Integration of innovative electrical systems - Technology streams

Electrical system architecture, electrical network, power management

The required functions and load profiles are established at vehicle level for different helicopter classes. The technology reference for these classes is defined in line with the baseline helicopter models required by the TE.
The key architectural options including the corresponding electrical network are selected according to performance metrics e.g. weight and engine power off-takes which depend on the combination of individual subsystems performance and on power management strategy. These studies are progressing together with the development of subsystems that are reviewed here below. However some clear conclusions have already been reached such as the selection of the 270 VDC standard for medium and heavy helicopters as exemplified on the left diagram.

Brushless starter/generator for turboshaft engine

For small engines, the 28 VDC S/G will remain a good option combined with low voltage batteries but current S/Gs feature poor energy efficiency and require substantial maintenance. A prototype brushless machine with the converter to match a high voltage network for helicopters was specified in GRC3 and is under development and test in the SGO ITD .

Energy recovery, conversion and storage systems

Prototype systems allowing waste energy recovery from several sources are developed in close collaboration with Partners selected from CFPs:

  • Heat recovery from engine nozzles (Partner PARS MAKINA) ;
  • Energy storage system (partnership being established).

These systems will be tested on ground rigs. The diagram hereafter illustrates the integration of recovery systems and conversion and storage systems in the electrical architecture.

Electro Mechanical Actuation for landing gear

This system is aimed at providing an alternative solution for taxiing a helicopter without rotor spinning (safety, fuel saving) and without hydraulic power. To be developed and tested in close collaboration with Partners being selected through a CFP.

Electro Mechanical Actuation for primary flight control

The eventual removal of hydraulic systems requires replacement of rotor boosters with all electric actuators. Two actuators are under development with different specifications: one for the light helicopter segment, the other for the heavy/medium. The first one will be tested on a helicopter on ground. The second one developed in the SGO ITD will be tested on the common Electrical Iron Bird (Eco Design for Systems, part of the ED-ITD).

Power Supply

Some rotor active control systems include piezoceramic actuators that require a dedicated power supply owing to their peculiar high voltage and reactive impedance characteristics. The development of a flight-worthy and compact supply equipment aims at enabling the usage of future active control systems. The PPSMPAB Partner Consortium led by CEDRAT Technologies contributes to this work.

Electric Tail Rotor

This will replace mechanical tail rotor drive shafts, gearboxes and couplings. Key potential advantages include reduced drive train vibration, fatigue and noise, and overall weight savings and improved through-life maintenance. A motor for a conventional tail rotor is developed for ground demonstration whilst the adaptation to Fenestron antitorque systems is limited to pre-project studies.