Voltage Quality Index Based Method to Quantify the Advantages of Optimal DG Placement

This paper presents the advantages of the optimal DG placement during the operation stage of the radial distribution system. The method taken for optimal DG placement (ODGP) is considered from our previous work, which gives optimal locations based on Load Concentration Factor (LCF). Various cases of random DG placement (RDGP) are considered which are divided into two main categories. In first, the locations are varied and in second DG sizes are rotated on same locations found by LCF method. In all these cases, the total active power delivered by the DGs is kept same as for the case of ODGP. The load growth in network is considered to correspond to the future operational stage. A novel Voltage Quality Index (VQI) is proposed in this work which provides a straightforward method for quantifying the system's voltage quality status. Furthermore, two different scenarios, with and without a centralized voltage control algorithm, are considered for the comparison purpose. The advantages of ODGP in all these cases are highlighted by comparing the active power loss reduction, and voltage profile and quality improvement. The results showed that, in case of voltage problem, algorithm could improve voltage to a better limit, while keeping the losses reduced, in case of ODGP than RDGP cases.