PD SERVICES

On-site On and Offline Measurements

Condition based maintenance of high voltage equipment becomes more and more important as aging of insulation materials is an ongoing process that should be controlled to prevent unexpected breakdowns. Partial discharge analysis is one of the most meaningful diagnostic tools to determine the condition of insulation systems.

 

Offline tests require the following preconditions:
  • The system has to be taken out of service for the duration of the measurements
  • An adequat power source is available to perform single- or three-phase tests according to the testing program
  • PD sensors or couplers can be installed temporarily
Online measurements:
  • PD sensors or couplers are already installed or special sensors like HF current transformers or antennas can be mounted during online operation
  • Access to the HV equipment under operation is approved

Our team of experienced service engineers is prepared to assist you with any testing situation

For off-line testing, we are equipped with two mobile test systems and portable equipment (see above).

With the large test set, a 2MVA converter based system, we can offer both induced (up to 90 kV) and applied voltage testing (up to 500 kV). The test system is self-contained for on-site tests requiring up to 100 kVA by using a generator mounted to the auxiliary tap axle. When more input power is needed, the test system can be supplied by diesel generator.

The medium voltage test system comes with a 100 kV/11 kVA AC dielectric for testing dry type transformers, medium voltage switchgear or short cable jumpers, for instance. In case of larger capacitive loads, the van can be extended with a trailer, providing a 500 kVA/50 kV resonant test system. Similar to the large test set, this system is also self-contained for power requirements up to 16 kVA. As alternative for the power frequency sources, several portable very low frequency (VLF) sources are available as well for on-site testing of medium voltage equipment up to 60 kV

PDIX offers the following on-site services

  • Partial discharge (PD) measurements
  • PD fault analysis by PD pattern recognition and interpretation
  • Loss factor (TD) measurements
  • Spectrum analysis
  • Time domain analysis
  • Acoustic PD location
  • Dielectric tests such as
    - Transformer ratio tests
    - Winding resistance measurements
    - Insulation resistance measurements
    - Polarization index measurements
    - Phase displacement measurements
    - Hi-pot testing
    - Step voltage tests
    - Dielectric absorption and re-absorption measurements
  • Three-phase induced tests up to 90 kV AC
  • Applied voltage tests up to 500 kV A