Partial discharges in electrical machines

The partial discharge testing technique is used on large electrical machines to assess the condition of the stator while the machine is in operation.

The partial discharge technique has been known for more than 30 years and is gradually becoming the most widely used method for testing medium-voltage insulation systems, as it is the only technique that allows for the evaluation of the insulation of a rotating machine while it is in operation. Measuring equipment, which was initially analog, has also undergone a revolution to become compatible with all electrical equipment applications (motors and alternators, cables, switches, etc.), providing the following information:

Monitoring parameters:

• Apparent discharge (pC)
• Leakage Current (nA)

Diagnostic Charts:

• PDA (Pulse Amplitude Distribution)
• PRPD (Pulse Distribution by Amplitude and Phase, or “fingerprint”)

Contact one of our engineers specializing in predictive maintenance for advice on how to implement predictive maintenance based on partial discharge for large electrical machines: info@preditec.com