1. High-efficient, ultra compact integrated electric drives for tomorrow’s alternative drivetrains
Mojgan Nikouei-Harnefors,
Funding period: –
Dept. Electrical Energy Conversion, KTH Royal Institute of Technology
Swedish Hybrid Vehicle Centre (SHC)
Granted funding: 1.58 MSEK

2. Motivation

3. Integrated drives (examples)
Volvo ReCharge

4. Project overview

5. Project overview

6. Stacked polyphase bridges (SPB)
Power converter
Electric machine
Battery

7. Machine considerations
Fractional-slot concentrated-winding (FSCW) - Short end-turns - Low cogging torque - High slot filling factor (segmented stator) Challenges - Suitable slot/pole combinations to obtain:
- High fundamental winding factor
- Low rotor losses
- Ease of integration (identical converter sub modules) - Fault tolerance to handle a converter sub module fault

8. Control considerations
Converter sub module - Current control
- Field weakening
Master control
- DC-link voltage control and communication (ongoing work)
- Fault handling (ongoing work)

9. Technical summary New method of machine and converter integration
New converter topology (SPB converter)
Low voltage Si MOSFETs provide very high efficiencies and allows reasonably high junction temperatures
Future GaN may enable even lower losses
Low voltage, high switch frequency → very small, non-electrolytic capacitors
Potential fault tolerance (limp home) is “in built”
9/31

10. Future/ongoing work Refine the design of the electric machine
Develop a robust control technique
Evaluate tolerance to faults
Investigate power electronic manufacturing techniques
Full-scale prototype evaluation
Identify suitable applications for the converter topology
10/31

11. High-efficient, ultra compact integrated electric drives for tomorrow’s alternative drivetrains
Mojgan Nikouei-Harnefors,
Funding period: –
Dept. Electrical Energy Conversion, KTH Royal Institute of Technology
Swedish Hybrid Vehicle Centre (SHC)
Granted funding: 1.58 MSEK