Solid-State 400Hz Ground Power Unit / Static Frequency Converter (40-144 kW), made by MAK Controls & Systems
Solid-state 400Hz ground power unit drawing from fixed airport power and converting it to aircraft-standard 400Hz at up to 144 kW, with unity power factor and below-65 dBA noise.
The MAK Static Frequency Converter (SFC) is a solid-state ground power unit that takes standard utility mains — 400/415V three-phase at 45–65 Hz — and converts it to the 400Hz, 200/115V three-phase power that aircraft avionics and systems require. Unlike diesel-driven GPUs, it produces no exhaust, consumes no fuel and operates quietly, making it the correct solution for fixed-gate installations at terminals, hangar bays, PBB-integrated gates and electrified apron stands.
The range covers 40 kW to 144 kW output, sufficient for single-aisle aircraft up to wide-body type support. Conversion efficiency exceeds 93%; active power factor correction (APFC) holds input power factor near unity across the load range, minimising reactive current demand on the airport electrical supply. Output voltage regulation is within ±1% across the full 0–100% load range, and total harmonic distortion at the output is below 2% at linear load, protecting aircraft avionics.
The overload envelope — 110% for one hour, 125% for five minutes and 150% for five seconds — accommodates the inrush currents that aircraft loads present at energisation. No-break power transfer capability allows seamless hand-off between SFC and pit-power sources without interrupting aircraft bus power. Noise output is below 65 dBA at one metre, meeting indoor terminal and overnight-maintenance requirements.
The unit is available in fixed-installation, trailer-mounted and jet-bridge-integrated forms. IP54 enclosure and a -20°C to +55°C operating range with no de-rating to 2,500 m altitude make it suitable for high-altitude regional airports as well as sea-level Gulf hubs. CE certified.
Technical specifications.
| Conversion efficiency | [confirm with supplier] |
| Overload capacity | [confirm with supplier] |
| Noise level | [confirm with supplier] |
| Output power range | 40 to 144 kW |
| Input voltage | 3-phase 400 / 415 V AC |
| Input frequency range | 45 to 65 Hz |
| Output voltage | 3-phase 200 V (L-L) |
| Output frequency | 400 Hz |
| Input power factor (full load) | [confirm with supplier] |
| Output THD | [confirm with supplier] |
| Voltage regulation (static) | [confirm with supplier] |
| Dynamic voltage recovery | [confirm with supplier] |
| Enclosure | [confirm with supplier] |
| Operating temperature | [confirm with supplier] |
| Altitude (no de-rating) | [confirm with supplier] |
| Mounting configurations | Fixed installation / trailer-mounted / jet-bridge integrated |
Use cases.
- ›Fixed-gate terminal installations replacing diesel GPUs to eliminate ramp fuel and emissions
- ›Jet-bridge-integrated power supply for electrified gates at terminal concourses
- ›Hangar and MRO bay power for avionics testing and maintenance without running APU
- ›Airports with sustainability mandates reducing ramp diesel consumption
- ›Overnight maintenance stands where noise restrictions preclude diesel GPU operation
- ›High-altitude regional airports requiring full-rated output without de-rating