Exploring the Effect of Conservative Voltage Reduction on Optimal Operation Scheduling of Smart Distribution Grids Considering the Presence of Electric Vehicles

To provide the required service quality to the consumers connected to the ending buses of radial distribution feeders, the voltage magnitude is set at higher values at the substation point and hence, at the buses located within the beginning feeder sections. The active and reactive powers are in touch with voltage magnitude at the corresponding buses. Accordingly, the voltage increase stimulates increased active and reactive powers consumption at the beginning buses along with increased operation cost. To mitigate these issues and ameliorate the operation scheduling of the network, this manuscript aims at developing a distribution management system based on conservative voltage reduction (CVR). In this process, a suitable voltage-dependent load model (referred to as the zip model), is deployed to tailor the effect of CVR consideration. The proposed model not only undertakes the active power charging/discharging processes of electric vehicles (EVs) interfacing inverters, but also makes suitable decisions in regard of their reactive power schedules, simultaneously. A distributed Volt/VAr control mechanism is then developed along the distribution feeder to improve the voltage profile. Seemingly, the voltage magnitude is lessened at the beginning buses and hence, the active and reactive powers are not increased in vain. Besides the economic metrics, technical enhancements are of significance, too. To this end, active power losses in distribution feeders are also underlined and the established model is extended to a multi-objective approach. The proposed model is evaluated on a low voltage distribution test system and the obtained results are discussed in depth.