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Electricmotors5
The document discusses sensorless motor drives, focusing on their industrial applications and challenges, including cost, reliability, and robustness. It presents various methods for sensorless control, emphasizing the importance of using existing hardware without additional sensors or complex installations. The report concludes that the proposed control scheme is efficient and adaptable for use with standard microcontrollers, reducing the overall need for additional equipment.
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Electricmotors5
- 1. EXPERT SYSTEMS ANDSOLUTIONS Email: expertsyssol@gmail.com expertsyssol@yahoo.com Cell: 9952749533 www.researchprojects.info PAIYANOOR, OMR, CHENNAI Call For Research Projects Final year students of B.E in EEE, ECE, EI, M.E (Power Systems), M.E (Applied Electronics), M.E (Power Electronics) Ph.D Electrical and Electronics. Students can assemble their hardware in our Research labs. Experts will be guiding the projects. Prof. Dr. -Ing. Ralph M. Kennel Wuppertal University Page 1
- 2. Tutorial 2 Sensorless MotorDrives Ralph M. Kennel Elektrical Machines and Drives Wuppertal University Page 2
- 3. Reasons for IndustrialApplications of Drives with Encoderless Control: • Cost • Reliability • Robustness Prof. Dr. -Ing. Ralph M. Kennel Wuppertal University Page 3
- 4. Industrial Drives withSensorless Control since several years / decades sensorless control is investigated and published on conferences and magazines - acceptance in industry, however, is rather low Why ? new ideas and concepts are interesting for industry, only if they do not result in higher cost or higher effort!!! What does that mean for industrial drives with sensorless control ? no additional or more powerful processors / controllers no additional hardware or additional sensors (e. g. voltage sensors) no increased installation effort with respect to parameter adjustments Prof. Dr. -Ing. Ralph M. Kennel Wuppertal University Page 4
- 5. Sensorless (Encoderless) MotorDrives introduction • fundamental model methods • high frequency injection methods sensorless control of electrical machines • machine response on high frequency injection voltages • tracking of magnetic saliencies / anisotropies practical results • experiences with industrial drives conclusions Prof. Dr. -Ing. Ralph M. Kennel Wuppertal University Page 5
- 6. Categories of MachineModels for „Sensorless“ Control Prof. Dr. -Ing. Ralph M. Kennel Wuppertal University Page 6
- 7. fundamental model high frequency injection • simple realisation • does not work at frequency 0 • parameter dependencies current injection voltage injection • measuring voltage is high enough • additional voltage sensors Basic Principles current response transient current response stationary • no additional hardware • standard microcontroller sufficient of Encoderless• very small measuring current • very short measuring time Control Prof. Dr. -Ing. Ralph M. Kennel Wuppertal University Page 7
- 8. Fundamental Model ofan Induction Machine stator rotor when knowing voltage uS mechanics as well as current iS it should be possible calculate speed ω Prof. Dr. -Ing. Ralph M. Kennel Wuppertal University Page 8
- 9. Calculation of Speedby Fundamental Model is not Practicable for Very Low Speeds ... because • the voltage signal becomes very small • errors between real voltage and values used for calculation cannot be avoided and become more significant • DC components of these errors let the integrators for flux calculation drift away the calculated speed gets more and more incorrect is an encoder/resolver the only feasable solution ?? Prof. Dr. -Ing. Ralph M. Kennel Wuppertal University Page 9
- 10. Signal Injection Method according to J. Holtz, H.Pan, etc. • this is basically a current injection method voltage sensors are necessary !!! • it is possible to use current derivatives instead of motor voltages measuring current derivatives, however, by standard current transducers is not really possible • but, industrial current transducers have a current derivative available internally can this be made available for customers ??? Prof. Dr. -Ing. Ralph M. Kennel Wuppertal University Page
- 11. INFORM method according to M. Schroedl (Technical University of Vienna, Austria) • this is basically a transient voltage injection method currents have to be sensed at specific times !!! • when using standard current transducers these cannot be synchronized with PWM the hardware of a standard industrial drive has to be changed nevertheless this method comes close to industrial needs ! Prof. Dr. -Ing. Ralph M. Kennel Wuppertal University Page
- 12. Stationary Signal InjectionMethods according to R. Lorenz, S.-K. Sul, R. Kennel, etc. • the basic idea is to use the electrical machine itself as a resolver !!! • a resolver is nothing else but an electrical machine can we operate the motor itself like a resolver ? • if the machine itself is a resolver (encoder) is that really an „encoderless“ control ??? good idea – but does it work ??? Prof. Dr. -Ing. Ralph M. Kennel Wuppertal University Page
- 13. Resolver injection of a sensing of a two-dimensional stationary (sinusoidal) stationary (sinusoidal) high frequency signal signal response Tamagawa S2 u1(γ) π 2π R1 0 γ Stator Rotor Stator ue uR u2 R2 S4 u2(γ) Stator π 2π 0 u1 γ S1 S3 Prof. Dr. -Ing. Ralph M. Kennel Wuppertal University Page
- 14. Stationary Signal InjectionMethods according to R. Lorenz, S.-K. Sul, R. Kennel, etc. • the basic idea is to use the electrical machine itself as a resolver !!! • a resolver is nothing else but an electrical machine can we operate the motor itself like a resolver ? • if the machine itself is a resolver (encoder) is that really an „encoderless“ control ??? now we do the same with an electrical AC machine Prof. Dr. -Ing. Ralph M. Kennel Wuppertal University Page
- 15. Fundamental Frequency Excitation (in α-β coordinates) Prof. Dr. -Ing. Ralph M. Kennel Wuppertal University Page
- 16. High Frequency Excitation (in α-β coordinates) Prof. Dr. -Ing. Ralph M. Kennel Wuppertal University Page
- 17. Machine Model forHigh Frequency Signals d ic(F) (F) lsσ d 0 uc(F) = rs ic(F) + lsσ (F) + jωa lsσ (F) ic(F) lsσ = dt 0 lsσ q Prof. Dr. -Ing. Ralph M. Kennel Wuppertal University Page
- 18. High Frequency Behaviourof the Machine Model Prof. Dr. -Ing. Ralph M. Kennel Wuppertal University Page
- 19. injection of highfrequency voltages fundamental voltage phasor/vector fundamental current phasor/vector injected high frequency voltage phasor/vector high frequency current phasor/vector (response) Prof. Dr. -Ing. Ralph M. Kennel Wuppertal University Page
- 20. injection of highfrequency voltages fundamental voltage phasor/vector fundamental current phasor/vector injected high frequency voltage phasor/vector high frequency current phasor/vector (response) Prof. Dr. -Ing. Ralph M. Kennel Wuppertal University Page
- 21. injection of highfrequency voltages fundamental voltage phasor/vector fundamental current phasor/vector injected high frequency voltage phasor/vector high frequency current phasor/vector (response) Prof. Dr. -Ing. Ralph M. Kennel Wuppertal University Page
- 22. injection of highfrequency voltages fundamental voltage phasor/vector fundamental current phasor/vector injected high frequency voltage phasor/vector high frequency current phasor/vector (response) Prof. Dr. -Ing. Ralph M. Kennel Wuppertal University Page
- 23. Injection of HighFrequency Rotating Phasors rotating voltage phasor uc elliptic current response ic Prof. Dr. -Ing. Ralph M. Kennel Wuppertal University Page
- 24. Position Information ofSalient Rotors in High Frequency Rotating Phasors • machine responds on a rotating voltage phasor with an elliptic current response • ellipse is correlated with the geometric anisotropy of the rotor • rotor position information is included elliptic current response ic (rotating) in the high frequency current Prof. Dr. -Ing. Ralph M. Kennel Wuppertal University Page
- 25. Saturation Anisotropy of aPermanent Magnet Synchronous Machine rotor flux saturation of a permanent magnet synchronous machine Prof. Dr. -Ing. Ralph M. Kennel Wuppertal University Page
- 26. Position Information ofnon-salient rotors in High Frequency Rotating Phasors • machine responds on a rotating voltage phasor with an elliptic current response • ellipse is correlated with the saturation anisotropy • rotor position information is included in the high frequency current elliptic current response ic (rotating) Prof. Dr. -Ing. Ralph M. Kennel Wuppertal University Page
- 27. Injection of HighFrequency Alternating (Pulsating) Voltage Phasors advantage : composing an alternating (pulsating) voltage phasor no rotational (HF) field by two phasors rotating in opposite direction no additional torque Prof. Dr. -Ing. Ralph M. Kennel Wuppertal University Page
- 28. High Frequency CurrentResponse of a Synchronous Machine Prof. Dr. -Ing. Ralph M. Kennel Wuppertal University Page
- 29. Current Response of a Misoriented System voltage and current show different orientation !! Prof. Dr. -Ing. Ralph M. Kennel Wuppertal University Page
- 30. Current Response under aMisorientation of 90° Prof. Dr. -Ing. Ralph M. Kennel Wuppertal University Page
- 31. Tracking Scheme forMagnetic Anisotropies ˆ icd (F) = K ⋅ sin ( ω c t ) lcq ˆ ( ) icq (F) = − K ⋅ sin ( ω c t ) lcq − lcd ∆ δˆa Prof. Dr. -Ing. Ralph M. Kennel Wuppertal University Page
- 32. Tracking Scheme forMagnetic Anisotropies Tracking the estimated angle of the rotor flux by controlling icq to 0 Prof. Dr. -Ing. Ralph M. Kennel Wuppertal University Page
- 33. tracking control ofinjection voltage fundamental voltage phasor/vector fundamental current phasor/vector injected high frequency voltage phasor/vector high frequency current phasor/vector (response) Prof. Dr. -Ing. Ralph M. Kennel Wuppertal University Page
- 34. tracking control ofinjection voltage fundamental voltage phasor/vector fundamental current phasor/vector injected high frequency voltage phasor/vector high frequency current phasor/vector (response) Prof. Dr. -Ing. Ralph M. Kennel Wuppertal University Page
- 35. tracking control ofinjection voltage fundamental voltage phasor/vector fundamental current phasor/vector injected high frequency voltage phasor/vector high frequency current phasor/vector (response) Prof. Dr. -Ing. Ralph M. Kennel Wuppertal University Page
- 36. tracking control ofinjection voltage fundamental voltage phasor/vector fundamental current phasor/vector injected high frequency voltage phasor/vector high frequency current phasor/vector (response) Prof. Dr. -Ing. Ralph M. Kennel Wuppertal University Page
- 37. ) e ns tracking control of injection voltage r( res po to /v ec s or fundamental voltage phasor/vector ph a t n rre y fundamental current phasor/vector cu e nc qu h fre hig injecte d hi gh freque voltag nc y e pha sor/ve ctor Prof. Dr. -Ing. Ralph M. Kennel Wuppertal University Page
- 38. tracking control ofinjection voltage fundamental voltage phasor/vector fundamental current phasor/vector injected high frequency voltage phasor/vector high frequency current phasor/vector (response) Prof. Dr. -Ing. Ralph M. Kennel Wuppertal University Page
- 39. Encoderless Control Structure step response of the PLL; PLL is locked after ca. 10 -15 ms Prof. Dr. -Ing. Ralph M. Kennel Wuppertal University Page
- 40. tracking control ofinjection voltage fundamental voltage phasor/vector fundamental current phasor/vector injected high frequency voltage phasor/vector high frequency current phasor/vector (response) Prof. Dr. -Ing. Ralph M. Kennel Wuppertal University Page
- 41. tracking control ofinjection voltage fundamental voltage phasor/vector fundamental current phasor/vector injected high frequency voltage phasor/vector high frequency current phasor/vector (response) Prof. Dr. -Ing. Ralph M. Kennel Wuppertal University Page
- 42. tracking control ofinjection voltage fundamental voltage phasor/vector cy fundamental currentnphasor/vector freque ctor e d hi gh pha sor/ve inject v oltage high frequency current phasor/vector (response) Prof. Dr. -Ing. Ralph M. Kennel Wuppertal University Page
- 43. control structure of an encoderless control with alternating high frequency signal injection the estimated angle can be used for field orientation as well as for speed or position control of synchronous machines Prof. Dr. -Ing. Ralph M. Kennel Wuppertal University Page
- 44. north and southpole can be distinguished a) theoretisch b) experimentell trajectory of stator admittance (SMPMSM, carrier frequency fc = 0.5 kHz) Stator Admittance in Complex Plane Prof. Dr. -Ing. Ralph M. Kennel Wuppertal University Page
- 45. Prof. Dr. -Ing.Ralph M. Kennel Wuppertal University Page
- 46. Prof. Dr. -Ing.Ralph M. Kennel Wuppertal University Page
- 47. Prof. Dr. -Ing.Ralph M. Kennel Wuppertal University Page
- 48. Prof. Dr. -Ing.Ralph M. Kennel Wuppertal University Page
- 49. Prof. Dr. -Ing.Ralph M. Kennel Wuppertal University Page
- 50. Tracking Control tracking ofestimated rotor flux angle by adjusting/controlling icq to zero Prof. Dr. -Ing. Ralph M. Kennel Wuppertal University Page
- 51. north and southpole can be distinguished a) theoretisch b) experimentell trajectory of stator admittance (SMPMSM, carrier frequency fc = 0.5 kHz) Stator Admittance in Complex Plane Prof. Dr. -Ing. Ralph M. Kennel Wuppertal University Page
- 52. the concept ofencoderless control as presented here works similar to radio broadcasting : the information of rotor position is modulated by a high frequency signal the information is demodulated / extracted from motor currents Prof. Dr. -Ing. Ralph M. Kennel Wuppertal University Page
- 53. Modulation of CarrierSignals by Electrcial Machines • Synchronous Machines works fine !! • Induction Machines further research to be done !! Prof. Dr. -Ing. Ralph M. Kennel Wuppertal University Page
- 54. Combination of Field Oriented Control and Encoderless Detection of Rotor Position • the estimated angle can be used for field orientation as well as for speed and/or position control of synchronous machines • high frequency test signals are superposed to the fundamental stator voltage(s) • drive control structure remains as before • no additional sensors required • the scheme is parameter independant Prof. Dr. -Ing. Ralph M. Kennel Wuppertal University Page
- 55. Sprungantwort der Drehzahlregelung Drive with Speed Control Prof. Dr. -Ing. Ralph M. Kennel Wuppertal University Page
- 56. Sprungantwort der Lageregelung StepResponse of Encoderless Position Control Prof. Dr. -Ing. Ralph M. Kennel Wuppertal University Page
- 57. Results • the trackingcontrol scheme presented here synchronizes on the saturation anisotropy of a synchronous machine. • the tracking control scheme is not depending on any machine parameter. • the size of additional software for the tracking control is comparable to the software of a rotor model for the field oriented control of an induction machine. • the high frequency current signal can be measured together with the fundamental current by the standard current transducers of a standard drive inverter. Prof. Dr. -Ing. Ralph M. Kennel Wuppertal University Page
- 58. Practical Experience withan Industrial Servo Drive Implementation of a sensorless control into a servo drive of • training of a development engineer 2 x 1 week in our laboratory • programming of additional software in manufacturer‘s factory • delivery of prototype after ca. 3 months • presentation on Hanover Fair in April 2006 Prof. Dr. -Ing. Ralph M. Kennel Wuppertal University Page
- 59. Conclusion • The proposed estimation method is simple and therefore suitable for usual microcontrollers no additional or more powerful processors / controllers • The sensorless control scheme presented here does not need additional voltage measurement devices - neither on the machine/motor side nor on the line side no additional hardware or additional sensors (e. g. voltage sensors) • The phase tracking method is very robust to variations of the system parameters no increased installation effort with respect to parameter adjustments Prof. Dr. -Ing. Ralph M. Kennel Wuppertal University Page