Fixed ground power is essentially the supply of 400Hz AC current using an installed ground power unit on a parked aircraft. Whether it’s railroad locomotive starter or even a tank starter, if a fixed unit is supplying adequate power, it’s considered well within the realm of fixed ground power.
When it comes to the amount of GPUs it takes to adequately charge an aircraft, you have to consider the size of the plane. For best practice, one of the most reasonable rules of thumb that you can implement into your maintenance plan is one GPU per plug.
The Conversion Process
The conversion of the main power source to 400Hz power is typically done at a centralised location or through a portable power system – prior to the turbine starting sequence. In a centralised system, large quantities of power are converted to 400Hz and distributed to the plane itself. While they may seem like the primary solution to everything power, there are some disadvantages to it. This includes the balancing of the system and maintaining adequate voltage drops. Remember, with varied power sources, the equipment is at risk of being damaged as well as causing problems to the plane.
Portable Diesel-Powered Generators
When fixed ground power is not available, maintenance crew turn to portable power. For instance, if the gas turbine start up sequence is about to initialize, the maintenance team will quickly deploy mobile power units to the plane.
These are normally towed or mounted on vehicles and deliver power by using diesel generators – which should not be underestimated, as the expert portable power manufacturers Start Pac state. Ground power units that aren’t connected to a centralised location are known for their high capacities and efficiency, due to a dramatic technological surge.