Overview
StaGeDis established new conceptual designs for a dual-use starter/generator disconnect system. New generation aircraft require higher levels of electrical power, increasing weight and volume of the electrical machines. In order to compensate this increase of weight and volume the generator was able to operate as an electric starter, eliminating the need of pneumatic starter.
Due to safety reasons, the starter/generator required a disconnection system to protect the machines and engine gearbox. This disconnection system was able to separate mechanically the gearbox from the starter/generator with the electrical machine operating whether as starter or generator. This system was commanded by an electrical pulse.
Different technologies and architectures were studied, evaluated and compared in order to define a proper disconnection system. Criteria of compactness, weight reduction and conformity with harsh aeronautic engine environment were also an important part of the study.
The selected solution required a detailed design and the definition and methodology of the verification tests.
Funding
Results
Executive Summary:
This project, named as StaGeDiS (electrical Starter / Generator Disconnect System) and developed by the consortium CT-Ingenieros and Indra Systemas, has answered the topic-call of the “JTI-CS-2013-03-SGO-02-052” which is inside of the call 16 of the FP7 of the European Commission
The StaGeDiS project has established a new conceptual designs for a dual-use over a starter/generator disconnect system. In the scope of new generation aircrafts, where it is required higher level of electrical power and leading to an increase in weight and volume of the electrical machines, it is important to compensate this increase of weight and volume by optimization of the aircraft systems. So, the generator shall be able to operate as an electric starter also, eliminating the need of pneumatic starter over the combustion engines (main engines and APU).
But in any case, due to safety reasons, the starter/generator requires a disconnection system to protect the machines and engine gearbox in case of a mechanical failure in one of them, especially in over the main engines, due to the catastrophic effect if all engines are damaged.
Most of current aircraft main engines are fitted with electrical generator and pneumatic starter. And the current safety disconnect system between generator and engine gearbox, where available, are mechanical fuses and/or clutching devices designed to transmit torque only in one rotating direction.
The electrical machine proposed in this CfP replaced the separated starter and generator machines by only one starter/generator (S/G) device which is able to work in two operational modes:
- Mode 1: starter to start the aircraft engine,
- Mode 2: generator to give electrical energy to the aircraft.
This feature required a disconnection system able to transmit torque in both rotating directions of the S/G shaft.
So, this disconnection system expected for this kind of new electrical machines shall be able to separate mechanically the gearbox from the starter/generator with the electrical machine operating whether as starter or generator according to initial requirements. Moreover, according to aeronautic requirement, the expected new disconnection devices shall comply with at least the same levels of performances, weight, dimensions, integration, safety, robustness, reliability, maintainability and operability that the current and legacy disconnection systems, and if possible to improve all or some of these requirements.
Along the project, different technologies and architectures have been studied, evaluated and compared in order to define a proper disconnection system. Criteria of compactness, weight reduction and conformity with harsh aeronautic engine environment were also taking into account, as very important part of these studies to ensure and maximize the compliance with those previous requirements.
And at the end of the project a deep compatibility study was performed to confirm these compliances under studies and simulations and also a preparation of a required test campaign was done to ensure its future verification under a potential prototype.