A winding in an electric motor or generator is the heart of the installation and correct operation is crucial. We take measurements to be able to guarantee the reliability and availability of the machine.
Condition of the winding
Besides mechanical monitoring by means of vibration measurements, Van Meer can also establish the electrical condition of your electric motors and generators.
Mobile surge test equipment for Low Voltage electric motors
The mobile surge tester generates a high voltage pulse over both motor windings. The pulse waves are displayed on an oscilloscope and should be exactly the same. This is the case when only one wave is visible; the waves are then exactly on top of each other. If two waves can be observed of a different of shape and size, this means there is a fault in one of the sections measured. A surge test increases the dependability of the machine, which in combination with a vibration measurement also increases the general reliability of the equipment.
The analysis of these measurement can identify machine faults including:
- Damage to the winding
- Damage to the lamination core
Mobile HV equipment for High Voltage electric motors
The Life Expectancy Analysis Program (LEAP) is a diagnosis tool to assess the insulation condition of the stator windings in medium and high voltage electrical machinery. LEAP on the one hand provides information about the condition and the expected working life of the stator winding, while optimising the planning of maintenance on the machine. Combining LEAP with time estimates for carrying out repairs and the replacement of parts means it is possible to have maintenance take place during a planned machine stoppage, and expensive emergency repairs can be avoided.
LEAP goes further than traditional performance monitoring programmes for medium and high voltage rotating machines. LEAP analyses the test results and provides detailed information on the remaining working life of the stator winding.
These measurements can be taken on location and comprise the following:
Direct current measurements
Polarisation and depolarisation current analysis (PDCA). Besides information about current loss and absorption current, the PDCA test shows:
- An indication of the quantity of charge storage in the machine and its location.
- A picture of soiling, even when the IW and PI values are ‘acceptable’.
- A correct picture of the condition of the winding insulation (e.g. ageing, looseness).
Alternating current measurements
A non-linear behaviour analysis, tangent and capacity analysis and partial discharge analysis confirm the results of the direct current measurements.
- Evaluation of the condition of the corona shield
- Identification of the degree of delamination or the pore volume in terms of the percentual airflow discharge volume in relation to the insulation volume
- Assessment of the condition of the stress classification system at the stator slots
- Indication of ageing effects