Pothisarn, Chaichan

Preferred name

Pothisarn, Chaichan

Alternative Name

Pothisarn, C.

Main Affiliation

School of Engineering

chaichan.po@kmitl.ac.th

Now showing 1 - 10 of 80

Some of the metrics are blocked by your
consent settings
Electrical line losses indistribution system with the inclusion of very small power producer
(2012-06-12)
Chiradeja, Pathomthat
;
Pothisarn, Chaichan
Distributed generation is becoming increasingly attractive to the power industry. Several distributed generation technologies such as wind energy systems, solar energy systems, biomass, and biogas are becoming economically viable. Thai government by the Department of Alternative Energy Development and Efficiency has issued the Renewable Energy Development Plan (REDP) in order to promote the usage of renewable energy. In addition, a policy that aims to increase the electric power generation from renewable energy is to expand the amount of electrical power to connect to the distribution system. After the implementing of this policy, both of the numbers and generation capacity of distributed generation who are willing to sell the electric power are significantly increasing. Under this policy, very small power producer (VSPP) has to pay the fee of 2% of its electrical energy sold to electricity utility. The main purpose of this fee is to cover the electrical line losses due to the employment of distributed generation (DG) or VSPP. However, the suitable and fairness for both VSPP and utility is still questionable. The goal of this paper is to analyze the effect of electrical line losses with the installing DG or VSPP into the distribution system. The results of this paper can be used and created the suitable and fairness of the fee for both VSPP and utility.
Some of the metrics are blocked by your
consent settings
Classification of Capacitor Bank Switching Using Fuzzy Interference Systems in 230 kV Substation
(2024-01-01)
Patcharoen, Theerasak
;
Pothisarn, Chaichan
;
Ngaopitakkul, Atthapol
;
Ananwattanaporn, Santipont
;
Lertwanitrot, Praikanok
Flexible AC transmission systems are used for enhancing the stability, transmission efficiency, and reliability of AC grids. Additionally, the most cost-effective devices for compensating reactive power are Mechanically Switched Capacitors (MSCs). This study proposes a novel algorithm for detection and capacitor bank switching transient signals in MSC, to prevent the protective relay maloperation by these transients. The Discrete wavelet transform (DWT) is used for effective time-frequency analysis and detection of measured three-phase current signals. DWT extracts the detailed wavelet coefficients of current signals at levels 1 to 30. In addition, the fuzzy inference system (FIS) has been used to determine the type of switching transient. The proposed combination of FIS and DWT has been tested on 230 kV substation and the result demonstrated precision for the identification and classification of both transient signals in MSC with 88% accuracy rate.
Some of the metrics are blocked by your
consent settings
Coefficient comparison technique of discrete wavelet transform for discriminating between external short circuit and internal winding fault in power transformer
(2012-01-01)
Pothisarn, C.
;
Jettanasen, C.
;
Klomjit, J.
;
Ngaopitakkul, A.
This paper proposes a technique for detecting and identifying internal winding fault of three-phase two-winding transformer which variations of coefficients of high frequency component obtained from DWT of differential current are analyzed. The maximum coefficient details of DWT are performed as comparison indicator in order to discriminate between internal fault and external short circuit. Various cases based on Thailand electricity transmission and distribution systems are studied to verify the validity of the proposed algorithm. Results show that the proposed technique has good accuracy to detect fault and to identify its position in the considered system.
Some of the metrics are blocked by your
consent settings
Effects of Conditional Changes on High-Voltage Direct Current Transmission Line Characteristic
(2022-01-01)
Pothisarn, Chaichan
;
Ngaopitakkul, Atthapol
;
Leelajindakrairerk, Monthon
;
Phannil, Natthanon
;
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.
Some of the metrics are blocked by your
consent settings
A phase diagram approach to the detection and location of faulty capacitor units in A 115-kV capacitor bank based on unbalanced current arguments
(2023-03-01)
Pothisarn, Chaichan
;
Lertwanitrot, Praikanok
;
Ngaopitakkul, Atthapol
The protection of traditional high voltage capacitor banks relies on an unbalance relay which operates when an internal fuse is blown. However, the unbalance relay cannot indicate cause or position of the fault. Thus, an operator wastes time and human resources investigating the fault issues. To address this issue, a method to locate the fault position in a capacitor bank is developed in this study. The study was simulated by using PSCAD software and modeled on the 115-kV system of the Electricity Generating Authority of Thailand (EGAT). Case studies involving faults with varied phases, side and branch connections, row connections, and inception angles were considered. Moreover, the magnitude and argument of the current phase and unbalanced current were analyzed to identify the fault location in a capacitor bank. The performance of the proposed method was verified via comparison with that of traditional methods and the results of laboratory experiments. In addition, various voltage systems were observed to verify the flexibility and accuracy of the proposed method. The results demonstrate that the proposed method was more efficient than traditional methods at locating the fault position in a capacitor bank.
Some of the metrics are blocked by your
consent settings
Performance and electromagnetic compatibility of a photovoltaic power converter
(2017-07-02)
Jettanasen, C.
;
Pothisarn, C.
This study aims to evaluate the performance of DC-DC converter in photovoltaic system. Electromagnetic compatibility (EMC) characteristics, issues and its effect on photovoltaic power converter are performed and taken into consideration. ĆUK converter has been built in this research. The proposed filter circuit is also created and integrated in ĆUK converter in photovoltaic system, and tested in field testing. The EN 55011 standard has been applied as a reference in order to verify the performance of the proposed filter circuit in terms of Electromagnetic Interference (EMI) reduction in actual application.
Some of the metrics are blocked by your
consent settings
Behaviour analysis of H-bridge high-voltage capacitor banks fault on 230-kV substation using discrete wavelet transform
(2023-11-01)
Chiradeja, Pathomthat
;
Lertwanitrot, Praikanok
;
Ngaopitakkul, Atthapol
;
Pothisarn, Chaichan
The protection of traditional high-voltage capacitor banks relies on an unbalance relay which operates when an internal fuse is blown. However, the unbalance relay cannot indicate the cause of the fault. Thus, an operator wastes time and human resources investigating the fault issues. In this paper, a fault which occurred in a 230-kV power system of Electricity Generating Authority of Thailand was observed by performing simulations using the Power Systems Computer Aided Design (PSCAD) program. The study system based on the double bus station and 72 MVAR capacitor banks was installed in the form of a back-to-back topology. Three scenarios were considered: normal condition, fault occurrence in one capacitor bank and fault occurrence in both capacitor banks. Current characteristics such as the current phase and difference in unbalance current were considered. In addition, discrete wavelet transform was applied to solve the ambiguity of current generated from the PSCAD. The authors’ results suggest that identifying fault events using a coefficient of wavelet is more efficient than relying on the current amplitude. The findings mentioned in this paper can be applied in a traditional power system protection scheme to enhance a system's reliability.
Some of the metrics are blocked by your
consent settings
Reduction of Impact from Voltage Sags During Faults in Distribution System by Installing Neutral Grounding Resistor
(2025-01-01)
Phannil, Natthanon
;
Ananwattanaporn, Santipont
;
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.
Some of the metrics are blocked by your
consent settings
An Evaluation Study on Electric Appliance Characteristics and Load Patterns in Residential Buildings
(2026-01-01)
Thongsuk, Surakit
;
Songsukthawan, Panapong
;
Ananwattanaporn, Santipont
;
Sottiyaphai, Chayanut
;
Ngaopitakkul, Atthapol
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.
Some of the metrics are blocked by your
consent settings
Relation among velocity of lightning travelling wave, lightning stroke current, and tower footing resistance to study back-flashover on the insulators in transmission tower
(2013-01-01)
Pothisarn, C.
;
Thongsuk, S.
This paper studies the impact of back-flashover on the insulators with various velocities of lightning travelling wave, the lightning stroke current, and the tower footing resistance. The impedance of transmission tower section such as top tower, upper phase, middle phase, and lower phase that is calculated with lightning velocity dependent parameters is also considered. The velocity of lightning travelling wave at 300 m/μs and 200 m/μs is compared to consider back-flashover including maximum voltage at the cross arm and voltage across insulators. The results is shown that the velocity of lightning travelling wave plays an important role for the back-flashover voltage across insulator as well as the tower footing resistance and the lightning stroke current. © 2013 Praise Worthy Prize S.r.l. - All rights reserved.

Pothisarn, Chaichan

Filters

Settings

Sort By

Results per page