CONVERDAN A/S

One of the most common technical challenges we face when developing converters: Getting the thermal design and system interaction right. On paper the efficiency and power ratings look fine. In the real application – within the customer’s enclosure, airflow, startup and system interaction and abnormalizes – things can look very different. That’s where experience matters. Sometimes a proven standard module (with the right control settings or minor hardware tweaks) is the fastest and most reliable path. Other times the application demands a custom design from the start with fast prototypes development for fast customer evaluation. At CONVERDAN A/S we do both. The hard part is knowing which path fits the application, and that decision is made in the details, not on the datasheet. As an engineer to fellow engineers, I'm curious – what’s the biggest “lab vs reality” gap you’ve run into with power converters?

Off-the-shelf works - until your installation doesn't match the catalogue. Tvindkraft's 800 kW turbine is one of a kind. So was the solution. See how Converdan approached a non-standard frequency converter installation on the world's first modern wind turbine.

Tvindkraft's drivetrain was unique when it was built. Decades later, that's still true - which made finding a compatible converter a challenge. Converdan developed custom firmware to match the turbine's non-standard topology. The turbine keeps running.

The world's first modern wind turbine has been producing power for nearly 50 years. When it needed a new frequency converter, standard solutions didn't fit. Tvindkraft runs on a non-standard topology. One the volume suppliers don't support. Converdan did.

A fifty-year-old wind turbine. A generator bought second-hand from a Swedish paper mill. And a frequency converter no one in Europe wanted to replace. Tvindkraft was built in the 1970s by teachers, students and volunteers, average age 21, to prove wind power could work. None of them had built a wind turbine before. Along the way they pioneered fibreglass blades, pitch control and grid-compatible AC conversion. Nearly fifty years later, the turbine still turns. But its original analogue converter was reaching the end of its life, and spare parts no longer existed. Modern digital converters were not an option either. They create voltage spikes the old generator's insulation cannot absorb. Off the shelf would have burned it out within years. Europe's largest suppliers passed. A one-off installation at this specification does not fit a volume product line. It fits ours. The hardware we delivered is our standard AFE333KAC inverter platform, the same modules running in EV chargers and battery storage systems today. Everything specific to Tvindkraft was solved in firmware: 24 parallel modules instead of the usual 16, input voltage tuned to a generator that exists nowhere else, dynamic braking calibrated to a fifty-year-old rotor. No hardware redesign. And because the 800 kW installation is modular, a single module can be lifted by one person and swapped while the turbine keeps running. The alternative class of inverters would need a crane. That is Custom & Standard in practice: a stable platform, customer-specific firmware, and an engineering team agile enough to adapt it. Full case in the comments.

Most engineers need a converter that fits their application. Some go with standard. Others need minor adaptions or customistaion. Either way, the timeline rarely has room for a long process. We have taken products from first spec to certified and market-ready in a matter of months. Not because we cut corners, but because power electronics is what we do and the process is built for it. Minor adaptations complete in 1 to 3 months. Major customisation takes longer, but the process is defined, the timeline is predictable and nothing gets stuck between handovers. From first spec to certified product, all in-house.