Charging infrastructure of medium voltage station upgraded to megawatt class

Sooner or later, charging stations alongside freeways, in parking heaps or at logistics facilities must ship rather more energy in a brief area of time than they do right now. Because of this, new charging stations can not merely be related to the low voltage energy grid.

Within the mission MS-Tankstelle, Fraunhofer ISE and companions from business due to this fact developed the medium voltage system expertise for quick charging stations that can allow peak a great deal of a number of megawatts sooner or later. The expertise, which makes use of environment friendly silicon carbide semiconductors and better voltages, results in decrease materials use and decrease prices for quick charging stations. It was printed within the convention proceedings 2024 Power Conversion Congress & Expo Europe (ECCE Europe).

On the similar time, the system could be very environment friendly and could be flexibly utilized to charging stations of various sizes and totally different automobile varieties. A demonstrator of 1 charging level could be seen on the Fraunhofer Power Alliance sales space on the E-World from 11–13 February in Essen, Germany (corridor 5, D 126).

Because the variety of e-vehicles will increase, so does the necessity for fast-charging stations that concurrently serve many autos in the identical approach as typical filling stations do right now. This requirement is especially related alongside freeways, but in addition in city parking garages and parking heaps.

The common output of a fast-charging system for a automotive is 150 kW. This rises to 350 kW for buses, vans and small vans, with greater charging capacities anticipated sooner or later. Since electrical charging is slower than the refueling course of, round 15 to 25 charging factors will probably be wanted sooner or later as an alternative of the standard eight fuel pumps at filling stations right now.

Collectively these charging factors will draw round 1.5 to three.5 megawatts of energy when quick charging in parallel, which signifies that future fast-charging stations can not be provided through the low-voltage grid. Even when the charging station is underutilized, the ability required would exceed 300 kW.

Additionally, the ability distribution inside the charging station or parking zone shouldn’t be distributed within the low voltage grid. This is able to result in large set up prices and enormous vitality losses in cables, because of the lengthy cable runs of, e.g., 100 meters or extra for 25 parking areas, coupled with the excessive energy.

The ability digital system developed within the mission with the companions Sumida Elements & Modules GmbH, Infineon Applied sciences AG and AEG Powersolutions GmbH due to this fact depends on a medium voltage grid that’s tailored to a voltage of 1,500 VDC utilizing a rectifier. The upper voltage stage allows a better output on the similar present with out necessitating the cable cross-section to be elevated.

The considerably decrease copper consumption that outcomes contributes considerably to environmental safety and useful resource conservation. The worth of 1,500 VDC was chosen for this unit, as it’s the boundary restrict of the low voltage customary. Above this worth, different requirements would apply.

Modular method for charging stations of various sizes

An electrically remoted converter {couples} the direct present (DC) distribution community to the automobile battery and controls the fast-charging course of. The DC converters, every with an output of 175 kW, are designed in order that they will simply be related in parallel within the system. This modular method makes it doable to construct charging stations with decrease energy charging factors for vehicles and better energy charging factors for vans.

In distinction to home wall containers, charging stations have to be extremely suitable for various automobile varieties. The idea of a central rectifier and a 1,500 V DC distribution, which was developed within the mission, is advantageous in that the grid connection elements (transformer and rectifier) could be dimensioned and scaled extra independently of the charging electronics. In view of the excessive demand for energy electronics and elements, like cables and transformers, the fabric necessities for this technique are considerably lowered in comparison with different present options.

For an uncomplicated charging course of, the charging station must be absolutely suitable with the CCS1 and CCS2 requirements, that are extensively established in Europe for automobile currents as much as 500 amperes and voltages as much as 1,000 volts. As well as, the idea additionally helps the Megawatt Charging System (MCS) customary. A second converter module is deliberate to deal with this. For this variant just a few elements must be tailored.

“The topology we developed on this mission finds functions not solely in charging stations but in addition for its integration in renewable hybrid energy vegetation or stationary battery storage programs,” explains Andreas Hensel, group supervisor of Excessive Energy Electronics and System Know-how at Fraunhofer ISE.

Supplied by
Fraunhofer-Institut für Solare Energiesysteme ISE