Chompoo_Inwai, Chow

Preferred name

Chompoo_Inwai, Chow

Alternative Name

Chompoo-Inwai, Chow

Chompoo-inwai, Chow

Chompooinwai, Chow

Chompoo-inwai, C.

Chompoo-Inwai, Chai Chow

Chompoo-Inwai, Chow Chai

Main Affiliation

School of Engineering

chow.ch@kmitl.ac.th

Now showing 1 - 10 of 31

Some of the metrics are blocked by your
consent settings
Comparision of power loss of three-phase induction motor of four techniques with PWM inverter supply
(2007-12-01)
Tadsuan, S.
;
Suechoey, B.
;
Saelee, V.
;
Chompoo-Inwai, C.
The purpose of this research is to study the power loss in three-phase induction motors linked with a three-phase PWM inverter by adjusting various fundamental wave voltages of the motors. The experimental procedures used four adjustment techniques as: 1. Constant DC link voltage inverter and adjusting the modulation amplitude 2. Constant modulation amplitude equal 1 and adjusting DC link voltage of inverter 3. Sixstep inverter and 4. Constant modulation amplitude equal 2.3 (over mod land adjusting DC link voltage of inverter. The four techniques were used to adjust V/f-type fundamental waves. The results indicated that the adjustment technique showing the power input, power output, power loss and efficiency of the motor. © 2007 RPS.
Some of the metrics are blocked by your
consent settings
An Optimum Technique for Renewable Power Generations Integration to Power System Using Repeated Power Flow Technique Considering Voltage Stability Limit
(2016-01-01)
Wannoi, Chaisit
;
Khumdee, Anurak
;
Wannoi, Narumon
;
Chompoo-Inwai, Chai Chow
This paper presents an optimum location definition and technique for a better placement location of renewable power generations in a wide area power system using repeated power flow technique considering voltage stability limit. In this study, for a better understanding, the author have implemented the newly proposed idea on Thailand's power system especially focusing on renewable generation support plan from the government policy under the current Power Development Plan (PDP 2015). The study results have compared between: 1) installation the renewable generation at the newly recommendation area and 2) installation the renewable generation facilities throughout into distribution system in the Northeastern area of Thailand. The study results focus on impaction to voltage stability when system has load demand increasing and generation capacity decreasing. This study, a Modified-Thailand's power system during peak load in 2013 was used as a system base case with generation capacity around 27,400 MW and load demand around 26,810 MW while system losses 590 MW. The results found that the newly proposed technique can define optimum location for install renewables generation in wide area to enhance system security in term of voltage stability impaction. This technique may also carry to define the installation of other equipment as FACTS devices or define generation dispatch for Automatic Generation Control system (AGC) for power system stability enhancement.
Some of the metrics are blocked by your
consent settings
Automatic Resonance-Frequency Tuning and Tracking Technique for a 1MHz Ultrasonic-Piezoelectric-Transducer Driving Circuit in Medical Therapeutic Applications Using dsPIC Microcontroller and PLL Techniques
(2019-01-01)
Boontaklang, Suttipong
;
Chompoo-Inwai, Chow
Driving ultrasonic piezoelectric transducer (UPZT) at maximum performance in real-time operations is a very challenging task due to the deterioration problem of ultrasound output causing by human-skin impedance fluctuations. This paper proposed ideas and solutions on how to maximize the UPZT driving circuit performance in or deter to solve the deterioration problem. A newly-designed feedback control block with a phase-locked-loop (PLL) technique controlled by microcontroller has been added to the conventional UPZT driving circuit to ensure the automatic resonance frequency tuning and tracking capabilities. After intensive experiments, it is clear that the proposed technique works flawlessly and much more efficient compared to the conventional one. The experimental results also confirm that the percentage of error in tuning to the desired frequency is less than ±0.2% and the speed of tuning convergence time is between 9-12 milliseconds on average.
Some of the metrics are blocked by your
consent settings
ANC System Modeling and Simulations in a Wide-Area Virtual Environment Using FDTD Approach with Perfectly Matched Layer Absorbing Boundaries
(2021-12-01)
Sookpuwong, Chadaporn
;
Chompoo-inwai, Chow
This paper presents a model and simulation results of the active noise control (ANC) system in a wide-area virtual environment using the acoustics finite-difference time-domain (FDTD) propagation approach defined by particle velocities and sound pressure level (SPL) within a certain absorbing boundary conditions called a perfectlymatched layer (PML) technique. The ANC excitation applies a single-frequency noise source with an adaptive feedforward configuration. The FDTD algorithm is used to model the area of interest acoustically, including a desired quiet zone, considering the effects from a primary path, a secondary path, and a feedback path. A processing unit of the ANC system based on the least mean-squared (LMS) algorithm is utilized to synthesize a cancelling noise using a secondary loudspeaker. A single-channel feedforward ANC system used in this paper is modified from the proposed multi-channel models and forms. Acoustics FDTD propagation results can be used to determine the optimum placements for ANC sensors and actuators. The SPL numerical and graphical results are plotted to demonstrate the performance of the proposed ANC system. All of the simulation results confirm that the proposed modeling approach can be combined with wide-area acoustic simulations and a feedforward LMS adaptive algorithm. The proposed model also provides a way for the optimum placement of the ANC sensors and actuators before being used in a more-complex practical environment
Some of the metrics are blocked by your
consent settings
Design optimization of wind power planning for a country with low-medium-wind-speed profile
(2008-10-13)
Chompoo-Inwai, Chai
;
Chompoo-Inwai, Chow
;
Leelajindakrairerk, Monthon
;
Banjongjit, Sulee
;
Fuangfoo, Pradit
The emerging energy crisis resulting from a high price of crude oil has drawn attention about renewable energy all over the world. Thailand is a developing country located at the heart of Southeast Asia, with about 66 million of population as of 2006. The electricity supply industry structure under the government of Thailand has been managed by the Electricity Generating Authority of Thailand, the Metropolitan Electricity Authority, and the Provincial Electricity Authority for almost 50 years. According to the 2004 Power Development Plan, the country would have generation reserve at a marginal of 15%. Due to the rapid economic growth and difficulty in building new centralized generating facilities, this has the potential to create a security issue of electricity energy shortage and may develop a severe system blackout. Renewable energy issues have been widely discussed and debated over the country. Although solar energy is the most prominent renewable energy source due to the appropriate geographic of Thailand, it is still considered as a low-density energy source which requires a large area of installation. Therefore, for the long-term investment, wind power seems to be a good candidate because it is quick to install, needs no fuel cost, and is environment friendly. Therefore, this paper investigates the impact of the penetration level of wind power generation to be integrated into the Thailand system. System stability has been observed in various system configuration changes due to different control strategies of wind farms. The economic analysis of wind-farm investment has been also considered. © 2008 IEEE.
Some of the metrics are blocked by your
consent settings
New techniques the computer-aided design for substation grounding
(2000-01-01)
Phithakwong, B.
;
Kraisnachinda, N.
;
Bayjongjit, S.
;
Chompoo-Inwai, C.
;
Kando, M.
This paper describes the use of software programming for the substation grounding system which is designed for worker's safety. This grounding system presents a new method to increase grounding resistance of the human foot. The new method can decrease the number of conductors of an unequally spaced grid and it is a supplement to ANSI/IEEE std. 80-1986. It also uses 10-30 percent less grounding grid material for safe and economical design. This paper also presents touch and step voltage for a safety design.
Some of the metrics are blocked by your
consent settings
Optimum Generated Power for a Hybrid DG/PV/Battery Radial Network Using Meta-Heuristic Algorithms Based DG Allocation
(2023-07-01)
Abdelwareth, Mohamed Els S.
;
Riawan, Dedet Candra
;
Chompoo-inwai, Chow
This paper presents four optimization outcomes for a diesel generator (DG), photovoltaic (PV), and battery hybrid generating radial system, to reduce the network losses and achieve optimum generated power with minimum costs. The effectiveness of the four utilized meta-heuristic algorithms in this paper (firefly algorithm, particle swarm optimization, genetic algorithm, and surrogate optimization) was compared, considering factors such as Cost of Energy (COE), the Loss of Power Supply Probability (LPSP), and the coefficient of determination (R<sup>2</sup>). The multi-objective function approach was adopted to find the optimal DG allocation sizing and location using the four utilized algorithms separately to achieve the optimal solution. The forward-backward sweep method (FBSM) was employed in this research to compute the network’s power flow. Based on the computed outcomes of the algorithms, the inclusion of an additional 300 kW DG in bus 2 was concluded to be an effective strategy for optimizing the system, resulting in maximizing the generated power with minimum network losses and costs. Results reveal that DG allocation using the firefly algorithm outperforms the other three algorithms, reducing the burden on the main DG and batteries by 30.48% and 19.24%, respectively. This research presents an optimization of an existing electricity network case study located on Tomia Island, Southeast Sulawesi, Indonesia.
Some of the metrics are blocked by your
consent settings
Optical and electrical performance comparisons between high power LED and HMI studio lighting including the engineering economics analysis
(2017-05-19)
Prechaveerakul, Jirasak
;
Chompoo-Inwai, Chow
A superior alternative to the conventional hydrargyrum medium-arc iodide (HMI) luminaires, high power light emitting diode (HP-LED) luminaires are increasingly being utilized in numerous modern lighting designs and applications. Specifically, this research is concerned with the comparative optical and electrical performance and engineering economic analysis of Fresnel-type HMI and HP-LED luminaires for studio lighting applications in the experiments conducted in a real studio environment. The findings revealed that, optically, the Correlated color temperature, luminous flux, luminous intensity and illuminance of the experimental HP-LED and HMI luminaires were comparable. The Color rendering index of the HP-LED was higher and its beam/spread output was more controllable. In the electrical aspect, the results showed that the HP-LED luminaire required significantly less power while producing lower %THD<inf>v</inf> and %THD<inf>i</inf> vis-à-vis the HMI counterpart. The payback period for the replacement of HP-LED luminaires was around 7 years and 7 months, which was shorter than the project life of 15 years. The commercial prospect of HP-LED luminaires is thus brighter as an excellent substitute for the conventional HMI luminaires in myriad applications, particularly in studio lighting for photography, cinematography, and broadcasting.
Some of the metrics are blocked by your
consent settings
Performance comparisons between a single-channel feedforward anc system and a single- channel feedback anc system in a noisy-enviroment classroom
(2017-10-27)
Sookpuwong, Chadaporn
;
Chompoo-Inwai, Chow
Adaptive or Active Noise Control System (ANC) is now widely used in many applications. The problem of interference or noise cancellation is one of the main focuses of the ANC solutions. In this paper, two classic ANC systems called a single-channel feedforward system and a single-channel feedback system will be simulated in MATLAB/Simulink environment for a demonstrative university classroom. This circumstance becomes an interesting issue since the aforementioned classroom is located right next to one of Asia Pacific's largest international airport in Bangkok City, Thailand. A very lousy-noise environment occurs when the time of airplane taking off and landing. Unfortunately, such a noisy environment happens almost every other minute on average. The main idea of this paper is trying to lower the level of the noise during those critical times in the classroom. Two simple ANC systems are brought into account here to see how they perform in resolving the problems in this particular circumstance. The least mean square (LMS) method is used for updating the weight vector in ANC control block diagram in order to achieve the optimal weight vector resulting in minimal errors. How to find bounds on the step size, how to estimate the rate of convergence and the steady-state errors of the proposed LMS method are also elaborated in this paper. The simulation results between two ANC systems will be presented in terms of noise attenuation capabilities and system performances. The discussions and the conclusions presented in this research paper will be used for further analysis to improve the selected ANC system performance before implementing in the real environment in a very near future to come.
Some of the metrics are blocked by your
consent settings
Advanced Design and Implementation of a 2-Channel, Multi-Functional Therapeutic Electrical Stimulator
(2024-10-01)
Lakatem, Rujira
;
Boontaklang, Suttipong
;
Chompoo-inwai, Chow
This research introduces the design, implementation, and rigorous evaluation of a novel 2-channel, multi-functional therapeutic electrical stimulator, meticulously engineered to meet the stringent demands of contemporary clinical applications. The device integrates a high-speed R-2R ladder DAC and a sophisticated pulse generator unit, capable of producing twelve essential current waveforms with fully adjustable parameters, including pulse amplitude, pulse duration, and pulse repetitive frequency. The proposed driving stage unit ensures precise voltage-to-current conversion, delivering stable and accurate output currents even under varying load conditions, which effectively simulate the diverse impedance characteristics of human tissue. Extensive testing confirmed the compliance with international medical standards, notably IEC 60601-1, IEC 60601-1-2, and IEC 60601-2-10. The experimental results underscore the device’s consistent operation within prescribed safety and performance thresholds, with all deviations in pulse parameters remaining well below the permissible limits. Furthermore, the proposed electrical stimulator demonstrated exceptional stability across variable load conditions, as evidenced by minimal amplitude errors and high correlation between waveform characteristics. These findings highlight the proposed device’s robustness and its potential as a versatile tool for a wide range of therapeutic applications, including pain management, muscle stimulation, and nerve rehabilitation, thus marking a significant advancement in the field of therapeutic electrical stimulation.

Chompoo_Inwai, Chow

Filters

Settings

Sort By

Results per page