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HVDC Electrical Power cOnversion and DIstribution System

Periodic Reporting for period 3 - HEPODIS (HVDC Electrical Power cOnversion and DIstribution System)

Reporting period: 2019-07-01 to 2020-12-31

The HEPODIS project aims to develop a new electrical power conversion and distribution system more efficient and reliable for High Voltage Direct Current (HVDC) for the electrical power supply of essential loads to be implemented and integrated in the Regional FTB2 Demonstrator. The need of a new Electrical Power Distribution in regional aviation comprehends: intelligent electronic systems to manage essential electrical loads, minimal voltage drops, minimal risk of safety issues from leakage currents, minimal risk of nuisance trips from lightning strikes and minimal risk of damage from high inrush currents.

The electrical power system for High Voltage Direct Current (HVDC) will comprised, mainly, two different sub-systems: power conversion unit and electrical power distribution center. This technology that will be brought up to TRL6 will continue the work on previous European and International Projects and will contribute to the demonstration activities that have been identified in CleanSky2 requiring more efficient, compact and reliable systems. High Voltage Direct Current (HVDC) developed in HEPODIS will have a lot of benefits and advantages, especially the weight savings either through higher voltage and a through simplified load converters. This means less fuel burn and less gas emissions.

The main objectives of the project are:

-Design, manufacturing and qualification of new regulated Transformer Rectifier Unit (TRU) equipment to supply an HVDC distribution system in order to supply essential loads in the regional aircraft FT2B.
-Improve the characteristics of TRU in relation to the existing equipment: functionality, electrical efficiency, power density, safety, advance control and monitoring and use of advance semiconductor technologies.
-Generate a realistic model of the TRU in order to be integrated with the rest of the models of the HVDC systems. The model must reproduce precisely the working conditions of the real system to avoid integration problems and support the permit to flight phase.
-Specify, design, develop, manufacture, qualify and validate a HVDC Distribution Equipment for essential loads from Flight Control System for IADP Regional Aircraft FT2B.
-Integrate power generation system and the electrical power distribution system.
-Improve effectiveness, reliability and efficiency compared with current architectures.
-Model and simulate electrical performance, compared with real system performance for supporting design, testing and certification strategies.
-Employ new technologies and innovative integration in the equipment. New levels of voltage, architecture, energy management concepts, power electronics devices. More safety due Power Distribution becomes more critical.
During this project two different units have been developed, HVTRU (developed by SkyLife, it will be an electric power conversion unit from 115VAC, triphasic and variable frequency, to 270 VDC) and PDU (developed by TEMAI, it will be an electric power distribution unit at 270VDC).

Since both equipment have to be installed in the aircraft, they had to be developed according to the DO-254 normative for Hardware electronics and DO-178 for embedded Software (Design, Traceability and Validation). Preliminary design was developed and validated by Topic Manager on 2017. After the preliminary phase, laboratory prototypes to validate the concepts were manufactured and tested.

Later, the detailed design was carried out, in which electronic design, mechanical design and simulation effort have been performed in order to develop and manufacture the Laboratory equipment (LUAR) that will be delivered to Airbus DS to be tested in its integration laboratory. Both PDU and TRU LUAR equipment were completed at 100% (only pending surface treatment for mechanical parts in the case of PDU and delivering to topic manager). Additionally, a Safety Analysis of both units was performed. The aim of this analysis was to assess the failure of the units.

Qualification Plan and Test Procedures for both units were generated. The aim of these documents is to define and describe the tests to be carried out during the process of qualification of the HEPODIS prototypes (Environmental, EMI-EMC, Vibrations and Electrical) and the locations in which are going to be performed. Qualification tests will be completed after the end of the project.

Once the first positive results of the project were obtained, the dissemination actions have started. Thus, a paper with the final results of the HVTRU has been sent to the journal “Energies” from MDPI. Moreover,an article summarizing the achievements of the project in the SSPCs based on Silicon Carbide field was presented in the EUCASS Congress on July 2019.
HEPODIS has developed a new electrical power conversion and distribution system more efficient and reliable to supply essential loads using HVDC voltages. To do this, advanced material, topologies and control strategies have been used. The main contributions of the technology addressed in HEPODIS to the identified impacts are:
o Improvement of fuel consumption due to a more efficient power density.
o Improvement of fuel consumption due to a more efficient power transfer and usage.
o Improvement of fuel consumption due to a reduction of weight of power converter and distribution units.
o Improvement of power generation capabilities due to better energy management.
o Decrease of maintenance operations and maintenance costs due to built-in testability.
o Improvement of reliability and safety due to architecture and high reliable switching devices with protections implementation.
o Increase of the power quality of the HVDC system.
HEPODIS establishes an important progress beyond the state-of-the-art as no previous systems based on HVDC for essential loads have been implemented and tested before in an aircraft. This project will close the gap between technology validation at lab level and prototype demonstration in an operation environment. Prototypes of TRU and PDU have been already tested at laboratory level checking their functionalities. Qualification tests and aircraft integration will be performed after the end of the project.
HEPODIS will contribute to the huge effort required to maintain global leadership for aviation in Europe and meeting the needs of its citizens, a sector being a key component of the existing European Gross Product (GDP) and employment. The forthcoming challenges expressed by Airbus and Boeing of over 29,000 aircraft needed in the coming 15 years set a large market opportunity for enhancing the European footprint. HEPODIS, aims to support development within Europe of indigenous solutions in order to support increased revenue, and hence jobs within the EU.
HEPODIS project contributes to and strengthens the leading role of the EU to combat climate change, since the HVDC Electrical Power Conversion and Distribution System developed, as aforementioned, allows improving power density and efficiency.
LUAR prototype