Full control in the underground cable network

Unplanned out­ages of long under­ground cable routes cause a lot of effort and high costs for net­work oper­a­tors. HIGHVOLT now offers an ear­ly warn­ing sys­tem.

Unplanned outages of long underground cable routes result in a great deal of effort and high costs for network operators. How nice it would be to have a system that closely monitors the cable routes and provides recommendations for action to reduce these costs. HIGHVOLT has a solution for this that can also be retrofitted.

The ener­gy tran­si­tion can only suc­ceed with high­er trans­mis­sion capac­i­ties. But com­mu­ni­ties and res­i­dents often oppose the erec­tion of high-volt­age pylons in their neigh­bor­hoods, and peti­tions, polit­i­cal con­flicts and long law­suits are often the result. To avoid this has­sle, net­work oper­a­tors like to use kilo­me­ter-long under­ground cables, but then get them­selves into oth­er trou­ble because lay­ing, repair­ing and replac­ing these cables is many times more expen­sive than with over­head lines. A mon­i­tor­ing sys­tem for detect­ing cable faults and eval­u­at­ing par­tial dis­charges would sig­nif­i­cant­ly reduce the cost of repairs, cut pos­si­ble down­times and allow net­work oper­a­tors to sleep more sound­ly again.

160 km under control

For­tu­nate­ly, there is now such a mon­i­tor­ing system—HiMON® from HIGHVOLT—which uses two types of sen­sors to record mea­sured val­ues: the HiMAG® Red and HiMAG® Blue high-fre­quen­cy cur­rent trans­form­ers. Matthias Kap­pler, HiMON® project man­ag­er, explains: “HiMAG® Red is respon­si­ble for detect­ing the trav­el­ing waves—also known as tran­sients — caused by cable break­downs in order to deter­mine the point of ori­gin.” For this pur­pose, a HiMAG® Red sen­sor with an asso­ci­at­ed HiRES® Loca­tor event recorder is placed at the begin­ning and end of each cable sec­tion. HiMAG® Blue, on the oth­er hand, is installed along the cable route at the ground­ing sleeves at dis­tances of up to twelve kilo­me­ters. “The HiMAG® Blue sen­sors detect micro­scop­ic puls­es that occur at pos­si­ble fault loca­tions in the cable insu­la­tion,” adds Dan Keller, Util­i­ty Busi­ness Sales Man­ag­er at HIGHVOLT.

“The sys­tem can record very pre­cise­ly where and in what inten­si­ty par­tial dis­charges occur. From this, clear rec­om­men­da­tions for action can be derived.” Dan Keller, Sales Man­ag­er Util­i­ty Busi­ness at HIGHVOLT

Detect­ing par­tial dis­charges in long under­ground cable runs is very cost­ly using tra­di­tion­al means. “The dis­ad­van­tage of sys­tems based on the tra­di­tion­al­ly pre­vail­ing par­tial dis­charge (PD) mea­sure­ment method­ol­o­gy is that they require a sen­sor at each joint,” says Keller. In the past, the high asso­ci­at­ed instal­la­tion costs often led cable oper­a­tors to choose to use only acoustic-sig­nal-sens­ing or tem­per­a­ture-sens­ing sys­tems using fiber optic cables. How­ev­er, this leaves cer­tain dam­age to the cable insu­la­tion unde­tect­ed.

HiMON® opti­mal­ly sup­ple­ments the fiber-optic-based sys­tems already in use with a sys­tem for detect­ing elec­tri­cal par­tial dis­charge sig­nals. The TruePD method­ol­o­gy devel­oped for this pur­pose sig­nif­i­cant­ly reduces instal­la­tion efforts because the mea­sur­ing points are only installed at the ground­ing sleeves at dis­tances of up to twelve kilo­me­ters. HiMON® thus saves a lot of mate­r­i­al and mon­ey. In addi­tion, for the first time, HiMON® also allows the cable sec­tions between the mea­sur­ing points to be mon­i­tored with cen­time­ter-exact accu­ra­cy. Alter­na­tive PD measur­ing sys­tems can usu­al­ly only mon­i­tor the joints.


Easy to install

The HiMON® mon­i­tor­ing sys­tem is also eas­i­er to install and retro­fit due to the low num­ber of mea­sur­ing points and the new­ly devel­oped design. Matthias Kap­pler explains, “Unlike con­ven­tion­al sys­tems, the HiMAG® sen­sors can also be retro­fit­ted to already installed cable sys­tems thanks to their sep­a­ra­ble core design.”

The coun­ter­parts for the HiMAG® Red or Blue sen­sors are locat­ed at the con­vert­er sta­tion or sub­sta­tion.
The ground­ing box con­tains the event recorder and data col­lec­tor.
HiMAG® Blue sen­sors mea­sure small sig­nals such as par­tial dis­charges < 10 V.

Action recommendations

Part of the ener­gy tran­si­tion is also the dig­i­ti­za­tion of exist­ing infra­struc­tures to improve con­di­tion monitor­ing and main­te­nance. The mea­sure­ment sig­nals cap­tured by the HiMON® sen­sors are dig­i­tized by the asso­ci­at­ed HiRES® TruePD event recorder and this data is then sent to a spe­cial­ly secured cloud where it is ana­lyzed by intel­li­gent algo­rithms. “The cable net­work oper­a­tor then receives infor­ma­tion about the con­di­tion of the cable route includ­ing visu­al infor­ma­tion in the form of traf­fic lights,” says Kap­pler. If the traf­fic light turns red, HiMON® shows fur­ther details about the prob­lem such as which cable com­po­nent is affect­ed, or the inten­si­ty of the par­tial dis­charges. “The sys­tem can record very pre­cise­ly where and in what inten­si­ty par­tial dis­charges occur, from which clear rec­om­men­da­tions for action can be derived,” Keller explains. This is impor­tant infor­ma­tion for cable net­work oper­a­tors in order to repair pos­si­ble defects dur­ing planned cable main­te­nance. This is easy on the wal­let and ensures secure net­works.


Do you have any ques­tions about the project?
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