Power Diagnostix provides a complete line of modular preamplifiers for various testing applications. The most significant difference among the preamplifiers is the frequency range in which they detect partial discharge signals. Other features that distinguish one preamplifier from another are: options for transparency and on/off switching, unipolar vs. bipolar charge detection, and the possibiltiy of galvanic isolation in the test setup.

When a quadrupole and a coupling capacitor are used together as the coupling device, high voltage is applied both to a test object and to the coupling capacitor in parallel with the test object. A quadrupole (sometimes called a measuring impedance) can then be placed in series with either the coupling capacitor or in series with the test object. Some quadrupoles also output a low-voltage copy of the applied high-voltage wave for synchronizing the PD detector. The three basic models of available Power Diagnostix quadrupoles are briefly described here.

Analyzing the discharge activity requires the permanent installation of coupling devices. Preferably, such coupling devices are capacitive couplers terminated by a power separation filter.

Acoustic Sensors AS75I and AS150I 

The AS75I and AS150I are active sensors with very high sensitivity for measurements on GIS, transformer tanks, or cable joints. They come with a built-in 40 dB preamplifier and can be connected to the RPA1D, RPA1F, RPA1G, or directly to the AIAcompact, ICMsystem, ICMcompact, or ICMmonitor.

Valve Sensor TVS2 & Flange Sensor TFS1 

UHF transformer sensors can be used to detect internal PD on power transformers in a frequency range between 300 MHz and 1 GHz. The UHF frequency range can be chosen under difficult on-site conditions, such as high impact of the measurements due to corona discharges or other disturbances within the typical HF range (100 kHz to 10 MHz).

Window Sensor WS80 / 95 / 140 

External window sensors are used to conveniently equip older GIS with UHF monitoring.

External Flange Sensor EFS1 

The external flange sensor EFS1 is a wide-band UHF antenna for PD detection on GIS and GIL.

Differential Foil Sensor DFS1

Besides the embedded coaxial sensor of cable accessories, external sensors can be applied to joints and terminations. Especially on cross-bonding joints differential foil sensors serve to capture partial discharge signals in elevated frequencies. Such foil sensors can be permanently installed for monitoring or temporary applied for survey type measurements.

Data Sheet

Partial Discharge Monitoring on Power Cables

The main task of the partial discharge monitoring system type ICMmonitor CA is to detect internal partial discharge in power cables caused by cracks in joints and terminations or degradation in the insulation system at an early stage. PD signals are picked up by a current transformer and preprocessed by an FCU3. A monitoring control rack (PDMCR) with ICMmonitor CA software installed receives the measured data from the monitoring units and processes it.

Partial Discharge Monitoring Device

The ICMmonitor Portable is part of the Power Diagnostix ICM series of digital partial discharge detectors. It is a compact, stand-alone instrument for evaluating the condition of medium and high voltage insulation. A built-in four-, or eightchannel multiplexer offers scanning of three-phase systems or multiple sensors. It is used principally for permanent, continuous on-line monitoring of rotating machines, cable systems, power transformers, and gas-insulated switch gear (GIS).

Partial Discharge Monitoring on GIS systems

The GISmonitor Portable is a portable unit for partial discharge measurements on gas-insulated switchgear (GIS) caused by hopping particles, floating potentials, cracks in insulators or spacers, or other degradation in the insulation system. The instrument offers parallel real time PD acquisition on up to 40 channels. To eliminate disturbance signals from the measurement, the instrument can be connected to a disturbance antenna that provides a gating signal.

Partial Discharge Monitoring on GIS Systems

The GISmonitor builds on 20 years experience in online PD monitoring on rotating machines, transformers, cables, and especially GIS systems. It combines proven technology of the ICMmonitor with new processor technology and embedded hardware capabilities. The hardware core of the system has been optimized for parallel, real time PD acquisition on multiple channels. Any UHF signal can be detected and digitized within micro seconds.

Partial Discharge and Tan Delta Measurement System

The ICMflex high voltage instrument family offers inherent operator safety and greatly simplifies distribution class cable testing and other field tasks involving partial discharge detection, loss factor (tanδ) measurements, and PD fault location. It has been designed to simplify the application and to combine different measurement tasks with one instrument.

Partial Discharge Measurement Device

The AIAcompact is a portable unit for in-service acoustic and electric (UHF) partial discharge measurements on gas-insulated switchgear (GIS), transformers, and cable accessories. The instrument is fitted with a battery pack for independent operation up to 3 hours and adapts to a variety of piezo-electric acoustic sensors and is supplied with a versatile sensor fixture. Additionally, the AIAcompact allows partial discharge measurements on external UHF sensors.

Digital Partial Discharge Detector

The ICMcompact is part of the ICM series of digital partial discharge detectors. The ICMcompact is a compact, stand-alone instrument for evaluating the condition of medium and high voltage insulation. It is often used in quality assurance and quality control tests in manufacturing.

Advanced Partial Discharge Detector

The multi-channel version of the ICMsystem is specifically designed to meet the requirements of partial discharge acceptance tests on large power transformers.