Skip to main content

Power Electronics High Voltage Technologies

Periodic Reporting for period 1 - PHiVe (Power Electronics High Voltage Technologies)

Reporting period: 2018-11-01 to 2019-10-31

Problem/Issues being addressed

With the overall objective to reduce CO2 emissions for aviation and the reduction of the overall costs of building, operating, and maintaining aircraft, one of the key enablers towards this objective, is the adoption of higher levels of electrification on aircraft. This higher level of electrification, more commonly known as More Electric Aircraft (MEA), looks at replacing traditional non-electrical systems with lighter and more efficient electrical alternatives.

As a consequence of this progression towards MEA, there is an increasing requirement for power conversion methods in the power distribution network, which provide high density, and higher levels of efficiency. In addition, the push towards standardization of components, avoiding bespoke designs for each new application, means that any solutions which are module based will be preferred. Traditionally, the only viable solution for power conversion requirements was to use passive solutions with transformers and controlled rectifiers, such as TRU and ATRU units, which results in a heavy and inefficient power conversion system. By replacing the passive system with active power conversion, the weight and power density of each power conversion stage can be significantly reduced, thus leading to the overall goal to reduce system weight and costs.

Benefits

The introduction of high voltage bidirectional power converter system in generation and actuation applications, will yield a number of benefits for airframe manufacturers, around lower-cost solutions, improved reliability and lower weight. The reduction in weight will have a direct impact on fuel consumption providing direct financial benefits to the airliner as well as additional resulting environmental benefits. The cost reductions from reduced maintenance and overall system costs will assist in reducing the overall costs of air travel with the subsequent societal benefits.

Objectives

The objectives of the PHiVe project is to demonstrate operation of a scalable converter that addresses the most critical aspects in a high voltage aviation converter design, which are the converter topology, the components, the interconnections and the packaging. The demonstrator will provide further validation to the use of high voltage SiC devices in aerospace applications with their associated efficiency and reliability benefits.
Over the course of the first part of the project, the following work has been completed by each of the consortium members.
Various different converter topologies have been evaluated by the University of Nottingham. Models have been created to analyze the switching and conduction losses, ripple and complexity of control and design. A test schedule was planned which was to be started when the new Research Assistant arrived in January.
A preliminary power module design was developed by DEEP concept. The design utilized a double-sided, water-cooled module package with stacked power substrates. The use of power bump technology was proposed for the chip interconnects. The details of the design were outlined in deliverable 4.1 which was submitted in October 2019.
Knowles have developed the MLCC capacitor that will be used inside the power modules. They have completed some of the characterization testing on the device and have delivered some initial parts to use in the evaluation tests in Nottingham.
Tecnalia have implemented FPGA in the loop testing on the Microchip Smart Fusion 2 advanced development board. They have also produced a preliminary design for the controller and sensor boards.
The University of Manchester have completed a report on interconnect technologies and have also developed an Excel based clearance and insulation thickness calculator which they have used to determine safe clearances and insulation thickness for the PHiVe converter. During the reporting period, they were in the process of commissioning a chamber to perform creepage tests.
Microchip have submitted four project management deliverables to the Clean Sky system (D1.1 D1.2 D1.3 and D1.4) and completed all associate work with these. A project plan has been created to track the progress on all tasks, deliverables and milestones. A fortnightly consortium Webex meeting and all major review meetings have been organised by Microchip.
The 3.3kV Silicon Carbide die that has been delivered is beyond state of the art for this type of technology. The power bumps that will be used as interconnects in the power module package can be considered beyond state of the art as they provide many benefits over the traditional wire bond interconnect method. The impact of both these technologies will reduce weight and cost, and increase efficiency for aircraft electrical systems. This will result in associated environmental benefits of reduced emissions and lower maintenance cost and effort.
3D model of the proposed power module package
Smart Fusion 2 Advanced Development Kit