จำนวน Repository ( 3447 )
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.
การตรวจจับกระแสฮาร์มอนิกสําหรับตัวกรองฮาร์มอนิกแบบแอคทีพชนิดปรับ ค่าได้เอง โดยใช้ขั้นตอนวิธีแบบ RLS
This thesis proposes a method for detecting harmonics current in the adaptive active harmonic filter with Recursive Least Square (RLS) algorithm. The proposed method is based on the theory of noise cancellation adaptive filter. Originally the theory was used for audio signal processing but this thesis is applied to the harmonic current detector of an active harmonic filter. The principle and construction of the harmonic current detector in the adaptive active harmonic current filter with Least Mean Square (LMS) algorithm and Recursive Least Square (RLS) algorithm are presented to compare the efficiency of both algorithms. Then simulate these two algorithms with Matlab-Simulink program to simulate the three case studies. All three case studies that simulate are generally available in industrial plants. The simulation results show that the harmonic current detector in the adaptive active harmonic current filter with the LMS algorithm and the RLS algorithm can detect the harmonic currents in the power systems. However the RLS algorithm is more efficient and has less error value than the LMS algorithm. Therefore it is confirmed that the RLS algorithm proposed in this thesis is appropriate to use with the adaptive active harmonic current filter to really work in the industry.
การปรับปรุงตัวประกอบกาลังด้วยวิธีการควบคุมกาลังไฟฟ้ารีแอคทีฟ
To Improvement the power factor is very important. Because the costs are increased or reduced. To Improvement the power factor the higher the value it is necessary to buildings offices and industrial buildings or the fact that the industry needs real power. And reactive power source to operate. This paper presents the design and construction of reactive power factor control. Which amounted to 6 working order by the first sequence is divided into three three-phase electrical power system and three consecutive singles phase by active power different. first1 is reactive at 5 kVAr second 2 and third 3 are reactive at 2.5 kVAr forth 4 fifth 5 and sixth 6 precious marine active 0.83 kVAr control. the power factor controller that controls RG3-12 pay Oval active in various sequences. As a result when not equipped with reactive power compensation software to control the power factor. This makes the flow of the high and low Power Factor schedule. When equipped compensate reactive power source to power factor control. Single-phase motor 1 kW and light bulb 164-watt making the current decline of 14 amps rest 12 amps of the power factor increases from 0.5 to 0.929. When connected to three-phase motor with 2 kW 0.82.2 flow down from 2.360 rest 0.942 amps of power factor value up from 0.308 to 1.0.
แผ่นเกราะเซรามิกส์กันกระสุนด้วยวัสดุเชิงประกอบ
This research has been studied and created the ceramic armor plates with composite materials that been proceeded from drying compression process with mold. Al2O3 that use for compression forming has been analyzed by SEM and XRD. It showed that compound and powder particle led to 5 microns-sized. It had flat circle shape of colundum Al2O3 and hexagonal crystal system. Upper punch of molding has designed and analyzed by FEA to 2 forms first form was the end-point had flat face and second form was the end-point had a convex. Upper punch had been made from AISI 52100 with 64 HRC ceramic armor plate had been produced by compression at 1000 kN which had hexagon side shape of width 25.98 mm for each side or height between parallel side of 45 mm. Al2O3 had been compressed to investigate the distribution of relative density for the height after compression of 15 and 30 mm by analyzing 4 cases that consist of 1.) a case of smooth face of upper punch which has green compact of 15 mm height 2.) a case of convex face of upper punch which has green compact of 15 mm height 3.) a case of smooth end face of upper punch which has green compact of 30 mm height 4.) a case of convex face of upper punch which has green compact of 30 mm height. The result of this study is to propose the distribution of relative density on horizontal axis as it is a relative radius and vertical axis is a relative distance from the upper punch that is an axis of moving down action. This study found that the distribution of relative density form had analogous form for these 4 cases the density had few differences and had high value at the town edge of green compact due friction between die wall and upper punch. The ceramic armor plate has been set up on UHMWPE fiber plate and used special silicone to connect them together then will get the NIJ 3 standard of ceramic armor plate with Composite materials
การเพิ่มความน่าเชื่อถือได้ของระบบไฟฟ้าสำหรับรถไฟฟ้าขนส่งมวลชน
The propose of this research present a comparative study of the Reliability Improvement of Electrical System for Electric Mass Rapid Transit Train which describes in term of the power supply efficiency including voltage imbalance that could indicate how much the electric power quality is being more or less. The electrical system to be used in the Mass Rapid Transit system has 4 types of connection between three (3) phases of Metropolitan Electricity Authority (MEA) transformer and station transformer which is Single phase V-Type Scott and Le- Blanc to be considered for the different transformer connections type could be carried out and resulted in the most unbalanced in power supply as well as properly solution for power supply mitigation of voltage imbalance. From foregoing the data analyst was discovered that a single phase connection could cause the most unbalance voltage but on the other hand Le-Blanc connection is the least unbalance which could be reduced the impact on the Mass Transit Train and increase the credibility of consumers in order to continuity implement service usage.