Ground Power Units (GPU) Aircraft & Aerospace | PSI

Carina House East, Sunrise Parkway,
Milton Keynes, MK14 6LS, United Kingdom

What are Aircraft Ground Power Units?

Ground power units allow the aircraft to function whilst on the ground

When parked on the ground an aircraft cannot use the normal 50Hz (or 60Hz in America) mains power as it needs 400Hz power. As a result, airports need specialised ground support equipment (GSE). Ground power units (GPUs) play a vital role in allowing the aircraft to function whilst on the ground. Our compact dimensioned frequency converters can be fixed to the gantry of a passenger loading bridge. Alternatively, they can be hung underneath the walkway or simply fixed to a convenient place close to the aircraft.

Make an enquiry
Split Test

Our range of GPU...


The SD 40 M series of mobile frequency converters replace the noisy, air polluting diesel engine driven 400Hz GPU’s, with the latest design in solid state frequency converters. Our SD Series product can be plugged into the normal 50Hz or 60Hz mains power source and produces a high stability 400Hz output suitable for most types of passenger aircraft.

The SD 40M series of frequency converters will accept wide variation in input voltage and frequency and utilise the latest in IGBT power conversion PWM inverter switching technology to provide 400Hz power for all types of passenger aircraft, helicopters and military aircraft of all types with an extremely flexible, cost effective, energy efficient “point of use” aircraft ground power system for indoor and outdoor applications.

The users of the familiar, traditional diesel engine driven GPU’s will recognise the obvious benefits of using an SD 40M series all electric frequency converter GPU: no combustion smells, smoke, fumes toxic emissions or air pollution. No fuel storage, spillage or bills, no engine start battery or engine maintenance costs.

Additional benefits of Ground Power Units
  • It limits the use of on board turbo generators (APU). The result, is a reduction in noise and air pollution.
  • Our ground power unit is connected to the normal 3 phase mains power source and delivers an output of 200V 3 phase 400 Hz power to the aircraft through a special flexible cable.
  • It has a built-in feature that allows the converter to synchronise with the on board aircraft power system. Thus, allowing the lights, air conditioning system and the avionics continue operating during the change over from aircraft power to the external converter power.

Dual Circuit GPU System

Power Systems International’s new product goes one step further. We now can deliver a dual system built into a single enclosure with two 90kVA output circuits. The new generation of wide-bodied aircraft can now pick up power with two cables from a single location.

We can also provide a combination system in a single enclosure with a 3 phase 200V 400Hz output. Coupled alongside a secondary output of 28V DC 600Amps with peak of 2000A for helicopter engine starting and battery charging.

All within a vertically-configured, compact dimensioned assembly. They can be installed in a maintenance hangar or on the apron of an airport.

This combination unit can also be built in the horizontal format for mounting under the passenger loading bridge and operate in conjunction with our automatic cable reeling unit.

The 90kVA, 120kVA and 180kVA systems can be supplied in outdoor or indoor enclosures. Our Ground Power Units are built with all-weather protection for fixed application, or mounted on a trailer for mobile applications.

GPU Energy Efficiency
  • The converter is only switched on when needed
  • It is also more flexible than the earlier generation concepts of centralised 400Hz systems on older airports that operate large converters in parallel
  • Thus, allowing operators to draw continuous power from the mains, in anticipation of an incoming aircraft docking, to connect to the distribution circuit

Useful information

The solid state GPU advantages

– Little audible noise
– No vibration
– Maintenance inspection once a year
– Simple fault diagnostics
– Repairs can be made quickly by the user
– No mechanical parts to wear out
– 25 years design life
– Isolation from external power disturbances.
– Can be handled by one person
– Highly stable chassis mounted on large
– Towable up to 20kMPH
– Large pneumatic tyred wheels
– Tow-bar actuated parking brake
– All weather IP54 high visibility enclosure
– Stowage for input and output flexible cables

The SD M40 series of frequency converters features

– Analogue metering
– 50Hz or 60Hz input frequency
– 10 metres flexible input cable
– Output contactor with interlock
– 10 metres 400Hz flexible cable with
aircraft connector
– No break power transfer to aircraft
– Remote monitoring by interface PCB
– Fault event logging digital display
– RS485 remote monitoring by computer
– Second output contactor and interface
– Ingress protection IP54
– Line drop compensation
– Special paint colours and finish

What sectors can benefit from Ground Power Units?

Operating internationally, with customers from Japan to the USA, we regularly work with customers who are leaders in their fields. Our focus is always to provide the right solution for our client’s, meaning location is less of a concern for us.

Downloads & Resources

PDF Icon


Filetype : pdf
Filesize : 142 KB
Uploaded : 27/07/2022
We’re proud to have worked with...
US Air Force Logo image
Henley Business School Logo image
Eon Logo image
BAE Systems Logo image
Natural History Museum Logo image
Babcock Logo image
Dubal Logo image
Seadrill Logo image
Siemens Logo image
KNPC Logo image