DiffDi® Common Mode Current Diagnostic System
Why is an engine repeatedly defective? How can you ensure extremely high system availability? How can you prevent engine bearing damage in hard-to-reach locations?
Questions that many machine manufacturers and service companies have probably asked themselves more than once. Cause-oriented measures are required, especially when circumstances are challenging. Using the DiffDi® diagnostic system, it is possible to record, analyze and evaluate high-frequency common mode currents and their effects on inverter-driven motors quickly and easily.
After a short menu-guided software and device driver installation under Windows, the currents in the kHz to MHz range are recorded on the motor side via the measuring device. The application is simple: you place the Rogowski measuring coil around the three motor phases – it is not necessary to separate the current path.
In the first step of the measurement, the actual state of the machine is recorded. The software DiffDi-Soft, which was specially developed for this purpose, enables snapshots of the high-frequency currents present in the drive system. Peak values can be analyzed, evaluated and documented. The selection of e.g. a motor filter for step two is based on the previously obtained data.
After installing the filter measure, step one is repeated and the effect of the method is confirmed by the measurement.
In the last step, the recorded measurements 1 and 2 can be compared with each other at the push of a button. This allows the recorded periods to be compared and evaluated. A before and after view of the measured values provides important information about the effectiveness of the EMC/filter measures taken, such as reducing the common mode currents.