Keeping Things Constant

We look at two exam­ples of how ECOTAP® VPD® helps Ital­ian grid oper­a­tor DEVAL to main­taina con­stant volt­age in the Aos­ta Val­ley.

1 The Mall

DEVAL is ahead of the game, being part of a group in which energy production comes entirely from renewable sources. To ensure that voltage levels remain constant following the construction of a new shopping mall, the operator is switching to a VRDT.

The Aos­ta Val­ley is the small­est region in Italy. DEVAL is the largest grid oper­a­tor in the local area and part of the CVA (Com­pag­nia Val­dostana delle Acque) Group, which is respon­si­ble for gen­er­at­ing ener­gy. The com­pa­ny relies on 32 hydro­elec­tric pow­er sta­tions, eight wind farms, and three solar parks to deliv­er a total of three bil­lion kilo­watt hours of elec­tric­i­ty every sin­gle year.

DEVAL dis­trib­utes this pow­er via a grid span­ning a length of some 4,150 kilo­me­ters. Lui­gi Tra­ver­so, who is respon­si­ble for main­te­nance and devel­op­ment at DEVAL, explains: “We are cur­rent­ly work­ing on mod­ern­iz­ing the grid and test­ing new equip­ment that will help us to achieve even bet­ter ser­vice.” This is the case, for exam­ple, at the busi­ness park in Nus, a small town locat­ed close to the region’s cap­i­tal of Aos­ta where a new shop­ping mall is cur­rent­ly under con­struc­tion. In the area there are sev­er­al solar ener­gy sys­tems boast­ing a rel­e­vant local capac­i­ty.

“It became clear to us that our exist­ing dis­tri­b­u­tion trans­former would have dif­fi­cul­ty cop­ing with the extra volt­age fluc­tu­a­tions. We are work­ing on from the under­stand­ing that ener­gy con­sump­tion is set to dou­ble with­in the space of a year” says Tra­ver­so. And that is why DEVAL decid­ed to invest in a new 400-kVA trans­former that takes care of volt­age reg­u­la­tion too. When it came to the tap chang­er, DEVAL opt­ed for the ECOTAP® VPD® togeth­er with the ECOTAP® VPD® Con­trol con­troller and the addi­tion­al CONTROL PRO mod­ule. Tra­ver­so: “We can now pro­vide custom­ers with a sta­ble grid even when the shops are open.”

Two loca­tions, one solu­tion: The ECOTAP® VPD® helps keep the grid in the Aos­ta Val­ley sta­ble.

2 The Village

Over in Rhême-Notre-Dame in the Italian Alps—as in many other locations—DEVAL had to disconnect power twice a year to manually change the transmission ratio of the transformer. But now that’s all in the past.

The tiny vil­lage of Rhêmes-Notre-Dame, locat­ed in the Aos­ta region and home to 250 peo­ple, is sit­u­at­ed in a pic­turesque val­ley. In fact, it’s the very def­i­n­i­tion of “off the beat­en track.” And it’s exact­ly this tran­quil­i­ty and seclu­sion that draws in hun­dreds of tourists. Dur­ing peak vaca­tion sea­son, the num­ber of inhab­i­tants shoots up and so does the demand for elec­tric­i­ty, which comes from sev­er­al hydro­elec­tric plants and some pri­vate solar ener­gy sys­tems.

There­fore, pow­er gen­er­a­tion is as up and down as the demand. After all, there is a great deal more hydropow­er once the snow has melt­ed away than after a long hot sum­mer. Until just recent­ly, grid oper­a­tor DEVAL had to inter­vene on a reg­u­lar basis for this rea­son, disconnect­ing the pow­er and man­u­al­ly chang­ing the trans­mis­sion ratio of the trans­former to com­pen­sate for fluc­tu­a­tions in the volt­age to the extent pos­si­ble.

Now this is in the past: “We decid­ed to replace the old trans­former with a new 250-kilo­volt-ampere volt­age reg­u­la­tion dis­tri­b­u­tion trans­former to test a new solu­tion to ensure our cus­tomers a bet­ter ser­vice with­out any need to man­u­al­ly dis­con­nect the pow­er” says Lui­gi Tra­ver­so. As far as tap chang­ing is con­cerned, DEVAL decid­ed to imple­ment the same solu­tion as in Nus: the ECOTAP® VPD® Con­trol con­troller and the addi­tion­al CONTROL PRO mod­ule. “This allows us to mon­i­tor the switch­ing oper­a­tions from our con­trol room. So far, we have observed 40 switch­ing oper­a­tions per day on aver­age. The volt­age is con­stant now,” says Tra­ver­so.


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