Ground Power Units (GPU) Aircraft & Aerospace | PSI

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

Ground Power Units


Ground Power Units, also known as GPUs, play an integral part in key operations within the aviation industry.

Here at PSI, we’re proud to offer a wide range of Ground Power Units, available in a variety of formats designed to suit all possible requirements.

We operate internationally, supplying, installing, servicing and maintaining Ground Power Units for well-known names in the industry.

For over 30 years, we’ve been delivering our expertise across the globe, providing custom-engineered power conversion systems to clients in all sorts of industries!

So, if you’re looking for a highly-trusted GPU supplier – then you’re in the right place!

Simply call +441494871544 or email the team at for a consultation and we’ll find the perfect Ground Power Unit to suit all your requirements.

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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

What is a GPU?

To put it simply, Ground Power Units allow aircraft to function whilst they’re on the ground. For context, when they’re parked on the ground aircraft cannot use the mains power supply of 50Hz (or 60Hz in the USA). Instead, they require a supply of 400Hz power – a clever decision made by the Aviation industry to help them reduce the weight of each aircraft by significantly reducing the size of electrical components and motors.

Our Ground Power Units connect to the regular 3-phase mains power source of 50/60Hz and converts this into an incredibly stable output of 400Hz power that is usable for all types of aircraft, including passenger aircraft, helicopters, and military aircraft.

An essential part of Ground Support Equipment (GSE), our compact GPUs can be fixed to the gantry of a passenger loading bridge, hung underneath the walkway or even fixed to a convenient place nearby for easy access at all times.

Types of Ground Power Units We Supply

Discover our most popular GPU types below.


Mobile power supply systems designed for aircraft engine starting applications and the charging of onboard batteries. Split into three main categories, including the DD range designed for offshore installations, the PS range suitable for hangars and outdoor uses, and the SP range which is integrated into the 400Hz GPU.

400Hz GPU

Our most popular range of GPUs, these 400Hz frequency converters come in a range of formats. Including all-weather units designed for use outdoors in military airfields and airport applications, as well as fixed or mobile units to suit your logistical needs whatever the environment.

400Hz/28vDC GPU

Part of our SP Series, this Combi Unit is an extremely flexible Ground Power source designed for use in avionic workshops, aircraft maintenance hangars and test laboratories where compact dimensions are required.

Don’t see what you’re after? Get in touch today on +441494871544 and we’ll be happy to help find the perfect GPU type to suit your needs!

GPU Installation, Servicing and Maintenance

As well as supplying our range of high-quality Ground Power Units, we also offer installation, servicing and maintenance services to all our customers. Our expert engineers can help you set up your GPUs and keep them in tip-top condition to ensure they last for years to come.

For more information, or if you require these services, please contact us today – a member of the team will answer your questions or arrange a suitable time to carry out the service.

Key Benefits of Our GPU Systems

  • Replaces traditional engine-driven GPUs, reducing noise and air pollution
  • Produces a high stability 400Hz output that’s suitable for most aircraft
  • Suitable for indoor and outdoor applications
  • No fuel storage, spillage, or bills necessary
  • No engine start battery required
  • Reduced maintenance costs with only one inspection required every year
  • Can be used as a fixed application or easily mountable on trailers for increased mobility
  • Designed to last 25 years
  • Minimal operational costs as they can be handled by just one person
  • Includes a feature which allows the GPU to sync with the on-board aircraft power system; allowing the lights, air con, and avionics to remain operational during the changeover

Purchase Aircraft GPUs from PSI

For all your GPU requirements, you can trust the frequency & conversion specialists here at Power Systems International. To purchase a Ground Power Unit, simply get in touch with us today by filling out our contact form, emailing us at or calling +441494871544 and let us know your requirements to get started.

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 service
– 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 clients, meaning location is less of a concern for us.

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