Datasheet TMC4671 (TRINAMIC) - 9
| Manufacturer | TRINAMIC |
| Description | Dedicated Motion Controller for 2-/3-Phase PMSM |
| Pages / Page | 159 / 9 — 3.4 How does FOC work?. 3.5 What is Required for FOC? |
| File Format / Size | PDF / 5.1 Mb |
| Document Language | English |
3.4 How does FOC work?. 3.5 What is Required for FOC?
Model Line for this Datasheet
Text Version of Document
TMC4671 Datasheet • IC Version V1.00 | Document Revision V1.06 • 2019-Feb-06 9 / 159 block and separate controller box wired with motor cable and encoder cable. The high integration of FOC, together with velocity controller and position controller as a SoC, enables the FOC as a standard peripheral component that transforms digital information into physical motion. Compact size together with high performance and energy efficiency especially for battery powered mobile systems are enabling factors when embedded goes autonomous.
3.4 How does FOC work?
Two force components act on the rotor of an electric motor. One component is just pulling in radial direction (ID) where the other component is applying torque by pulling tangentially (IQ). The ideal FOC performs a closed loop current control that results in a pure torque generating current IQ – without direct current ID. Figure 2: FOC optimizes torque by closed loop control while maximizing IQ and minimizing ID to 0 From top point of view, the FOC for 3-phase motors uses three phase currents of the stator interpreted as a current vector (Iu; Iv; Iw) and calculates three voltages interpreted as a voltage vector (Uu; Uv; Uw) taking the orientation of the rotor into account in a way that only a torque generating current IQ results. From top point of view, the FOC for 2-phase motors uses two phase currents of the stator interpreted as a current vector (Ix; Iy) and calculates two voltages interpreted as a voltage vector (Ux; Uy) taking the orientation of the rotor into account in a way that only a torque generating current IQ results. To do so, the knowledge of some static parameters (number of pole pairs of the motor, number of pulses per revolution of an used encoder, orientation of encoder relative to magnetic axis of the rotor, count direction of the encoder) is required together with some dynamic parameters (phase currents, orientation of the rotor). The adjustment of P parameter P and I parameters of two PI controllers for closed loop control of the phase currents depends on electrical parameters of the motor (resistance, inductance, back EMF constant of the motor that is also the torque constant of the motor, supply voltage).
3.5 What is Required for FOC?
The FOC needs to know the direction of the magnetic axis of the rotor of the motor in refrence to the magnetic axis of the stator of the motor. The magnetic flux of the stator is calculated from the currents through the phases of the motor. The magnetic flux of the rotor is fixed to the rotor and thereby determined by an encoder device. For the FOC, the user needs to measure the currents through the coils of the stator and the angle of the rotor. The measured angle of the rotor needs to be adjusted to the magnetic axes. The challenge of the FOC is the high number of degrees of freedom in all parameters. ©2019 TRINAMIC Motion Control GmbH & Co. KG, Hamburg, Germany Terms of delivery and rights to technical change reserved. Download newest version at www.trinamic.com Document Outline 1 Order Codes 2 Functional Summary 3 FOC Basics 3.1 Why FOC? 3.2 What is FOC? 3.3 Why FOC as pure Hardware Solution? 3.4 How does FOC work? 3.5 What is Required for FOC? 3.5.1 Coordinate Transformations - Clarke, Park, iClarke, iPark 3.5.2 Measurement of Stator Coil Currents 3.5.3 Stator Coil Currents I_U, I_V, I_W and Association to Terminal Voltages U_U, U_V, U_W 3.5.4 Measurement of Rotor Angle 3.5.5 Measured Rotor Angle vs. Magnetic Axis of Rotor vs. Magnetic Axis of Stator 3.5.6 Knowledge of Relevant Motor Parameters and Position Sensor (Encoder) Parameters 3.5.7 Proportional Integral (PI) Controllers for Closed Loop Current Control 3.5.8 Pulse Width Modulation (PWM) and Space Vector Pulse Width Modulation (SVPWM) 3.5.9 Orientations, Models of Motors, and Coordinate Transformations 4 Functional Description 4.1 Functional Blocks 4.2 Communication Interfaces 4.2.1 SPI Slave User Interface 4.2.2 TRINAMIC Real-Time Monitoring Interface (SPI Master) 4.2.3 UART Interface 4.2.4 Step/Direction Interface 4.2.5 Single Pin Interface 4.3 Numerical Representation, Electrical Angle, Mechanical Angle, and Pole Pairs 4.3.1 Numerical Representation 4.3.2 N_POLE_PAIRS, PHI_E, PHI_M 4.3.3 Numerical Representation of Angles PHI 4.4 ADC Engine 4.4.1 ADC Group A and ADC Group B 4.4.2 Internal Delta Sigma ADCs 4.4.3 External Delta Sigma ADCs 4.5 Delta Sigma Configuration and Timing Configuration 4.5.1 Internal Delta Sigma Modulators - Mapping of V_RAW to ADC_RAW 4.5.2 External Delta Sigma Modulator Interface 4.5.3 ADC Configuration - MDAC 4.6 Analog Signal Conditioning 4.6.1 FOC3 - Stator Coil Currents I_U, I_V, I_W and Association to Terminal Voltages U_U, U_V, U_W 4.6.2 Stator Coil Currents I_X, I_Y and Association to Terminal Voltages U_X, U_Y 4.6.3 ADC Selector & ADC Scaler w/ Offset Correction 4.7 Encoder Engine 4.7.1 Open-Loop Encoder 4.7.2 Incremental ABN Encoder 4.7.3 Secondary Incremental ABN Encoder 4.7.4 Digital Hall Sensor Interface with optional Interim Position Interpolation 4.7.5 Digital Hall Sensor - Interim Position Interpolation 4.7.6 Digital Hall Sensors - Masking and Filtering 4.7.7 Digital Hall Sensors together with Incremental Encoder 4.7.8 Analog Hall and Analog Encoder Interface (SinCos of 0° 90° or 0° 120° 240°) 4.7.9 Analog Position Decoder (SinCos of 0°90° or 0°120°240°) 4.7.10 Encoder Initialization Support 4.7.11 Velocity Measurement 4.7.12 Reference Switches 4.8 FOC23 Engine 4.8.1 PI Controllers 4.8.2 PI Controller Calculations - Classic Structure 4.8.3 PI Controller Calculations - Advanced Structure 4.8.4 PI Controller - Clipping 4.8.5 PI Flux & PI Torque Controller 4.8.6 PI Velocity Controller 4.8.7 P Position Controller 4.8.8 Inner FOC Control Loop - Flux & Torque 4.8.9 FOC Transformations and PI(D) for control of Flux & Torque 4.8.10 Motion Modes 4.8.11 Brake Chopper 4.9 Filtering and Feed-Forward Control 4.9.1 Biquad Filters 4.9.2 Standard Velocity Filter 4.9.3 Feed-Forward Control Structure 4.10 PWM Engine 4.10.1 PWM Polarities 4.10.2 PWM Frequency 4.10.3 PWM Resolution 4.10.4 PWM Modes 4.10.5 Break-Before-Make (BBM) 4.10.6 Space Vector PWM (SVPWM) 5 Safety Functions 5.1 Watchdog 6 Register Map 6.1 Register Map Overview 6.2 Register Map Full 7 Pinning 8 TMC4671 Pin Table 9 Electrical Characteristics 9.1 Absolute Maximum Ratings 9.2 Electrical Characteristics 9.2.1 Operational Range 9.2.2 DC Characteristics 10 Sample Circuits 10.1 Supply Pins 10.2 Clock and Reset Circuitry 10.3 Digital Encoder, Hall Sensor Interface and Reference Switches 10.4 Analog Frontend 10.5 Phase Current Measurement 10.6 Power Stage Interface 11 Setup Guidelines 12 Package Dimensions 13 Supplemental Directives 13.1 Producer Information 13.2 Copyright 13.3 Trademark Designations and Symbols 13.4 Target User 13.5 Disclaimer: Life Support Systems 13.6 Disclaimer: Intended Use 13.7 Collateral Documents & Tools 14 Errata 15 Figures Index 16 Tables Index 17 Revision History 17.1 IC Revision 17.2 Document Revision
3.4 How does FOC work?
Two force components act on the rotor of an electric motor. One component is just pulling in radial direction (ID) where the other component is applying torque by pulling tangentially (IQ). The ideal FOC performs a closed loop current control that results in a pure torque generating current IQ – without direct current ID. Figure 2: FOC optimizes torque by closed loop control while maximizing IQ and minimizing ID to 0 From top point of view, the FOC for 3-phase motors uses three phase currents of the stator interpreted as a current vector (Iu; Iv; Iw) and calculates three voltages interpreted as a voltage vector (Uu; Uv; Uw) taking the orientation of the rotor into account in a way that only a torque generating current IQ results. From top point of view, the FOC for 2-phase motors uses two phase currents of the stator interpreted as a current vector (Ix; Iy) and calculates two voltages interpreted as a voltage vector (Ux; Uy) taking the orientation of the rotor into account in a way that only a torque generating current IQ results. To do so, the knowledge of some static parameters (number of pole pairs of the motor, number of pulses per revolution of an used encoder, orientation of encoder relative to magnetic axis of the rotor, count direction of the encoder) is required together with some dynamic parameters (phase currents, orientation of the rotor). The adjustment of P parameter P and I parameters of two PI controllers for closed loop control of the phase currents depends on electrical parameters of the motor (resistance, inductance, back EMF constant of the motor that is also the torque constant of the motor, supply voltage).
3.5 What is Required for FOC?
The FOC needs to know the direction of the magnetic axis of the rotor of the motor in refrence to the magnetic axis of the stator of the motor. The magnetic flux of the stator is calculated from the currents through the phases of the motor. The magnetic flux of the rotor is fixed to the rotor and thereby determined by an encoder device. For the FOC, the user needs to measure the currents through the coils of the stator and the angle of the rotor. The measured angle of the rotor needs to be adjusted to the magnetic axes. The challenge of the FOC is the high number of degrees of freedom in all parameters. ©2019 TRINAMIC Motion Control GmbH & Co. KG, Hamburg, Germany Terms of delivery and rights to technical change reserved. Download newest version at www.trinamic.com Document Outline 1 Order Codes 2 Functional Summary 3 FOC Basics 3.1 Why FOC? 3.2 What is FOC? 3.3 Why FOC as pure Hardware Solution? 3.4 How does FOC work? 3.5 What is Required for FOC? 3.5.1 Coordinate Transformations - Clarke, Park, iClarke, iPark 3.5.2 Measurement of Stator Coil Currents 3.5.3 Stator Coil Currents I_U, I_V, I_W and Association to Terminal Voltages U_U, U_V, U_W 3.5.4 Measurement of Rotor Angle 3.5.5 Measured Rotor Angle vs. Magnetic Axis of Rotor vs. Magnetic Axis of Stator 3.5.6 Knowledge of Relevant Motor Parameters and Position Sensor (Encoder) Parameters 3.5.7 Proportional Integral (PI) Controllers for Closed Loop Current Control 3.5.8 Pulse Width Modulation (PWM) and Space Vector Pulse Width Modulation (SVPWM) 3.5.9 Orientations, Models of Motors, and Coordinate Transformations 4 Functional Description 4.1 Functional Blocks 4.2 Communication Interfaces 4.2.1 SPI Slave User Interface 4.2.2 TRINAMIC Real-Time Monitoring Interface (SPI Master) 4.2.3 UART Interface 4.2.4 Step/Direction Interface 4.2.5 Single Pin Interface 4.3 Numerical Representation, Electrical Angle, Mechanical Angle, and Pole Pairs 4.3.1 Numerical Representation 4.3.2 N_POLE_PAIRS, PHI_E, PHI_M 4.3.3 Numerical Representation of Angles PHI 4.4 ADC Engine 4.4.1 ADC Group A and ADC Group B 4.4.2 Internal Delta Sigma ADCs 4.4.3 External Delta Sigma ADCs 4.5 Delta Sigma Configuration and Timing Configuration 4.5.1 Internal Delta Sigma Modulators - Mapping of V_RAW to ADC_RAW 4.5.2 External Delta Sigma Modulator Interface 4.5.3 ADC Configuration - MDAC 4.6 Analog Signal Conditioning 4.6.1 FOC3 - Stator Coil Currents I_U, I_V, I_W and Association to Terminal Voltages U_U, U_V, U_W 4.6.2 Stator Coil Currents I_X, I_Y and Association to Terminal Voltages U_X, U_Y 4.6.3 ADC Selector & ADC Scaler w/ Offset Correction 4.7 Encoder Engine 4.7.1 Open-Loop Encoder 4.7.2 Incremental ABN Encoder 4.7.3 Secondary Incremental ABN Encoder 4.7.4 Digital Hall Sensor Interface with optional Interim Position Interpolation 4.7.5 Digital Hall Sensor - Interim Position Interpolation 4.7.6 Digital Hall Sensors - Masking and Filtering 4.7.7 Digital Hall Sensors together with Incremental Encoder 4.7.8 Analog Hall and Analog Encoder Interface (SinCos of 0° 90° or 0° 120° 240°) 4.7.9 Analog Position Decoder (SinCos of 0°90° or 0°120°240°) 4.7.10 Encoder Initialization Support 4.7.11 Velocity Measurement 4.7.12 Reference Switches 4.8 FOC23 Engine 4.8.1 PI Controllers 4.8.2 PI Controller Calculations - Classic Structure 4.8.3 PI Controller Calculations - Advanced Structure 4.8.4 PI Controller - Clipping 4.8.5 PI Flux & PI Torque Controller 4.8.6 PI Velocity Controller 4.8.7 P Position Controller 4.8.8 Inner FOC Control Loop - Flux & Torque 4.8.9 FOC Transformations and PI(D) for control of Flux & Torque 4.8.10 Motion Modes 4.8.11 Brake Chopper 4.9 Filtering and Feed-Forward Control 4.9.1 Biquad Filters 4.9.2 Standard Velocity Filter 4.9.3 Feed-Forward Control Structure 4.10 PWM Engine 4.10.1 PWM Polarities 4.10.2 PWM Frequency 4.10.3 PWM Resolution 4.10.4 PWM Modes 4.10.5 Break-Before-Make (BBM) 4.10.6 Space Vector PWM (SVPWM) 5 Safety Functions 5.1 Watchdog 6 Register Map 6.1 Register Map Overview 6.2 Register Map Full 7 Pinning 8 TMC4671 Pin Table 9 Electrical Characteristics 9.1 Absolute Maximum Ratings 9.2 Electrical Characteristics 9.2.1 Operational Range 9.2.2 DC Characteristics 10 Sample Circuits 10.1 Supply Pins 10.2 Clock and Reset Circuitry 10.3 Digital Encoder, Hall Sensor Interface and Reference Switches 10.4 Analog Frontend 10.5 Phase Current Measurement 10.6 Power Stage Interface 11 Setup Guidelines 12 Package Dimensions 13 Supplemental Directives 13.1 Producer Information 13.2 Copyright 13.3 Trademark Designations and Symbols 13.4 Target User 13.5 Disclaimer: Life Support Systems 13.6 Disclaimer: Intended Use 13.7 Collateral Documents & Tools 14 Errata 15 Figures Index 16 Tables Index 17 Revision History 17.1 IC Revision 17.2 Document Revision
