Electromagnetic Core Imperfection Detection (ELCID) Testing

ELCID Testing of Core Imperfections in Generators using Rover Robots

Generators are crucial components in an industrial power plant and are designed to operate reliably for many years. One of the most expensive parts of a 3-phase generator is the stator, which is where the energy from the magnetic field is converted into electrical energy. The condition of the generator and its core deteriorates over time, increasing the likelihood of failures. Quantitative testing and periodic inspections of the generator core are necessary to avoid unplanned outages. ARGIS enables inspections to be carried out not only when the rotor has been removed, but also with the rotor still in place, thus saving you time, effort and money.


A chain containing motor drives and a docking station for the Generator Inspection Vehicle (GIV) is mounted around one of the retaining rings of the generator. The chain is positioned accurately in front of each slot so that the GIV can be inserted into a gap as small as 17 mm (0.67 inch) and up. The GIV then moves to the other end of the stator core and back in order to perform the LFCT, Wedge tightness test and visual inspections all in the same run to save time.
Low flux leakage test
Electromagnetic core flux leakage testing (ELCID or equivalent) is a standard feature. The step irons are measured with a separate module.
Wedge tightness testing
The GIV is provided with a stator wedge tap tester that
determines the wedge tightness based on spectral analysis of the sound response.
Visual testing
The GIV is equipped with 4 camera modules: a forward-viewing camera is used for general inspection of the stator teeth and wedges, another camera inspects the rotor body and cooling slots, and 2 further cameras inspect the stator cooling slots.