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 presents an Analysis of Voltage Sags on the Installation of Distributed Generation in the Distribution System. The computer program PSCAD/EMTDC (Power Systems Computer Aided Design / Electromagnetic Transient in DC system) version 4.2 is applied to provide electrical parameters for the modeling and simulation and to analyze the fault occurred which resulted in voltage sag. Test results from PSCAD/EMTDC show the values of voltage sag when 5 types of fault are occurred (Single Line to Ground Fault Double Line to Ground Fault Three Phase to Ground Fault Line to Line Fault and Three Phase Fault). For all cases the value of root mean square voltage before fault is 100% or 1.0 pu. It can be seen that for both radial line and closed circuit when DG are installed in the system the value of phase to ground RMS residual voltage and phase to phase RMS residual voltage at the bus of Bang-pa-in 2 substation are more than the values in case of the system without DG.

This paper presents reliability evaluation in distribution system with distributed generation. The main objective is to minimize the customer interruption cost subject to given number of distributed generation. The minimization problem for customer interruption cost in solved by the developed tabu search algorithm together with reliability worth analysis that provide an indirect measure for cost implication associated with power outages. The developed methodology is tested with a distribution system of Roy Billinton Test System (RBTS) bus 2 consist of 15 buses and 22 load points. Numerical results from the tests demonstrate that the optimal distributed generation placement can be used to promote reliability of the distribution systems.

This thesis presents an assessment of voltage sags when faults are happened in the 115 kV transmission line of the Provincial Electricity Authority (PEA) when distributed generation (DG) is installed in the system. The computer program PSCAD/EMTDC (Power Systems Computer Aided Design / Electromagnetic Transient in DC system) version 4.2 is applied to provide electrical parameters for the modeling and simulation and to analyze the fault occurred which resulted in voltage sag. Test results from PSCAD/EMTDC show the values of voltage sag when 5 types of fault are occurred (Single Line to Ground Fault Double Line to Ground Fault Three Phase to Ground Fault Line to Fault and Three Phase Fault). For all cases the value of root mean square voltage before fault is 100% or 1.0 pu. It can be seen that for both radial line and closed circuit when DG are installed in the system the value of phase to ground RMS residual voltage and phase to phase RMS residual voltage at the bus of Bang-pa-in 2 substation are more than the values in case of the system without DG.

This thesis presents the combined loss reduction approach to apply in distribution system. The thesis objective reduces the loss in the distribution system when all voltage magnitude levels at connection points must under the limits. Therefore the Simulated Annealing Technical selects as searching tool to find the suitable location of DG and Capacitor. The propose technique applies to the distribution system 69 buses model. The results shown that this technique can reduce in power losses from properly organize the location of DG and Capacitor. Moreover it can also balance and increase the voltage levels. The propose Simulated Annealing Technical is used to determine and organize the sectionalizing and tie switches in the feeder which installs DG and Capacitor by considering the power losses and the number of time to change the status of disconnecting switches.