A method and system for detecting defects in a wire (100) or wire bundle (200) includes a pair of sensors (150) wrapped around the wire or bundle, a data acquisition device (310) for monitoring pulses in the signal produced by the sensors around the wires, and a diagnostics engine (320). The diagnostics engine includes an analysis module (450) to determine features of the signals captured by the data acquisition device and a decision module (470) for determining whether the pulse represents a defect in the wire and the location of the defect. The system operates passively and can be used to monitor the wires while they are in use for carrying signals or current and does not require disconnecting the wires to be monitored.

Method and system for passively detecting and locating wire harness defects

A system and device for detecting insulation defects in a cable are provided. The system and device include using signals received from sensors to detect a partial discharge caused by insulation defects in a cable. The system is passive, without signals being injected into system cables, and may use one or more sensors, data acquisition systems, gateway devices, and monitoring stations and is based on detecting partial discharge from insulation defects and reporting the detection when it occurs.

System and device for detecting defects in underground cables

A method for detecting, identifying and locating partial discharges occurring in a discharge site along an electric apparatus comprises the following steps: detecting (1) electrical signals in a detection station; attributing (2) to each detected signal a value of a phase parameter; deriving (3) for each signal at least one shape parameter and one amplitude parameter; separating (4) the set of signals detected into sub¬ sets that are homogeneous relative to the shape parameter; identifying (5) sub-sets related to partial discharges and cataloguing them; repeating the above steps in a plurality of detection stations positioned along the apparatus; correlating (7) the sub-sets of signals detected in different detection stations and catalogued similarly; selecting (8) as a function of the amplitude and shape parameters of a sub-set among the correlated ones and locating (9) the partial discharges related to said sub-sets at the detection station of the selected sub-set. Known methods have poor effectiveness and/or reliability, especially for cables whose length exceeds 1-2 km or, alternatively, they require an excessively complex and costly field implementation.

A method for detecting, identifying and locating partial discharges occurring in a discharge site along an electric apparatus

A partial discharge acquisition system (500) comprising: - a synchronization signal sensor device (200) comprising: a sensor module (202) structured to remotely detect a first synchronization electromagnetic signal (S ES1 ) generated by an alternate current electrical voltage associated with the operation of an electrical object (101) and provide a corresponding first detected electrical signal (S syn1 ); a transmitting device (203, 204) structured to irradiate a second synchronization electromagnetic signal (SEs2) related with said first detected electrical signal (S syn1 ); - a partial discharge detection apparatus (400) comprising: a receiving device (700) structured to receive said second synchronization electromagnetic signal (S ES2 ) and generate a corresponding received electrical signal (S synw3 ) representing at least a timing parameter of said alternate current electrical voltage; the receiving device (700) and the transmitting device (203, 204) being configured to establish a wireless communication link defining a deterministic transmission delay.

Partial discharge detection system and method with synchronization

A data acquisition system is provided that in one example comprises a sensor electrically coupled to a data acquisition unit via a signal splitter. In use, the sensor senses one or more signals transmitted over a “live” power cable carrying, for example, 50 Hz or 60 Hz, medium voltage power. The one or more signals are then transmitted to the data acquisition unit to be stored, displayed, and/or analyzed. The data acquisition system includes a synchronizer that allows the data acquisition unit to synchronize the storage of the sensed signals to the frequency of the power transmitted over the tested power cable or system. In one embodiment, the synchronizer provides an accurate phase angle reference or trigger signal for accurate phase resolved data acquisition and testing.

Synchronizer for a data acquisition system

In order to detect, localize and interpret a partial discharge occurring in a partial discharge site along an electrical equipment, two measurement probes and a synchronization probe are installed along the electrical equipment. The measurement probes detect pulses travelling in the electrical equipment while the synchronization probe detects a phase angle in the electrical equipment and is usable for calibration purposes. A control unit receives the signals sensed by the probes and conditions them. Digital processings applied on the conditioned signals, involving their correlation, a time-frequency distribution and a form factor estimation, allows establishing a diagnosis indicating a detection of a partial discharge and its localization along the electrical equipment.

Detection, localization and interpretation of partial discharge

Most of power failures occur at cable joints in Hydro-Quebec underground conduit network. Some are due to partial discharges inside these joints and the corresponding degradation of their electrical insulation. Hydro-Quebec Distribution conduit network consist mainly of XLPE cable with rubber premoulded accessories. In 2001, Hydro-Quebec started a research project for the diagnosis of underground cable and their accessories. This project was implemented for safety issues, to perform predictive maintenance and to withdraw defective accessories before failure.

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Detection, localization and interpretation of partial discharge in the underground distribution network at Hydro-Québec

Afin de detecter, localiser et interpreter une decharge partielle susceptibl e de survenir dans un site de decharge partielle le long d'un equipement electrique, deux sondes de mesure et une sonde de synchronisation sont installees le long de l'equipement electrique. Les sondes de mesure detectent des impulsions voyageant dans l'equipement electrique alors que la sonde de synchronisation detecte un ang le de phase dans l'equipement electrique et peut servir a des fins de calibration. Une unite de controle recoit les signaux captes par les sondes et les conditionne. Des traitements numeriques faits sur les signaux conditionnes, dont leur correlation, une distribution temps-frequence et une estimation de facteur de forme, permette nt d'etablir un diagnostic indiquant une detection d'une decharge partielle et sa localisation le long de l'equipement electrique.

Yvan Roy

Papers

Detection, localization and interpretation of partial discharge

Detection, localization and interpretation of partial discharge in the underground distribution network at Hydro-Québec

Detection, localisation et interpretation d'une decharge partielle

Detektion, lokalisierung und interpretation einer teilweisen entladung