Single Sensor Three - Phase Permanent Magnet Synchronous Motor Drive based on Luenberger Style - Observers Bahaa Hafez 1 , A. Abdel-Khalik 2 , A. M. Massoud 3 , Shehab Ahmed 4 , and Robert D. Lorenz 5 1 Texas A&M University, College Station TX, U.S.A, 2 Alexandria University, Alexandria, Egypt, 3 Qatar University, Doha, Qatar, 4 Texas A&M University at Qatar, Doha, Qatar 5 University of Wisconsin-Madison, WEMPEC, Madison WI, U.S.A IEEE-ICEMS2012-Fall – Sapporo, Japan – October 22, 2012 This paper presents a technique to estimate phase currents and rotor position in a vector-controlled PMSM drive using only dc-link current measurement based on Luenberger style observers. Abstract Proposed Algorithm + i dc + v dq s * 1 L s r - ^ -E sal dq s ^ i dq s - + abc ab i abc K io R o + s ^ DC link Current Mapping PMSM Luenberger style observer i dq s ^ DC link measurement Limitation V 5 V 6 V 1 V 4 V 7 100 011 110 010 001 101 V 0 V com a Sector 1 Sector 2 Sector 3 Sector 4 Sector 5 Sector 6 V 2 V 3 S A_UP S B_UP S C_UP T 0 /4 T 0 /4 T 0 /4 T 0 /4 S A_LOW S B_LOW S C_LOW i a i a i c i c T 1 /2 T 2 /2 T 2 /2 T 1 /2 T pwm /2 T pwm /2 S A_LOW S B_LOW S C_LOW i dc i a i b i c S A_UP S B_UP S C_UP V 3 V 1 V 2 V 4 V 5 V 6 V 0 V 7 Sector boundary region Measurable region Low Modulation region t (sec) t com t set t on t A2D Full system and Hardware results Performance Improvement Motor current - full sensors Motor current - single sensor Conclusion • Better “Dynamic Stiffness” and lower harmonic motor current due to higher resolution estimated position. • Overcome the sector boundary region limitation. • No PWM modification needed. • Simple algorithm which can be implemented by an industry standard DSP (F2812). • Controllers orientation is simple and straightforward due the observer linearity. • No hardware modification needed. • 0.2 [PU] lower speed transient limit Test setup Parameter Parameter Value DC bus Voltage 100 V Phase resistance 1.4489 Ohms D,Q axis Inductance- 0.0049325 H Flux Linkage 0.077393 V.s/rad Pole pairs-P 6 Motor inertia-J 0.00924 kg/m 2 Motor viscous friction-b 0.005 N.m/s.rad Base current 7 A Base voltage 57.735 V Base mechanical speed 85 rad/s Base Torque 4 N.m Electrical loop freq. 5000 Hz Mechanical loop freq. 500 Hz CRO loop freq. 5000 Hz Elect. loop Eigen values freq. 10 Hz,100 Hz Mech. loop Eigen values freq. 0.1 Hz,1 Hz BEMF est. Eigen values freq. 80 Hz,800 Hz BEMF Tracking Observer Eigen values freq. 1Hz,10Hz,100Hz Speed Filter Eigen values freq. 0.1Hz,1Hz,10Hz Inverter 1 L s r K t 1 J s b 1 s K e - - - + + K io K o + s + + 1 J s ^ + + 1 s P 2 j( + ) e q r p 2 ^ ^ 1 J s w rm ^ q rm ^ q r ^ K io-2 K o-2 + s b o-2 + + + + ^ 1 J s 1 s + + - - q rm ^ w rm ^ w rm-2 ^ q rm-2 ^ Cascaded Position Observer Back-emf Tracking Observer E sal dq s ^ + i dc + 1 L s i dq s ^ r - ^ -E sal dq s ^ i dq s - + abc ab i abc R io R o + s Three phase Current Reconstruction/ Back-emf State Filter -1 ^ i d = 0 * T e * K i K p + s K t -1 i q * i d * + j i q * K io-1 K o-1 + s v dq s dq ab * SVM q r ^ T e * T e * w rm-2 ^ w rm * + - + - Physical motor/inverter setup Drive Controller ab dq i dq ^ E sal dq s v dq s T e T d + w rm q rm 0.5 P