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 Thesis presents an analysis of wind turbines in a power distribution system that has a wind power source. By comparing the wind turbine with 3 blades and 4 wind turbines while there is no distribution in the distribution system. And the load is distributed in the distribution system To analyze the differences of these 2 wind turbines analyze the pressure values The power quality in the distribution system that occurs. And able to apply wind turbine energy for sustainability And practices to support the correct power supply In the distribution system and able to provide electricity with efficiency and reliability Wind turbine when connecting to the electricity distribution system There is a significant impact on the power distribution system such as the impact on the power loss. Pressure impact etc. It can be seen that the wind turbine with 3 blades works less than the wind turbine with 4 blades not so much. Therefore the test shows that the analysis of the electricity quality in this distribution system for use as a case study And continue to improve the production of wind turbines in the electricity distribution system.

This thesis presents the Power Quality (PQ) analysis of solar power plant 1MW and economic impacts in the distribution power networks. The case study focuses on the penalty fee (fine) from consume the reactive power less than the limit of the Provincial Electricity Authority (PEA) of Thailand. The fine have been charged up to 900000 baht per year. Therefore the thesis studies and purposes the possible solution by analysing the operating function of the inverter (supports reactive mode) installing the adjustable capacitor bank 1500kVar in the Medium Voltage (MV) level and lastly installing the adjustable capacitor bank 1500kVar in the Low Voltage (LV) level. The results shown that the possible solution that reduces the fine is installed the adjustable capacitor bank 1500kVar in the MV. The investment of this installation is cost 1800000 baht with the nominal operation over 10 years. The analysis of financial investment which bases on the Net Present Value (NPV) the Benefit-Cost ratio (B/C) the Pay Back period (PB) is presented the NPV at 4902971 baht B/C 3.72 and PB 2 year (with the Internal Rate of Return; IRR 49.7 percent).

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.

This paper presents an assessment of the quality of electricity transmission and distribution system to supply power to the industrial area. The objective is to analyze the power quality that customer in the industrial area need high level. By analyzing the power quality of Provincial Electricity Authority (PEA) in transmission system 115 kV distribution system 22 kV and 400/230 volt in Rojana industrial park from power quality meters. The study concluded that the phenomenon occurs continuously consist of RMS voltage power frequency voltage unbalance short term flicker long term flicker Harmonic meet the standards applied to all. The phenomenon occurs temporary consist of transient voltage dip voltage swell interruption in the conclusion the power quality problems caused by voltage dip most especially with loads which are sensitive to voltage. From the moment the measurement showed that the voltage dip on transmission system 115 kV maximum of 19 times. The voltage dip that occur including three voltage level of 30 times there are events that do not pass SEMI F47 standard 12 times or 40%.