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Efficient, Modular and LigthWeight Electromagnetic Induction Based Ice Protection System

Periodic Reporting for period 2 - InductICE (Efficient, Modular and LigthWeight Electromagnetic Induction Based Ice Protection System)

Période du rapport: 2018-01-01 au 2019-06-30

Heating by electromagnetic induction is known as a very fast and efficient method for heating metallic surfaces, with very good controllability of the delivered power as well as for the lack of direct contact between the heated and the heating element. Induction heating is currently used in several industrial applications due to their advantages in efficiency, heating speed, low maintenance, safety and an accurate control. The aim is to achieve these clear advantages in the development of a novel de-icing system for air transport. Direct and fast action of inductive systems eliminate the ice created in very critical areas of aircraft, and allow better use of on-board resources, improving efficiency and reducing power demand of the aircraft.
INDUCTICE project will contribute to achieve the major expectations from a more/all electrical aircraft architecture. In the framework of the Electrical Aircraft Airframe technologies, the low power electrical ice protection system to be developed in the project will include a high degree of structural integration in order to minimize weight while maximizing system efficiency.
Efficiency is one of the main objectives in order to make a better use of aircraft on-board resources. Thus one of the main objectives of the induction based ice-protection system to be developed in this project is to achieve at least a 95% heating efficiency.
In addition to efficiency, ice-protection system speed is essential in order to act on time and accurately without excessive on-board system consumption. Therefore, another one of the objectives of this project is to improve the speed, while providing a precise and targeted control of the generated heat facing the drawbacks of current on-board ice-protection systems. Finally, the weight of the whole solution must be minimized, essential in on-board aircraft systems. The final objective is to reach an ice-protection system with at least the same weight as current on-board ice-protection systems or on the contrary, the sum of its weight and its impact on on-board resources due to its high heating efficiency must be at least equal to current ice-protection solutions.
Although a general sizing of the system was done throughout reporting period 1, due to the new specifications all the work packages were still to be done within reporting period 2.
With these new specifications instead of a chordwise heating strategy, with single chordwise modules, a combined spanwise and chordwise strategy has been sized for a wing and for the demonstrator to be tested in the IWT.
The optimal coil for uniform heating has been designed choosing for that purpose the most appropriate coil pitch (λ). The new coils have been manufactured and validated reaching the expected heat distribution.
Regarding the power electronics converter, despite existing different resonant converter configurations, the half-bridge topology has been the chosen one. However, although the difference in power density is not high, the area covered by the coils is much smaller in the parting strip. As a result, a converter working in higher frequencies is required, to achieve the required equivalent resistance of the system.
One of the heaviest parts of a power electronics converter is the heatsink for the power semiconductors. In this case as the system is intended for an ice protection system the skin of the leading edge has been used to dissipate the heat of the semiconductors. In that way all the semiconductors have been placed in the base plate of the housing of the converter and this surface is in contact with the leading edge.
Once the converter has been build and verified with passive loads, the conjoint operation of the induction coils and the converter has been carried out and the operation strategies have been prepared for the IWT.
Regarding the progress beyond the state of the art of Electromagnetic Induction Heating Systems prior art (US Pat. No. 2008/0251642) locates the coils in the leading edge surface without any geometrical superposition neither any time based shifting of the induction currents. The configuration introduced in the patent, lacks of a uniform heat distribution. In addition the operating frequency of the solution is kept below 100kHz which will turn into a heavy ice protection solution.
In the solution proposed in this proposal, a geometrical superposition of coils is proposed with a time shifting induction current solution, in order to reach a uniform current distribution in the shedding areas. Moreover, due to the advances carried out in semiconductor technologies the operation frequency is increased providing a smaller induction based solution.

The ice-protection system based on electromagnetic induction presented in this proposal is an innovative electrical ice protection system that will enable to encounter a more/all electric aircraft concept. By the elimination of one or more hydraulic and pneumatic system, the major expectations from a More/All Electrical Aircraft architecture are, among others:
• To Save Weight And Contributes To Less Fuel Consumption, And Then Less Contaminant Emissions;
• To Remove Non Environmental Friendly Fluids From The Aircraft
• Simplify The Architecture And Improve The Reliability And Maintainability
Heating coils and thermal distribution.