Further Information about PD-Diagnostics:
 PD-Diagnostics on Medium Voltage Cables with OWTS
 5th Volta Colloquium on PD ...
The oscillating wave test system OWTS is used to identify, evaluate and locate partial discharge (PD) faults in a cable insulation and in joints and terminations. The system can be used for of all types of medium voltage cables. Detailed information of the operational reliability of a cable system can be determined.
The test system can be installed either in a cable test van in combination with a modern, centrally controlled cable test and fault location system (e. g. Compact PD in a 3.5 t vehicle), or can be used as a stand-alone unit.
The cable under test is charged up in a few seconds to a pre selected peak value with a DC voltage. By closing the electronic switch the short circuit of the cable capacitance with the resonant coil leads to a sinusoidal oscillating wave test voltage. Depending on the capacitance of the test object, the oscillating frequency is fixed in a range of 50 Hz up to several 100 Hz.
The voltage level and the test frequency for the cable segment are close to the nominal service conditions, thus all measured PD activities can be effectively evaluated.
The oscillating voltage is only in contact with the test object for a few 100 ms and therefore nearly all long-term influences can be neglected.
Analysing the decrease of the test voltage, the PD extinction voltage can be determined easily. As a result, critical PD levels responsible for the future status of the cable insulation can be evaluated.
The OWTS unit is controlled by an industrial PC with an integrated data and signal storage ability. The system automatically evaluates the measured PD data and gives the user detailed information of the cable under test.
Features
- PD diagnosis under oscillating wave test voltage - electrical field distribution as in nominal
- service conditions
- PD evaluation possibility and pattern recognition at the nominal voltage level
- Modern industrial PC for system control and user interface
- PD level measurement according to IEC 270 at a bandwidth of 150 ... 650 kHz
- Semi- and fully automatic PD analysing software for defect location with mapping feature
- Calculation of the cable capacitance and the tan delta value of the test object from the characteristic decrease of the voltage wave shape
- Simple to use and easy to handle menu-driven unit for operation of the test sequence
- Compact design; low weight
- Compact PD: combination of OWTS, vlf test unit and the fault location system "Compact System"
Click here for more information about OWTS |
Current exibitions
