Eight Charger Configurations Built on One Architecture

Project in a Nutshell: A European manufacturer of industrial charging systems needed a new generation of high-power charger modules: eight configurations from 24V/150A to 120V/80A, two power classes (7.5 kW and 11.5 kW), one standardized enclosure, and one EU certification path for the entire lineup. 

Promwad took on hardware architecture, firmware, mechanical design, and pre-compliance validation. The platform targets a cost reduction from €83.61 to €67.61 per kW at a production volume of 8,000 units per year. 

Client & Challenge

Our client is a European OEM supplying industrial charging cubicles to logistics, manufacturing, and critical infrastructure operators. As their customers moved into higher-power applications, the existing charger modules fell short, and the product lineup needed a major update to stay in contention. 

The engineering scope was demanding. Eight hardware configurations had to share a standardized module form factor (87.55 × 396 × 419.6 mm with quick-access inspection hatches), communicate over CAN with an existing control board, and go through one EU certification process covering every variant in the family. The unified form factor was a hard constraint: all modules had to be interchangeable within the client's existing charging cubicles. 

In power electronics, splitting a program across multiple vendors risks catching critical issues only when it's expensive to fix them. The client needed one team that owned the full scope. 

Solution

Rather than developing each variant as a separate product, Promwad designed one platform architecture that all eight configurations are built on. The same enclosure, the same documentation, and the same certification path serve the entire family.

The power chain pairs a Vienna Rectifier on the AC-DC stage with a Dual Active Bridge for DC-DC conversion. This combination was selected for its balance of efficiency, size, and cost when implemented with Infineon CoolSiC MOSFETs. Each module delivers AC-to-DC conversion with under 5% voltage variation and a power factor of 0.94 or higher, with integrated protection against overcurrent, overvoltage, and electromagnetic interference.

For sites without a neutral conductor, remote locations running on generators, for example, a TNPC topology is available as an alternative path, so those installations can be accommodated without re-architecting the platform. All modules communicate with the existing control board over CAN, and a secure bootloader handles firmware updates at the unit level.

Business Value

One certification, eight configurations. A shared architecture and shared documentation mean the client manages one compliance package covering EN 60335-1, IEC 60335-1, EN 61000-6-4, LVD, RoHS, REACH, and WEEE across all variants. Adding a new configuration to the family doesn't restart that work. 

Cost target embedded in design decisions. The platform is built to reach €67.61/kW at 8,000 units/year, which is 19% below the current €83.61/kW baseline. That number drove topology selection, component sourcing strategy, and every thermal trade-off in the programme. 

A foundation, not a one-off. The architecture is sized for next-generation cubicles and product extensions. Knowledge transfer sessions with the client's engineering team are included in the handover package.

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