จำนวน Repository ( 103 )
การวิเคราะห์ผลตอบสนองความถี่เพื่อประยุกต์ใช้กับหม้อแปลงไฟฟ้ากำลัง
This paper presents an analysis of transformer faults to determine the damage occurring within the transformer by the frequency response analysis (FRA) method. Enter the frequency from 10 Hz to 3 MHz and then the measured value is compared to the standard reference value. Consider the different graphs of frequency response in various frequency ranges to analyze the deformation of the iron cores and transformer coils to know the internal condition of the transformer. The tests show that the 50 MVA 115 kV/22 kV transformer has severe damage to the high voltage side and low voltage side of phase-A coil. As a result the transformer can not be used in the power system and make a reminder to repair the transformer.
การประมาณและการตรวจติดตามผลผลิตข้าวในประเทศไทยโดยใช้การวิเคราะห์ข้อมูลตามยาวและเชิงพื้นที่
The objectives of this research are to propose a model for estimating and detecting rice yields in Thailand to investigate the factors related to the rice yields to find the trend and to construct the maps of rice yields in Thailand. A linear mixed model (LMM) including the spatial effects which follow the conditional autoregressive model (CAR) and the time effects which follow the first-order linear autoregressive (AR(1)) model is proposed. The estimated rice yields are used to construct the rice yield maps in Thailand. The dependent variables are the rice yield in each month of each province. The factors considered are rainfall average temperatures and regions. The results indicate that the factors enfluencing the rice yields are rainfall average temperatures and regions (North Northeast South East West Central region is a refrence region). The trend also effects the rice yields. The rice yeilds maps are easy for readers to identify which areas have high or low yields and easy to compare the yields among areas by looking at their different colors.
การวิจัยเพื่อการพัฒนาปฏิบัติการเคมีวิเคราะห์ : การวิเคราะห์กึ่งจุลภาคเพื่อเป็นมิตรต่อสิ่งแวดล้อม
Analytical chemistry laboratory manual was developed for the student in the Division of Enviromental Science and Technology Faculty of Science and Technology Rajamangala University of Technology Phra Nakhon with the aim of promising the laboratory skill of the student in the preparation and standardize the solution gravimetric analysis volumetric analysis and finally spectroscopy analysis. Traditionally in the analytical laboratory pricey analytical grad of the reagent with large amounts and quantities is required. Moreover some of them are toxic and harmful to the environment. These can cause a problem for the university in which the budget is limited. In this work the idea of the small but powerful experiment was conducted. All the chemical and reagent was reduced to 50%. In the final laboratory instead of costly and toxic reagent some substances were replaced with the natural material such as water extraction from purple cabbage. According to the results the developed experiments were accurate enough for practicing the student except for the precipitation titration experiment. In order to evaluate the understanding a mini-project was assigned to the student in the group. By using the developed manual the student can overcome the problem in the lab and the awareness of the environment was also improved.
การวิเคราะห์ผลทางเศรษฐศาสตร์สำหรับติดตั้งสถานีจำหน่ายไฟฟ้าย่อย
This research study is the application of Geographic Information System (GIS) for distribution substation. The main purpose is to satisfy user by planning to support the increase of load at present and in the future. Moreover increase in creditability of distribution system by increasing new substation or expand the area of exist substation. Then Geographic Information System is necessary for the mentioned reason. Geographic Information System is the process of geographical data in computer system that defined useful information and related to spatial data such as residential property house number location latitude and longitude. Geographic Information System consists of capture store manipulate analyze manage and present all types of geographical data according to user’s objective. So Geographic Information System is the utility that be useful for distribution substation project. The research is planning to use Geographic Information System for finding Break-even point between increasing new substation or expand the area of exist substation which is 2 case studies.
การวิเคราะห์แรงดันตกคร่อมหัวสายเคเบิลใต้ดินที่ใช้รูปแบบการจัดวางสายของการไฟฟ้าส่วนภูมิภาค
System of The Provincial Electricity Authority using the grounding wire connected between the cable end and Surge arrester format it is connect the cable from the end of the cable set to the end of the Surge arrester and grounded wire that splits the ground between the cable connecting point and the Surge arrester format it is a separate grounding connecting point to the cable end and Surge arrester on both sides of cable riser pole by Computer program. Resulting from computer analysis and the comparison of line setting found that if setting line lead to ground and join with ending cable line and Surge arrester lead in to line voltage drop less than setting line to ground with separate line and Surge arrester.