Transient Earth Voltage (Tev); Capacitive Coupler Sensor; Specification - Baur PD-SGS User Manual

Trans ient E arth V oltage (T E V )
5 T
RANSIENT
Partial discharge activity inside a metal-clad high-voltage plant induces small voltage
impulses called Transient Earth Voltages on the surface of the metal cladding. These TEVs
travel around the cladding surface to the outside of the gear where they can be picked up
using capacitively coupled transducers.
The TEV signals emerge at the joins between the metal panels and it is at these points that
the highest readings are generally detected.
Figure: PD pulse propagation in AIS panels
5.1

Capacitive Coupler sensor

The built-in Capacitive Coupler sensor detects TEVs as they pass over the cladding of the
high-voltage plant. The very fast transient signals are detected by the PD-SGS and their
magnitude is measured and displayed.
5.2

Specification

Specification
Sensor
Measurement range
Frequency range
Resolution
Accuracy
16 / 46
E V
ARTH OLTAGE
Capacitive
0 – 80 dBmV
20 MHz – 200 MHz
1 dB
±1 dB
(TEV)
P D-S G S
822-162-1