User's Manual

Turbo PMAC User Manual
iv Table of Contents
Current Loop in Turbo PMAC or Not.................................................................................................................91
Setting Up for Direct PWM Control .......................................................................................................................91
Introduction ........................................................................................................................................................91
Digital Current Loop Principle of Operation .....................................................................................................91
Turbo PMAC Parameter Setup...........................................................................................................................94
Special Instructions for Direct-PWM Control of Brush Motors .......................................................................100
Testing PWM and Current Feedback Operation ..............................................................................................101
Position Feedback and Polarity Test................................................................................................................102
Establishing Basic Current Loop Operation.....................................................................................................107
Setting Up Turbo PMAC for Sine-Wave Output Control .....................................................................................110
Hardware Setup ................................................................................................................................................110
Turbo PMAC Parameter Setup.........................................................................................................................111
Establishing Basic Output Operation ...............................................................................................................114
Finishing Setting up Turbo PMAC Commutation (Direct PWM or Sine Wave), Synchronous Motors...............115
Confirming Commutation Polarity Match ........................................................................................................115
Establishing a Phase Reference........................................................................................................................116
Finishing Setting up Turbo PMAC Commutation (Direct PWM or Sine Wave), Asynchronous (Induction) Motors
...............................................................................................................................................................................127
Calculating Ixx78 Slip Constant .......................................................................................................................127
Setting Ixx77 Magnetization Current................................................................................................................128
Direct Microstepping of Motors (Open-Loop Commutation) ...............................................................................129
Setting the I-Variables ......................................................................................................................................130
What to Do Next ...................................................................................................................................................132
User-Written Phase Algorithms ............................................................................................................................133
Writing the Algorithm .......................................................................................................................................133
SETTING UP THE ENCODER CONVERSION TABLE ..................................................................................135
Conversion Table Execution .................................................................................................................................136
Conversion Table Structure...................................................................................................................................136
Setup Structure..................................................................................................................................................136
Result Structure.................................................................................................................................................138
Using the Results ..............................................................................................................................................139
Conversion Methods .............................................................................................................................................140
Digital Quadrature Encoders ...........................................................................................................................140
Analog Sine/Cosine Encoders...........................................................................................................................142
Acc-28 Analog-to-Digital Converters...............................................................................................................143
Parallel Feedback.............................................................................................................................................143
Exponential Filter.............................................................................................................................................145
Sum and Difference...........................................................................................................................................145
Time Base (Differentiation) ..............................................................................................................................146
SETTING UP THE SERVO LOOP.......................................................................................................................149
Servo Update Rate.................................................................................................................................................149
Reasons to Change Servo Update Rate.............................................................................................................149
Ramifications of Changing the Servo Update Rate...........................................................................................149
Types of Amplifiers ..............................................................................................................................................150
Amplifiers for Which Servo Produces Velocity Command................................................................................150
Amplifiers for Which Servo Produces Torque/Force Command.......................................................................151
PID/Feedforward/Notch Servo Filter ....................................................................................................................152
PID Feedback Filter .........................................................................................................................................152
Feedforward Filter ...........................................................................................................................................153
Actual PID/Feedforward Algorithm .................................................................................................................154
Notch Filter.......................................................................................................................................................154
Servo-Loop Modifiers .......................................................................................................................................159
Extended Servo Algorithm....................................................................................................................................161
Cascading Servo Loops.........................................................................................................................................163
Selecting Turbo PMAC Motors to Use .............................................................................................................164