Enhancement of Voltage Profile in Unbalanced Distribution Systems with Variable Loads

Nowadays, interconnection of distributed generation (DG) units to distribution grids becomes more popular due to the many benefits they provide to grids. Their contribution in voltage regulation can improve the voltage profile in distribution networks. In addition, optimal power flow as a powerful tool in planning and load management can be applied to the distribution networks as well as at transmission level. This paper proposes a multi-objective function to address the nonlinear optimal power flow (OPF) problem in the medium voltage (MV) distribution networks. Cuckoo Search (CS) optimization approach is applied to solve the OPF problem. The proposed method is applied to IEEE 13 nodes test case with variable load. The results indicate the enhancement in voltage profile in addition to reduction of the network losses and more balanced system.

I. Introduction

Demand for electricity is increasing nowadays as many devices are required to run with electrical energy. The electricity consumption increases during daily or annually peak periods. Aging infrastructures and limitation on power transfer through transmission and distribution networks increase the need for installation of new sources closer to the consumers rather than investment in new centralized power plants or expansion of power networks. In addition, the price of energy and environmental concerns incentivize the application of renewable sources. Therefore, installation and operation of renewable-based distributed generation (DG) has been expanding in the last decade.