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.

Most of Metropolitan Electricity Authority (MEA) electric power system is using overhead line. It is 94% in the system including subtransmission distribution and low voltage system. All of them were installed on concrete pole. At present many public facilities have been built such as Sky-Train. It causes more constrains for construction with concrete pole due to lack of right of way. MEA needs to using electrical monopole plays an important role. It’s easier than concrete pole for construction and it requires less construction area than concrete pole. This research evaluation of The Reduce Effect of Lightning on Transmission Line. Case lightning strike on overhead ground wire (OHGW) at pole top of electrical monopole with suspension insulator Focusing on three factors is pole top voltage critical current and back flashover rate (BFOR). ATP-EMTP software is used for simulation. The results show that BFOR is reduced by 79% on electrical monopole structure with suspension insulator compared with existing concrete pole. BFOR is also reduced by 33.17% on concrete pole with external ground wire. The results could be served as a guideline in subtransmission line design and improvement in MEA power system.