Architectural and Algorithmic Solutions for Large-Scale PEV Integration into Power Grids
Abstract:
The main goal of this project is to design algorithms and architectures for large scale integration of electrical vehicles in power grids. In particular the following topics will be explored:
1. Commercial charging of PEVs without V2H or V2G capabilities: Relying on residential charging alone can severely constrain driving patterns. Charging at commercial stations, office buildings, parking lots, shopping malls and so on will be required for any significant PEV penetration. Our first research goal will consider charging of PEVs at such commercial stations. This will require a design of the interactions between the station owner and the electricity suppliers (aggregators and distribution companies) on one hand, and the station owner and the PEV owners on the other. Since PEVs are time and location varying loads, this problem is quite different from problems of designing similar interfaces for, say, gas stations. We will develop charging scheduling algorithms, possible contracts that the charging station owners can offer and analyze the impact on the power grids. We will also study how the charging stations can take advantage of power generation from renewable sources, and the problem of optimal charging station location.
2. Residential charging for PEVs without V2H and V2G capabilities. The nature of residential charging is quite different than commercial charging due to reasons such as the availability of the PEVs to charge; the ability of the household energy managers to coordinate the PEVs charging with all the other household loads and the charging rates allowed for the PEVs under residential contracts with the electric utilities. PEVs are expected to be parked at home during night hours, when electricity prices are low, and intermittently during day hours when electricity prices are high. For the distribution company, this provides an opportunity to use demand response mechanisms to obtain a favorable load profile, or other ancillary services. The effect of the additional load on the physical infrastructure of the distribution level should also be considered. Effects of latencies or errors in information flow, possibility of aggregators mediating this interaction, and design of contracts to entice customers to participate are all relevant questions. This research stream aims at solving these problems.
3. PEVs with V2H or V2G capabilities. By being able to defer their load in time, and even to inject power back into the home in V2H mode, or even all the way up into the grid in V2G mode, the PEVs will create a new stream of services and products that can be traded at different levels of the electricity supply chain. These services embody: load shifting, voluntary reserve capacity and frequency regulation services. These new streams of services will be explored at the various stages of electricity supply chain. That is, the trading of flexible demand at the wholesale level as well as to provide voluntary reserves, and at the distribution level. Their use in support of the optimal operation of the grids will be investigated not only to operate the system in an efficient manner, but also to allow the further penetration of renewable energy sources, such as solar and wind. A careful assessment of the impact on the distribution grids will be carried out. Distribution grids were not designed to support reverse flows, and the V2G injections could affect not only the active but also the reactive power flows and the voltage profile in the networks. Moreover, how to recompense PEV owners suitably for these services (especially considering issues such as loss of battery life through charging and discharging) is an open question.