Part 1: An operation algorithm of reactive power control buses in power-flow studies

Recently, distributed energy resources (DERs), including not only an active load that controls active power and reactive power but also power electronics-based inverters capable of supplying reactive power, have been introduced into the power generation, transmission, and distribution grids. For example, properly controlled reactive power can reduce voltage variations and losses. Therefore, the objective of this study is to present an algorithm to control reactive power in power-flow studies. For this purpose, this study introduces the Newton-Raphson power-flow analysis algorithm, which is able to examine the effect of reactive power control and management on voltage variations, and combines the proposed algorithm into the Newton-Raphson power-flow algorithm. This study also verifies the proposed algorithm in various test systems, including IEEE 30-bus test system. As a case study, the proposed algorithm can be used for the power-flow analysis studies of reactive power control and management.