Check & Detect

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Check.

Bushing monitoring

Bush­ings are among the most sen­si­tive com­po­nents in trans­form­ers. Not only do they have to with­stand sev­er­al hun­dred thou­sand volts, they must also be able to sup­port high ther­mal and mechan­i­cal loads. That’s why around 17% of major trans­former fail­ures are attrib­uted to defec­tive bush­ings. Like­wise, such defects are also the main cause of trans­former fires and explo­sions. Nev­er­the­less, these can be avoid­ed with an ear­ly warn­ing sys­tem and time­ly replace­ment. For this pur­pose, Rein­hausen has devel­oped the MSENSE® BM online mon­i­tor­ing sys­tem, with which the con­di­tion of bush­ings can be con­tin­u­ous­ly mon­i­tored. If the sys­tem detects a fault, an alarm is trig­gered, allow­ing the oper­a­tor to inter­vene before a fail­ure occurs.

To do this, the new mon­i­tor­ing sys­tem uses two key met­rics – capac­i­ty and dis­si­pa­tion fac­tor – which pro­vide infor­ma­tion on the con­di­tion of the insu­la­tion. A devi­a­tion of the bush­ing val­ues in one phase (C1 or tan δ ) from the orig­i­nal val­ues indi­cates that the con­di­tion of the insu­la­tion has changed and the user is noti­fied using a two-stage lim­it-val­ue sys­tem (warn­ing and alarm).The process for ana­lyz­ing the mea­sure­ment data is com­plex. An algo­rithm devel­oped by Rein­hausen known as the dou­ble-ref­er­ence method (2/3 ref­er­ence method) elim­i­nates the reliance on net­work imbal­ances and tem­per­a­ture fluc­tu­a­tions and there­fore enables reli­able and unam­bigu­ous con­di­tion assess­ment. Trans­form­ers that are already in oper­a­tion can also be retro­fit­ted with the MSENSE® BM online mon­i­tor­ing sys­tem.

www.reinhausen.com/msensebm

YOUR CONTACT

Want to know more about the new MSENSE® BM sys­tem?
Tobias Gru­ber is here to help:
t.gruber@reinhausen.com

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Detect.

HiRES Locator

Where is the fault? Search­ing for break­downs in miles of medi­um-volt­age and high-volt­age cabling is a lit­tle bit like look­ing for a nee­dle in a haystack. Pre­vi­ous­ly, a fault could only be pin­point­ed offline after a mal­func­tion had occurred. The mea­sure­ment need­ed would then be com­plex and time-con­sum­ing, and often addi­tion­al inves­ti­ga­tion was need­ed before the fault could be local­ized. How­ev­er, the experts at HIGHVOLT have now devel­oped a new mea­sur­ing device called the HiRES Loca­tor, which makes fault local­iza­tion quick, easy, and cost-effec­tive. This is good news not only for grid oper­a­tors and ener­gy providers, who are required to mon­i­tor cabling sys­tems of ever greater com­plex­i­ty, but also for cable man­u­fac­tur­ers, who can inte­grate the HiRES Loca­tor into their test­ing pro­ce­dures for the pur­pos­es of qual­i­ty assur­ance.

The HiRES Loca­tor works in the fol­low­ing way: A dig­i­tal recorder is con­nect­ed to the cable dur­ing active oper­a­tion and local­izes a breakdown imme­di­ate­ly while it’s occur­ring, so the fault is local­ized with the sys­tem still online, not after the fact. The mea­sure­ment is based on the impulse reflec­tion method, also known as TDR (time-domain reflec­tom­e­try). Pre­vi­ous­ly, mea­sure­ment tech­ni­cians using this method would gen­er­ate an arti­fi­cial break ‑down sig­nal – an elec­tri­cal impulse which would prop­a­gate through the con­duc­tor in wave form. If the wave encoun­ters a mate­r­i­al fault, it is reflect­ed back. The loca­tion of the break­down is then cal­cu­lat­ed from the time dif­fer­ence between the sent and received sig­nal. The HiRES Loca­tor can now deter­mine this live and in real time.

www.reinhausen.com/hires

Your Contact

Want to know more about the HiRES Loca­tor?
Tobias Mießler is here to help:
miessler@highvolt.de