Fast DC Charging - Charging the Future

➤ Return to front page

Charging

Trends, system architectures and new designs.

Select and learn more about ...

Trends
System Architectures for Fast DC Chargers
New Designs
- Charging Solutions for Battery-Electric Heavy duty vehicles: Megawatt Charging System
- New compact and efficient three-phase PFC product line
- Deeper Integration for More Compact Designs

Key trends/drivers in DC charger engineering

High power charging stations

Charging will shift towards public and workplace options, as more people without access to home charging start to buy EVs. There will be a growing need for DC fast chargers with nominal power beyond 22 kW in the next years.
For commercial vehicles like trucks and busses for long-haul trips on the move charging availability of 45min will be needed which will require >1 MW chargers.

Bi-directional charging

V2L, V2G or V2H

Battery voltage 400 V → 800 V → 1000 V

Trend towards higher system voltage
500 V → 1000 V → 1500 V

Reliability

More challenging mission profiles

Modular Design

For 30 kW the module design is more dominant than the monolithic design approach, giving the benefits of high design flexibility
Several 30 kW or 50-to-60 kW charger modules are connected in parallel to deliver the desired amount of power

Power module Solution

for >30 kW The power module solution is more preferred than the discrete solution, thus benefiting from optimal thermal management, simplified mechanical assembly, and low parasitic inductance

Efficiency: from today 95% to 98%

WBG components are playing a key roll to achieve this goal
3% efficiency improvement will save 2,1 billions kWh electricity per year*

* 30 million electric vehicles by 2025 / 15000 km annual driven kilometers / average power consumption 15 kWh

System Architectures for Fast DC Chargers

This is the state-of-the-art system architecture for DC Charger. Depending on output power, this can be a system built from one or more charger modules. With this modular concept a broad output power range can be realized from some KW up to MW. Supply is taken mainly from low-voltage 3-phase grid but also from a medium voltage transformer for the higher power ranges. In some designs, the DC/DC stage is split in 2. These parts can be connected in series or in parallel. This is done in order to cope with the available battery voltages: 400 V and 800 V

For bi-directional requirements the same system architecture is used but with topologies which can support power flow back to the grid.

Charging Solutions for Battery-Electric Heavy duty vehicles

Megawatt Charging System

Heavy electric vehicle adoption, like buses and trucks, are gaining momentum worldwide thanks to strong and ambitious policies, such as the European Union’s CO₂ standard for HDVs, which target a 45% CO₂ reduction by 2030*.
* EC: Reducing CO₂ emissions from heavy-duty vehicles

Currently available electric trucks are relying on the charging infrastructure designed for light-duty vehicles, such as the CCS standard. To satisfy the market demand of the Truck and Bus Industry - charging electric heavy-duty vehicles within a reasonable time - a new solution for high-power charging is needed, such as the MCS**. However, not every HDV will require MCS, it will depend on the use case requirements.
** CharIN: Megawatt Charging System (MCS)

Standard Name	Max voltage and current	Max Power
CCS	920 V and 500 A	450 kW
MegaWatt Charging system (MCS)	1250 V and 3000 A	3.75 MW

Note: the above values are documented as possible but may not be implemented in typical installations

Simply paralleling more charger units, such as 60 kW - 100 kW to increase the power level up to MW, might not be the best approach. MW-Charger stations will be connected to the 20 kV grid and use a medium voltage transformer. The charger unit power range has to be increased and the V_in and V_out specification as well. An assumed system architecture is shown in the below schematic.

Power module concepts

To address the new MCS specification various power module concepts are in development utilizing mainstream topologies, such as MNPC, ANPC, and FC (Flying Cap) for the AC/DC stage, and H-bridge for the DC/DC stage.

Optimized for 1500 Vdc applications addressing maximum power density and high efficiency

flowMNPC E2 SiC *

flowMNPC E3 SiC *

fastPACK E2 SiC *

fastPACK E3 SiC *

* typical appearance

Features

Latest SiC MOSFET technology with high blocking voltage (2300 V) and low on-resistance
High speed switching with low capacitance
Advanced solder technology
Temperature sensor
High thermal conductive ceramic AlN substrate
CTI >600 housing material
Press-Fit connections
Available with pre-applied 150°C rated phase-change material

For more details, please contact your sales representative

New compact and efficient three-phase PFC product line

flowCSPFC S3 SiC – your PFC solution for DC fast chargers

The race for power conversion efficiency over 99% in three-phase PFC applications continues.
The demand for SiC semiconductors is increasing to achieve high power density and greater efficiency.
These requirements are becoming standard for both uni-directional and bi-directional solutions.
Achieving greater efficiency and high-power density with cost-effective solution is the target of power electronics industry.
And all this considering a long lifetime and high reliability of the final product.
The topology of current synthesizing PFC (CSPFC), in which the 3rd harmonic is actively injected into all three phases, was investigated with respect to meeting today’s PFC requirements.

B0-SP12CFA016ME-PD98G68T

The first module of this new product family is well suited for a DC fast charger PFC converter stage up to 35 kW power, a “sweet spot” for building scalable DC charger units on a modular approach.

Benefits

Current-synthesizing PFC slashes module costs by > 25% with conversion efficiency ranging as high as >99%
System costs come down with fewer and smaller inductors on the PCB
No large electrolytic DC-link capacitors for even more system-level savings
Pinout is ready for bidirectional applications and optimized for easy PCB routing
High power density for compact designs and fast charging

Show product

Deeper Integration for More Compact Designs

flowRPI 1 3-in-1 module

This compact power module design has been developed to address charger applications that requires compact, high density, and highly efficient solutions like automated guided vehicles, forklifts, pallet trucks, and other industrial e-vehicles.

Mainly these chargers are built into the vehicle (OBC), thus they must be smaller than stationary chargers (off-board) and be compact and perfectly adapted to the vehicle.