What Are GPUs Aircraft Ground Power Units?

GPUs provide either AC, or AC and DC power for the operation of aircraft avionics and engine start up on the ground. Solid-state Ground Power Units (GPUs) convert utility power into 400 Hz power for the aircraft. The GPUs take over when the Auxiliary Power Units (APUs) onboard aircraft are switched off, in order to reduce the noise, the air pollution, and the maintenance required by the APUs.

The use of ground power also means cost savings, the power can be converted on the ground much cheaper and much more efficiently than by burning jet-fuel on the aircraft. GPUs can also be mobile units, giving further flexibility. GPUs have also been developed to meet the needs of operators who have a requirement to carry portable ground power aboard the aircraft on a regular basis.

These gpus are extremely powerful for their size and weight and can be loaded and carried aboard if required. All units can be used plugged into a 110 power outlets to provide continuous power for hangar or workshop applications, to test aircraft systems. The units are usually equipped with a 110/220 switchable power supply. They are ideal for working at remote locations. Older GPU technology included a rotary converter, to convert the 50 Hz from the gene- rator into the 400 Hz required by the aeroplane.

PCA/GPUs

New GPU/PCA combination unit designs are being developed to accommodate some of the new jets. As well as power, the units supply preconditioned air PCA.

In passenger aircraft such as Boeing 747s and A380s, the air conditioning component is not such a necessity, as the electronic components are not in danger of overheating while being active on the ground. Instead, the cooling unit serves to provide comfort to those remaining inside the cabin of the aircraft as it docks on the ground. In a sealed cabin on a hot day, the effects can be extremely uncomfortable. Once again, it is the financial economies that the units provide to the airlines in competitive and straightened times that sell them. Compare the cost of running air conditioning from a ground-based unit, rather than the aircraft auxiliary power units (APUs).

At some airports, in more remote locations, fixed GPUs are not always available, and so portable PCA/GPUs are used. These can either come in the form of fully fitted trucks, complete with a diesel generator, converter, and pressurised air conditioning unit installed. Otherwise, the units may come in the form of a trailer, which can be towed behind any vehicle.

Future developments are guaranteed, because those who concern themselves with noise at city airports are increasingly against the Ground noise from GPUs, which as we have already established, are significantly quieter than running the aircraft.

Ground Power Units GPUs are, after all, small diesel powered generators used as we have seen, to power aircraft on the stands where Fixed Electrical Ground Power (FEGP) is not available. FEGP uses silent mains electrical supply. Pressure groups continue to monitor the use of GPUs and FEGP availability, ensuring that the use of GPUs is minimised wherever possible, imposing even tighter controls on GPU usage.