8.16.4.2 Password ......................................................................................................................... 258
8.16.4.3 Conguring a safety function ........................................................................................... 260
8.16.4.4 Interconnecting the "STO active" signal............................................................................. 261
8.16.4.5 Signal lter for STO selection............................................................................................ 262
8.16.4.6 Setting the signal lter for STO selection........................................................................... 264
8.16.4.7 Forced checking procedure .............................................................................................. 264
8.16.4.8 Setting forced checking procedure ................................................................................... 265
8.16.4.9 Complete commissioning................................................................................................. 267
8.16.4.10 Checking the assignment of the digital inputs .................................................................. 268
8.16.4.11 Acceptance test ............................................................................................................... 269
8.17 Setpoints ......................................................................................................................... 270
8.17.1 Overview......................................................................................................................... 270
8.17.2 Analog input as setpoint source ....................................................................................... 272
8.17.3 Specifying the setpoint via the eldbus............................................................................. 273
8.17.4 Motorized potentiometer as setpoint source ..................................................................... 274
8.17.5 Fixed speed setpoint as setpoint source............................................................................ 276
8.18 Setpoint processing.......................................................................................................... 279
8.18.1 Overview......................................................................................................................... 279
8.18.2 Invert setpoint ................................................................................................................. 281
8.18.3 Inhibit direction of rotation .............................................................................................. 282
8.18.4 Skip frequency bands and minimum speed....................................................................... 283
8.18.5 Speed limitation .............................................................................................................. 285
8.18.6 Ramp-function generator................................................................................................. 286
8.19 PID technology controller................................................................................................. 289
8.19.1 Autotuning the PID technology controller......................................................................... 296
8.20 Motor control................................................................................................................... 299
8.20.1 Reactor, lter and cable resistance at the converter output................................................ 299
8.20.2 U/f control ....................................................................................................................... 300
8.20.2.1 U/f control ....................................................................................................................... 300
8.20.2.2 Optimizing motor starting................................................................................................ 304
8.20.2.3 U/f control with Standard Drive Control ............................................................................ 305
8.20.2.4 Optimizing motor starting using Standard Drive Control ................................................... 308
8.20.3 Sensorless vector control.................................................................................................. 310
8.20.3.1 Structure of vector control without encoder (sensorless)................................................... 310
8.20.3.2 Optimizing the speed controller ....................................................................................... 312
8.20.3.3 Advanced settings............................................................................................................ 314
8.20.3.4 Friction characteristic....................................................................................................... 316
8.20.3.5 Moment of inertia estimator ............................................................................................ 319
8.20.4 Application examples for closed-loop motor control.......................................................... 324
8.21 Electrically braking the motor........................................................................................... 324
8.21.1 Electrical braking ............................................................................................................. 324
8.21.2 DC braking....................................................................................................................... 326
8.21.3 Compound braking .......................................................................................................... 331
8.21.4 Dynamic braking.............................................................................................................. 332
8.22 Overcurrent protection..................................................................................................... 336
8.23 Converter protection using temperature monitoring ......................................................... 337
8.24 Motor protection with temperature sensor ....................................................................... 340
8.25 Motor protection by calculating the temperature .............................................................. 342
Table of contents
SINAMICS G120C Converters
Operating Instructions, 02/2023, FW V4.7 SP14, A5E34263257B AK 9