When the engines of the aircraft are switched on it is capable of generating its own power. But when the aircraft is grounded and parked, there is a need to provide from an external source because at that time the engine is switched off. Typically a power supply of 115V to 400 Hz is needed which is called as ground power.
An airplane starting unit or the aircraft ground power unit is the equipment which allows operators to provide power in AC and or DC to the aircraft when it is on the ground. These units are utilized to help start the engine, perform its maintenance, and provide general on board power at a time when the aircraft is on the ramp or in the hangar. These ground power units are capable of operating via single phase or three phases input voltage forms a hangar or via diesel or gas. This airplane starting unit or the ground power unit is a vehicle parked on the ground. The electricity is transferred from a generator to the aircraft. Standard connectors are used for all aircraft as per the description in ISO 6858. A solid state unit is there which converts power from AC to DC. It also separates current for aircraft power requirements. These solid state units are supplied as stationary, bridge mounted or as mobile units.
The stationary or fixed power units are those which are permanently installed on the ground in the airport. These are capable of supplying 400 Hz power to the parked aircraft. There is a need to convert the mains power to 400Hz. This is done by a centralized method or at the point of use frequency converters can do the conversion. In the case of a centralized system, large amounts of power are converted in a central place and then the 400Hz power is supplied and distributed to the aircraft. In the case of the second method called as a point of use, the main power is moved close to the aircraft, and the conversion of frequency is carried out at the point of use by the use of various frequency converters. The centralized power system is good as it is cheaper. But it has several disadvantages as compared to the point of the use mode of a power supply. The major disadvantages include balancing of the system and adequate voltage drops.
In the absence of fixed ground power unit or military tank starter, the mobile power units can be helpful. The mobile power units are mounted on vehicles and they deliver power by the aid of diesel generators. Special plug-in connectors are there which can be used to connect them to the aircraft. Generally, one to four connectors can be used to supply power to the aircraft depending on the size of the aircraft. Standard IP67 connectors are used for the supply of power.
Start Pac provides an array of reliable power units for the aircraft of different sizes. At Start Pac, we do custom manufacture as per the need of the customers.