KMITL

Permanent URI for this communityhttps://dspace.kmitl.ac.th/handle/123456789/1

Browse

Search Results

Now showing 1 - 8 of 8

Some of the metrics are blocked by your
consent settings
Induced current estimation algorithm of gas insulated line
(2018-07-02)
Thungsook, K.
;
Sontayananon, N.
;
Chuayin, C.
;
Nganpitak, T.
;
Chamnong, C.
This paper presents the analysis of induced voltage and induced current in enclosure pipe of three-phase gas-insulated transmission line. The induced current and induced voltage are carried out so that generalized mathematical model can be obtained. The current is derived based on electromagnetics theory. The estimated results are compared with the measured results. The highest error from the comparison between the computed and actual data is 12.89% because a large amount of induced current cannot be measured accurately.
Some of the metrics are blocked by your
consent settings
Breakdown characteristics and partial discharge phenomena of gas-insulated system under slightly nonuniform electric field with floating object
(2018-07-02)
Chuayin, C.
;
Chamnong, C.
;
Sontayananon, N.
;
Kachachaveevong, T.
;
Nganpitak, T.
The characteristics of breakdown voltage of air under slightly non uniform field with floating object was investigated experimentally. The sphere-plane electrodes with sphere diameter of 4.5 cm and plane diameter of 10 cm were used to study. The gap spacing between the sphere-plane electrodes was fixed at 3 cm. In this paper, the floating objects were divided into 2 types according to types of materials used, i.e., aluminum material represents a conductive particle and plastic material represents a nonconductive particle. The floating object position was varied between the sphere-plane electrodes in the test chamber. It was found that both types of floating objects clearly had negative effect on the breakdown voltage. Moreover, to more understand the effect of these floating objects, an ultra-high frequency sensor was used to detect partial discharge signal occurring during the experiment before breakdown occurred.
Some of the metrics are blocked by your
consent settings
Passive EMI filter performance improvements with common mode voltage cancellation technique for PWM inverter
(2007-12-01)
Khun, C.
;
Khan-Ngern, W.
;
Kando, M.
The common modulation strategy adopted for motor control in adjustable speed drives (ASDs) is pulse width modulation (PWM). The carrier frequency along with fast rise and fall time of the IGBTs employed results in non trivial common-mode (CM). The high dv/dt and di/dt causes shaft-voltage, which leads to bearing currents. This phenomenon has been well-known as one of the reason for premature bearing failure in PWM drive motors. To reduced EMI emission, this paper presents the experimental works that investigate the conducted emission from pulse width modulated (PWM) inverter feeding an induction motor using CM voltage cancellation technique to develop the ability of conventional passive EMI filter. The typical passive EMI filter also use in this work to compare and prove the effectiveness proposed method. The experimental results of two operation conditions: with load and without load are verified the effectiveness of proposed filters, respectively. © 2007 IEEE.
Some of the metrics are blocked by your
consent settings
Modeling for PWM Voltage Source Converter Controlled Power Transfer
(2004-12-01)
Douangsyla, S.
;
Indarack, P.
;
Kanthee, A.
;
Kando, M.
;
Kittiratsatcha, S.
In this paper, a model for PWM Voltage Source Converter (VSC) Controlled Power Transfer has been developed. A vector control strategy with PI controllers is proposed. This paper studied the PWM Voltage Source Converter connected to an active ac network with vector control strategy. PWM pattern generation is based on a carrier technique. The instantaneous 3-phase voltages and currents are transformed to a 2-axis (d-q) reference frame system [1] which rotates at the supply angular frequency (ω<inf>e</inf>). Thus it is possible to have decoupled control of the active (P) and reactive (Q) power flow and it is necessary to develop a mathematical model for VSC to determine controlling variables. The design and the performance of controllers are investigated. Digital simulation shows the feasibility of the proposed control strategy.
Some of the metrics are blocked by your
consent settings
The result analysis of economic distribution transformer design in Thailand
(2002-12-01)
Suechoey, Boonlert
;
Bunjongjit, Sulee
;
Kando, M.
Thailand's medium-sized industries, with demands rating from 30 - 999 kW., currently need to develop distribution transformers that provide the highest efficiency regarding the transformer low losses and lowest costs. This is partly because the energy authorities that provide the electricity have fixed the transformer losses. In this paper, the result analysis of transformer design is presented. The considered factor include efficiency, losses throughout the transformer costs. The analysis includes an example of calculation and selection.
Some of the metrics are blocked by your
consent settings
Fault diagnosis in transmission lines using wavelet transform analysis
(2002-12-01)
Makming, Pongsak
;
Bunjongjit, Sulee
;
Kunakorn, Anantawat
;
Jiriwibhakorn, Somchart
;
Kando, M.
This paper presents a new method to diagnose faults in a transmission system, This is based on detecting high frequency components contained in a fault signal spectrum. The Discrete Wavelet Transform (DWT) is used in the analysis in order to classify fault types and to locate fault positions. Simulations are performed using ATP/EMTP. It is found that the proposed method gives satisfactory results, and will be very useful in the development of a power system protection scheme.
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
An analysis and selection of distribution transformer for losses reduction
(2000-01-01)
Suechoey, B.
;
Ekburanaway, J.
;
Kraisnachinda, N.
;
Banjongjit, S.
;
Chompoo-Inwai, C.
Thailand's medium-sized industries, with demands ranging from 30-1999 kW., currently need to select transformers that provide the highest efficiency regarding transformer losses. This is partly because the energy authorities that provide the electricity have fixed the loss ratio values for transformers. In this paper, an analysis of how to select the suitable size of transformer is presented. The considered factors include efficiency, losses, rating, capital cost throughout the transformer commission time, the cost of the energy, and % interest rate. The analysis includes an example of calculation and selection.

KMITL

Browse

Filters

Settings

Sort By

Results per page

Search Results