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Comparative Study between On- and Off-Grid Photovoltaic to Reduce Peak Demand in Residential Houses
(2026-01-01)
Jettanasen, Chaiyan
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Sottiyaphai, Chayanut
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Bunjongjit, Sulee
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Songsukthawan, Panapong
;
Phannil, Natthanon
This study proposes a programmable logic controller (PLC)-based energy management system integrated with an off-grid photovoltaic (PV) system and battery storage to reduce residential peak demand. The proposed system dynamically manages power supply between the distribution grid, PV generation, and battery storage based on real-time power demand measurements. When the measured power exceeds a predefined threshold, stored renewable energy is utilized to support high-load conditions and mitigate peak demand. Experimental results obtained from a residential-scale test system demonstrate that the proposed off-grid PV system with PLC control can reduce peak demand by up to 29.68% and 15.57% under office-working and work-from-home scenarios, respectively, compared with conventional grid supply and on-grid PV systems without storage. In addition, the system achieves electricity cost reductions of up to 13.63% under Time-of-Use tariffs and up to 11.42% under normal electricity rates, depending on load behavior. These results indicate that integrating PLC-based control with off-grid PV and battery storage can effectively mitigate residential peak demand and reduce electricity expenses under realistic operating conditions.
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Reduction of Impact from Voltage Sags During Faults in Distribution System by Installing Neutral Grounding Resistor
(2025-01-01)
Phannil, Natthanon
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Ananwattanaporn, Santipont
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Pothisarn, Chaichan
This research focuses on a small power producer operating a cogeneration power plant that utilizes natural gas as fuel to generate electricity. The plant, with a capacity of 90 MW, supplies both electricity and steam to industrial customers within a designated industrial zone. Power is delivered to four feeder industrial customers and the Electricity Generating Authority of Thailand (EGAT) at voltage levels of 115 kV and 22 kV. The five customers connected to Feeder 4 at 22 kV experienced voltage sags caused by short circuits in the distribution system. These sags had a significant impact on their production processes, as the machinery in their factories is interdependent and requires high-quality power to function properly. Certain machines, being highly sensitive to voltage fluctuations, stop operating if the voltage drops outside their acceptable range. This disrupts the production process, as the halted machinery must undergo recovery and restart procedures, which are time-consuming. Consequently, this downtime leads to delays and lost revenue opportunities for the affected customers. This issue is a significant concern for factories in industrial estates. Therefore, to address this problem, this research focuses on studying methods to mitigate the impact of voltage sags by installing a Neutral Grounding Resistor (NGR). The study simulates the distribution system during a single line to ground fault. This research examines the effects of voltage sags to inform the design of NGR installations, including investment and cost-effectiveness for resistances of 0, 6, 13, 19 and 26 ohms. Simultaneously, the study also investigates the potential for voltage swell in the distribution system due to the installation of the NGR. The study is conducted using MATLAB Simulink simulations. The findings suggest that installing an NGR with a resistance of 13 ohms is the optimal choice, offering optimal voltage sag, voltage swell, and fault current performance. The budget for the NGR installation by a contractor is approximately 1,000,000 THB, while the total cost for replacing the surge arresters in the system would be 135,000 THB.
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Auto-tuned Active Filter Design for Lighting System in Buildings
(2025-01-01)
Phannil, Natthanon
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Bunjongjit, Sulee
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Ananwattanaporn, Santipont
The lighting system is a continuously used energy system found in all buildings. This system is highly complex as it includes various types such as incandescent bulbs, fluorescent tubes, HID lamps, and LEDs. These types of loads consist of many electronic components and are significant sources of Auto-Tuned Active Filter signals. These harmonic signals directly affect protective devices and electronic equipment in the building's electrical system. Therefore, reducing the harmonic signals generated by the lighting system is crucial for buildings. Generally, harmonic reduction can be achieved by installing one of three types of filters: active, passive, and hybrid. This research presents the design of an auto-tuned active filter using the MATLAB Simulink and tests it using four lighting load cases. The designed circuit can effectively reduce harmonic signals while also improving the energy efficiency of the building.
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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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Ananwattanaporn, Santipont
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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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Very Small Power Plant Transformer Without and With Installation of Neutral Ground Resistance on Relay Operation
(2024-01-01)
Pothisarn, Chaichan
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Chiradeja, Pathomthat
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Yoomak, Suntiti
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Srisuksai, Panu
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Ngaopitakkul, Atthapol
In this study, a double-feeder 22 kV distribution system connected to a very small power plant (VSPP) was simulated in the PowerFactory DIgSILENT program. A neutral ground resistance (NGR) was introduced to reduce a ground fault current from the VSPP, extend the relay operating time to the delay range, and reduce undesired trip of non-faulty feeder that VSPP connected. Thus, the overcurrent protection relay was simulated to analyze working patterns during faults. Three types of VSPP transformer NGR installations were considered: VSPP without NGR, VSPP with a Bisection method approach, and VSPP with the proposed symmetrical component calculation approach. Moreover, this study analyzed the effect of overvoltage on the distribution system with the proposed systematic component calculation approach under fault conditions. The result from the case study indicated that the NGR installation with the proposed approach can reduce the fault current and shift delay time of the protection device to avoid maloperation.
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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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Jettanasen, Chaiyan
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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Downtime Reduction with Fast Restart Function in a Beverage Production System
(2023-01-01)
Jettanasen, Chaiyan
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Phannil, Natthanon
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Yoomak, Suntiti
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Thongsuk, Surakit
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Bunjongjit, Sulee
Bottled-beverage production systems require considerable machinery and sophisticated control systems. A malfunction in the production system can result in machine stoppages, thereby decreasing productivity and resulting in the production output not meeting the required target. Therefore, the problem of frequent stoppages of the production system must be resolved. The ‘Fast Restart Function’ is a proposed feature that can help reduce machine downtime by decreasing the time required for the product to drain from the conveyor. In this study, using this strategy, the investigated manufacturing system’s efficiency increased from 86.81% to 90.29%, enabling an increase in the average production capacity by 27,187 bottles per day, i.e., a 3.48 percent increment of the daily capacity. When employed in inefficient production systems or systems facing frequent shutdowns, this system is of considerable value for mitigating production stoppages.
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Effects of Conditional Changes on High-Voltage Direct Current Transmission Line Characteristic
(2022-01-01)
Pothisarn, Chaichan
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Ngaopitakkul, Atthapol
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Leelajindakrairerk, Monthon
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Phannil, Natthanon
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Bunjongjit, Sulee
The high-voltage direct current (HVDC) transmission system, which links the Gurun Substation of the National Electric Authority of Malaysia (Tenaga Nasional Berhad, TNB) with the Khlong Ngae Station of the Electricity Generating Authority of Thailand (EGAT), has been extensively researched to achieve the highest quality because it is the largest of its kind in Thailand, and there is a plant to expand its transmission power. However, the impact on the whole system is under-researched. To study and develop this system, the HVDC transmission line is modelled with the MATLAB/Simulink program and a laboratory setup to investigate the effect of transmission line distance, load power, and voltage on power loss, voltage drop, and waveform. The HVDC transmission line parameters are calculated from the actual transmission line parameters and converted to the simulation model parameters using the per-unit method. The model is verified and tested by the simulation program before creating the experimental setup. The simulation and experimental results demonstrate the effects of changing system conditions via the three aspects. All the three conditions directly affect the HVDC transmission line; nevertheless, they affect each aspect differently.
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Study on Installation of Neutral Ground Resistance in Very Small Power Plant Transformer
(2022-01-01)
Chiradeja, Pathomthat
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Pothisarn, Chaichan
;
Srisuksai, Panu
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Yoomak, Suntiti
;
Ngaopitakkul, Atthapol
Faults in the distribution system of the Thai electrical system occur frequently. Such faults directly affect the protective equipment of the distribution system. The protective device disconnects the circuit unnecessarily on many occasions because it detects a higher current than expected. In this study, a 22-kV distribution system and a very small power plant (VSPP) were connected. The system consists of two feeders. Feeder 1 supplies electricity directly to the load; a fault was enforced in this feeder. Feeder 2 supplies electricity directly to the load; the VSPP was connected to this feeder. The fault in Feeder 1 was simulated, and the behavior of the defense system was studied. Unnecessary disconnection of the VSPP circuit took place because the high fault current caused the overcurrent protection relay to operate instantaneously. Therefore, a neutral ground resistance was installed at the VSPP transformer to reduce the fault current, extend the relay operating time to the delay range, and reduce unnecessary disconnections of the overcurrent protection relay of the VSPP. In addition, when a fault occurs in the distribution system, the faulted phase voltage decreases, whereas the non-faulted phase voltage increases. Surge arresters and voltage transformers must be able to withstand an increase in voltage. This is also explained and discussed in this paper.
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Design of a Personal Mobility Device for Elderly Users
(2021-01-01)
Phannil, Natthanon
;
Jettanasen, Chaiyan
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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