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.

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 is to develop and experiment the hybrid solar dryer by using cultivated banana as the ingredient in the experiment. The objective is to design create and test the hybrid solar dryer that using heat energy with infrared heater. The result from the experiment of drying cultivated banana at night-time by using heat energy from infrared heater is found that at night-time experiment cultivated bananas moisture is decrease more than at day-times experiment for 61.25 %. The temperature inside the hybrid solar dryer at night when using heat energy from infrared heater is at 49.1-55.0°C. Using heat from sunlight together with infrared heater cause the cultivated bananas moisture to decrease better approximately 27 % when compare to drying with heat energy by only sunlight.

This paper presents a mathematical simulation to compared to operations a small distributed photovoltaic power plant in the distribution system. Practices transmission of electric power by small distributed solar energy With the PVSyst and IEC 61724 mathematical modeling programs the main objective was to study the % performance ratio photovoltaic power plants 5.95 MWp connected in the distribution system of the Provincial Electricity Authority voltage level 22 kV. Therefore this paper is presented as a mathematical simulation compared to operations a small distributed photovoltaic power plant in a distribution system. The results of the study show that the operation of small distributed solar power plants increases the efficiency to be able to produce the maximum electricity and continuously. The system was able to produce the highest power of 8954.9 MWh/year and had an average annual efficiency ratio of 77.84% receiving the highest solar radiation intensity and the highest annual total energy output of approximately 1837 kWh/m2

This research aimed to experimentally study of solar panel efficiency with water cooling. Three mono-crystalline solar panels with the capacity of 80 W (for each panel) were used for this test. The first panel was a solar panel without water cooling. The second panel was a panel with water spray cooling. The last panel was a solar panel with water drop cooling. The cooling water flow rate was varied to 50 75 and 100 LPH. From the test it was found that the temperatures of all solar panels had the similar trends. The solar panel efficiency decreased when the temperature of solar panel increases. The solar panel efficiency increased when the cooling water flow rate was increased for both of water spray cooling and water drop cooling. For all water cooling flow rates the water spray cooling solar panel performed higher efficiency than water drop cooling solar panel. The highest solar panel efficiency in this test occurred when the water spray cooling flow rate of 100 LPH.