KEMA Labs tests on three-phase current limiting reactors

KEMA Labs (the CESI Testing, Inspection and Certification Division) has recently tested two types of starting reactors according to IEC 60076-6 and GOST 14794-79.

Electricity transmission and distribution systems are a very complex chain of several components and equipment that improves the quality of electricity and safety of the system in general. Amongst the parts that need to be tested, reactors are essential elements.  Starting reactors are used to control starting current of electrical machines as synchronous and asynchronous motors, thus must withstand a series of temporary overloading. Therefore, testing them is fundamental to avoid safety and productivity issues that could massively affect the resilience of the customer’s power grid.

Our experts at KEMA Labs in Prague (Czech Republic) have successfully conducted temperature rise tests of two three-phase current-limiting dry-type reactors with natural air cooling and vertical arrangement of phases.

After completing such tests at rated currents 630 A and 1,600 A, the reactors were supplemented by special overload modes up to 1.6 times the rated current. In order to obtain such parameters, the equipment of both high-voltage and high-power laboratory had to be combined for the tests. Due to the size of test circuit, the test object had to be placed in such a way that all circuit elements, including auxiliary switches, disconnectors, busbar systems etc., were able to carry out continuous currents up to 2,560 A.

Aside from this challenge, the KEMA Labs experts had to overcome the possible problem related to the measurement of temperatures at potential and measurement of temperatures exceeding 180 °C with regards to fixation of thermocouples. This was achieved by data loggers operating in a special mode, using insulating thermometers powered by their own batteries. Additionally, a thermal camera was used to monitor temperatures and possible hot spots.

All technical challenges were overcome, and both cases resulted in valuable and recognized KEMA Type Test Certificate of Temperature Rise Performance according to IEC 60076-6.

Read more about such tests here.