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FDS-PDC Dielectric Response Analyzer
DIRANA - Dielectric Response Analyzer
The most important aging indicator of transformers is the water content in the solid part of the insulation (paper, pressboard). An accurate knowledge about the actual moisture concentration is thus required in order to decide if further corrective action, such as on-site drying, is necessary. OMICRON's DIRANA determines the moisture content in oil-paper insulations of power transformers, CT's and VT's, bushings and power cables by analyzing the dielectric response. The patented device combines the high frequency advantages of the FDS (Frequency Domain Spectroscopy) method in the upper frequency range with the test speed advantages of the PDC (Polarization Depolarization Current) method in the lower frequency range.
Features and Benefits
- Dielectric Reponse Analyzer: Combined Polarization and Depolarization Current (PDC) and Frequency Domain Spectroscopy (FDS) method
- Non-intrusive, reliable test of any HV insulations: transformers, bushings, cables and generators
- Two input channels: reduces outage time and measurement effort to an absolute minimum
- Flexible curve representation: PDC results can be displayed either as FDS or PDC curves
- Easy-to-use Software with intuitive user interface: facilitates automatic determination of the water content, even without expert knowledge
- Advanced import function: allows the importation of external PDC or FDS results and their analysis with the DIRANA software
- Built-in processor: makes it possible to run DIRANA even without PC
Applications
- Moisture assessment of any oil-paper-insulation, such as power transformers, current and voltage transformers, insulated cables and OIP bushings.
- Capacitance and dissipation factor measurements of power transformers as well as bushings, cables, generator and motor insulations
- Aging detection for bushings even at ambient temperature
Further Information
How does it work?
DIRANA determines the moisture content of the solid insulation (paper, pressboard) by analyzing the dielectric response. An automated fitting algorithm compares the dielectric response as measured at an oil-paper-insulation to a modelled dielectric response. Two dielectric response measurement techniques have become established: the Polarization and Depolarization Current Measurement (PDC) and the Frequency Domain Spectroscopy (FDS). DIRANA's patented technique combines the advantages of both principles. It acquires data in the frequency domain from 5 kHz to 0.1 Hz and in the time domain from 0.1 Hz to 100 μHz. This reduces the measuring duration by more than 50 % compared to exclusive frequency domain measurements.