An agile tester

---

When most peo­ple think of Aus­tralia, they prob­a­bly think of the end­less expans­es of the out­back rather than cramped con­di­tions. But this is exact­ly what Yilin Xu often has to deal with in his work: “In urban areas, many of our sub­sta­tions are very tight­ly built and can only be reached via nar­row access roads.” Xu is respon­si­ble for the test­ing ser­vice at Aus­grid, the largest grid oper­a­tor on Australia’s east coast, in a grid area cov­er­ing approx­i­mate­ly 22,275 square kilo­me­ters, which also includes the metrop­o­lis of Syd­ney. The mea­sure­ments car­ried out by his team of 21 test engi­neer­ing offi­cers are essen­tial to enable Asset Man­age­ment to bet­ter eval­u­ate the con­di­tion of the oper­at­ing equip­ment and react quick­ly in the event of impend­ing fail­ures, so that the lights do not go out for the more than four mil­lion cus­tomers.

To ensure that this remains the case, Xu need­ed a new test truck for mobile AC volt­age test­ing of trans­form­ers, switchgear and volt­age con­vert­ers. “Our cur­rent test vehi­cle dates back to the 1970s and is out­dat­ed,” explains Xu. An impor­tant require­ment: the test truck must not exceed a length of 11.2 meters and must have a small turn­ing cir­cle so that it can dri­ve into the tight­ly built sub­sta­tions. Xu there­fore turned to HIGHVOLT: “We have been work­ing togeth­er for many years and are impressed by the high qual­i­ty and pro­fes­sion­al­ism. We already have a HIGHVOLT trail­er in use for cable test­ing.”

High voltage in a small space

At HIGHVOLT in Dres­den, Andreas Thiede, Head of Inno­va­tions, and Anne Cholawa, Project Man­ag­er, are very famil­iar with AC volt­age test­ing sys­tems. This method exam­ines the dielec­tric con­di­tion of the equip­ment. For this pur­pose, an increased test fre­quen­cy and an increased test volt­age are used to inves­ti­gate whether par­tial dis­charges occur in the object to be test­ed. If these exceed a cer­tain lim­it val­ue, this indi­cates weak points in the insu­la­tion sys­tem. Noth­ing spe­cial for HIGHVOLT so far. How­ev­er, the request from Aus­tralia was also a first for Thiede and Cholawa. “We have pre­vi­ous­ly imple­ment­ed mobile test sys­tems as a trail­er or con­tain­er solu­tion, but pack­ing the entire tech­nol­o­gy onto a truck—we’ve nev­er done any­thing like this before,” explains Thiede.

It was par­tic­u­lar­ly tricky to fit all the com­po­nents into a small space and to opti­mize the mass dis­tri­b­u­tion. In some cas­es, it was real mil­lime­ter work: “The box body had to be a max­i­mum of two and a half meters. How­ev­er, when it came from the coach­builder, it was ten mil­lime­tres too wide, so we had to go at it again.” The project was also chal­leng­ing from Cholawa’s point of view: “The Aus­tralian safe­ty require­ments are very strict, the need for coor­di­na­tion is high and the export and import is com­plex”. But in the end, the truck arrived safe­ly in Syd­ney Har­bour.

Better testing possible

Xu is delight­ed with the result. “With our old test­ing sys­tem, we could only test at 50 hertz, now we are much more flex­i­ble in terms of frequencies—100 or 200 hertz are also pos­si­ble. This makes our mea­sure­ment results much more accu­rate.” The truck is also quick­ly ready for use and easy to oper­ate: “We can pre-pro­gram the fre­quen­cy tests and record the test data. That wasn’t pos­si­ble before.” And what Xu also real­ly appre­ci­ates is the tech­ni­cal sup­port: “We can always turn to HIGHVOLT for assis­tance.”