Periodic Reporting for period 3 - InductICE (Efficient, Modular and LigthWeight Electromagnetic Induction Based Ice Protection System)
Okres sprawozdawczy: 2019-07-01 do 2019-12-31
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 was 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 contributed 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 developed in the project has a modular distribution in order to minimize weight while maximizing system efficiency.
The specific objectives for the project were:
1. Achieve 95% of heating Efficiency
2. Improve the speed, while providing a precise and targeted control of the generated heat facing the drawbacks of current on-board ice-protection systems
3. Direct Heating System Modular and flexible solution able to overcome the drawbacks of current electrothermal de-icing systems
In order to face the first objective, the ratio between the resistance of the heated element and the heating element was maximized. The resistance of the heated element was increased by using thin conductive layers, and, on the contrary, the resistance of the heating element (the coil) was reduced using Litz wire conductors. Regarding the targeted control of the generated heat, the coil was designed following a superimposed winding solution. The geometrical distribution of the coils, along with the phase shifted current distribution through them generated a uniform magnetic field, and therefore a uniform heating pattern.
Summarizing:
1. Achieve 95% of heating efficiency -> Yes but with respect of both the carbon fiber and the metallic mesh.
2. Improve the speed, while providing a precise and targeted control of the generated heat facing the drawbacks of current on-board ice-protection systems -> Yes because part of the generated power by the coil reached the metallic mesh.
3. Design a direct heating system -> No because all the power generated by the coil did not reach the metallic mesh.
4. Modular and flexible solution able to overcome the drawbacks of current electro-thermal de-icing systems -> Yes, a completely modular system was designed.
5. Design a lightweight system -> Yes, but if more power is needed to overcome the loss in the carbon fiber it is must be reevaluated.
INDUCTICE project contributed 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 developed in the project has a modular distribution in order to minimize weight while maximizing system efficiency.
The specific objectives for the project were:
1. Achieve 95% of heating Efficiency
2. Improve the speed, while providing a precise and targeted control of the generated heat facing the drawbacks of current on-board ice-protection systems
3. Direct Heating System Modular and flexible solution able to overcome the drawbacks of current electrothermal de-icing systems
In order to face the first objective, the ratio between the resistance of the heated element and the heating element was maximized. The resistance of the heated element was increased by using thin conductive layers, and, on the contrary, the resistance of the heating element (the coil) was reduced using Litz wire conductors. Regarding the targeted control of the generated heat, the coil was designed following a superimposed winding solution. The geometrical distribution of the coils, along with the phase shifted current distribution through them generated a uniform magnetic field, and therefore a uniform heating pattern.
Summarizing:
1. Achieve 95% of heating efficiency -> Yes but with respect of both the carbon fiber and the metallic mesh.
2. Improve the speed, while providing a precise and targeted control of the generated heat facing the drawbacks of current on-board ice-protection systems -> Yes because part of the generated power by the coil reached the metallic mesh.
3. Design a direct heating system -> No because all the power generated by the coil did not reach the metallic mesh.
4. Modular and flexible solution able to overcome the drawbacks of current electro-thermal de-icing systems -> Yes, a completely modular system was designed.
5. Design a lightweight system -> Yes, but if more power is needed to overcome the loss in the carbon fiber it is must be reevaluated.
With the new specifications on mind instead of a chordwise heating strategy, with single chordwise modules, a combined spanwise and chordwise strategy was sized for a wing and for the demonstrator to be tested in the IWT. The optimal coil for uniform heating was designed choosing for that purpose the most appropriate coil pitch (λ). The new coils were manufactured and validated reaching the expected heat distribution. Regarding the power electronics converter, despite existing different resonant converter configurations, the half-bridge topology was the chosen one. However, although the difference in power density was not high, the area covered by the coils was much smaller in the parting strip. As a result, a converter working in higher frequencies was 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 was used to dissipate the heat of the semiconductors. In that way all the semiconductors were placed in the base plate of the housing of the converter and this surface was in contact with the leading edge. Once the converter was build and verified with passive loads, the conjoint operation of the induction coils and the converter was carried out and the operation strategies were prepared for the IWT.
Finally, the system was tested at IKERLAN facilities, and also in the Ice Wind Tunnel at RTA Austria. The system operated as expected from the control and converter point of view. Regarding the coils there were some manufacturing issues that must be improved. From a global system point of view, the impact of the carbon fiber on the heating speed of the system was higher than expected, reducing the heating power that reached directly the external part of the skin and therefore the expected heat speed and de-icing capabilities.
Regarding the dissemination activities, there is a webpage at IKERLAN’s website where the project is described https://www.ikerlan.es/en/lines-of-research/research-projects/project/inductice-h2020-induction-technology-to-prevent-ice-build-up-on-aircrafts-during-flight. Moreover, an article was published in CORDIS (https://cordis.europa.eu/article/id/415548-a-hot-new-ice-protection-concept-for-aircraft-attracts-interest).
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 was used to dissipate the heat of the semiconductors. In that way all the semiconductors were placed in the base plate of the housing of the converter and this surface was in contact with the leading edge. Once the converter was build and verified with passive loads, the conjoint operation of the induction coils and the converter was carried out and the operation strategies were prepared for the IWT.
Finally, the system was tested at IKERLAN facilities, and also in the Ice Wind Tunnel at RTA Austria. The system operated as expected from the control and converter point of view. Regarding the coils there were some manufacturing issues that must be improved. From a global system point of view, the impact of the carbon fiber on the heating speed of the system was higher than expected, reducing the heating power that reached directly the external part of the skin and therefore the expected heat speed and de-icing capabilities.
Regarding the dissemination activities, there is a webpage at IKERLAN’s website where the project is described https://www.ikerlan.es/en/lines-of-research/research-projects/project/inductice-h2020-induction-technology-to-prevent-ice-build-up-on-aircrafts-during-flight. Moreover, an article was published in CORDIS (https://cordis.europa.eu/article/id/415548-a-hot-new-ice-protection-concept-for-aircraft-attracts-interest).
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
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