the Focus layer, using the ShuffleNetv2 algorithm, and then channel pruning YOLOv5 at the head of the neck layer. All the convolutional layers and the cross-stage partial bottleneck layer with three convolutional layers in the backbone network were replaced with ShuffleBlock, the spatial pyramid pooling layer and a subsequent cross-stage partial bottleneck layer structure with three convolutional layers were removed, and the cross-stage partial bottleneck layer module with three convolutional layers in the detection header section was replaced with a depth-separable convolutional module. Experimental results show that the parameters of the improved YOLOv5 algorithm decreased from 7.2 M to 0.72 M, and the inference speed decreased from 3.3 ms to 1.1 ms.