电动汽车 (EV) 充电会对配电网产生影响，其充电成本取决于充电时的电价。为了最大程度地降低成本，一个负责大EV集群的集中器可采用基于市场的控制算法来协调车辆充电。在这一优化中，不考虑连接EV的配电网的运行参数。这可能会导致不符合电网技术限制条件的情况出现 ( 如电压偏低、相位不平衡) ；例如，当电价较低时大量汽车开始同时充电。同时考虑经济方面和技术方面的多目标优化是比较复杂的，因为该优化必须将市场层面的时间驱动型控制与运行层面的事件驱动型控制结合起来。不同的案例研究调查了在何种情况下协调EV充电的基于市场的控制会与配电网的运行限制条件发生冲突。尤其是在弱电网中，相位的不平衡和电压问题会随着EV的高份额而出现。如果局部电压较低，在EV 的充电位置可以采用低水平电压下垂控制器，通过降低充电功率来满足电网的运行限制条件。虽然这一操作意味着会偏离成本最优运行点，但结果表明该方法对集中器工作状况的影响是非常有限的，即使是在承载大量EV的弱配电网中，也能够满足配电网技术的限制条件。

The charging of electric vehicles (EVs) impacts the distribution grid, and its cost depends on the price of electricity when charging. An aggregator that is responsible for a large fleet of EVs can use a market-based control algorithm to coordinate the charging of these vehicles, in order to minimize the costs. In such an optimization, the operational parameters of the distribution grid, to which the EVs are connected, are not considered. This can lead to violations of the technical constraints of the grid (e.g., under-voltage, phase unbalances); for example, because many vehicles start charging simultaneously when the price is low. An optimization that simultaneously takes the economic and technical aspects into account is complex, because it has to combine time-driven control at the market level with event-driven control at the operational level. Different case studies investigate under which circumstances the market-based control, which coordinates EV charging, conflicts with the operational constraints of the distribution grid. Especially in weak grids, phase unbalance and voltage issues arise with a high share of EVs. A low-level voltage droop controller at the charging point of the EV can be used to avoid many grid constraint violations, by reducing the charge power if the local voltage is too low. While this action implies a deviation from the cost-optimal operating point, it is shown that this has a very limited impact on the business case of an aggregator, and is able to comply with the technical distribution grid constraints, even in weak distribution grids with many EVs.