จำนวน Repository ( 136 )

แบบจําลองการวิเคราะห์การไหลของกําลังไฟฟ้า
แบบจําลองการวิเคราะห์การไหลของกําลังไฟฟ้า

his project presents a power flow analysis model for the purpose of studying power flow in a power system model. At present electric power is an important factor driving the country both in industry and transportation. The demand for electric power tends to increase the production is insufficient to meet the demand. Therefore it is necessary to make the most of the energy resources available in the system. An effective system must be analyzed to detect possible errors. A sudden increase or decrease in load in the system may result in inadequate production and distribution efficiency. Therefore this project is presented for the analysis of power flow in a 3 bus 5 bus and 30 bus power system model using a math simulation program. It is divided into 3 case studies: Case 1 power flow under normal conditions Case 2 transmission line disconnection Case 3 adding distributed power generation sources.

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การปรับปรุงคุณภาพไฟฟ้าในระบบจำหน่ายไฟฟ้าโดยการเชื่อมต่อแหล่งผลิตไฟฟ้าแบบกระจายตัวพลังงานแสงอาทิตย์
การปรับปรุงคุณภาพไฟฟ้าในระบบจำหน่ายไฟฟ้าโดยการเชื่อมต่อแหล่งผลิตไฟฟ้าแบบกระจายตัวพลังงานแสงอาทิตย์

This thesis presents improving power quality in power distribution system with integration of photovoltaic energy distributed generation having objectives to improve power quality in distribution system model of voltage sag and voltage swell in distribution system model of power loss in distribution system application of mathematical model model of power generation by using solar energy and distributed generation connection technique simulation. In this thesis the power flow was tested with Newton-Raphson algorithm joining with mathematical model. The case study was done by reduction of power loss in distribution system by using techniques of connection of distributed generation joining with model of distribution system 33 bus. The case study about improvement of voltage sag and voltage swell in distribution system used connection techniques of distributed generation joining with model of distribution system 69 bus. The study found that technique of connection of distributed generation that was presented could reduce power loss and showed the percentage of improvement of voltage sag and voltage swell in distribution system especially voltage sag case according to IEEE 1159-1995 standard. This thesis showed that severity level of voltage sag depended on the size and duration of each distribution system model situation by photovoltaic energy distributed generation can reduce voltage sag.

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การศึกษาผลของกระแสฮาร์มอนิกส์ต่อค่าสูญเสียของหม้อแปลงไฟฟ้าเลื่อนเฟสและการทำให้เป็นจริงด้วยหม้อแปลงไฟฟ้าเลื่อนเฟส 15 องศา
การศึกษาผลของกระแสฮาร์มอนิกส์ต่อค่าสูญเสียของหม้อแปลงไฟฟ้าเลื่อนเฟสและการทำให้เป็นจริงด้วยหม้อแปลงไฟฟ้าเลื่อนเฟส 15 องศา

The trend of energy savings has been widely interested and phase shift transformers (HMT) have been extensively used. This paper presents the investigation of the effect of harmonic currents on losses of the HMT. In this paper a 15-degree HMT with quad secondary winding is applied to find the relationship between harmonic currents and losses of the HMT. This relation can be met by testing the active power of primary and secondary sides while the HMT supplies for two and four non-linear loads at 25% 50% 75% and 100% rated currents respectively. The results reveal that harmonic currents affect winding eddy current losses significantly and the losses for loading the two secondaries 1 and 2 are the same as loading the two secondaries 1 and 3 while both %THDi are different. However for loading the secondaries 1 and 2 the %THDi is more than 15% so it is not met IEEE 519 Std. while the HMT is supplied with four loads the %THDi has met IEEE 519 Std. and the losses are less than 57% compared to one load. As a result of these if the HMT is applied to an adjustable speed drive system it is not only reduced the harmonics but also saved the energies.

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ผลของอุณหภูมิที่มีต่อค่าความต้านทานและความจุไฟฟ้าของข้าวเปลือกที่มีความชื้นแตกต่างกัน
ผลของอุณหภูมิที่มีต่อค่าความต้านทานและความจุไฟฟ้าของข้าวเปลือกที่มีความชื้นแตกต่างกัน

This research proposes an application of resistive and capacitive soil moisture sensors to investigate the influences of paddy temperature on the electrical signal received from sensors when tested with paddy moisture in the range 9.2 - 22.75%wb at 40 - 80ºC to determine the relationship between paddy moisture and electrical signals. It was found that the mean signal values between 20 - 40 seconds from both sensors were inversely linear correlation with the moisture content of the paddy. Temperature is the factors that influence the measured electrical signal. R2 Adjust R2 (95% confidence interval) and RMSEC showed that the model developed from the resistive sensor signals was accurate in calculating the moisture content of paddy between medium to high temperature in range 60 - 80ºC more than the low temperature range. While the capacitive sensor signals model is accurate in calculating paddy moisture between low to medium temperature in range 40 - 60 ºC. Therefore the resistive soil moisture sensor is possible and more suitable for applying as a paddy moisture sensor in the high temperature drying processes than a capacitor soil moisture sensor.

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การวิเคราะห์แรงดันไฟฟ้าตกในแบบจำลองระบบจำหน่ายไฟฟ้า
การวิเคราะห์แรงดันไฟฟ้าตกในแบบจำลองระบบจำหน่ายไฟฟ้า

Voltage drop is one of the power quality problems affecting power users. This happens due to the higher demand for electric power. Or a short circuit in the transmission system. This causes a voltage drop is one of the power quality problems affecting power users. This happens due to the higher demand for electric power. Or a short circuit in the transmission system. This results in drop in Solving of voltage drop problems in power distribution model with distributed generator were presented with MATLAB program by installing a generator in the distribution system. Therefore simulated a case study 5 case 1 simulation by not installing a generator at any bus case 2 simulation by installing a Generator at bus 1 case 3 Simulation by installing a Generator at bus 18 case 4 simulation by Generator installed at bus 33 and case 5 simulation by Generator installed at bus 13 17 21 31 to study the suitable location of generator installation to solve the problem of voltage drop.

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