Once the power of charging stations reach MW levels, the system architecture cannot be an afterthought anymore. Every building block becomes large, civil engineering works needs to be performed, weight of the overall system becomes an issue, as well as distance between the parking spots and the power converter.
One clean way to address the topic of breaking down the large monolith into smaller, more practical, segments is to use DC voltage as interconnecting link. A sensible split is to have a dedicated rectifier for the total required charging power of the installation - let’s say 3MW. And then use rectified voltage (around 850VDC) as an input for the individual MCS charging stations.
The problem quickly becomes apparent - the IEC 61851-23 (and the corresponding UL standards) require reinforced isolation between mains, and between individual charge pistols/stalls. Therefore each charging station should perform two tasks - isolation of the 850VDC link, and then provide the output control in the range of 200V - 1250V (up to 1500V for some MCS applications).
ADVANTICS has developed power converter solution that achieves just that - two stage conversion system based on the latest SiC transistors, providing reinforced isolation using high frequency technology, and step down (buck) conversion stage for voltage and current control. The second trick incorporated in the following diagram is to use ADVANTICS off-the-shelf 950V converters, instead of developing 1500V hardware. With isolated DC/DC converters being connected in parallel on their input, and series on the output, voltage is effectively doubled. By installing output contactors capable of series/parallel reconnect, we also double our effective current for lower voltage vehicles.
The proposed system would look like this:
Example calculations of power per block:
The mains rectifier acts as a common point for all the charging stations - therefore a full utilization of the mains and power capacity can be used. If one station needs full power, others can still operate at reduced power, and later re-adjust the limits to match the occupancy of charge pistols/stalls. Another beautiful thing about DC coupled systems is how easy it is to add a battery buffer to them - simply connect a large battery to the DC port through a (non-isolated) DC/DC converter, and the total power capacity of the MCS charger can be a lot higher than the mains feed could supply. Since the converters are inherently bidirectional, energy trading with the grid during off-peak hours becomes another revenue stream for the CPO (Charge Point Operator).
Compact and versatile, it supports EV charging protocols like MCS, CCS AC/DC, DIN SPEC 70121, ISO15118-2/-20, NACS, and CHAdeMO. With bidirectional power transfer, Plug and Charge (coming soon), OCPP support, OTA updates, and its flexible mounting options, the SPCC is ideal for charging stations and wallboxes.
Electric Vehicle onboard charge controller for DC and AC charging standards. Aimed to be embedded in any kind of electric vehicle using conductive charging. Enables advanced features such as bidirectional charging using latest standards and Plug’n’Charge.
This power module fits any application where you need bidirectional AC/DC rectification, DC/DC conversion or DC/AC generation, with up to 99% efficiency in a wide operating range.
This bidirectional DC/DC transformer operates at very high frequencies allowing it to reach an impressively high power density. It is perfect to add isolation to your application, or even as a transparent add-on in preexisting topologies, while keeping bidirectionality and high efficiency.
Optimized to be the last power conversion stage for battery charging, it includes galvanic isolation, insulation fault measurement and fast output discharge circuit. With a maximum efficiency of 98%.
