Effects of randomly charging electric vehicles on voltage unbalance in micro grids

Abstract

Unscheduled charging of Electric Vehicles (EVs) may shift voltage unbalance beyond the desired limit. Effects of uncoordinated charging of EVs were assessed by calculating voltage magnitudes and voltage unbalances at the end node of a residential feeder. The assessment was illustrated by presenting loading conditions of distribution transformers and distribution lines. Power losses of these components also have been recorded. Four uptakes of EVs were considered based on the number of EVs per phase. These cases were simulated considering daily profiles of residential loads and EV loads. A 50% EVs uptake has led to an excessive voltage unbalance with a 3-phase 4-wire connection. However, only a 25% EVs uptake caused the violation of voltage unbalance with a 3-phase 3-wire connection. Therefore, 4-wire connections permit more uptake of EVs on the network than 3-wire connections, before voltage unbalances exceed their limits.

Analysis of the Impact of Unbalanced Connection of Consumers and Electric Vehicles on Voltage Variation and Voltage Unbalance

“…Single-phase chargers have been a major factor in the development of unbalanced EV loads, according to [10]. The network component parts lose more energy as a result.…”

Applications and Challenges of Lithium-Sulfur Electrochemical Batteries

“…Key stages of modern power systems include planning and operation of microgrids with the integration of renewable energy sources. The use of sophisticated energy storage batteries is required to cover important aspects in microgrids with high penetrations of electric vehicles and renewable resources [23][24][25][26][27]. Due to the ongoing depletion of nonrenewable resources, clean energy and energy-storage technologies, particularly batteries, have become essential.…”

Power Quality of Electrical Distribution Systems Considering PVs, EVs and DSM

“…A probabilistic methodology was used in Al Essa and Cipcigan (2016a, b) to study the impact of EVs and PVs on power quality of a distribution system, while evaluating different combinations of such distributed energy resources. Deterministic and stochastic approaches were presented in Al Essa and Cipcigan (2015) and Al Essa (2017) to assess the effect of EVs and PVs on a number of electricity systems. Although three-phase systems were used in Leou et al (2014) and Sharma et al (2012) to study the influence of EVs on distribution networks, voltage unbalance was not assessed.…”