Troubleshooting of Rockwell AutoMax DPS

Fiber optic communication failure: The fiber optic link between GDI module and LPI module is interrupted. Test using the same method as UDC-PMI.

Gate fault feedback: The power unit reports IGBT short circuit or open circuit. Need to check the power module.

Replacement precautions: The GDI module is paired with a specific power unit and needs to be recalibrated after replacement (executed through AutoMax software).

Power module and bus malfunction

5.1 SA500 Driver

The PMI of the SA500 driver is integrated into the power module without a separate rack. Common faults:

Abnormal DC bus power supply: Check the LED on the DC Bus Supply panel. If the bus voltage is too low, check the input power supply, fuses, and braking resistors.

Overheating of power module: Check if the fan is running and if the ambient temperature exceeds 50 ° C.

IGBT fault: Report "overcurrent" or "ground fault". Measure the resistance of the power module output terminal to the DC bus using a multimeter to determine if the IGBT has broken down.

5.2 SA3000 Medium/High Power Drivers

The medium power module (70-240A) adopts IPM intelligent power module with built-in protection and diagnosis. The high-power module (534-1457A) consists of multiple power units connected in parallel, requiring additional attention to current sharing issues.

Troubleshooting of current sharing faults:

Measure the current feedback signal of each parallel unit (through LPI module), and if the deviation exceeds 10%, check whether the gate drive signal is synchronized.

Check whether the PMI output reactor is overheated or damaged.

5.3 1567 PowerMax Medium Voltage Drive

This driver uses a three-level NPC inverter with GTO as the power device. Typical faults:

Liquid cooling system alarm: Check the coolant level, pump pressure, and temperature sensors.

Gate Drive Unit (GDU) malfunction: Fiber optic link or GDU power supply issue.

Neutral point potential deviation: monitored through PMI's MV power technology module, the DC bus capacitor bank needs to be checked.

Software configuration and programming issues

All configuration and programming of the AutoMax DPS system are completed through the AutoMax programming execution software (Windows environment). The most common software malfunctions on site include:

6.1 Driver parameter configuration error

When configuring drive parameters in Rack Configurator, inputting incorrect motor nameplate data (rated voltage, current, speed) or power module model can cause the drive to malfunction.

Solution:

Re enter the drive configuration form and verify the following parameters:

Rated power/current/speed of motor

Current transformer ratio (if any)

Twisted polar logarithm

Power module types (S6, S6R, SA500, etc.)

Download the modified configuration to the UDC module (UDC task needs to be restarted).

6.2 UDC task cannot be compiled or run

UDC tasks are written in Control Block language and are limited by predefined block sets. Common compilation errors:

Undefined predefined variables: Each UDC task must contain predefined variables specific to the driver type (such as gain data, spin calibration data). Refer to the template in the software manual (SKELETON. UDC).

Improper scanning time setting: When using the SCAN_LOOP statement, the scanning period (tick count x tick rate) must match the feedback period of PMI. The UDC fixed tick rate is 0.5ms.

Debugging skills:

Monitor the variable values of UDC tasks online in AutoMax Executive and observe the updates of dual port registers.

Check the SPI% register (2001), which determines the relationship between the number of UDC task scans and dual port memory updates and interrupt triggering.

6.3 Operating system loading failure

When the UDC module or PMI's operating system is damaged, it needs to be reloaded. Steps:

Ensure that the corresponding DPS software product (such as 57C653 SA3000 DPS software) has been purchased.

Use the "Load OS" function of the programming execution software to select the correct operating system file (. HEX).

Do not turn off the power during the loading process. After completion, the UDC module will automatically download the operating system to PMI.

Note: If PMI powers on before UDC, PMI will continue to request the operating system until UDC responds. Therefore, the rack should be powered on first, and then the PMI rack should be powered on.

Typical Fault Case Analysis

Case 1: SA3000 Drive Jumps "Communication Fault" During Startup

Phenomenon: After pressing the start button, the motor micro rotates and immediately stops, the UDC panel COMM A LED flashes red, and the PMI processor LED "COMM" goes out.

Troubleshooting process:

Measure the optical power at the receiving end of the fiber optic link: -28dBm (sensitivity below -25dBm).

Check the fiber optic cable routing: It was found that a section of fiber optic cable was pressed under the cable tray, with a bending radius of about 2cm.

Repay the fiber optic cable and restore the optical power to -18dBm after bending with a radius greater than 5cm.

Restart the system and restore normal communication.

Conclusion: Macrobending leads to excessive attenuation of optical power, resulting in loss of bit synchronization.