Skip to main content

HYbridization via Parallelization based on NOvel Topologies for Innovative Converters

Periodic Reporting for period 1 - HYPNOTIC (HYbridization via Parallelization based on NOvel Topologies for Innovative Converters)

Reporting period: 2020-05-01 to 2021-08-31

HYPNOTIC project, being part of the Clean Sky Programme, will rely on the extensive research, management and technical expertise of the Consortium, to achieve a substantial breakthrough in the field of aircraft electrical hybridization, requiring more HVDC power sources to be simultaneously active on a single electrical network. The accomplishment of the hybridization is strictly related to the ongoing More Electrical Aircraft (MEA) research activities. This initiative, which has major implications for the future aircraft design, eliminates much of the pneumatic and hydraulic fluid and power systems required in today's traditional heavy, maintenance-intensive systems, but increases the demand of electrical power onboard.

One of the most challenging technological problems faced by the aircraft related research is therefore the integration of tailored electronic conversion equipment, which shall be designed according to the very specific constraints that the current European aerospace industry is pursuing. An outstanding effort shall be made between all EU players to boost the technology development of new electronic conversion equipment, which shall increase the efficiency and reduce the weight of final equipment.

In this context, HYPNOTIC will focus on the development of a set of 6 DC/DC bidirectional converters, acting together as only one equipment. The HYPNOTIC converter will be connected to HVDC network of the aircraft on one side, and to a HVDC battery on the other side, for providing paralleling of the HVDC battery on the main HVDC bus.

Specifically the equipment, composed by several DC/DC bidirectional converters (i.e. the “modules”) plus a Supervisor, will be able to reconfigure itself in terms of delivered power on the HVDC network as a consequence of load/source variations, or as a reaction to a fault. This feature will be achieved by using droop control, which will assure an optimal power sharing between the HVDC main generator(s) and the HVDC battery connected via the HYPNOTIC converter.

The proposed modular architecture will support the design of a scalable converter (30 to 60KW) which could be used to support the integration of new HVDC sources, even beyond the scope of the HYPNOTIC project itself. Moreover, modularity will be a key point to achieve the demanding targets of the project, related to high efficiency (>99%) and power density (higher than 3 kW/kg).

The scope of the project can be therefore summarized as the design and development of a modular bi-directional converter, composed by hardware and software acting together in order to achieve paralleling of additional DC sources in any HVDC network.
Main activities of HYPNOTIC project include:
• Development of DC/DC converter cells with enhanced performances, including power density and reconfiguration capabilities.
• Development of accurate simulation models, at both “behavioural” and “functional” levels, integrated with external environments for the aims of energy management functionalities verification.
• Implementation of reliable control laws to allow the parallelization of several HVDC sources
• Demonstration of the operation of such converter inside any suitable HVDC network
- WP1 Preliminary Design Review:

Supplier Equipment Specification (SES) and Compliance Matrix documents have been successfully finished and attached to the D1.1 – Preliminary Design Review deliverable document.

Using parallel modules may also improve the system reliability, allowing degraded operation by turning-off modules in damage.Then a more refined version of the model was executed considering 6 converters in parallel, since an even number is better for a physical symmetry. Some simulations have been performed, in order to verify the compliance with Airbus standards. These standards are related to the aircraft network stability and they are described in Airbus HVDC source and load documentation.

A preliminary CAD Model Design of the HBBCU is release in this Periodic Report. Its modular rack enclosure design allows the high power density inherent in this converter. The initial design is divided in modules: The máster module which is in charge of the main control of the HBBCU and external communication between HYPNOTIC Converter and Battery or HVDC NET side. In the other hand we have the three Slaves Modules, that contains two DC/DCs each. This Slave Modules are the power units of the HBBCU and are controlled and communicated with the Master Module of the converter. Also, a set of custom PCBs have been designed to fix and fulfill all the capabilities needed in the converter.

An high level overview of system interfaces from a software perspective has been provided. The HBBCU is connected to the EPDC (A/C) and to the Battery through digital I/Os and an CAN bus.

- WP2 Modelling and Simulation

Behavioural models: Detailed simulation models of the HBBCU and the proposed control algorithm have been designed. Specifically, the behavioural model has been implemented using both SimPowerSystem and Simscape toolboxes. Functional models: functional simulation models have been derived from the behavioural ones by replacing the switching elements with their average models. This will allow for faster simulation time. Also, the average models have been implemented using both SimPowerSystem and Simscape toolboxes.

- WP3 Critical Design Review

Power electronic, cooling, and structural elements are perfectly distributed inside the HBBCU Design model. Several voltage, current and temperate measures have been design to be acquire during the functioning of the HBBCU. These measures exist for Control and Health Monitoring purpose. Due to a critical lack of space inside the HYPNOTIC Converter, these measures are mainly collected inside the Slave Modules Units. These are the power management units of the HBBCU. Inside every of three Slave Module, two DC/DC converters can be found.

In the State Machine of the HYPNOTIC Converter, four states have been identified: Charge/Idle Mode, Droop Mode, Bus Voltage Regulation and Bus Voltage Stabilization.
HYPNOTIC 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 Domestic 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. HYPNOTIC aims to support development within Europe of indigenous solutions in order to support increased revenue, and hence jobs within the EU. The European air transport system consists of a fleet of about 5,000 aircraft, and moves 1 billion people per year. European aerospace industry is also a strong exporter: more than 53.3% of sales are generated outside the European Union. In spite of the actual economic situation, the forecasts of air traffic and, therefore, of construction of passenger airplanes it is expected to maintain an annual 5% growth for the next twenty years. Considering these forecasts, which turns into an increased number of a/c moving around the world and producing pollution and noise, as well as the actual burden that transport puts upon environment, the EU strategy is to create a more affordable, safer, cleaner and quieter aeronautic sector.