Year: 2010
Type: dissertation
Abstract: Plug-in hybrid electric vehicles, are rapidly gaining interest. Batteries of plug-in hybrid electric vehicles are charged by either plugging into electric outlets or by an on-board generator. For grid charging, these batteries are supplied by power from the grid at home from a standard outlet or on a corporate car park. The extra electrical load, from charging the batteries, has an impact on the electricity system in general and more specifically on the distribution grid and the electricity generation system. The impact of such vehicles on the distribution grid is analyzed in terms of power losses and voltage deviations. The impact on the electricity generation system is investigated in terms of available generation capacity. Uncoordinated charging of plug-in hybrid electric vehicles may cause local grid problems. These grid problems can be avoided by coordinated charging. The aim is to determine the optimal charge pro¯le for each vehicle and to minimize the impact on the electricity system. For the coordination, the linear or quadratic programming technique is found to be the most e±cient and is applied for this optimization problem. Plug-in hybrid electric vehicles cannot onlycharge when connected to the grid, but also discharge and thus inject power. In that way, electric vehicles may offer grid services to support the grid. It is not clear whether offering grid services is economic forthese vehicles. A voltage controller could be easily implemented in the charger and the grid services may be enabled. Such a controller avoids large voltage deviations at the household level. The vehicles may also be matched with distributed generation units such as combined heat and power units, small-scale wind turbines and photovoltaicpanels. If there is power or energy produced by these units, the batteries of the vehicle could be charged with this energy and their curtailment due to grid congestion is avoided. Charging of plug-in hybrid electric vehicles also has an impact on the electricity generationsystem. When the penetration level of these vehicles is high, charging during the evening peak must be avoided since not enough generation capacity is available. Therefore, the charging must be shifted in time. From the perspective of the distribution grid, the management or coordination of charging plug-in hybrid electric vehicles allows for grid reinforcements to be postponed. On the other hand, the introduction of smart chargers or meters is inevitable for the coordination of the charging of plug-in hybrid electric vehicles.
Source: Lirias (KU Leuven)
Author: Kristien Clement-Nyns
Language: English
Subfield: Electrical and Electronic Engineering
Field: Engineering
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W2338327374