Introduction to E-Mobility and Drives

Electro-Mobility (E-Mobility) includes a broad range of vehicles and applications where a movement is created by an electric propulsion system, e.g. battery electric, hybrid or fuel cell cars, small utility electric vehicles, autonomous electric vehicles, electric ferries, etc. 
 
Drives include various processes resulting in a mechanical movement, e.g. for propulsion or actuation. The movement is caused by an electric machine powered and controlled by a power electronic converter. Applications include actuators, fans, pumps, etc. 
 
The research group in E-Mobility and Drives combines and apply its competences within control theory, electrical machines, energy storage devices, and power electronics. 
 
Research is conducted at component level and system level as well. A main motivating factor is to develop more efficient components or systems at lower cost, weight and mass, but with an increased performance. 

Focus areas

Electric motor drives

Our focus areas in electric motor drives include both hardware configurations and advanced control. From hardware point-of-view, we are working with active front end rectifiers, small DC-links drives, multi-level converters for drives, and combined inverter/charger solutions. Modern microprocessors and DSPs provide good computation power. Therefore, we are also working with active damping, harmonic mitigation, sensorless control, and fault diagnostics. 

Electric machines

Electric machines are the workhorses of industrial processes and electric vehicles. We design, build and test many kinds of machines, e.g. low-cost reluctance machines or high performance and highly efficient permanent magnet machines. Applications include traction motors for electric vehicles, magnetic gears for efficient and robust mechanical power conversion, linear actuators like lead screws and active suspension systems for energy harvesting or vibration dampening, etc. 

Hydraulic drive technologies

Hydraulic drive technologies like actuators, pumps, motors, etc. offer very high force and power densities and is often used in applications where electric machines not are feasible. However, traditionally hydraulic systems suffer by significant higher losses than the electric counter part. Therefore, we are working on improving the efficiency and to allow bidirectional power flow of various hydraulic drive technologies. This will allow operation from electric low energy density sources like batteries rather than the pollutive internal combustion engine.

Power electronic converter

Power electronic converters are a key component for motor control and intelligent energy management. We built power converters for various applications, e.g. electric machines, battery charging, fuel cells, wireless inductive power transfer, etc. Depending on the application, the converters have different features, e.g. high gain, bi-directional, DC/DC or DC/AC conversion, etc. 

System integration and evaluation

System integration is a key competence to reduce the total cost and volume and to increase the performance. Prior to the laboratory implementation a complete simulation model is developed in order to assess the interaction between each component. A proper energy management strategy is necessary in order to comply with the constraints of each component and to obtain a high system efficiency. The whole system is evaluated with respect to energy consumption and lifetime.

Energy storage devices 
The battery of an electric vehicle is one of the most essential components of the vehicle. We work with different energy storage devices like lithium-ion based batteries, super capacitors, lithium-ion capacitors, etc. Our focus is to increase the applicability of the storage devices, and our work is therefore focused on understanding the device and its limitations and how it can be integrated into a system. Our field of interest includes estimation of state-of-charge, state-of-health, and state-of-power (SoX in short), electric, lifetime, and thermal modelling, battery-management-systems, diagnostics, etc. 

Applications

The E-Mobility and Drives research group is very application-oriented and we work with many different applications, e.g., construction equipment, electric and hybrid electric vehicles, drones, wave energy, wind turbines, micro-robots, fans, pumps, etc.