As the worlds energy resources are currently insufficient to meet human needs energy-saving and energy-efficient appliances have to be invented that are readily available and accessible to everyone. To have enough energy to meet human needs and to reduce the waste from the waste of energy resources each year to meet the demand for energy that can be produced by itself. This research presents the construction of a portable DC to AC voltage converter or “Constrution of Portable DC to AC Voltage Converter” which can be operated through a solar cell. By charging energy from the sun and storing energy at the battery. and can also bring electrical energy to use inside the pressure converter There is an inverter circuit that converts voltage from DC to AC so that AC power can be used in daily life. which has a lighting system power socket USB port and helps reduce electricity bills in the house and is convenient to carry From the experimental results of creating a portable DC to AC voltage converter it can be used in daily life and saves electricity and is also clean energy from sunlight that does not cause pollution like a generator that uses oil. be a generator

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

Rail transport is a type of transportation that strongly influences economic due to its ability to transport a large number of passengers and products per trip relying on diesel-electric engines. The objectives of this thesis were set to investigate and develop the electrical performance tracking system of long-distance diesel electric locomotives and compare the electrical performance measured by the diesel electric locomotive performance tracking system and measured from the measuring instrument at Diesel Engine Maintenance Station in Bang Sue. The electric diesel locomotive no. 4513 (Cummins KTA50-L) was selected as the study subject of the experimentation. The results showed that the power loss of the diesel electric locomotive from the conversion of alternating current to direct current was inversely proportional to the engine speed. The power losses between the low and high engine speeds were equal to 77.11 and 2.49 percent respectively. The above data reflects the limitation of diesel electric engine performance and should lead to the construction of a database for making decision on the right engine selection suitable for the towing load of the locomotive.