Taking a Breath

Con­ven­tion­al dehy­drat­ing breathers require reg­u­lar main­te­nance. In order to elim­i­nate this extra work, ener­gy sup­pli­er VSE Verteil­netz GmbH uses the main­te­nance-free solu­tion from MESSKO in all of its trans­form­ers — sav­ing both time and mon­ey.

Atrans­former breathes out and in again a cou­ple of times a year, depend­ing on uti­liza­tion. This is because an increase in load caus­es the insulat­ing medi­um in the trans­former to heat up and expand, push­ing the air in the expan­sion tank out into the atmos­phere. When the oil cools down again, it con­tracts and draws in the out­side air.

Dehy­drat­ing breathers are used to make sure that no mois­ture gets into the insu­lat­ing medi­um when the trans­former breathes in. Each trans­former most­ly has a min­i­mum of two breathers: one for the oil cir­cuit in the tap chang­er, the big­ger ones for the trans­former tank. The sub­stance that elim­i­nates the mois­ture is called sil­i­ca gel. Thanks to its water-absorb­ing prop­er­ties, it is also used as a des­ic­cant in oth­er applications—inside the pack­ag­ing of mois­ture-sen­si­tive elec­tron­ics, for exam­ple.

As its abil­i­ty to absorb water is lim­it­ed, the sil­i­ca gel in con­ven­tion­al dehy­drat­ing breathers has to be replaced and dis­posed of reg­ularly—around two to three times a year on aver­age. This fre­quen­cy increas­es fur­ther as more renew­able pow­er is fed into the grid, as this means the trans­former has to work under high load con­di­tions more often. For grid oper­a­tors, this is a task that takes up valu­able time and ties up resources, and the result­ing costs are not to be under­es­ti­mat­ed.

The main­te­nance-free dehy­drat­ing breathers make life much eas­i­er for Karl-Heinz Jenal, oper­a­tional super­vi­sor at VSE Verteil­netz GmbH. (© Alexan­der Neu)

Karl-Heinz Jenal, who works as an oper­a­tional super­vi­sor at Saar­land-based ener­gy sup­pli­er VSE Verteil­netz GmbH and is respon­si­ble for main­tain­ing the equip­ment, explains: “We have 56 high-volt­age instal­la­tions in our grid, each of which con­tains two trans­form­ers. Some­one has to go out to each one on a reg­u­lar basis to check whether the des­ic­cant is still work­ing prop­er­ly. Over the course of a year, the time spent on main­te­nance real­ly adds up. And then you have to fac­tor in the met­ric ton of sil­i­ca gel that we have to dis­pose of and replace.” At least, that’s how things used to be.

For VSE Verteil­netz GmbH, these tasks and the asso­ci­at­ed costs will soon be a thing of the past, as all of its trans­form­ers have been fit­ted with the main­te­nance-free MTRAB® dehy­drat­ing breather from Rein­hausen sub­sidiary MESSKO. The breather still uses sil­i­ca gel, but unlike the pre­vi­ous tech­nol­o­gy, the MTRAB® is able to regen­er­ate itself. Sen­sors mea­sure the mois­ture in the des­ic­cant. An algo­rithm stored in the con­trol sys­tem eval­u­ates these mea­sure­ments and an elec­tric heat­ing sys­tem is acti­vat­ed auto­mat­i­cal­ly when the sat­u­ra­tion point is reached. After around two and a half hours, the sil­i­ca gel is dry again.

A Cost-Effective Solution

VSE Verteil­netz GmbH first used the MTRAB® in 2008, when it was adding a new trans­former to the fleet. Jens Leinen­bach, head of grid oper­a­tions, recalls: “We were try­ing to work out how we could cut down on main­te­nance in the long term. That’s why we were keen to try out a new prod­uct and see whether it proved its worth in prac­tice.” And the MTRAB® def­i­nite­ly passed the test. Eight years lat­er, VSE Verteil­netz GmbH ordered MESSKO dehy­drat­ing breathers for anoth­er 35 trans­form­ers and in 2019, the com­pa­ny decid­ed to con­vert the entire fleet.

Karl-Heinz Jenal (right) togeth­er with Wern­er Sam­met, Area Sales Man­ag­er Europe of Messko/MR, in a sub­sta­tion of VSE Verteil­netz GmbH. (© Alexan­der Neu)

“We want­ed to bring all of our equip­ment up to the same lev­el. We delib­er­ate­ly opt­ed for a qual­i­ty product—something that is not offered by many man­u­fac­tur­ers on the mar­ket. The fact that we have been work­ing with MESSKO and Rein­hausen for many years also played a key role in the deci­sion. Hav­ing a part­ner that we know and trust is impor­tant to us,” explains Leinen­bach.

As an addi­tion­al advan­tage, the MTRAB® dehy­drat­ing breathers can be net­worked so that error mes­sages are sent straight to the con­trol room. And even if the elec­tron­ics sys­tem fails at some point, the MTRAB® still func­tions as a con­ven­tion­al dehy­drat­ing breather. The com­pa­ny has yet to see a sin­gle error mes­sage: “Our expe­ri­ence has been entire­ly pos­i­tive so far. We haven’t had to wor­ry about a thing since the equip­ment was installed,” says Leinen­bach

Simple Installation

Jenal, who over­saw the con­ver­sion work, agrees. “The instal­la­tion process is self-explana­to­ry and very straight­forward. Our own staff were able to car­ry out the work when they were going to a pri­ma­ry sub­sta­tion any­way for oth­er rea­sons.” The new equip­ment has freed up resources that the oper­a­tional super­vi­sor and his team can now allo­cate else­where. When you work for an ener­gy sup­pli­er, there are always plen­ty of oth­er things to be get­ting on with.

“From a medi­um and long term per­spec­tive, VSE has made the right deci­sion to save costs and, in doing so, joins the ranks of over 1,000 sat­is­fied cus­tomers world­wide who have been suc­cess­ful­ly using our MTRAB® dehy­drat­ing breathers for many years,” explains Wern­er Sam­met, Messko/MR Area Sales Man­ag­er for Europe.

REINHAUSEN INSIDE

The MESSKO® MTRAB® has proven itself many times over in the field since it was first launched over 15 years ago — there are now about 80,000 of these breathers installed world­wide. The main­te­nance-free dehy­drat­ing breather min­i­mizes the ingress of mois­ture into the insu­lat­ing flu­id of trans­form­ers, tap chang­ers, and oth­er elec­tri­cal equip­ment filled with insu­lat­ing flu­ids. The MESSKO® MTRAB® can regen­er­ate the sil­i­ca gel itself thanks to the use of tem­per­a­ture and mois­ture sen­sors com­bined with intel­li­gent algo­rithms — sav­ing inspec­tion and main­te­nance costs.


YOUR CONTACT

Would you like to know more about the MESSKO® MTRAB®?
Wern­er Sam­met, Area Sales Man­ag­er Europe is here to help:
W.Sammet@messko.com


Share with your network!

Never miss an issue again!

Click here to subscribe for free.