Report

Teaser, summary, work performed and final results

Periodic Reporting for period 2 - HASTECS (Hybrid Aircraft; academic reSearch on Thermal and Electrical Components and Systems)

Teaser

The general objective of the HASTECS is to support Hybrid Electric Demonstration by developing models and tools that can help designers in assessing main benefits of architectures and power management. Assessments will be integrated at the system level and will include design...

Summary

The general objective of the HASTECS is to support Hybrid Electric Demonstration by developing models and tools that can help designers in assessing main benefits of architectures and power management. Assessments will be integrated at the system level and will include design and analysis of the main components of the hybrid power chain: electric machines and its cooling, cables, power electronics and related thermal management by taking into account the main environmental constraints, especially partial discharges due to new high power and ultra-high voltage standards.

Work performed

\"* During the RP1 period (Sep 2016 – Nov 2017), main progress were:
- A target setting tool has been developed for electric machines preliminary design. For sinusoidal radial flux non salient permanent magnet motor the sizing procedure calculate the losses accurately and can be already used to make a good sizing of motor of specific power of 5kW/kg.
- The development of a design tool for power converters has been launched. We are now able, for classical and known topologies and using silicon-type components, to quickly evaluate performance and efficiency for a given operating point or for a mission. The effects of the DC bus voltage level on both sizing and performance of the associated converters have been studied.
- Innovative solutions for machine cooling : a thermal model was developed to predict temperatures and heat fluxes inside the motor and to quantify the effect of different cooling methods.
For power electronic converter cooling, only innovative high efficiency solutions have been taken into account. Because of the high efficiency and reduced weight of passive cooling systems, tests were performed on a CPLIP (Capillary pumped Loop for Terrestrial Applications).
- the WP5, dedicated to partial discharge studies has just started since October 2017 (2 months during the RP1). The main result is related to first numerical simulations of electric stresses on the basis of single wires configuration.
- Integration (WP6) of simplified models has been launched by integrating PWM inverter – PMSM (Synchronous Motor) association. From Airbus data, development of simplified (surrogate) models for Gas turbine (turboshaft), propeller, gearbox and cables has been launched. Finally, a complete design process for overall simulation of the hybrid power chain has been defined by setting inputs/outputs for each device.

* During the RP2 period (Nov 2017 – Feb 2019), main progress were:
- eMotor design (WP1): two different tools have been completely developed: a target setting tool and a second tool called \"\"SM-PMSM\"\" for Surface Mounted Permanent Magnet Synchronous Machine. A complete set of validation tests by means of field calculation have been conducted during the two first reporting periods.
- eMotor cooling design (WP3): a detailed and accurate Lumped Parameter Thermal Modeling has been developed for the electric motor and its cooling system. Considering the machine designed by the WP1 for 2025 target, a solution has been proposed consisting of liquid cooling in the shaft and the stator. The overall weight of the motor and its cooling system leads to a specific power density slightly above the target of 5 kW/kg.
- Power converter design (WP2): the main objective focused during the RP2 period was oriented towards power losses minimization in order to reduce the cooling effort, thus reducing the weight of the whole power conversion system weight. This has been done by adjusting three main key design drivers:
o use of small rating components which can be done by using multilevel topologies, such as 3-level FC and NPC;
o modulation strategies that may reduce the switching losses ;
o use of new generation IGBTs that have better performances than the previous ones.
These three design drivers, in addition to an optimized cooling system, have led to a solution that reaches and go beyond the 2025 target of 15 kW/kg. Currently, a specific power of 19kW/kg has been reached.
- Converter cooling design (WP4): several tasks have been achieved during RP2 period:
o a preliminary analysis was presented to explain how the design point was chosen for the CPLIP concept;
o experimental tests made to verify that the cooling loop behaves properly in a real application;
o study on the start-up behaviour of the loop proposed by coupling experimental and numerical results ;
o studies on the transient behaviour of the loop.
- Partial discharges and high voltage effects (WP5): Performance indicator:
a) For power electronics in fusel\"

Final results

The HASTECS project involves two successive:
“target 2025” currently studied : most performant components and materials currently existing will allow to increase power densities, targeting 15 kW/kg for power and 5kW/kg for electric machines (including cooling). Then, we will have to propose new concepts with technological breakthroughs of the main components for a “long term target of 2035”. For power electronics, the specific power target is 25kW/kg and 10kW/kg for electric machines (including cooling).
A set of breakthrough improvements will be necessary to reach these targets; innovative technologies and concepts in machine cooling and thermal management system constitute a key challenge to reach these goals: the consortium expertise is based on this finding, strongly coupling research teams with a transdisciplinary (“electro-thermal”) vision.

Website & more info

More info: http://www.laplace.univ-tlse.fr/Projet-HASTECS-vers-l-avion-plus-electrique.