Bunlaksananusorn, Chanin

Preferred name

Alternative Name

Bunlaksananusorn, C.

Main Affiliation

School of Engineering

chanin.bu@kmitl.ac.th

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Dielectric analysis of degraded stator bars of a hydro generator
(2022-04-01)
Pattanadech, Norasage
;
Phumipunepon, Natnaree
;
Srinangyam, Chissanupong
;
Jeenmuang, Siwakorn
;
Bunlaksananusorn, Chanin
This paper presents the investigation of dielectric analysis of degraded stator bars by Polarization and Depolarization Current (PDC) measurement. The stator bars obtained from the 30-year in-service synchronous machine were divided into two groups. The first group was the unmodified stator bars. The second group was the simulated degradation stator bars which were composed of the thermal stress stator bars, conductive tap abrasion stator bars, multiple air cavity stator bars, multiple oil filled stator bars and multiple water filled stator bars. PDC test experiment was performed with the stator bar samples. PDC test results were analyzed in time domain and in frequency domain with the derived parameters i.e. R<inf>dc</inf>, real and imaginary part of complex capacitance, C ratio, conduction loss factor and polarization loss factor. It was found that PDC shapes obtained from the conductive tape abrasion stator bar and multiple water filled cavity stator bar were clearly different from that of the unmodified stator bar. For other case studies, the derived parameters showed the usefulness in analysis the degraded stator bar characteristics. For example, the increase in the imaginary capacitance and conduction loss factor can be observed from most cases of degraded stator bar test results.
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Analysis design and experimental verification of a two-switch forward converter
(2015-12-01)
Wuti, V.
;
Bunlaksananusorn, C.
A forward converter is an isolated DC-DC converter widely used in switching power supplies with output power ratings ranging from 50W to 400W. The conventional forward converter requires a transformer with a tertiary winding to assist in magnetic core reset and subjects its power switch to a high voltage at turn-off. These shortcomings are eliminated in the two-switch forward converter. This paper presents analysis, design and experimental verification of a two-switch forward converter. First, the converter operation is analyzed, enabling its key equations and important waveforms to be established. Then, the converter design, including both the power circuit and feedback controller, is illustrated in detail. Finally, experimental results from the prototype circuit are presented to confirm the validity of the analysis and design.
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A self-oscillating flyback converter with primary feedback control
(2020-01-01)
Khemmanee, Bundit
;
Bunlaksananusorn, Chanin
Due to its simplicity and low component count, a self-oscillating flyback converter is an ideal topology for cost sensitive applications, such as mobile phone chargers and auxiliary power supplies. To regulate the output voltage, the conventional self-oscillating flyback converter employs a secondary feedback current mode control scheme whose major components include a TL431 error amplifier and optocoupler. These two components nonetheless contribute significantly to a total cost of the self-oscillating flyback converter. A further cost reduction can be achieved, if the error amplifier and optocoupler can be eliminated altogether. This paper proposes a self-oscillating flyback converter with primary feedback control. In the proposed converter, the error amplifier and optocoupler are replaced by a Zener diode, and the output voltage from the auxiliary winding is used as a feedback variable, instead of the actual output voltage from the secondary winding. In the paper, the operation of the proposed converter is described. The prototype converter operating from a 220 V AC main and producing an output of 24 V/0.5 A is fabricated and tested. Experimental results are presented to verify the converter performance as well as to validate the principle of operation.
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Design and evaluation of a Quadratic Buck Converter
(2022-04-01)
Trakuldit, Siripan
;
Tattiwong, Kaweewat
;
Bunlaksananusorn, Chanin
This paper presents design and evaluation of a Quadratic Buck Converter (QBC). A step-by-step procedure to select the converter's component values and semiconductor device ratings is demonstrated. A prototype QBC with a simple closed loop output voltage control is constructed and experimentally evaluated. It is shown that the converter performs well within the design specification, has good output voltage regulation and fast transient response, and achieves the highest efficiency of 82%.
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A novel clamp-mode coupled-inductor boost converter with high step-up voltage gain
(2017-03-01)
Tattiwong, Kaweewat
;
Bunlaksananusorn, Chanin
In this paper, a new coupled inductor DC-DC converter with a high step-up voltage gain is proposed. It is developed from a clamp-mode coupled-inductor boost converter by incorporating an additional capacitor and diode. The proposed converter is able to achieve the higher voltage gain, while still retaining the switch voltage clamp property of its predecessor. In the paper, operation and analysis of the proposed converter are described. Experimental results from a prototype converter are presented to verify the validity of the analysis. The prototype circuit attains the highest efficiency of 92.8%.
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Measurement and Investigation of HB-UWB Transmission Link for BAN System
(2023-01-01)
Sanguanpuak, Chanidaphar
;
Promwong, Sathaporn
;
Bunlaksananusorn, Chanin
The short-range wireless multimedia is consider used a ultra wideband (UWB) technology for human body mobile and multimedia applications shows promise for wireless multi-media systems. Based on IEEE 802.15.6, wireless body area networks (BAN) require understanding the human body’s effects on channel characteristics. This paper presents how to evaluation of human body ulra-wideband (HB-UWB) transmission with line-of-sight and non-line-of-sight scenario. Our research aims to enhance HB-UWB channel propagation on the body media by employing with CLEAN algorithm to eliminate noise. This research leverage findings from previous studies to facilitate performance comparison. Furthermore, for analyze system performance using the CLEAN algorithm at different body positions. The measurement setup covers band the FCC regulated from 3.0 GHz to 11 GHz. It includes the tested with wideband antenna and vector network analyzer (VNA). HB-UWB characteristics are shows in the path loss and power delay profile are discussed as relevant parameters. This research very useful for design and evaluation of human body mobile network and wireless multimedia systems.
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A New Tapped Inductor Buck Converter with Large Step-Down Voltage Conversion
(2023-01-01)
Trakuldit, Siripan
;
Bunlaksananusorn, Chanin
;
Kittiratsatcha, Supat
This paper presents a new DC-DC converter with large step-down voltage conversion. The proposed converter is obtained by cascading an input circuit of a Quadratic Buck Converter (QBC) to a Tapped Inductor Buck Converter (TIBC). It uses only one active switch and provides a wider voltage conversion range than other well-known step-down converters. In the paper, the operation of the proposed converter is described. Circuit analysis is performed to derive the voltage gain and key current and voltage equations. The prototype circuit operating with the input voltage of 150 V, the output voltage of 5 V, the load current of 10 A and the switching frequency of 100 kHz is implemented. Experimental results show that the prototype converter exhibits good output voltage regulation and achieves the 30-to-1 voltage step-down operation with a maximum efficiency of 82%. In addition, measurement results confirm that the converter operation is consistent with the theoretical analysis.
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Output power control using artificial neural network for switched reluctance generator
(2021-01-01)
Kittiratsatcha, Supat
;
Kerdtuad, Paiwan
;
Bunlaksananusorn, Chanin
We propose an output power control of a variable-speed switched reluctance generator (SRG) by implementing an artificial neural network (ANN) in the control loop. In the high-speed operation with single pulse mode, the phase current waveform, and subsequently, the output power, depend on the conduction angles. The conduction angles, i.e., the turn-on and turn-off angles, can be determined by the proposed method using an ANN. A dynamic model of an SRG with eight stator poles and six rotor poles is used for simulation to obtain the output power profiles, which subsequently become the ANN training data. The inputs of the ANN are the reference value of the output power and the rotor speeds, while the outputs of the ANN are the turn-off and turn-on angles. The control algorithm is implemented by integrating the trained data into the dynamic model using MATLAB. The experimental setup of the SRG is implemented using a digital signal processor (DSP) to control the two-switches-per-phase drive system, which includes highly accurate phase current and dc-link voltage sensor circuits. The trained biases and weights of the ANN are also coded in the DSP. To validate the proposed method, comparisons are made between simulation and experimental results.
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Physical and chemical properties’ comparison of natural ester and palm oil used in a distribution transformer
(2023-03-01)
Kittikhuntharadol, Yannaphol
;
Pattanadech, Norasage
;
Maneerot, Sakda
;
Jongvilaikasem, Korraya
;
Jariyanurat, Kittipod
Because of its low cost and suitable qualities, mineral oil (MO) has been commonly employed in transformers. Alternative liquid insulations with great characteristics have recently been presented. Natural ester (NE) and palm oil (PO) are considered alternative liquid insulations. This paper aims to study the physical and chemical properties of NE and PO which were used in a transformer for 21 months. All of the liquid insulation test specimens were sampled every 3 months. Physical properties of the liquid insulation, i.e., interfacial tension (IFT), viscosity, and particles count, were examined. Chemical properties of the liquid insulation, i.e., moisture content, acidity, corrosive sulfur, and furanic compound (2-FAL), were investigated. IFT, particles count, moisture content, acidity, and 2-FAL test results indicated deterioration of liquid insulations of the used liquid insulation; however, there is no observation change for particles amount and acidity of NE. The other test results were not found significantly change.
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Additional parameters for elucidation of the dielectric behavior of stator winding in high voltage motors
(2022-11-01)
Pattanadech, Norasage
;
Phloymuk, Natthawut
;
Nimsanong, Pethai
;
Srinangyam, Chissanupong
;
Jeenmuang, Siwakorn
This paper proposes additional parameters for describing the dielectric behaviors of the stator winding in high voltage motors used in coal power plants. The on-site MV induction motors with indirect air-cooling rated 6.6 kV, 260 to 3091 kW, were investigated. These motors were installed in different parts of the plants and operated under different conditions. Therefore, the stator winding conditions of such motors were different. The integral insulation conditions of stator winding were examined by analysis of the dielectric response. Whereas the local insulation conditions of the stator winding, the so-called weak spot condition, were examined by analysis of the off-line PD test results. To deeply understand the dielectric behavior of such stator windings, a proposed simplified equivalent circuit for modeling the insulation system of the stator winding was introduced and constructed, which aimed to distinguish the dielectric behavior into conductivity, polarization, and ionization mechanisms. The additionally parameters, i.e., the minor capacitance (C<inf>i</inf>), the minor resistance (R<inf>i</inf>), the dc resistance (R<inf>dc</inf>), the minor capacitance at defect site (C<inf>PD</inf>), the conductivity loss factor (Tan δ<inf>σ</inf>), and the polarization loss factor (Tan δ<inf>pol</inf>) were estimated and proposed. It can be concluded that the proposed additional parameters are a valuable tool for assessing the insulation condition, which reduces the ambiguity in the interpretation of the insulation test results and is suitable for monitoring insulation conditions over the service life of the high voltage motors.

Bunlaksananusorn, Chanin

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