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FP7

MAGMOLIB Report Summary

Project ID: 620087
Funded under: FP7-JTI
Country: Spain

Final Report Summary - MAGMOLIB (Modelica library of detailed magnetic effects in rotating machinery)

Executive Summary:
MAGMOLIB is a project developed under the Topic SGO-02-065 of Clean Sky Joint Technology Initiative, the Public-Private Partnership between the European Commission and the EU Aeronautical industry. The project has been developed by MCIA Center, at the Universitat Politècnica de Catalunya (Gaia Building, Campus UPC Terrassa, Spain).
General objective of the project is to design and develop Modelica® libraries of rotating electric machinery with detailed magnetic effects and non-ideal flux coupling.
MAGMOLIB comprised two main goals. First the elaboration of pre-design and sizing tool for a wide range of types of electrical motors: IM, SMPMSM, IPM family, SRM and Synchronous. Until date no pre-design tool is available in commercial software with such a wide range of machines and able to perform a simple, quick and accurate pre-design including efficiency maps, sections, fail-conditions and possible design solutions.
Second a multi-physics (electrical, magnetic, thermal) model of a SMPMSM based on reluctance networks and thermal lumped parameters. By means of thermo-reluctance network a detailed thermo-electro-magnetic dynamics taking into account discrete distribution of windings, stator and rotor slotting, magnetic steel saturation, skewing, demagnetization and non sinusoidal currents can be modeled. Therefore spatial and time harmonics in the magnetic flux distribution and torque ripples will be reflected in the great level of precision, providing a singular, realistic, computationally efficient equivalent circuit model which virtually facilitates the enhancement of classic control and diagnosis strategies and paves the way for the new ones.
At the end of the project, they have been implemented in Modelica® the Basic Predesign Motor Tool and a rich featured SMPMSM Reluctance & Thermal model that is compatible with the pre-design tool. Both motor pre-design and Multy-physics modelling were validated against FEM Simulation and experimental testing in a Mechatronics Laboratory,
The validation performed goes from validation of Modelica®’s Code, final predesign modelling, complete reluctance & thermal network validation and comparative results of Modelica®’s models and real experimental data obtained from a manufactured motor as design performed.

As a conclusion, MAGMOLIB contributes to the goals of SGO by means of stablishing a motor design tool for early systems design phase as well as establishing a library with detailed magnetic effects of and non-ideal flux coupling.

Project Context and Objectives:
The main objectives of the MAGMOLIB project were:
• New Modelica® library for basic design purposes of Externally Excited
Synchronous Machines, Permanent Magnet Synchronous Machines, Synchronous Reluctance Machines and Asynchronous Induction Machines.
• New advanced reluctance and improved thermal Modelica® model for Permanent Magnet Synchronous Machines.
• New Software Tools with GUIs for guided model design from geometric motor considerations and torque and power demand profiles.
The project developed an Interactive Development Tool Modelica®-Based for Electric Machines, which is able first to generate an Modelica® model for the electric machine, and later to estimate electrical, mechanical and thermal machine properties, all from completed or basic design choices, initially specified as parameters and torque/power demand profiles and basic consideration of thermal effects and cooling, as stated in project requirements. The Interactive Development Tool is foreseen as a type of IDE (integrated development environment), here targeted to support the process of designing electric machines.
First, a predesign tool for electric machines was implemented with a GUI for guided model design from geometric motor considerations and torque and power targets. In this way the basic pre-design tool includes the following machines: Asynchronous Induction Machine [IM], Surface Magnet Permanent Magnet Synchronous Motors [SMPMSM], Internal Permanent Magnet Synchronous Motors (in three variants: Spoke, V-shape and Planar) [IPM], Synchronous Reluctance Machine [SRM], and Synchronous Machine [Sync]. This tool uses a table of inputs in order to manage the information the software needs to generate the machine model and calculate the performances.
Second a multi-physics (electrical, magnetic, thermal) model of a SMPMSM based on reluctance networks and thermal lumped parameters. By means of thermo-reluctance network a detailed thermo-electro-magnetic dynamics taking into account discrete distribution of windings, stator and rotor slotting, magnetic steel saturation, skewing, demagnetization and non sinusoidal currents will be modeled. Therefore spatial and time harmonics in the magnetic flux distribution and torque ripples will be reflected in the great level of precision, providing a singular, realistic, computationally efficient equivalent circuit model which virtually facilitates the enhancement of classic control and diagnosis strategies and paves the way for the new ones.
In this sense the currently available Modelica® libraries for electrical machines has been greatly improved, in two ways:
• No pre-design tools are available in commercial software with such a wide range of machines able to perform a simple pre-design in minutes including efficiency maps.
• A rich featured SMPMSM model including high frequency effects and distortion of magnetic flux is now available, which is also compatible with the pre-design tool developed in this project

Open libraries of detailed rotating electric machinery including common machines as permanent magnet and externally excited synchronous machine and induction machine already exist with special emphasis on the machines’ loss modeling. However, they consider fully symmetrical machines and distortions of magnetic flux are not included yet. For example, in the Modelica® Standard Library (MSL) the induction machines are based on the assumption, that the number of phases is limited to three and that stator and rotor windings are fully symmetrical. Improved libraries including electrical motor asymmetries have been presented that take into account the full topology of the motor , but a Modelica® library of rotating electric machinery with detailed magnetic effects and non-ideal flux coupling should be designed.
In order to mature the motor and generator design process and enable a consistent design chain for these essential systems, a strong need for ready-to-use libraries for the more detailed level including machine geometry, which is needed for spatial harmonics and voltage waveform computation, appear. Moreover, high magnetic saturation requirement due to high peak to rated torque ratio necessary for decreased motor weight and high acceleration capability in new electromechanic actuators leads to nonlinear saturation behavior of the motor, which must be taken into account in the new machine libraries.
Thermal behavior of the machine results fundamental during design phases, and consequently several thermal models have been presented for basic and sophisticated machine modeling. A lumped parameter thermal model that will combine accuracy and reduced computation time will be analyzed and programmed in this project, as an auxiliary tool for machine design and simulations.
Furthermore, during pre-systems development phase a quick layout of machines is beneficial, despite no easy to use tools are available for a model based design process to estimate typical motor properties and generate models from such a tool. For this reason, a predesign tool for electric machines has been implemented in MAGMOLIB Project.

1. “A Modelica® library for the simulation of electrical asymmetries in multiphase machines - the extended machines library”, C. Kral, A. Haumer, and F. Pirker, in Proc. of The 6th IEEE International Symposium on Diagnostics for Electric Machines, Power Electronics and Drives, SDEMPED 2007, Cracow, Poland, 2007.
2. “The Electromagnetic Actuator design problem: A General and Rational approach”. E. Fitan, F. Messine and B. Nogarèda, in IEEE Transactions on Magnetics, vol. 40. May 2004,
3. “Improved lumped parameter thermal modelling of synchronous generators”, C. Mejuto, M. Mueller, E. MacPherson and M Shanel, in Engineering thesis and dissertation collection of the Edinburgh Research Archive of the Univ. of Edinburgh, 2010.

Project Results:
The work performed in the project and obtained results are described in the following text:
• Working code in Modelica for the basic design of rotating machines, specifically:
- SRM Machine:
- Asynchronous Machine
- Synchronous Machine
- IPM Machines
- SMPMSM Machine

• Full Reluctance & Thermal Network Model for a SMPMSM

During the elaboration of the code of the V-shape (ready to deliver) several issues were faced and solved, such as:
1. Inductance calculation
2. Rotor geometrical characterization
3. Mechanical properties identification (Moment of Inertia, mass of each region)
4. Flux leakages (quantitative approach)
5. Flux concentration (quantitative approach)
7. Demagnetization (qualitative approach)
This led to a new more flexible method of pre-design for rotaing machines because of the rotor complexity. The new methodology takes into account the aforesaid issues. Given the method is extensible to V-shape, a new whole package for rotating machines was supplied.
A detailed study of MMF shape generation based on geometry has been performed, as well as an intensive work on determination of the proper point location to generate an accurate reluctance network because of the necessity of speed in execution of the aforesaid implementation. The airgap flux path model for proper and reluctance network has been also studied and developed.
Winding detailed winding is very important for a correct MMF definition. We have developed A function able to predict MMF shape based on currents per slot in single layer winding has been developed and included into the software model. Also, the tooth reluctance network has been developed and included into the the modelica® environment.
Finally, the reluctance and thermal networks developed in Modelica in the project have been validated against simulation and experimental data.

Potential Impact:
The project will have a high contribution to the European competitiveness with a potential for a reduction of energy consumption and environmental pollution while developing a tool with large possibilities of industrial and sector-wide applications.

The project appears to be in line with the environmental targets of the SRA of ACARE. On the other hand, the Clean SKY SGO initiative aims to meet the increasing social demand to reduce fuel consumption, emissions and noise through the adoption of a new approach when designing systems.

The project is in line with this general objective as it aims to develop a design tool optimized for electric motors. More specifically, SGO environmental objective consists in the reduction of CO2 emissions (between a 5 and 9% of reduction) through an improved energy management.

The project aims to develop a design tool optimized for electric motors, which allows a more rapid design, with better performance than the approximate packages used hitherto. Machine design optimized from the point of view of behaviour and losses allows better use of energy. This energy performance improvement occurs both by improving motor efficiency during normal operation for the improved design, as by the increased life expectancy for better treatment of loss and oscillations caused by electromechanical pairs not covered at the stage design when using existing Modelica tools. The Modelica tool has as target the improvement of the overall engine efficiency of around 2.5% in 20kW engine, which, in turns, implies a saving of 12 kWh per day of operation, if we
compare this with the classic design not FEM used so far, despite the major advantage of the new tool is the is the optimal tradeoff between design time and accuracy of results.

The project contributes to the European transport policy which is in line with the Euro 2020 initiative in working towards “resource efficient Europe”. This is achieved by facilitating economic progress, enhancing competitiveness and offering high quality mobility while using resources more efficiently.

The project will certainly enhance European competitiveness and facilitate economic progress as electrical motors are gaining importance as primary source of the systems’ energy and, in the different aircraft design phases, the process needs support by dedicated tools. The European Air Transport sector has an annual turnover of more than € 95 billion and employs over half a million people directly with another 2.6 million indirect jobs.

By developing a tool which will allow the improved and faster design of electric motors while improving motor energy efficiency and reducing CO2 emissions, the project will highly contribute to the RTD European targets for strengthening the European competitiveness in the Aeronautics sector.

Modelica is designed to be domain neutral and, as a result, is used in a wide variety of applications, such as fluid systems (for example, steam power generation, hydraulics, etc.), automotive applications (especially powertrain) and mechanical systems (for example, multi-body systems, mechatronics, etc.). Therefore, the Modelica tool developed in the project could potentially be applied to several other industrial sectors, including:
• The manufacturing industry, helping to model quickly and efficiently productive plants and motion systems
• The industry for the design and manufacturing of electric motors, for applications of sea, land and air transport

The project will have significant secondary impacts through positive interactions with other programmes of work within the areas of aeronautics. In addition, the MAGMOLIB project will establish relations, synergies and joint dissemination activities with the Advisory Council for Aeronautics Research in Europe (ACARE), the European Technology Platform for aeronautics and the Aerospace and Defence Industry Association for Europe, which promotes the interests of the aeronautics, space, defence and security industries in Europe.

List of Websites:
http://magmolib.upc.edu/en

MCIA Innovation Electronics Center
Dr. Luis Romeral
Universitat Politècnica de Catalunya,
Edifici Gaia, Rambla de Sant Nebridi, 22,
08222 Terrassa, Barcelona
Phone: +34 93 739 85 22
Fax: +34 93 739 89 72
luis.romeral@mcia.upc.edu
Internet: https://www.mcia.upc.edu

Related information

Contact

Mercé Torrellas, (Manager of Administration Area)
Tel.: +34 934017126
Fax: +34 934017130
E-mail
Record Number: 189844 / Last updated on: 2016-10-07