Voltage sags are considered as one of the most detrimental power quality (PQ) disturbance due to their costly influence on sensitive loads. This paper investigates the voltage sag mitigation in distribution network following the occurrence of a fault. Two software are used in this work; the 1st is MATLAB R2017a for implementation of the Differential Evaluation (DE) algorithm to find the optimal location and size DG and while the 2nd software is CYME 7.1 for the distribution system modelling and analysis. The effectiveness of the proposed method is tested by implementing it on IEEE 33-bus system, and then it is applied to Al-Masbh distribution network in Baghdad city as a case study. The paper aims to enhance voltage profile, power loss reduction, and relieve distribution lines overloading, by optimal placement of distributed generation (DG). The results indicate the efficiency of the proposed method comparing with Real Coded Genetic Algorithm (RCGA).

This research introduces the study carried out on one of Baghdad East 132/33/11(6.6) kV distribution substations to mitigate 50Hz magnetic field of indoor distribution substation under normal operation. Shielding was performed at the power sources such as busbars rather than at the affected areas. Threedimensional finite element method (FEM) is used to calculate the magnetic field density in the space nearby the busbars so as to analyze the shielding effectiveness of an eddy current shield applied to a 132/33/11(6.6)kV substation. It also deals with the influence of shield distance from busbar, thickness and material of shield on the eddy current losses and shielding efficiency applied to 3D finite element model of a particular busbar configuration.