i-LinkBox actually refers to “Intelligent’’ Link Box, which is a new development of a standard link box with the ability of collecting online intelligence on proper performance of the Link Box in-self, and more important on Partial Discharge (PD) occurrence in solid insulating layer of the High Voltage (HV) Power transmission Cable system, which the Link Box is an integral part of the cable system, also to transmit the same intelligence to a command center in charge of monitoring the operation of a HV Underground (buried) Power Cable System.

i-LinkBox is mechanically and electrically connected to the SHEATH Layer built in cable construction, running parallel to Insulation Layer. So there was a good chance to detect the same undesirable, damaging cable fault. The sheath of a single conductor of a HV cable for a AC Power transmission acts as a secondary of a transformer, the current in the conductor induces a voltage in the SHEATH. So any surges of high frequency impulses (avalanche of electrons) in the insulation will be transmitted to copper of Sheath material, acting as a secondary of the transformer.

The same effect of high frequency current impulses will be transmitted to the Bonding Cables leading in to Link Box and mechanically, and electrical fastened to the Linking copper construction. A high frequency current transformer placed around the Bonding Cable inside the Link Box should detect the occurrence of PD inside or around the insulation (XLPE) layer of the power cable. EM R&D Dept. develop a PD Sensor, which is basically a high frequency transformer capable of detecting PD induced transient currents in a HV Power Transmission Cable System.

If the PD signal is wanted to be researched with the PD testing devices, i-LinkBox has terminal to reach out the PD sensors. This interface provide an easy access to the user without disassemble the link box.

The main control unit is gathering all the data from the sensors and then sends them to the scada system via GSM or F/O network. It is possible to set an alert level for all kinds of data. When the alert level is reached the desired level, the main control unit will send a SMS or an E-mail to registired address.

This was the inception point of Intelligent i-LinkBox. The detected transit current pulses are converted into voltages can be recorded for monitoring purposes. Surely, the process of converting detected electrical signals to useful information requires Signal Conditioning. Signal Conditioning refers to the elimination unwanted ‘noise’ from the basic signal, which requires specialized circuits. Such circuits are primarily ‘analog to digital (A/D) converters’ and their associated filters.

In addition to detection of PD, and conversion to useful / meaningful information, a complete range of information related to Link Box operational conditions are also generated by embedding highly sensitive Sensors / transducers in the Link Box. Such additional information are as following;

1. Sheath Bonding System and SVL functioning failures can be detected by measurements of circulating AC current and induced voltages.
2. Link Box operational conditions by detecting, Internal are failures can be detected by pressure sensor.
3. Temperature & Humidity sensor for evaluation condensation issues or other abnormal conditions.
4. A Water sensing sensor for detecting water penetration / entering into the Link Box.
5. A switch embedded in the lid of Link Box to show the open / close status of the eid.

i-LinkBox can easily be classified as a ‘smart’ product for its capability of collecting intelligence and also to transmit the collected intelligence in a very informative format. When analyzed serves a very useful information of alerting for corrective action of servicing and maintenance.

Thus prevent costly repair and interruption of electrical power transmission to residential areas and industrial zones. Also a loss of revenue of sales, which is a big financial matter.

EMELEC, a well established Link Box supplier, exporting to so many different countries offers such a smart product; Intelligent Link Box (i-LinkBox). In addition to PD detection, it offers additional information related to Link Box performance, which is a reflection of how well is the performance of the cable system itself. A well functioning Link Box is a reliable, trustworthy source of accurate PD detection.

EMELEC Designed System is also financially more attractive, and easy to install, and to operate compared to current ‘Sophisticated Systems’ in the market.