Scope of work 1 Objective

The scope of this CfP is to design, develop, manufacture, validate and integrate a 270V DC SEPDC embedding a supercapacitor-based ESD for the purposes of E2-EM functionalities. A number of items shall belong to this project:

 A SEPDC, embedding a 270 VDC bus bar, with relevant contactors and protections, as well as the computational core (namely the “supervisor”) of the energy management system;

 An ESD based on supercapacitors, used as a rapid energy buffer;

 A bidirectional DC/DC converter connected to the ESD (both constituting the Energy Storage System, ESS), able to manage the power flows related to the ESD;

 A motor load simulating an Electro-Mechanical Actuator used for primary A/C surfaces or landing gear, as example of regenerative load, without dissipation resistors;

CS-GB-Written Procedure 2016-09 Amended WP & Budget 2016-2017 116 These above components shall be provided by the applicant, and together will constitute an advanced ESRS for the scopes of E2-EM functionalities to be then integrated and tested on the primary electrical network of the Regional Iron Bird platform in order to demonstrate that relevant solutions for innovative EPDS correctly perform in a relevant operative environment (TRL 5).

The SEPDC shall exchange information with the primary electrical network using a devoted communication protocol (e.g. CAN, ARINC 429, TBD) for the aims of E2-EM logics implementation.

The DC/DC converter equipment shall be suitable to perform advanced energy management functions by automatically reverse the operating mode, from buck to boost mode, and viceversa, as reaction to energy management objectives persecution.

2.2. Requirements

2.2.1. General Requirements

The overall system shall be fully interfaced with the Iron Bird test rig, and the energy management mode (i.e. automatic inversion of the modes) shall be activated or deactivated in case of needs depending on the specific test configuration. When activated in energy management mode, the supervisor embed into the SEPDC shall take autonomous full control of the converter, reacting to the current power absorption of the network, as well as to other parameters.

All the documentation required for allowing the correct electrical, mechanical and control interfaces with the electrical test rig will be provided to the selected Candidate as an input at the early stage of the Project.

2.2.2. Energy Management Requirements

A key challenge of the CfP is to design the ESS control to effectively limit the rate-of-change in load experienced by the generator over the full load range, while also ensuring careful use of the ESD energy, as sufficient energy must be reserved to minimise the rate-of-change of load experienced by the generator at high loads.

The intended overall behavior of the system is summarized in Fig. 1, which also provides the key elements constituting the object of this Call Topic and the power flows in the different phases.

Figure 1: System architecture and power flows (a. EMA supplying phase, b. EMA braking phase, c. Supercap charging phase)

In Fig. 1a, the EMA load is activated, resulting in bus load power sudden variations. In this case, the ESS (DC/DC converter + ESD) shall be able to provide extra power on the HVDC bus, in order to smooth the power peak experienced by the generator correspondent to the EMA power request.

CS-GB-Written Procedure 2016-09 Amended WP & Budget 2016-2017 117 be able to absorb the extra power linked to the regenerative effect, managed by the supercapacitor.

Thus, the energy management logic to be implemented shall be able to control the behavior of the converter, by selecting in each operating phase the conversion direction (buck or boost) and the operation set point, in order to minimize the genator fatigue consequent to a sudden load variation on the HVDC and/or to a regeneration effect as consequence of EMA operation. The selection shall be performed by analyzing a set of parameters able to give an indication about the intensity of the power flow managed by the DC/DC converter. Such parameters can include also simulated environmental factors, flight phases and priorities of the loads connected to the SEPDC.

Given the complexity of the scenario, a strong formal and theoretical approach must be proposed in order to properly define the structure of the energy management strategy, using control methods for rate-limit of the ESS system operations and supervisory control strategies for global coordination of the operations.

Moreover, automatic or semi-automatic technique of translation of the formal structure into a firmware (microprocessor or FPGA) shall be proposed, in order to minimize the chance of programming error.

2.2.3. ESS Requirements

A bi-directional DC/DC converter shall be provided as integrant part of the SEPDC. The converter shall be able to manage bi-directional power flows between the 270 VDC bus bar embed into the SEPDC, and the supercapacitors, recharging them at a predefined voltage (see Fig 1c). The rated power will be provided to the Candidate at early stage of the Project, referring to the Iron Bird network specifications. Reductions of weight and volume by using innovative solutions with respect to the current state of the art are desirable.

Moreover, innovative techniques for DC/DC converters regulation shall be proposed, in order to comply with requisites of rapid control set point variation, as required by the energy management strategy. Formal proof of robustness against uncertainties and industrial stability of such techniques shall also be evaluated.

An adequate number of supercapacitors must be chosen and arranged in order to comply with the energy flows to be managed (i.e. charging and discharging phase). The supercapacitors shall be electrically interfaced with the DC/DC converter, using technical solutions in order to guarantee the installation safety and the correct charge/discharge cycles operations.

2.2.4. EMA requirements

A motor load simulating an Electro Mechanical Actuator representative of a Regional A/C primary surface or main landing gear shall be provided by the applicant, and adequately interfaced with the SEPDC for the purposes of the E2-EM. The EMA load shall not embed any resistor for energy dissipation, to be instead managed with the ESS. It shall be electrically interfaced with the 270 VDC bus. Moreover, its operation shall be controlled by remote, hence the EMA load shall embed an adequate interface communication with the Iron Bird structure. Finally, its operations shall be monitored and associated measurements shall be available to the Iron Bird network as well as to the SEPDC supervisor.

2.2.5. Environmental Requirements

The SEPDC equipment, including the ESS, and any other equipment referred to in this CfP will be located in a laboratory room for validation and functional tests. Therefore, the environmental requirements shall be limited to a compatibility of the equipment with the laboratory environmental conditions. Anyway, a detailed Interface Control Document (ICD) will be provided to the selected Candidate detailing all the environmental conditions that the module shall comply with.

As an example, as the equipment shall not be installed on the aircraft, the temperature requirement shall be taken into account just for the selection of the appropriate technologies and components and not for a full qualification. The range to be considered for the selection shall be 15 ÷ 40 °C.

2.2.6. Electrical Power Requirements

CS-GB-Written Procedure 2016-09 Amended WP & Budget 2016-2017 118 and abnormal characteristics in steady-state and transient are in accordance with MIL-STD-704F reference power quality standard.

The system shall include connectors and wires to connect the various inputs and outputs to/from the different voltage busses, according to the detailed electrical scheme contained with the ICD document. All the connections shall support the rated voltage as specified in MIL-STD-704F. All the connections shall be isolated from the ground and between them.

The specific power ratings of the SEPDC will be provided to the Candidate at the early stage of the Project. However, they will be compliant with typical Regional A/C power systems and loads.

2.2.7. Operational Requirements

 The system shall continue to work for an acceptable period in case of lack of cooling features.

 FMEA or FMECA analyses shall be provided for failure analyses.

 The system design shall avoid, as much as possible, scheduled maintenance.

 The system shall be able to communicate with a central system for monitoring and control purposes, by means of appropriate protocols (e.g. CAN or ARINC).

 The system shall allow easy reprogramming, by specific ports (e.g. USB or RS232) accessible from a laptop. 2.2.8. Safety Requirements

 The system shall comply with European standards related to electrical power installations, and low voltage electrical installations;

 The system shall embed safety and protections logics (e.g. overcurrents, overvoltages) in order to react to potential failures and communicate the faulty status to an external device.

2.2.9. Software Requirements

During the design phase, the SEPDC and any other equipment referred to in this CfP shall be modeled and tested in a simulation environment in order to pretest their functionalities and performances. Detailed models (preferably SABER models) shall be provided by the applicant, demonstrating the effectiveness of the proposed converter topology by means of accurate simulations. Also the equipment supervisory control and monitoring stategy effectiveness and performances shall be demonstrated by means of simulations, in SABER or other simulation tools. Both “behavioral” and “functional” level models shall be implemented.

The firmware for equipment control and monitoring shall be automatically or semi-automatically generated starting from the simulation models. Multi-platforms simulation approach shall be preferred. A preliminary testing phase for the firmware using simulation tools is required.

Tasks

Ref. No. Title - Description Due Date

KOM A Kick off meeting will be organized to review the technical requirements and the project logics and organization agreed with the partner during the Grant Preparation phase.

T0

Task 1 Requirements analysis: To review the customer requirements, and