HVPD Longshot™ Diagnostic PD Spot Tester

HVPD Longshot™

Product Overview

The HVPD Longshot™ PD Diagnostic Spot Tester is a 4-channel, synchronous wideband (0-400MHz) on-line partial discharge (PD) test and monitor technology suitable for the PD testing of all types of medium voltage (MV) and high voltage (HV) cables and plant (up to 500kV).

On-line PD Testing Of:

• MV/HV PILC/XLPE Cables, Joints, Terminations and Sealing Ends
• MV/HV Current and Voltage Instrument Transformers (CT and VT)
• MV Metal-Clad Switchgear (Air and Solid Insulated)
• Motors and Generators

The HVPD Longshot™ 4-Channel Diagnostic PD Tester has been the core technology of the company for over 6 years where it has been used to carry out both on-line (in-service) and off-line (on commissioning or after repair) PD tests on cables of voltages up to 500kV. The synchronous, multi-channel data acquisition on all four channels of Longshot™ test unit (to within 2ns of each other) and combined with the unit's PDGold© software (containing three unique software solutions, 'wavelet denoising', knowledge-based PD pulse shape 'event recognition' and 'precedence' detection) provides the basis by which on-line PD tests can be carried out on in-service high voltage plant, even in the harshest of environments such as with outdoor HV cable sealing ends.

The HVPD Longshot™ test unit can now be regarded as a universal and versatile on-line PD test unit for testing of 3-phase MV and HV systems, further to the successful application of the unit testing a wide range of plant over the past 6 years. In-service MV and HV plant which has been tested to date with the Longshot™ technology includes cables, switchgear, transformers, motors/generators, CT's/VT's and other HV plant.

The HVPD-Longshot™ unit is a portable, lightweight, 4-channel synchronous PD test device which can be used as both a PD 'spot tester' and short-term PD monitor. The primary usage of the unit is to perform short duration, on-line diagnostic PD 'spot tests' (typically of 5-10 minutes) and the system can be used in this capacity in Phase 2 of the HVPD 4-Phase PD Test and Monitoring Solution.

The Longshot™ unit's on-line PD 'spot test' process is now fully automated with HVPD's easy-to-use PDGold©v5.0 data acquisition software. Data collected by the unit in the field is saved onto the unit's 30GB hard drive and this can be downloaded using the 160GB USB portable hard drive supplied with the unit. Post-processing and analysis of the test data files acquired using PDGold© acquisition software is carried out by the PDReader©v5.0 data analysis software which is installed on the unit for immediate viewing in the field and also provided as a free-issue reader onto the customer's PC or laptop for post-analysis in the office.

Multi-Channel, Synchronous On-line PD Detection

Multi-Channel, Synchronous, High Resolution Data Acquisition -This is made possible by virtue of a combination the unit's synchronous, 4-channel data capture capability , PDGold©'s three unique software modules and the high data acquisition rates of between 100 and 500 MS/s.

HVPD have successfully used the Longshot™ technology's synchronous data capture capability (to within less than 2ns across the 4-Channels) to carry out on-line PD tests on both MV and HV cables the entire installed cable system (cable, joints and terminations) can be assessed on-line, under normal working conditions, with no need to de-energize or to take the cable out of service.

HVPD have developed three unique software solutions to solve both of these issues which utilize a combination of three software algorithms ('wavelet denoising', knowledge-based PD pulse shape 'event recognition' and 'precedence' detection). All three of these algorithms are used in the PDGold© software for the HVPD-Longshot™ unit.

By detecting and storing the signals at this high resolution it is then possible for the PDReader© software to automatically analyse the pulses based on frequency and PD waveshape analysis. It should be noted that the highest sampling rate is not always required and generally a sampling rate of 100MS/s (2MPts) is acceptable for testing cables and 250MS/s (5MPts) for testing metal-clad switchgear and other 'local' plant.

Features Include

• PD signals captured synchronously (within 2ns) on all 4x channels with 'Precedence Detection' software to differentiate local and external signals based on time-of-arrival measurements.
• Automatic "Event Recognition" of PD pulses with automatic noise pulse rejection
• Typical 'spot-test' time of 5 to 10 minutes per plant item or cable
• Short-term PD monitoring possible, typically 1-24 hours and up to 1 week
• On-line cable PD measurements can be made in picoCoulombs (pC) when used in conjunction with HVPD's calibrated HFCT sensors (no need for external pC calibrator)
• Software-based RF noise reduction filter
• Also suitable for off-line testing at 50/60 Hz

PDReader© Features:

• Post data collection analysis of PD test files
• May be installed on any Windows 2000/XP PC - Test in the field, analyse in the office
• PDF and MS WORD report output

Additional Software Options

• PDMap©: On-line PD location on cables of up to 5km
• ScopeControl©: Waveform capture package for advanced PD signal analysis

The HVPD Longshot™ is supplied with all the sensors and equipment necessary to make partial discharge measurements on an MV or HV cable network.

Standard Scope of Supply to Include:

1x HVPD Longshot™ PD Diagnostic Spot Tester
3x HVPD HFCT100/50 3x HVPD HFCT140/100 Portable Split-core HFCT Sensors
4x HVPD CC-SG1 TEV Sensors
Ultrasonic PD Probe Amplifier
10m BNC Cables
1x Soft Carry Case

Training and Support

• 3 day site training course at customer's site recommended
• Free software upgrades and off-site support via email for one year from date of purchase
• Further training, support and software upgrade packages available

Further Information

• Download HVPD Longshot™ Summary Guide here.
• Read about other HVPD Products.
• For further information, including applications advice, please contact us.