Periodic Reporting for period 2 - HIVOMOT (HIgh power and VOltage operation of electric MOTors in aeronautics)
Reporting period: 2022-01-01 to 2023-11-30
HIVOMOT project will contribute to the fundamental understanding of high power, high voltage electrical systems and more precisely to the reliability and safety concerns related to high voltage insulation and high temperature superconductor utilization for electric drives in aeronautics. The deployment of these electrical systems and the new concepts that will arise from the studies of HIVOMOT project will enable the future hybrid and full electric aircraft.
HIVOMOT project’s proposal is to combine both an investigation about scientific and technical challenges of using high power density electric machines in high voltage – high power electric systems for aircraft applications, and a deep look into HTS based electrical machines for this environment.
For this purpose, this main objective splits into the following technical objectives:
• Investigation on modelling of high voltage electrical systems at high altitude for fundamental understanding of the technical issues related to inverter-fed HV insulation and arcing effects in electrical machines.
• Research into insulation approaches and assessment of their reliability and safety at high altitude.
• Electromagnetic, electrical, thermal and mechanical design of actual topologies of electrical machines in order to evaluate technology limits for high power and high voltage operation in A/C applications.
• Comparison of available and foreseen HTS materials for their use in electric machines for high volumetric and mass power density.
• Investigation on thermal management systems for cryo-cooled HTS windings for electric machines in aircraft environment.
• Preliminary design and comparison of different HTS based electric machine topologies for aircraft applications at high voltage and high-altitude in terms of power density, reliability and safety.
• Analysis of manufacturing processes to achieve the required HTS coils geometry, provide the winding voltage to the conductor in order to avoid quenches and optimize the winding volume.
• Full design of a MW-class HTS electric motor concept and development of a lab-scale validator, applying the most suitable techniques investigated during the project for HV and high altitude operation, including the thermal management.
The main conclusion from this work is that today SC technology can’t compete with non-SC technology in terms of power-density for applications requiring low power (0,5 – 2 MW). In addition, SC technology is restricted to low-speed applications (<3000 rpm). On the other hand, SC technology becomes more competitive for higher power demands (and for very low-speed applications).
HIVOMOT project’s proposal is to combine both an investigation about scientific and technical challenges of using high power density electric machines in high voltage – high power electric systems for aircraft applications, and a deep look into HTS based electrical machines for this environment.
For this purpose, this main objective splits into the following technical objectives:
• Investigation on modelling of high voltage electrical systems at high altitude for fundamental understanding of the technical issues related to inverter-fed HV insulation and arcing effects in electrical machines.
• Research into insulation approaches and assessment of their reliability and safety at high altitude.
• Electromagnetic, electrical, thermal and mechanical design of actual topologies of electrical machines in order to evaluate technology limits for high power and high voltage operation in A/C applications.
• Comparison of available and foreseen HTS materials for their use in electric machines for high volumetric and mass power density.
• Investigation on thermal management systems for cryo-cooled HTS windings for electric machines in aircraft environment.
• Preliminary design and comparison of different HTS based electric machine topologies for aircraft applications at high voltage and high-altitude in terms of power density, reliability and safety.
• Analysis of manufacturing processes to achieve the required HTS coils geometry, provide the winding voltage to the conductor in order to avoid quenches and optimize the winding volume.
• Full design of a MW-class HTS electric motor concept and development of a lab-scale validator, applying the most suitable techniques investigated during the project for HV and high altitude operation, including the thermal management.
The main conclusion from this work is that today SC technology can’t compete with non-SC technology in terms of power-density for applications requiring low power (0,5 – 2 MW). In addition, SC technology is restricted to low-speed applications (<3000 rpm). On the other hand, SC technology becomes more competitive for higher power demands (and for very low-speed applications).
The project has been dedicated to the following activities in each WP.
WP1: Project management
The technical progress, financial aspects and potential issues concerning the development of the project has been monitored through regular (virtual and physical) meetings held between the research groups of Alconza, Antec, Suprasys and Ceit.
WP2: Challenges and technology potentials for electrical propulsion drives
A detailed analysis of the non-superconducting (NSC) technology for electric aircraft propulsion and its limits was performed in this WP, including a complete modelling of different electric motor topologies and cooling systems through FEA and CFD simulations.
WP3: Fundamental understanding and modelling of high-power systems at high altitude
In this task, firstly, a brief state of the art is developed introducing partial discharges and the existing work in bibliography on their detection, with a focus on aeronautical propulsion. On this chapter, a classification of the partial discharges is presented, as a function of the topology of the discharge and the medium surrounding the test unit. Moreover, different aspects of this phenomena are assessed as follows: detection methods of partial discharges, usually used measuring equipment, PRPD and PSA pattern recognition, acceptance limits and the time-frequency map. This chapter concludes with a brief explanation of the standards on which the test will be based.
Later, the information relative to the tests performed regarding the insulation assessment of different elements of the designed electric motor and their reliability and safety is retrieved. First, tests assessing the dielectric strength of winding slot insulation material are performed under different surrounding conditions, and the obtained values are compared with the ones provided by the material supplier. The different conditions are obtained varying the temperature, relative humidity, and pressure parameters and a test with the specimen immersed in oil shall be performed.
WP4: Design of a MW-class HV HTS motor
The main outcome of this WP is the design of a 2 MW HTS HV electric motor and the design of a mock-up to validate the key points of the design, consisting on a scale electric motor.
WP5: Experimental Development
Based on the results of the conceptual design carried out in the WP4 Design of a MW-class HV HTS motor, the manufacturing design of the scale demonstrator was carried out.
WP6: Test evaluation
The main goal of this WP is to validate the design and manufacture of the mock up. Therefore, a series of functional tests have been carried out on the different active parts of the motor as well as on the motor assembly.
WP7: Dissemination and exploitation
A number of communication and dissemination activities have been carried out within the project, resulting in a dedicated website (https://hivomot.eu/(opens in new window)) and Twitter (https://twitter.com/hivomotproject(opens in new window)) whereby disseminating the project results.
With regards exploitation, 4 different HIVOMOT products have been identified, classified under Key Exploitable Results (KERs). For these KER, an exploitation and business plan has been developed.
Also, 2 articles in journals have been published and a patent has been developed. In addition, there has been representation of HIVOMOT’s members in different conferences and workshops during the project.
WP1: Project management
The technical progress, financial aspects and potential issues concerning the development of the project has been monitored through regular (virtual and physical) meetings held between the research groups of Alconza, Antec, Suprasys and Ceit.
WP2: Challenges and technology potentials for electrical propulsion drives
A detailed analysis of the non-superconducting (NSC) technology for electric aircraft propulsion and its limits was performed in this WP, including a complete modelling of different electric motor topologies and cooling systems through FEA and CFD simulations.
WP3: Fundamental understanding and modelling of high-power systems at high altitude
In this task, firstly, a brief state of the art is developed introducing partial discharges and the existing work in bibliography on their detection, with a focus on aeronautical propulsion. On this chapter, a classification of the partial discharges is presented, as a function of the topology of the discharge and the medium surrounding the test unit. Moreover, different aspects of this phenomena are assessed as follows: detection methods of partial discharges, usually used measuring equipment, PRPD and PSA pattern recognition, acceptance limits and the time-frequency map. This chapter concludes with a brief explanation of the standards on which the test will be based.
Later, the information relative to the tests performed regarding the insulation assessment of different elements of the designed electric motor and their reliability and safety is retrieved. First, tests assessing the dielectric strength of winding slot insulation material are performed under different surrounding conditions, and the obtained values are compared with the ones provided by the material supplier. The different conditions are obtained varying the temperature, relative humidity, and pressure parameters and a test with the specimen immersed in oil shall be performed.
WP4: Design of a MW-class HV HTS motor
The main outcome of this WP is the design of a 2 MW HTS HV electric motor and the design of a mock-up to validate the key points of the design, consisting on a scale electric motor.
WP5: Experimental Development
Based on the results of the conceptual design carried out in the WP4 Design of a MW-class HV HTS motor, the manufacturing design of the scale demonstrator was carried out.
WP6: Test evaluation
The main goal of this WP is to validate the design and manufacture of the mock up. Therefore, a series of functional tests have been carried out on the different active parts of the motor as well as on the motor assembly.
WP7: Dissemination and exploitation
A number of communication and dissemination activities have been carried out within the project, resulting in a dedicated website (https://hivomot.eu/(opens in new window)) and Twitter (https://twitter.com/hivomotproject(opens in new window)) whereby disseminating the project results.
With regards exploitation, 4 different HIVOMOT products have been identified, classified under Key Exploitable Results (KERs). For these KER, an exploitation and business plan has been developed.
Also, 2 articles in journals have been published and a patent has been developed. In addition, there has been representation of HIVOMOT’s members in different conferences and workshops during the project.
ALCONZA, as the final engine manufacturer, through this project and its future continuation aims to develop design and manufacturing techniques for certain components of the superconducting engine, as well as the assembly process of the final product. In this way, and always within a collaborative framework, the objective of being able to supply the propulsion machine for its integration into the complete superconducting system is presented.
ANTEC, for its part, is developing capabilities for the manufacturing and testing of superconducting windings and systems with high-critical temperature materials that allow their integration into electric motors developed by ALCONZA.
All of this implies for the partners a new positioning in a demanding market in terms of reliability, power density and performance, facts aligned with the sustainability, diversification and growth strategy of both companies. However, because gradual growth is expected with business opportunities in the medium-long term, in the short term it is not seen that this new line of products can compete and/or displace in any way the products and services currently present in their wallets.
Even though, in the short term, the entry into service of applications that incorporate this technology is not expected, ALCONZA and ANTEC, by means of this work and its future continuation, intends to continue developing the key exploitation results.
ANTEC, for its part, is developing capabilities for the manufacturing and testing of superconducting windings and systems with high-critical temperature materials that allow their integration into electric motors developed by ALCONZA.
All of this implies for the partners a new positioning in a demanding market in terms of reliability, power density and performance, facts aligned with the sustainability, diversification and growth strategy of both companies. However, because gradual growth is expected with business opportunities in the medium-long term, in the short term it is not seen that this new line of products can compete and/or displace in any way the products and services currently present in their wallets.
Even though, in the short term, the entry into service of applications that incorporate this technology is not expected, ALCONZA and ANTEC, by means of this work and its future continuation, intends to continue developing the key exploitation results.