Power Forum Bologna Implementation of sensorless BLDC Control

Power Forum Bologna Implementation of sensorless BLDC Control Davide Lissoni South Europe FAE Manager 23 rd Sept. 2010

Agenda Introduction Common applications Review of motor types DC motors AC motors Motor Drive Topologies BLDC Sensorless methods 9/23/2010 2

Why we need to design a motor drive? Energy Efficiency Uncontrolled AC induction motors draw more current than necessary under most conditions (except full load) Variable-speed compressors and fans can be much more efficient for refrigeration and HVAC applications Reliability For example, a washing machine can be direct-drive, eliminating the mechanical transmission and belt Performance Variable speed for garage door opener is faster/safer/less wear Faster spin in washer means less time (energy) in dryer 9/23/2010 3

Common Motor Drive Applications Appliance (180 2200Watts) White Goods Washer, Refrigerator & A/C Compressor Blowers, Fans, Pumps Vacuum cleaner Garage Door Opener Industrial (350 12KWatts) Adjustable-Speed Drives Servo Drives Blowers, Fans, Pumps 9/23/2010 4

Asynchronou s Major Commonly-Used Motors AC Motor Synchronous DC Motor Commutator Induction Poly-Phase Cast Rotor 3 AC Induction (3-phase) 2 Brushless DC Sine 1 Permanent Magnet AC Reluctance 4 Switched Reluctance (SR) 5 Permanent Magnet (DC Brush) 9/23/2010

Common Motor Drive Types Motor type DC Brush Motor Drive Chopper Drive or H-Bridge Drive BLDC/PMAC/Induction motors 3-Phase Voltage Source Inverter SR Motor Single phase SR or 3-Phase SR 9/23/2010 6

Unidirectional Chopper Brush-Motor Drive BRUSH MOTOR LINE INPUT BIAS POWER SUPPLY CONTROL ELECTRONICS AND GATE DRIVER Switch can be high or low-side INPUT RECTIFIER DC BUS CAP OUTPUT CHOPPER 9/23/2010 7

Chopper Drive Attributes Simple uses only one switch Motor current (therefore torque) in only one direction No braking motor must coast down Only works for DC brush motors Brush lifetime not infinite Commutators arc Arcing generates EMI and Ozone Switching transistor can be on high or low-side 9/23/2010 8

Bi-Directional H-Bridge Brush-Motor Drive LINE INPUT BIAS POWER SUPPLY CONTROL ELECTRONICS AND GATE DRIVERS BRUSH MOTOR INPUT RECTIFIER DC BUS CAP BRAKE OUTPUT INVERTER 9/23/2010 9

H-Bridge Drive Attributes 4 switches (2 fewer than 3-phase) Current (Torque) can be driven either direction Control strategy can be designed for 4-quadrant operation May require shunt regulator for braking (regeneration) Several modulation strategies 2 transistors steer, 2 PWM to control current All 4 transistors PWM Same issues as before with brushes 9/23/2010 10

Three-Phase Motor Drive (Always Brushless) LINE INPUT BIAS POWER SUPPLY CONTROL ELECTRONICS AND GATE DRIVERS AC MOTOR INPUT RECTIFIER DC BUS CAP BRAKE OUTPUT INVERTER 9/23/2010 11

Motor Drive Topologies Summary Voltage Source Inverter is the Dominant topology today AC Induction, Permanent Magnet AC, and Brushless DC motors share the same basic inverter topology SR motors use a variation of the VSI 9/23/2010 12

BLDC - Motor 2 main components of Brushless Motor (BLDC) N S S 1. rotor made up of permanent magnets and 2. stator with a winding connected to control board N similar poles repel each other opposite poles attract SCS 13

BLDC: Torque Ripple + Ideal: flux vector perpendicular to magnetic flux max. torque Real: flux vector is maintained between 60 and 120 relative to magnetic flux SCS actual flux vector before commutation new flux vector after commutation Company Confidential 14

BLDC vs. Universal Motor Advantages of BLDC High efficiency Reduction of noise and vibration Free of maintenance High temperature control accuracy High reliability Decreasing cost compared to universal motor due to need of less copper/iron (needs magnets instead) Company Confidential 15

BLDC Motor Cross Section permanent magnets on rotor Stator (laminated stack) slots for conductors 16

BLDC Motor Equivalent Circuit (with inverter) R b L b R a L a + e a - - - e b + R c L c e c + 17

Commutation of Trapezoidal BLDC Motor (1) e a i a I p E p B+ C- A+ B- A- C+ e b i b C+ A- e c B- B+ A+ C- i c 18

Commutation of Trapezoidal BLDC Motor (2) e a i a I p E p B+ C- A+ B- A- C+ e b i b C+ A- e c B- B+ A+ C- i c 19

Commutation of Trapezoidal BLDC Motor (3) e a i a I p E p B+ C- A+ B- A- C+ e b i b C+ A- e c B- B+ A+ C- i c 20

Commutation of Trapezoidal BLDC Motor (4) e a i a I p E p B+ C- A+ B- A- C+ e b i b C+ A- e c B- B+ A+ C- i c 21

Commutation of Trapezoidal BLDC Motor (5) e a i a I p E p B+ C- A+ B- A- C+ e b i b C+ A- e c B- B+ A+ C- i c 22

Commutation of Trapezoidal BLDC Motor (6) e a i a I p E p B+ C- A+ B- A- C+ e b i b C+ A- e c B- B+ A+ C- i c 23

Commutation of Trapezoidal BLDC Motor (7) (same as 1) e a i a I p E p B+ C- A+ B- A- C+ e b i b C+ A- e c B- B+ A+ C- i c 24

Ideal Trapezoidal Commutation e a I p E p i a e b i b e c i c Phase Back EMFs and Impressed Currents in an Ideal Trapezoidal Drive 25

Brushless DC Motor Bipolar Switching HS Gate Signal Output Current LS Gate Signal Company Confidential 26

BLDC: Back-EMF +V DC +V real BEMF DC BEMF U real BEMF BEMF V -V DC BEMF W Regenerative Braking Output Current I U Company Confidential 27

How to control sensorless? Back-EMF based methods from app. 10% to 100% of nominal speed Based on the BEMF integration Based on terminal voltage sensing Based on 3 rd harmonics of BEMF Based on freewheeling diode conduction Flux calculation based method Signal injection method Inductance based method IPM: Saliency poles Source: Position sensorless brushless DC motor/generator drives: review and future trends, Kim et al., IET Electr. Power Appl. 2007, pp.557-564 Company Confidential 28 from 0 to app. 20% of nominal speed

Terminal Voltage sensing BEMF BEMF=0 in reference to neutral point Measured phase is disconnected and without current flow Inaccessible neutral point of BLDC motor V DC BEMF Company Confidential 29 SCS

Sensorless Control of BLDC Based on terminal voltage sensing - Part 1 Company Confidential 30

Sensorless Control - Part 2 BEMF U BEMF V BEMF W Company Confidential 31

Start Up Part 1 Back-EMF based methods Speed range from app.10% up to 100% of nominal speed Company Confidential 32

Start Up Part 2 V U V V V W Output Current I U Alignment Blind Commutation Steady State Company Confidential 33

Start Up Part 3 UL UH VL VH WL WH I U I U Company Confidential 34

Start Up Part 4 ZCD U V U I U Company Confidential 35

Start Up Part 5 ZCD U V U I U Company Confidential 36

Start Up Part 6 ZCD U ZCD V ZCD W I U Company Confidential 37

Failed at Start Up! ZCD U BEMF U ZCD V I U Company Confidential 38

SPM Board BLDC Current Sense SPM ZCD Hall Sensor Current Sense 5V 15V 3.3V Microcontroller 400VDC 24VDC Company Confidential 39

Motion-SPM TinyDIP Line-Up 10W 200W (1) COM (2) V B(U) (3) V CC(U) (4) IN (UH) (5) IN (UL) (6) V S(U) (7) V B(V) (8) V CC(V) (9) IN (VH) (10) IN (VL) (11) V S(V) (12) V B(W) (13) V CC(W) (14) IN (WH) (15) IN (WL) (16) V S(W) VCC HIN LIN COM VCC HIN LIN COM VCC HIN LIN COM FSB50250 FSB50450 FSB50550U VB HO VS LO VB HO VS LO VB HO VS LO (17) P (18) U (19) N U (20) N V (21) V (22) N W (23) W FSB50250US FSB50450US FSB50550US FSB50325S FSB50825US FSB52006S * Voltage rating x10 S=SMD, T=Double DIP * Low Voltage TinySMD Company Confidential 40 FSB50450T FSB50550T FSB50325T 10W 200W

Motion-SPM µ-minidip Line-Up 200W 1.5kW (26) VB(U) (25) VS(U) (24) VB(V) (23) VS(V) (22) VB(W) (21) VS(W) (20) IN(UH) (19) IN(VH) (18) IN(WH) (17) VCC(H) (16) VCC(L) (15) COM (14) IN(UL) (13) IN(VL) (12) IN(WL) (11) VFO (10) CSC UVB UVS VVB VVS WVB WVS IN(UH) IN(VH) IN(WH) VCC COM VCC COM IN(WL) IN(VL) IN(UL) VFO CSC FNA40560 FNA40860 FNA41060 FNA41560 OUT(UH) UVS OUT(VH) VVS OUT(WH) WVS OUT(UL) OUT(VL) OUT(WL) NTC FNB40560 FNB41060 FNB41560 (1) VTH (2) RTH (3) P (4) U (5) V (6) W (7) NU (8) NV (9) NW Current rating T c = 25 C Voltage rating x10 A => normal f sw B => high f sw Company Confidential 41

Motion-SPM MiniDIP Line-Up 200W 3kW (19) V B(W) (18) V CC(WH) (17) IN (WH) (20) V S(W) (15) V B(V) (14) V CC(VH) (13) IN (VH) (16) V S(V) (11) V B(U) (10) V CC(UH) (9) IN (UH) (12) V S(U) (8) C SC (7) C FOD (6) V FO (5) IN (WL) (4) IN (VL) (3) IN (UL) (2) COM (1) V CC(L) VB VCC COM IN VB VCC COM IN VB VCC COM IN C(SC) OUT(WL) C(FOD) VFO IN(WL) OUT(VL) IN(VL) IN(UL) COM VCC OUT VS OUT VS OUT VS OUT(UL) V SL FSBS3CH60 FSBS5CH60 FSBS10CH60 FSBS15CH60(F) N W (23) Company Confidential 42 P (27) W (26) V (25) U (24) N V (22) N U (21) FSBB15CH60(F) FSBB20CH60(L)(F) FSBB30CH60(F) Current rating T c = 25 C Voltage rating x10 Short Lead Version Over Temperature Protection (19) V B(W) (18) V CC (17) IN (WH) (20) V S(W) (15) V B(V) (14) V CC (13) IN (VH) (16) V S(V) (11) V B(U) (10) V CC (9) IN (UH) (12) V S(U) (8) C SC (7) C FOD (6) V FO (5) IN (WL) (4) IN (VL) (3) IN (UL) (2) COM (1) V CC VB VCC COM IN VB VCC COM IN VB VCC COM IN C(SC) C(FOD) VFO IN(WL) IN(VL) IN(UL) COM VCC OUT VS OUT VS OUT VS OUT(WL) OUT(VL) OUT(UL) FSBF3CH60B FSBF5CH60B FSBF10CH60BT(L) FSBF10CH60B FSBF15CH60BT(L) V SL P (27) W (26) V (25) U (24) N W (23) N V (22) N U (21) FSBB15CH60BT FSBB15CH60C FSBB20CH60CT FSBB20CH60C(L) FSBB30CH60C 200W 3kW

Smart Power Modules SPM 3 phase Motor Protection Functions SPM Company Confidential 43

High Voltage Gate Drivers 600V Product Portfolio Full Release In Development Type Input Output Driving Current (Source / Sink) 90 / 180mA 350 / 650mA Over 2 / 2A High Side Only 1 1 High & Low Side 2 2 FAN7361 FAN7362 FAN7385 (Dual) FAN7842 (200V) FAN7382 FAN7371 FAN7390 FAN73901 FAN7392 Half-bridge 1 2 2 2 FAN7380 FAN73832 FAN7383 FAN7384 FAN73833 FAN7393 FAN73932 FAN73933 Half-bridge (Self OSC) 1 2 FAN7387 3-Phase Half-bridge 2 2 FAN7388 (3 Ch.) FAN7389 (3 Ch.) AN-6076 Design and Application Guide of Bootstrap Circuit for High-Voltage Gate-Drive IC Company Confidential 44

Half-Bridge Gate Driver FAN73832/FAN7383 Sink: 650mA Source: 350mA Dead-time control Shutdown Sink: 650mA Source: 350mA Split outputs Dead-time control Shutdown Company Confidential 45

Three Phase Half-Bridge Drivers FAN7388 Sink: 650mA Source: 350mA Shoot through prevention Deadtime 270ns Company Confidential 46

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