Datasheet TMC4671 (TRINAMIC) - 10
| Manufacturer | TRINAMIC |
| Description | Dedicated Motion Controller for 2-/3-Phase PMSM |
| Pages / Page | 159 / 10 — 3.5.1 Coordinate Transformations - Clarke, Park, iClarke, iPark. 3.5.2 … |
| File Format / Size | PDF / 5.1 Mb |
| Document Language | English |
3.5.1 Coordinate Transformations - Clarke, Park, iClarke, iPark. 3.5.2 Measurement of Stator Coil Currents
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TMC4671 Datasheet • IC Version V1.00 | Document Revision V1.06 • 2019-Feb-06 10 / 159
3.5.1 Coordinate Transformations - Clarke, Park, iClarke, iPark
The FOC requires different coordinate transformations formulated as a set of matrix multiplications. These are the Clarke Transformation (Clarke), the Park Transformation (Park), the inverse Park Transforma- tion (iPark) and the inverse Clarke Transformation (iClarke). Some put Park and Clarke together as DQ transformation and Park and Clarke as inverse DQ transformation. The TMC4671 takes care of the required transformations so the user no longer has to fight with implemen- tation details of these transformations.
3.5.2 Measurement of Stator Coil Currents
The measurement of the stator coil currents is required for the FOC to calculate a magnetic axis out of the stator field caused by the currents flowing through the stator coils. Coil current stands for motor torque in context of FOC. This is because motor torque is proportional to motor current, defined by the torque constant of a motor. In addition, the torque depends on the orientation of the rotor of the motor relative to the magnetic field produced by the current through the coils of the stator of the motor.
3.5.3 Stator Coil Currents I_U, I_V, I_W and Association to Terminal Voltages U_U, U_V, U_W
The correct association between stator terminal voltages U_U, U_V, U_W and stator coil currents I_U, I_V, I_W is essential for the FOC. In addition to the association, the signs of each current channel need to fit. Signs of the current can be adapted numerically by the ADC scaler. The mapping of ADC channels is programmable via configuration registers for the ADC selector. Initial setup is supported by the integrated open loop encoder block, that can support the user to turn a motor open loop.
3.5.3.1 Chain of Gains for ADC Raw Values
An ADC raw value is a result of a chain of gains that determine it. A coil current I_SENSE flowing through a sense resistor causes a voltage difference according to Ohm’s law. The resulting ADC raw value is a result of the analog signal path according to ADC_RAW = (I_SENSE ∗ ADC_GAIN) + ADC_OFFSET. (1) The ADC_GAIN is a result of a chain of gains with individual signs. The sign of the ADC_GAIN is positive or negative, depending on the association of connections between sense amplifier inputs and the sense resistor terminals. The ADC_OFFSET is the result of electrical offsets of the phase current measurement signal path. For the TMC4671, the maximum ADC_RAW value ADC_RAW_MAX = (216 − 1) and the minimum ADC raw value is ADC_RAW_MIN = 0. ADC_GAIN = ( I_SENSE_MAX ∗ R_SENSE ) ∗ SENSE_AMPLIFIER_GAIN (2) ∗ ( ADC_RAW_MAX/ADC_U_MAX ) For the FOC, the ADC_RAW is scaled by the ADC scaler of the TMC4671 together with subtraction of offset to compensate it. Internally, the TMC4671 FOC engine calculates with s16 values. Thus, the ADC scaling needs to be chosen so that the measured currents fit into the s16 range. With the ADC scaler, the user can choose a scaling with physical units like [mA]. ©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
3.5.1 Coordinate Transformations - Clarke, Park, iClarke, iPark
The FOC requires different coordinate transformations formulated as a set of matrix multiplications. These are the Clarke Transformation (Clarke), the Park Transformation (Park), the inverse Park Transforma- tion (iPark) and the inverse Clarke Transformation (iClarke). Some put Park and Clarke together as DQ transformation and Park and Clarke as inverse DQ transformation. The TMC4671 takes care of the required transformations so the user no longer has to fight with implemen- tation details of these transformations.
3.5.2 Measurement of Stator Coil Currents
The measurement of the stator coil currents is required for the FOC to calculate a magnetic axis out of the stator field caused by the currents flowing through the stator coils. Coil current stands for motor torque in context of FOC. This is because motor torque is proportional to motor current, defined by the torque constant of a motor. In addition, the torque depends on the orientation of the rotor of the motor relative to the magnetic field produced by the current through the coils of the stator of the motor.
3.5.3 Stator Coil Currents I_U, I_V, I_W and Association to Terminal Voltages U_U, U_V, U_W
The correct association between stator terminal voltages U_U, U_V, U_W and stator coil currents I_U, I_V, I_W is essential for the FOC. In addition to the association, the signs of each current channel need to fit. Signs of the current can be adapted numerically by the ADC scaler. The mapping of ADC channels is programmable via configuration registers for the ADC selector. Initial setup is supported by the integrated open loop encoder block, that can support the user to turn a motor open loop.
3.5.3.1 Chain of Gains for ADC Raw Values
An ADC raw value is a result of a chain of gains that determine it. A coil current I_SENSE flowing through a sense resistor causes a voltage difference according to Ohm’s law. The resulting ADC raw value is a result of the analog signal path according to ADC_RAW = (I_SENSE ∗ ADC_GAIN) + ADC_OFFSET. (1) The ADC_GAIN is a result of a chain of gains with individual signs. The sign of the ADC_GAIN is positive or negative, depending on the association of connections between sense amplifier inputs and the sense resistor terminals. The ADC_OFFSET is the result of electrical offsets of the phase current measurement signal path. For the TMC4671, the maximum ADC_RAW value ADC_RAW_MAX = (216 − 1) and the minimum ADC raw value is ADC_RAW_MIN = 0. ADC_GAIN = ( I_SENSE_MAX ∗ R_SENSE ) ∗ SENSE_AMPLIFIER_GAIN (2) ∗ ( ADC_RAW_MAX/ADC_U_MAX ) For the FOC, the ADC_RAW is scaled by the ADC scaler of the TMC4671 together with subtraction of offset to compensate it. Internally, the TMC4671 FOC engine calculates with s16 values. Thus, the ADC scaling needs to be chosen so that the measured currents fit into the s16 range. With the ADC scaler, the user can choose a scaling with physical units like [mA]. ©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
