The PD Surveyor™

PDSurveyor™ testing AIS for Surface PD	HV Motor PD Testing - TEV & CT	TEV Testing of Solid Insulated Switchgear

• The World's First, handheld, multi-purpose, Partial Discharge (PD) Test Technology.
• Lightweight & Portable device suitable for On-line insulation condition testing of in-service High Voltage (HV) plant.
• Enables first-line PD 'screening' of HV cables, switchgear, motors and transformers.
• Seven-Level PD Magnitude Detector to provide an immediate PD level measurement.
• Unique Technology incorporating 3x Partial Discharge Sensors (Ultrasonic, Acoustic, HFCT - Electromagnetic and TEV-Transient Earth Voltage) into one test unit.

The PDSurveyor™ can be used to test HV Cables, CTs, VTs, Switchgear, Motors and Transformers in the following applications:

• As a Safety and Security Device - To provide an immediate indication to the user the HV Plant in the substation is safe to approach.
• As a First-Line Screening/Diagnostic Device to provide a quantified, colour-coded ' PD scan' of large numbers of HV plant items prior to higher level, PD diagnostic testing. (Refer to OSM-Longshot™ On-line PD Test Technology from IPEC HV.)

The PDSurveyor™ was developed by IPEC HV further to requests from our customers for a simple, portable and easy-to-use partial discharge detector. The unit is intended to be used as a first-line PD 'checker' for HV plant, providing the user with the ability to test the condition of their HV plant in seconds.

PD Level Guidelines

The PDSurveyor™ units simple, 7-level, colour-coded PD level indications (displayed as a range of LEDs from green to red as shown opposite) allows very quick identification of potential insulation defects. Used in this way a large number of HV plant items can be scanned for PD activity in a fraction of the time required by other commercially available systems.

The PDSurveyor™ incorporates three individual partial discharge sensors and corresponding measurement circuits which are designed to pick up variations of PD activity in different types of HV plant, as follows:

• AA - Airborne Acoustic Circuit - Acoustic PD signals are generated by partial discharges into air and are detected using the unit's 40kHz airborne acoustic sensor ('line-of-sight' to pd site required). This sensor is very useful when testing Air Insulated Switchgear.

• CT - Cable PD Circuit - Cable PD is measured using an external, split-core, High Frequency Current Transformer (HFCT) sensor which is clipped around the earth strap of the cable. These pulses are generally in the frequency range of between 200kHz - 4MHz and are typically monopolar in shape. The unit measures the Cable PD pulses in picoCoulombs (pC's) by measuring the charge content (area under the monopolar pulse).
• TEV Circuit - Transient Earth Voltage (TEV) PD signals are generated by internal partial discharges in switchgear, cable terminations, motors and transformers. TEV signals are in a higher frequency range of between 4MHz - 100MHz and are oscillating in general. The unit has a built-in TEV sensor which is placed against the equipment under test to measure these signals. The resultant PD signals are measured in dB (decibels), as is the convention for on-line switchgear testing.

Testing the PD level of 33kV XLPE Cable with a High Frequency Current Transformer

The CT LEDs (top line) show an 'Orange 1' Cable PD Level which equates to 3300pC. The Action here would be to investigate this further by PD testing with the OSM-Longshot™ On-Line PD Spot Tester.