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.

This research aimed to study the influence of P/E ratio and market capitalization on returns of the securities in the energy sector in the Stock Exchange of Thailand. In this research the researcher has studied and collected data from the closing prices of the securities in energy sector that are currently traded in the Stock Exchange of Thailand. From January 2015 to December 2019 from the Stock Exchange of Thailand 15 companies and used descriptive analysis mean and standard deviation to test the relationship between independent variables by using correlation analysis and multiple regression analysis to determine the influence of P/E ratio and market capitalization on returns of the securities in the energy sector. The results of the research showed that the P/E ratio had a significant positive influence on returns of the energy securities in the Stock Exchange of Thailand. The market capitalization factor also found that it had no influence on returns of the energy securities in the Stock Exchange of Thailand.

The purpose of the research is to devise and implement for testing the ability to absorb energy from vibration. The results are obtained from simulating the operating status of small machines. In order to get the mechanical force from the vibrating of the machine by using piezoelectric materials (PZT) It was found that the size of the piezoelectric materials used in each condition affected the energy absorption. There are variables interested in different diameters at 27 and 35 millimeters. The result shows that the dielectric displacement is directly proportional to the force used but is inversely proportional to the size of the cross-sectional area of the piezoelectric material. In addition the ability to absorb energy in one second is 4.51 volts and has a maximum energy of 7.4 x10 -8joules.

In this study we investigated the effects of Sm2O3 addition in ceramics 0.93(Bi0.5- x/0 . 9 3Smx/0 . 9 3Na0 . 5 ) TiO3 - 0 . 0 7 BaTiO3 by mixing solid oxide solutions. The crystalline properties of the X-ray diffraction and ferroelectric properties were studied from the P - E loop. The physical properties showed that BSNT-BT ceramic density increased and the percentage of shrinkage decreased due to the increase of the amount of Sm2O3. Moreover it was found that the results were consistent with the structural study for sintered samples at a temperature of 950 °C for 7 hours. It can be determined that the BSNT-BT ceramics have a perovskite structure which is like the main structure of ceramic type BNT. Dielectric properties and dielectric losses at room temperature showed that when increasing the amount of Sm2O3 in BSNT-BT ceramics the dielectric and low dielectric loss were consistent with reduced material resistance. Further the ferroelectric test found that BSNT-BT ceramics improved the ferroelectric properties when increasing the amount of Sm2O3 in the BSNT-BT ceramics.

In this study the wind speed characteristic and evaluation of wind power generation at Samoeng district Chiang Mai were investigated using wind speed data and wind direction data during time of January 2011 to December 2011 and measured at a height of 20 40 and 80 m above ground level. It was found that the mean wind speed of 3.8 3.92 and 4.30 m/s. While the mean wind direction of 20.73% and indicating from the southwest. The mean of power density of 107 W/m2 the shape parameter (k) was 1.715 1.633 and 1.783 scale parameter (c) of 3.649 3.651 and 4.092 m/s the mean of wind shear coefficient was 0.19. The evaluation of wind energy for electricity generation by install the wind turbine of Nordex N50 from Germany and Vestas V90 from Denmark were capacity of 800 kW and 3 MW. It could produce annual electricity of 1761379 kWh and 3772400 kWh and the capacity factor show 25.13% and 14.35% respectively. Finally the results showed the northern area of Thailand was suitable for wind power development in further.