Arc Research Laboratory

The arc research la­bo­ra­to­ry ser­ves pri­ma­ri­ly for ap­p­li­ca­ti­on-driven re­se­arch for the in­crea­se of re­lia­bi­li­ty and life­time of swit­ching de­vices. The­re­fo­re, ex­pe­ri­ments on vacuum arcs and wall-stabilized arcs are uti­li­zed to stu­dy the arc be­ha­viour and the elec­tro­de load in low, medium and high vol­ta­ge switch­ge­ars at dif­fe­rent cur­rent pul­se shapes. Spe­ci­fic elec­tro­de ar­ran­ge­ments in­clu­ding ab­la­ti­on nozz­les can be used to si­mu­la­te con­di­ti­ons in re­al swit­ching de­vices or to stu­dy the in­ter­ac­tion of the electric arc with elec­tro­des, walls as well as with ma­gne­tic fiel­ds. The cou­pling between different op­ti­cal dia­gnostics for the phy­si­cal ana­ly­sis of the arc is a uni­que feature of the la­bo­ra­to­ry. For in­stan­ce, op­ti­cal emis­si­on spec­tro­sco­py al­lows for the mea­su­re­ment of tem­pe­ra­tu­res and spe­cies den­si­ties in the electric arc. High-speed ima­ging tech­ni­ques is used to stu­dy of the dy­na­mics and struc­tu­re of the arc starting from the arc igni­ti­on pro­ces­s. In ad­di­ti­on, sur­face tem­pe­ra­tu­res of the elec­tro­des can be ana­ly­sed using combined diagnostic methods. 

The la­bo­ra­to­ry equipment in­clu­des in par­ti­cu­lar:

• Set­up for the ope­ra­ti­on of high-cur­rent arcs by me­ans of pul­sed cur­rent ge­ne­ra­tors with the pa­ra­me­ters (peak va­lues): si­nuso­idal cur­rent pul­ses (DAC) up to 80 kA/ 5 ms, 40 kA/ 10 ms, or 25 kA/20 ms, squa­re wa­ve pul­ses up to 10 kA/ 2 ms or 2kA/10ms, fle­xi­ble elec­tro­de ar­ran­ge­ment in­clu­ding ac­tua­tors for elec­tro­de movement
• Va­cu­um cham­ber in­clu­ding moun­ting sup­port for elec­tro­des, pneumatic ac­tua­tor and ac­cess for op­ti­cal dia­gnostics and pro­be mea­su­re­ments
• Electri­cal and op­ti­cal sen­sors (pho­to­di­odes) for re­cor­ding of temporal evolutions of cur­rent, vol­ta­ge and emission si­gnals in spe­ci­fic spec­tral ran­ges as well as cor­re­spon­ding me­thods for their ana­ly­sis
• 0.5 and 0.75 m spec­tro­graphs with in­ten­si­fied CCD ca­me­ras (sin­gle images with ex­po­sure ti­mes from few ns to ms) for op­ti­cal emis­si­on spec­tro­sco­py, in par­ti­cu­lar for mea­su­re­ments with high spa­ti­al and spec­tral re­so­lu­ti­on in the in spec­tral ran­ge from 300 nm to 900 nm with re­so­lu­ti­on of up to 0.05 nm
• High speed ima­ging ca­me­ras for up to 70000 frames/s for the stu­dy of the arc dy­na­mics in­clu­ding spec­tral selec­tive fil­ters (nar­row band MIF, edge fil­ters, po­la­ri­zer fil­ters), double frame optics for si­mul­ta­neous re­cor­ding with two dif­fe­rent fil­ters and one ca­me­ra
• Framing ca­me­ra (4 in­de­pen­dent images wi­t­hin e.g. 5 ns with ex­po­sure ti­me of 3 ns) and Streak ca­me­ra (tem­po­ral re­so­lu­ti­on <1 ns, 1 spa­ti­al di­men­si­on) for the ob­ser­va­ti­on of arc igni­ti­on pro­ces­ses in the ns-ran­ge
• Ther­mo­gra­phy / py­ro­me­try for con­tact­less mea­su­re­ment of sur­face tem­pe­ra­tu­res of e.g. elec­tro­des

Most of the mea­su­re­ment equipment (spec­tro­sco­py, high-speed ima­ging, ther­mo­gra­phy) are mo­bi­le and can be used for ex­ter­nal mea­su­re­ment cam­pai­gns.