Development and test of conservation voltage reduction application for Korean Smart Distribution Management System

Korea Electric Power Corporation (KEPCO) developed a Korean Smart Distribution Management System (K-SDMS) to address many issues of distribution system control, including the lack of receptivity of distributed generations (DGs). Voltage-VAR control (VVC) program is one of the K-SDMS real-time mode applications. VVC calculates the references of voltage and reactive power control equipment, which minimize the power loss while satisfying a number of operational constraints. The VVC application is upgraded to have a new control objective, i.e. conservation voltage reduction (CVR). CVR is based on the simple premise that reduction of the voltage will lead to reduced energy consumption by the end-use loads. This paper presents the algorithm of developed CVR function and the test results. The CVR function calculates the references of the voltage control devices such that the bus voltages are maintained at as close to the lower operation limit as possible. Firstly, the system is divided into small sections. Secondly, the reactive power references of the DGs are determined such that the voltage profile of the section is flattened. Finally, the tap references of the on-load tap changers (OLTCs) and step voltage regulators (SVRs) are calculated. The effectiveness of the CVR is presented with case studies using the K-SDMS simulator.