The Power2Power consortium, led by EAAT GmbH Chemnitz, developed a high‑current test bench for power capacitors that can reproduce the current spectra of real‑world applications. The bench must supply up to 1 200 A effective at frequencies between 10 Hz and 5 000 Hz over periods of three to five days, depending on capacitor size. To meet these demands the design incorporates a 3‑level ANPC inverter that combines silicon carbide MOSFETs with newly developed silicon IGBTs. The inverter operates from three 400 V supplies (±10 %) and delivers a maximum output of 800 V eff and 1 200 A eff (2 000 A peak). The intermediate DC bus is limited to 0 – 750 V DC, and the overall power consumption is capped at 35 kW.

Key technical milestones began with the selection and testing of the IGBTs. Driver boards were fabricated and validated in a double‑pulse test rig together with prototype IGBTs, confirming normal operation and safe shutdown under short‑circuit conditions. Parallel to hardware validation, the current‑control algorithm was upgraded from a PI to a PIDT1 structure, enabling tighter regulation of current ripple and improved tracking of complex waveforms. Simulation and component‑level calculations guided the low‑impedance design of the DC bus, which is critical for high‑frequency operation.

The final demonstrator was assembled in a single cabinet thanks to compact power modules and 3‑D‑printed cooling units, reducing the footprint from two cabinets to one. During commissioning the system exhibited thermally stable behaviour, although the first key performance indicator—0.8 kW loss per switch—was not achieved. Nevertheless, overall switching losses were lowered by approximately 14 %. The compact architecture also reduced parasitic inductances, thereby diminishing voltage overshoot during switching events. The third KPI, a 5 kHz switching frequency at 1 250 A, was successfully met. A remaining challenge was temperature measurement: the internal NTC sensors of the modules were coupled to the negative side of the module, causing interference during operation. A low‑pass filter was introduced to obtain a stable temperature reading, and long‑term tests confirmed its effectiveness.

The project ran from 1 June 2019 to 30 September 2022 under the funding code 16ESE0387S, provided by the German Federal Ministry of Education and Research. EAAT GmbH Chemnitz coordinated the effort, while other consortium members contributed expertise in power electronics, thermal management, and system integration. The outcome is a demonstrator that is both more compact and more powerful than previous designs, with reduced voltage transients and improved efficiency. Further testing will explore the full parameter space of the system, as the current results indicate that additional performance margins remain available.