Electromechanical Engineering - Motion ProductsUGent-M&F has a strong track record in motion products based on electromechanical engineering competences.
Electromechanical Engineering - Motion Products
Scope overview
Our expertise enables the design and development of the next generation energy-efficient, compact and reliable electromechanic drivetrains and drivetrain components.
Our research activities are focussed on the following aspects:
Parametric model or experimental data based research on various combinations of motor, power electronics, controls, cooling and lubrication
Multi-physical modelling to capture interaction between drivetrain components
Testing & validation of drivetrains & components
Experimental characterisation of drivetrains and mechatronic systems
Data capturing
Electromechanical (novel) actuators & controls
We have a long standing track record on the study and design of several types of (novel) electric machines e.g. Switched Reluctance Machines (SRM), Synchronous Reluctance Machines (SynRM), Brushless DC Motors BLDC, Electric Variable Transmissions (EVT) , Permanent Magnet Synchronous machines (PMSM), ..etc...and this for several industrial applications such as electric vehicles, wind or hydro turbines and industrial machines in general. We have experience and knowledge in FE modelling of the electromagnetic and thermal aspects of electric machines, using simulation packages including both commercial as well as UGent proprietary tools. With our models we can compare several types of machines and materials. We are used to carry out dedicated machine designs including controller for you company-specific application.
Axial Flux Machine Technology
Axial-flux permanent magnet machines inherently combine a good energy-efficiency with a high torque density. Axial-flux permanent magnet machines have a large diameter to axial length ratio and allow the construction of light-weight direct-drive machines for e-mobility and renewable energy conversion. Multiphysical analysis, including electromagnetic, thermal and mechanical aspects, has been carried out at EELAB. This extensive research has resulted in an integrated design which combines an excellent energy-efficiency and torque density with an optimal usage of materials. Magnax now commercialises our software and the joint technology built up.
This novel (patent-pending) actuator is designed to drive machines and application with a large –compared to a nominal- sinusoidal or pulsed torque profile. The device consist of an electric motor with an integrated magnetic spring and has a lower amount of active materials and a lower inertia compared to standard motors used for those drive trains. It makes the drivetrain more compact and reduces the power consumption. We have fully parametrized electro-magnetic models, simplified thermal models and control algorithms available to evaluate the use of this component in any drivetrain. A prototype will be tested in our laboratory on an industrial-relevant test bench.
High speed electrical machines
For high-speed motors and generators we are performing electromagnetic studies using our exact analytical models to determine slotting and eddy-currents. The direct steady state solution without time stepping allow fast simulation of torque components (e.g. magnet torque, asynchronous torque in shielding cylinder on rotor).We can model the impact of manufacturing operations like cutting and punching on the material properties in the machines (e.g. steel lamination).And evaluate the magnetic properties of the materials in-situ, i.e. once they are placed inside the machine.
Modular power electronics for drive trains
Drive trains that are modular in the sense that they are built up of the same/similar hardware components (power electronics, electric motors, mechanical drive systems) hold a lot of potential towards improved performance (higher torque, lower losses), reduced cost (module re-use), increased reliability (high reliable modules, fault tolerant operation) and additional functionalities (e.g. multiple speed & DC ranges). We contribute to the development of innovative concepts, design tools and distributed reconfigurable controllers which will not only enable those modular drivetrain architectures but also make them more versatile and better suited to be used in an X-as-a-service context.
Synchronous and Switched Reluctance machines (SRM and SynRM)
The synchronous reluctance motor is a promising alternative for induction machines to achieve a higher efficiency, as required by the European Commission. The research focusses on the detailed electromagnetic design in order to achieve three targets: high efficiency, low torque ripple and high power density. Moreover, the control of the machine is investigated in order to obtain a stable behavior and a fast dynamic response. New developments at UGent are the combined star-delta winding in the stator and a permanent magnet assisted rotor, leading to 5% - 8% more output torque and 0.3% point more efficiency.
High Reliability Multiphase Synchronous Reluctance Motor Drive Systems Based on Matrix Converter
A combination of multiphase synchronous reluctance motor (SynRM) and a power electronic “matrix” converter without vulnerable electrolytic capacitors is being studied. This drive is suitable for critical processes in developing countries, with possibly high ambient temperatures and limited maintenance. Novel rewinding approaches have been proposed to obtain a five-phase winding from the existing standard three-phase stator frames. The proposed rewinding techniques are applied to construct a five-phase star-connected SynRM (SynRM 1) and a novel combined star-pentagon winding (SynRM 2). The performance of both is compared: SynRM 1 and 2 provide 6.56% and 13.35% higher torque compared to the three-phase SynRM at rated current and at optimal current angle. The torque ripple is decreased by 17% and 30% respectively. Moreover, SynRM 1 and 2 offer a better performance at the faulty case; e.g. at one phase opened, the average torque of SynRM 1 and 2 is 82% and 108% higher compared to the three-phase SynRM. In addition, the torque ripple is reduced by about 63% and 81%.
Cooling, lubrication & thermal energy management
Through innovative cooling with high cooling capacity and low thermal resistance the power density of electromechanical drivetrain components can be increased, as well as their reliability. Emerging lubrication techniques increase the reliability and performance of those drive trains. This enables further integration of more compact drivetrains with higher performance and lower cabling, assembly and material cost. We perform research on topics such as direct conductive and convective coil cooling, two-phase immersion cooling and phase shifting materials within the actuator and its drive; and lubrication in drive train components.
Innovative Cooling of Electrical Machines
Nowadays electrical machines reach ever increasing targets in terms of power density and efficiency. When used in dynamic applications, the temperature will vary leading to mechanical stresses, fatigue and insulation degradation of the windings. This degradation can be countered with various innovative cooling techniques (e.g. direct coil cooling). Our integrated multi-physical design approach allows to evaluate the impact of different emerging cooling techniques on the temperature distribution in the windings and as such helps to improve the reliability of the electrical machines by reducing the risk on insulation degradation.
We have a patent-pending (EP19173364.1) technology which consists of “inserts” that are designed to drastically improve the cooling of the end-windings of an electric motor with concentrated windings by reducing the resistive path. Measurements on our prototype revealed a power density increase of 40% compared to machines with conventional water jacket cooling. These inserts can be combined with existing forced air or water cooling and are particularly suited for mobility applications where higher power density and energy efficiency is required.
See out technology offer for more details
Modelling and experimental testing of heat sinks for power electronics
We have in-house developed & validated parametrized thermal models for liquid cooling of power electronics (PE). These models include various heat sink concepts such as cold plates, base plates and pin-fin designs with different geometries and are validated for cooling media such as water-glycol and ATF oil. Our models and expertise allow evaluation of innovative cooling solutions for PE’s. We have built up extended know-how about experimental measurements with high accuracy. (picture courtesy Flanders Make)
Modelling of TEHL contacts in gears and bearings
We are developing reliable, accurate and well-validated multi-scale computational models to simulate the transient dynamic response of Thermo-Elasto-Hydrodynamic Lubricated (TEHL) contacts for gears and bearings under variable operating conditions (e.g. oscillating motion, vibrations). This allows to evaluate the influence of those operating conditions on vibration and noise in multi-component drivetrains. The models include detailed 3D CFD-FSI modelling and simulation, derived meta-models for response-mapping, Flexible Multi-Body models to incorporate TEHL meta-models and novel reduced-order models for large-scale deformations. We have a long track record in numerical and experimental tribology and material behaviour under various damage mechanisms.
Proprietary tools for industrial fluid systems incl. access to supercomputer
We provide services w.r.t. the use of computational fluid dynamics (CFD) and fluid structure interaction (FSI). Our calculations help you to understand fluid dynamics of liquids (e.g. hydraulic oil, lubrication fluids, water) and gasses (e.g. air) in industrial applications (e.g. expanders/compressors, pumps, fans, valves, cooling, hydraulic circuits, lubricated structures … ). The CFD simulations might include thermal aspects; be linked to lower order 1D models (e.g. for basic structures setting boundary conditions); and ‘flexible’/’movable’ structures. We are experienced users of the well-known tools and developed specific add-ons to increase performance; and have access to the High Performance Computing power (HPC).
Drives and drivetrain (emerging) component integration
Toolchain to optimize the performance of electric machines for specific applications
Any electric machine is made to be integrated into a system for a specific application. If such system specifications are known, the machine and its controller can be optimised towards maximum performance. We have developed a toolchain to optimize the electromagnetic and thermal performance of electric motors with concentrated windings. The toolchain was originally designed for switched reluctance motors (SRM) but can be applied to other concentrated windings machines and similar motor geometries (radial double salient machines). It consists of validated parametrized models for (stretched) end winding cooling both for wet or dry end winding cooling and slot cooling with tubes of arbitrary shape. Based on various input parameters such as geometry, material properties, excitation, fingerprint curves and set points for torque and speed from system level these models provide reliable outputs such as CAD drawings, ON-OFF current angles (control), losses (core, tubes and copper), output power, efficiency and temperature distribution. This toolchain allows e.g. to find the desired output power and efficiency without exceeding the maximum temperature limit.
Integration of multi-port convertors
Platform to evaluate the application feasibility of an EVT
Can you imagine the range of applications for a transmission without gliding or sliding contact surfaces, a transmission which is moreover continuously variable in an electrical manner? We have been studying such an Electrical Variable Transmission (EVT) a.o. using a unique set-up including an EVT from EVT BV. Our activities resulted in a profound understanding of the device, the power flows, the losses, ... . The EVT can act as a power sharing transmission and/or a continuous variable transmission. Functionally it replaces as a single device the planetary gear set and electrical motor of a typical hybrid transmission system (e.g. Toyota Prius). Our toolset includes (i) fully validated static and dynamic models (Magnetic Equivalent Circuit and FEM); (ii) methods to optimize the operating points; (iii): scaling laws (also for the control settings) ; and (iv) a design methodology. The test infrastructure has HIL capabilities allowing you to evaluate the feasibility on system level of the EVT for your application. Detailed studies revealed that the EVT in combination with super capacitors and/or a small battery has a potential to reduce fuel consumption up to 30% and total cost reduction up to 15%. Additional benefits are reduced ICE motor peak power up to 20%, low tracking error on high-dynamic motion load profiles and increased flexibility (e.g. reverse motion).
We developed validated parameterized models for push-belt and CVT’s and toroidal CVT’s (with or without active slip compensation) which allow to assess the added value of the variable transmission in a vehicle in terms of losses and efficiency.
Electromechanical systems: use case stepper motor soft sensing control and flexible gripper control
In collaboration with companies we developed electromechanical systems with advanced functionality for energy and industry related applications. In this case e.g. we developed an automated unit to pick up and transport medicine packages with different sizes. form the medicine stock to brings it to the pharmacist. For positioning of the grippers, four stepping motors are used. These motors are preferred because they are ideally suited for low-power positioning applications. To increase the reliability the stepping motors are used in combination with mechanical position sensors which leads to an increased purchase and implementation cost. Therefore, intelligent sensor less stepping motor drives have been implemented and tested. Feedback of the load angle obtained via voltage and current measurements is used to detect when the gripper touches the package. After a pre-determined threshold is exceeded, the motor stops rotating but the holding torque is maintained. In this way, the gripper can hold the different packages even if their size is not known in advance, without unnecessary squeezing them.
Torque ripple reduction
The reduction of torque ripple in a drive train is an important objective as it affects lifetime, performance, cost (oversizing of components), user comfort and sound radiation. For electric machines with a high torque ripple, classic PI controllers with a feedforward control fail to accurately track highly dynamic torque profiles. We developed 3 control architectures that minimize the torque ripple in an electric machine: (i) A PI controller with an advanced feedforward control (ii) a resonant control and (iii) an Iterative Learning Control. The control architectures were tested on a 80 kW permanent magnet synchronous machine up to 100 Nm and 1000 rpm. A torque ripple up to 83% was achieved on the setup. Additionally, the dynamic response of the torque control of the permanent magnet synchronous machine was significantly improved. The control architectures were developed for an automotive platform, but they can be applied for other industrial applications.
Motion system design tool AMOCAD
Motion systems are typically described using CAD tools. Recent developments allow to use these tools in the design phase of the motion systems, i.e. for motion simulations. We developed a design methodology for virtual engineering and optimization of electromechanical drive lines which is easy and useful for complex motion challenges. To this end we extract key parameters such as mass, inertia, .... to optimize the motion behaviour. We applied this method already to an mechatronic application in the pharma sector as well as to a to optimize the trajectory of a production machine: a high speed pick and place (200ms), with complex kinematic system (combined crankshaft and 4 bar system), with variable system load (load torque and system inertia).
Free Piston Variable Volume Ratio Device
Our patented free piston expander/compressor technology is available for transfer/licenses. (WO/2016/198554) Key features are: a variable volume ratio control to maximize system level efficiency at partial load, only one moving part yields a hermetically sealed robust device incorporating the electric motor/generator, on the fly reversible operation expander to compressor and vice versa. This allows structural integration of electric motor, expander and compressor. More details available in our technology offer
Testing & validation of drivetrains & components
With our extended and flexible drive train test setups including a calorimeter with direct measurement principle and high speed thermal camera we can measure very accurate power losses allowing to build up and/or validate power loss models. We have experience in the development of emulation techniques of load conditions and have extensive load conditions available for ICE, wave and wind energy. This enables to build up the digital twin of your drive train or drive train component. We can even develop dedicated test setups for your application. For example for the company Mazaro we supported the design and build of a customized test bench for their innovative type of Continuous Variable Transmission (CVT). More about Mazaro
