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.

Voltage drop is one of the power quality problems affecting power users. This happens due to the higher demand for electric power. Or a short circuit in the transmission system. This causes a voltage drop is one of the power quality problems affecting power users. This happens due to the higher demand for electric power. Or a short circuit in the transmission system. This results in drop in Solving of voltage drop problems in power distribution model with distributed generator were presented with MATLAB program by installing a generator in the distribution system. Therefore simulated a case study 5 case 1 simulation by not installing a generator at any bus case 2 simulation by installing a Generator at bus 1 case 3 Simulation by installing a Generator at bus 18 case 4 simulation by Generator installed at bus 33 and case 5 simulation by Generator installed at bus 13 17 21 31 to study the suitable location of generator installation to solve the problem of voltage drop.

Ground grid design of substation is very important. It will help prevent the danger caused by the fault which causes the high step voltage and high touch voltage and may cause the operator to die. It also helps prevent damage to equipment and increases reliability for power systems as well. Currently the Gas Insulated Substation (GIS) has been built a lot especially in areas with limited space because it takes less space than the Air Insulated Substation (AIS). In order to create a substation of the GIS model instead of the AIS model. In order to create the GIS instead of AIS including the improvement or maintenance of the substation it is necessary to build another small substation to supply electricity to replace electricity from the original substation. However there are two substation stations in the same area may cause an increase of high-slope ground potential between the ground grid systems of both substations. It will cause high step voltage and high touch voltage while the fault is diminished. Therefore before improvement or maintenance of substation the ground grid distance and the size of the newly constructed substation must be analyzed that what effect on step voltage and touch voltage generation. Including studying the effects of step voltage and touch voltage that will occur.

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.

This research presents the studying of short circuit in distribution system that affect to critical equipment voltage sag and overvoltage while short circuit event. Lead into the quality of electric user. Effect on economics damaged Distribution system voltage level 22kV of The Provincial Electricity Authority. It is the analysis model by computer program. The event of short circuit set in a many distribution systems. The analysis result Magnitude of voltage while short circuit bring to assessment voltage sag and overvoltage from average voltage of the repeat event. Then set boundary of voltage at load point in a many. The experiment shows the problem of the quality of electric be affect to critical equipment less than load point close connection with substation.