Abstract

In literature, several mechanisms are proposed to prevent Plug-in Electric Vehicles (PEVs) from overloading the distribution grid. However, it is unclear how such technical mechanisms influence the market level control strategies of a PEV aggregator. Moreover, the presence of multiple aggregators in the same distribution grid further complicates the problem. Often, grid congestion management mechanisms are proposed to solve the potential interference between the technical and market objectives. Such methods come at the expense of additional complexity and costs, which is not beneficial for the large scale application of demand response. In our work, we investigate this problem by combining a simple low level voltage droop controller with an event driven control strategy for the coordination of charging PEVs. The approach is evaluated in different distribution grid settings, using two different market objectives for the aggregator. Document type: Part of book or chapter of book

Abstract

This paper studies four voltage dependent solutions for modulating the charging of multiple Electric Vehicles (EVs) in a real Danish network. Uncontrolled EV charging, especially in grid with high EV penetration, can result in overloaded lines and transformers, low-voltages and other performance degradations which lead to poor quality of supply. Therefore, a decentralized control for modulating the EVs’ charging current is developed, which sets the EV reference current based on the phase-to-neutral voltage at the EV connection node. Due to the controller’s decentralised feature, EVs plugged-in on phases with lower voltages are constrained during the charging period. In order to solve instability issues which may occur due to lack of communication between the controllers, several improvements are applied to the aforementioned droop control. Simulation results demonstrate the performance of the voltage dependent"br/"controls for a real Danish distribution grid."br