SOUND DETECT & SOUND DETECT PRO USER MANUAL
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8-6-3 Partial Discharge Settings
8-6-3-1 PRPD Graph
A PRPD pattern is a visual representation of partial discharge (PD) activity
relative to the 360 degrees of an AC cycle and is often critical to understanding
partial discharge in high voltage (HV) insulation systems.
The PRPD plot shows the amplitude of each discharge event (y-axis) plotted
against their phase angle (x-axis). As the primary voltage on a power system
rises and falls over time, the voltage applied across each defect also rises
and falls over time – causing the defect to discharge only at certain times and
amplitudes. This is what creates the PRPD pattern.
Each PRPD pattern will be unique as each discharging defect will be slightly
different to one another as the physical defect will be of a certain type and
certain physical shape. Although each pattern is unique, common trends can be
seen for each defect type.
These defect types include corona, internal void, poor contact, floating metal
work etc. The severity of discharge can also be determined from the PRPD
patterns.
Enable the PRPD pattern graph as follows:
1.
Using the touchscreen, tap the Display Window to open the main menu.
2.
Tap More; then, select Partial Discharge. A window appears and the user
gains access to mode settings.
3.
Toggle the PRPD Graph to the On position by tapping the switch. The switch
turns blue and graph is seen on the Display Window when active. Disable
the settings by tapping the switch again. The switch turns gray and graph
disappears when inactive.
4.
Tap outside window to exit the mode settings window. The main menu
closes automatically due to inactivity.
