จำนวน Repository ( 40 )
การประเมินสมรรถนะการป้องกันฟ้าผ่าในระบบส่งกําลังไฟฟ้า
This Research purposes assessment of lightning performance on transmission system 69 kV in Metropolitan Electricity Authority (MEA). The case studies illustrated the lightning strike to direct top pole in order to guideline considering the critical flashover voltage value of insulator is able to withstand it and improvement lighting protection in the future. This solution analyzes using the Alternative Transient Program-Electromagnetic Transient Program (ATP-EMTP). The result found that voltage across insulator before and after improvement lightning protection by external ground wire. Factor effect to voltage across the insulators is the tower footing resistance wave of lightning current and interval between towers. It depends on relation with front time of wave. The analysis economics is very important. This Research is studying interruption cost of outage since back flashover so analysis the break even point of the installation external ground. The result found upon improvement lightning protection by installed external ground. The pay back period of that is 9 years installed ago. This result can conclusion is external ground able reduction interruption costs of outage.
Compensation of low frequency oscillation on power system using flexible ac transmission systems devices
This paper presents a study of low-frequency oscillations in compensated electric power systems with Flexible AC Transmission System of the power system frequency using PSAT Tool box To assist in the analysis of the stability of the system When the power transients in power systems is simulated By using standard IEEE 14 bus system as a case study. The Equipment that used to control the swing frequency of the is a flexible electrical power control devices or FACTS are two kinds of serial and parallel. The analysis showed that two models are compared with the time (Time Domain) and see the effect of the Eigen (Eigen Value) of the simulation results show work to see that controls are electrical flexible compensation. of low frequency oscillations in power systems in acceptable coordinates
Solving parameters calculation of transmission line with computer program
This paper presents the method to solve the transmission line parameters calculation problem with computer program. The transmission line parameters are an important of power system which calculates the voltage current power and other. Transmission line parameters program is programmed with Delphi in graphical user interface. This program can calculated the resistance inductance and capacitance of single and three phase transmission line. To verify the performance of the proposed program the results are compared with the manual method. The results show that the program method is able to obtained 100 percent accuracy
Determination of metals in some thai tradition medicines using inductively coupled plasma–optical emission spectrometry (ICP-OES)
This research work aims to analyse of metals in thai tradition medicines using Inductively Coupled Plasma–Optical Emission Spectrometry (ICP-OES). The sample groups were divided into four catagories which were Snuff balsam gentian violet and drug pickled liquor. Six metals Aluminium (Al) Cadmium (Cd) Chromium (Cr) Copper (Cu) Magnesium (Mn) and Lead (Pb) were studied. In Snuff the amount of Al was in the range of ND-0.017 ppm the amount of Cd was in the range of ND-0.017 ppm the amount of Cr was in the range of 0.041-0.173 ppm the amount of Cu was in the range of ND-0.244 ppm Moreover Mn content was in the range of 0.633-2.384 ppm. In the case of balsam the amount of Al was in the range of 0-0.575 ppm the amount of Cd was in the range of ND-0.004 ppm the amount of Cr was in the range of 0.025-0.570 ppm the amount of Mn was in the range of 0.460-0.754 ppm whilst none of Cu and Pb was detected. In the case of gentian violet the amount of Cr was in the range of 0.033-0.063 ppm the amount of Mn was in the range of 0.165-0.543 ppm whilst none of Al Cd Cu and Pb was detected. In the case of medicine pickled the amount of Cr was in the range of ND-0.058 ppm the amount of Mn was in the range of ND-0.264 ppm the amount of Ni was in the range of 0-0.034 ppm no metals Al Cd Cu and Pb was observed. The detected metals in thai tradition medicines have the contamination value under the optimization scale for consumable under WHO. It show that some metals were retained in thai tradition medicines and the contamination level of metals in were acceptable.
Design and development of calculation program for magnetic fields intensity of high voltage transmission and distribution lines
This paper presents a program developed for calculating magnetic field intensity of high voltage transmission line and high voltage distribution lines. This program was developed with Microsoft Visual Basic and Microsoft Access program was used to store the database of the peak ratings current height and space of transmission lines. The developed program was able to calculate magnetic field intensity of high voltage transmission line and high voltage distribution lines according to 2 standards of Provincial Electricity (PEA): “A 22 kV Single Conductor Circuit High Voltage Distribution System” and “115 kV Single Conductor Circuit High Voltage Transmission System”. The program was able to select structure of the electrical system to be calculated as well as types and specification of Transmission line from the stored database that corresponded with the structure. The calculated output waveforms were displayed on computer monitor. Results from the developed program enable more convenient and faster calculations of magnetic field intensity of high voltage transmission line and high voltage distribution lines and are useful for analysis of possible impacts on electric and electronic devices.