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 was studied and transferred the biogas production technology with the community participation using anaerobic dry fermentation system from agricultural residues. The production of renewable energy for replacing LPG in household cooking of Koh Khan Sub-district community Cha-Uat District Nakhon Si Thammarat Province was carried out. The efficiency of the biogas production from different co-digestion material with fresh cow manure was studied for 45 days. The experiment 1 bananas and papaya and the experiment 2 rice straw and coconut meal were used for fermented materials. It was found that the system using rice straw and coconut meal as a fermented material had a higher potential than using bananas and papaya. The system produced averaged biogas of 150 L/d and an average methane content of 67.68% respectively within just 15 days after start-up. While bananas and papaya as fermented materials took more time with more than 30 days after start-up the system. The system produced averaged biogas of 120 L/d and an average methane content of 64.64%. For usability test It was found that 150 L of biogas could continuously cook for 45-60 minutes. The 85% of the technology transfer recipients regarded that the knowledge gained as practical and reduced household expenditures. Additionally the system can produce biogas for a long time without adding new fermented materials. Therefore this biogas system could be applied to local agricultural waste for biogas production which can be expanded to other areas.

The amount of dissolved oxygen (DO) in aquaculture ponds is considered to be one of the most important aspects for the survival of fishes. The water in aquaculture ponds is stratified into distinct layers with different DO caused by differences in temperature. This temperature difference occurs when the surface layer of water heated by the sun becomes hotter than the lower water layer. Since the top layer is in contact with the air it contains the most DO. On the other hand the deepest layer is isolated from the air it contains the lowest amount of DO. This study proposed an aeration system called a Solar Circulating-Water Aeration System (SCWAS). The SCWAS uses solar thermal energy to create a natural water circulation. In other words it provides an upward current of water from the bottom to the pond surface and a downward current from the surface to the bottom. This circulation creates the movement of surface water and then increases the DO content of the surface water. This water circulation moves highly oxygenated surface water to the bottom layer forcing low oxygen water from the bottom up to the surface where it can absorb oxygen. To evaluate this design concept the numerical simulations of the system were conducted using ANSYS Fluent software. According to the simulation results the SCWAS can provide the natural water circulation. It was found that a flow rate of 2.24 L/s is obtained when the ratio between the draft tube inlet (r) the draft tube outlet (R) the base (L) is 1: 2: 3. In addition an SCWAS prototype was built and installed in a tilapia aquaculture system. A calibrated measuring system was installed to investigate the prototype performance. The experimental results indicate that the average DO values at the water surface and at the bottom of the pond increased by 1.45 and 1.40 times respectively compared with those of a pond without SCWAS. Economic analysis shows that the payback period of SCWAS is 4.58 years and its investment cost is 17.49% less than that of the paddle-wheel aerator.

This research objective is to improve the overall equipment effectiveness of the water filtration systems in the case study of the Water Treatment Plant which divides the water production into 4 production lines. The water filtration system has an electric actuator and gear is the main machine in the water filtration system. An electric actuator and gear have more machine breakdowns. That makes the water filtration system is the bottleneck of the water production process. This research study is divided into two steps: the first step is the presentation of the equation and the steps to measure the Overall Equipment Effectiveness of the water filtration system. The equation used data from the computer maintenance management system to analysis on mean time between failure data (MTBF) mean time to repair data (MTTR) and water production process data. The results can be improved the overall equipment effectiveness of the water filtration system increased to 0.11% 0.68% 0.44% and 2.44% respectively in each production process line. And increased Quantity of Filtration Water increased to 328500 m3/year 1168000 m3/year 1022000 m3/year and 3832500 m3/year respectively in each production process line. In this research used the pillar of focus improvement. By adding a protection system to prevent machine breakdown because of the most of the problems are found that the protection system malfunctions. This is the most problem in the 4th And then used engineering knowledge to improve water production and the success factor are required a human resources of all parties to cooperate brainstorm and analyze the causes of various losses in order to eliminate them.

The study of drought factors to analyze and manage water is very important. The main contributing factor to drought is unusual summer weather wind pressure and air mixtures include water vapor and water droplets. In this factors can be analyzed for rainfall in the lower central river basin area and the preliminary data of the research used to analyze drought from Thai Meteorological Department (TMD). This research analyzes the factors that cause drought including rainfall temperature pressure wind and precipitation. The Multiple linear regression analysis used to determine the relationship of factors causing drought. It was found that rainfall had a statistically significant relationship with temperature and pressure. In addition using the Geographic Information System (GIS) an analysis of rainfall in the lower central river basin from October 1920 to September 2021 to found that from August to October there is a lot of heavy rainfall according to the multiple linear regression equation. Therefore the created multiple linear regression equations can be effectively used in the analysis of drought areas in the lower central river basin area.