1. Control Strategy for an Interior Permanent Magnet Synchronous Motor : A Survey
Hak-Jun Lee and Seung-Ki Sul
Power Electronics Laboratory
Seoul National University, Korea
Power Electronics Laboratory, Seoul National University

2. Contents Introduction Basic Study for the Control Strategy
Recent Study for the Control Strategy
Torque Control Strategy of an IPMSM Considering the Flux Variation of the Permanent Magnet
Novel Flux-Weakening Control of an IPMSM for Quasi Six-Step Operation
Future Work for the Control Strategy
Conclusions
Power Electronics Laboratory, Seoul National University

3. Introduction IPMSM High Efficiency High Power Density
Wide Flux-Weakening Region
 Too Complex To Control !!
Power Electronics Laboratory, Seoul National University

4. Basic Study Mathematical Model Voltage Equation Torque Equation
Torque due to
Flux of PM
Reluctance Torque
Power Electronics Laboratory, Seoul National University

5. Basic Study Operation Region Current Limit Circle
Voltage Limit Ellipse
MTPA
Maximum Torque Per Ampere
MFPT
Minimum Flux Per Torque
Current Increasing
Flux Increasing
Current Increasing
Flux Increasing
Power Electronics Laboratory, Seoul National University

6. Basic Study Flux-Weakening Operation
For Extended Torque Control Capability
Power Electronics Laboratory, Seoul National University

7. Basic Study Control Diagram
Power Electronics Laboratory, Seoul National University

8. Recent Study (1) Torque Variation due to Temperature
Power Electronics Laboratory, Seoul National University

9. Recent Study (1) Changing of the Current Ref.
MTPA, MFPT and Torque Curve is changed
Without temperature compensate algorithm, real torque will be reduced at higher temperature
Power Electronics Laboratory, Seoul National University

10. Recent Study (1) Interpolation of the Current ref.
Power Electronics Laboratory, Seoul National University

11. Recent Study (1) Control Diagram
Power Electronics Laboratory, Seoul National University

12.  Torque error is reduced
Recent Study (1)
Experimental Result
Motor at 70 [℃], Ref. table at 30 [℃]  Proposed method
 Torque error is reduced
Power Electronics Laboratory, Seoul National University

13. Recent Study (2) Problem of the Basic Study Voltage Limitation
Less Torque than Six-Step Operation
Power Electronics Laboratory, Seoul National University

14. Recent Study (2) Problem due to the Changing Voltage Limitation
Confliction between the anti-windup and flux-weakening control
Power Electronics Laboratory, Seoul National University

15. Recent Study (2) Control Diagram No Anti-Windup
Power Electronics Laboratory, Seoul National University

16. Recent Study (2) Experimental Result
The Capability curve represents larger torque than basic method
Quasi six-step operation and the current regulation are worked simultaneously
Power Electronics Laboratory, Seoul National University

17. Future Work Defects of the control method
Hard to set the gains of the closed-loop controller
Hard to make the Lookup tables
Power Electronics Laboratory, Seoul National University

18. Conclusions Basic Study for the Control of IPMSM
IPMSM are widely used due to their wide flux-weakening region
Basic Study was presented which has the ability to control the output torque precisely over a wide speed region
Recent Study for the Control of IPMSM
Torque varies with the temperature, so the control method was presented considering the flux variation of IPMSM
There is confliction between the anti-windup and flux-weakening control, so the control method was presented for the quasi six-step operation
Future Work for the Control of IPMSM
Because it is hard to set the gains of the closed-loop controller and to make pre-calculated lookup table, future work will be the control algorithm for the IPMSM without any tables
Power Electronics Laboratory, Seoul National University

19. Thank You For Your Attention
Power Electronics Laboratory, Seoul National University