Page 6 - PDTrac II - Use data effectively

ON-LINE MONITORING THE EFFICIENT WAY

The What?

The What … Partial Discharge
… because the PD monitoring system uses VHF and time-of-flight to automatically filter out noise and classify
disturbances, then the output of the PDTrac monitor is only the PD detected by each sensor. As such, the DCS can be
configured to trend (doubling over a twelve-month interval) and when compared to the Iris database issue alerts,
warnings, and notifications. Additionally, the polarity of the PD pulses is tracked individually, so whether the source
is polarity predominant and/or correlates with load or temperature can be determined. This makes it possible to

400
High 217-360mV
350
300
Peak Magnitude (mV) 200 C1 Qm+
250
C1 Qm-
150
Linear (C1 Qm+)
100
Moderate 62-316mV Linear (C1 Qm-)
50
Typical <62mV
0
9/15 10/15 11/15 12/15 1/16 2/16 3/16 4/16 5/16 6/16 7/16 8/16 9/16 10/16
Month/Year

Iris Power provides a solution that separates electrical noise like
partial discharge and other disturbances in the power system
from the asset partial discharges. In cases where there is 30 m or
more of power cable to the generator, high frequency system
noises that resemble machine partial discharges are attenuated
by the power cable.

The remaining low frequency disturbances from the power system
are eliminated using the Iris Power 80 pF capacitive sensors. The
sensors attenuate all low frequency electrical noises below 40MHz
leaving only the machine partial discharges to be analyzed. Pulse
shape is then automatically analyzed to ensure only machine
partial discharges are presented in the data output. Low
frequency solutions like those using 1000 pF couplers do not block
these frequency ranges.