Ever wonder how heavy-duty and commercial electric vehicles get electrically charged? The following information is sponsored by Littelfuse. You can read the full article here. National Fuse Products is a licensed distributor of Littelfuse products.
As the electrification of heavy-duty or commercial vehicles gains more acceptance, charging larger batteries than the ones in electric passenger cars increases in importance. Because time is money, especially in logistics, the preferred options are increasing charging power or assigning idle times for charging. These preferences result in three different charging scenarios:
Scenario 1: Depot-Charging and Fleet Operation
Modern battery technologies and cutting-edge power semiconductor solutions allow the design of highly efficient infrastructure. The image above depicts contemporary depot charging for bus fleets. Depot charging is the best option for local fleet operations, particularly for buses and delivery vehicles. These are operated on relatively fixed routes and are idle during night-time hours.
Scenario 2: Opportunity Charging
Fleet vehicles operating along predefined routes open the option to extend the driving range by adding smaller amounts of energy more frequently. Called opportunity charging, this works best if it takes place in a fully automated manner. There are two recommended solutions for opportunity charging. Mechanical systems, known as pantographs, allow large electric contacts to move over larger distances and safely contact their counterparts. A proven reliable technology, pantographs are widely used in tramways and railway applications. Pantographs are separated into top-down and bottom-up systems depending on the mounting position.
Scenario 3: Individual Long-Haul Operation
Traveling on random routes, as long-haul logistics demands, requires individual high-power charging similar to today’s gas stations. This high-power charging needs to become part of the existing infrastructure to allow for the seamless integration of electric trucks into the mobility sector. With a DC voltage up to 1500 V and a maximum charging current up to 3000 A, charging at rates exceeding 2 MW becomes possible. At 2 MW charging, 500 kWh to go another 300 km can be delivered in about 15 minutes which is well covered by the breaks a driver must take to comply with legal requirements. However, urban low-voltage 3-phase grids up to 400 V would not support this power level.
