Design and control of a novel multi-rotor structure Manfred Schrödl Andreas Brunner Institute of Energy Systems and Electrical Drives Technische Universität Wien A3PS Nov. 2017
Contents Deriving the topology of the Planetary Motor Electrical equivalent circuit Functional prototype Control strategy Sensorless INFORM method Applications Future work 9.11.2017 A3PS 2017 2
3-phase motor 3 single coils 2-pole PM rotor 9.11.2017 A3PS 2017 3
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Arrange 4 equivalent motors symmetrically 9.11.2017 A3PS 2017 5
Combine into single structure 9.11.2017 A3PS 2017 6
Combine into single structure 9.11.2017 A3PS 2017 7
Areas of zero net flux 9.11.2017 A3PS 2017 8
Areas of zero net flux 9.11.2017 A3PS 2017 9
Rotors turn in opposite directions 9.11.2017 A3PS 2017 10
Rotors turn in opposite directions 9.11.2017 A3PS 2017 11
After 90deg: same areas with zero net flux 9.11.2017 A3PS 2017 12
Omit magnetically inactive parts: 9.11.2017 A3PS 2017 13
Corners are also magnetically inactive 9.11.2017 A3PS 2017 14
Corners are also magnetically inactive 9.11.2017 A3PS 2017 15
Corners are also magnetically inactive 9.11.2017 A3PS 2017 16
Corners are also magnetically inactive 9.11.2017 A3PS 2017 17
Omit magnetically inactive parts: Reduced Active mass Motor volume Iron losses Same power as 4 combined single motors 9.11.2017 A3PS 2017 18
Combine coils 9.11.2017 A3PS 2017 19
Combine coils 9.11.2017 A3PS 2017 20
Combine coils: 12 coils 6 coils 9.11.2017 A3PS 2017 21
Integrated gear: sun gear 9.11.2017 A3PS 2017 22
Integrated gear: ring gear 9.11.2017 A3PS 2017 23
Integrated gear 9.11.2017 A3PS 2017 24
Integrated planetary gear Sun gear and ring gear rotate at same speed mechanical link for combined output power 9.11.2017 A3PS 2017 25
Integrated planetary gear One point of contact for each gear (instead of two) Gear ratios typ. 10:1 9.11.2017 A3PS 2017 26
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Conventional motor + spur gear R gear ratio v circumferential speed 9.11.2017 A3PS 2017 28
Integrated Planetary gear R gear ratio v circumferential speed 9.11.2017 A3PS 2017 29
Electrical Circuit 9.11.2017 A3PS 2017 30
Electrical Circuit Original Circuit: 9.11.2017 A3PS 2017 31
Electrical Circuit 9.11.2017 A3PS 2017 32
Electrical Circuit Reduced Circuit: 3-phase inverter Star or delta connection 9.11.2017 A3PS 2017 33
Functional Prototype 9.11.2017 A3PS 2017 34
Functional Prototype 4 rotors and 3-phase stator winding 6 concentrated coils Gear ratio 10:1 Sensorless control (INFORM / EMF) Connection of all coils on the rear side of the motor Simple assembly 9.11.2017 A3PS 2017 35
Functional Prototype Terminal voltages at 200rpm on output shaft: 9.11.2017 A3PS 2017 36
Control Strategy 9.11.2017 A3PS 2017 37
Control Strategy High-speed range (> 10% rated speed): EMF-method Based on induced voltage State of the art Low-speed range and standstill: INFORM method Based on inductance differences Already used in series applications 9.11.2017 WM 2017 38
INFORM Method / INFORM-error: mean 0.65deg Standard deviation 6.01deg (electrical) 9.11.2017 A3PS 2017 39
Applications Electric vehicle axle drive Integrated gear box Hollow central motor shaft differential drive Wheel-hub motor Low speed / high torque Wind power PLANETARY MOTOR with differential gear D (housing T, bevel wheels K1, K2), functionally combined with sun wheel Z1. Planets P1, P3 (shown without connected rotors of the electrical part). Half axes A1, A2, connected to driving wheels 9.11.2017 A3PS 2017 40
Future Work 4-pole rotors 12 coils 9.11.2017 A3PS 2017 41
Future Work 6 rotors (series connection of 3 elements) 9.11.2017 A3PS 2017 42
Conclusion 1 rotor 4 rotors: half circumferential speed at same power Integrated transmission Low speed / high torque applications Simple assembly Concentrated coils Integrated coil connections and power electronics on rear side possible Standard 3-phase inverters Sensorless control 9.11.2017 A3PS 2017 43
Thank you for your attention TU Wien offers cooperation Please contact us! Manfred.schroedl@tuwien.ac.at