Technical Q&A: Inside ABB’s MV Switchgear Testing
What makes ABB’s climatic test chamber for energized MV switchgear so extreme? EE Power asked ABB’s engineering team to bring you the answers.
ABB recently made an announcement about opening Europe’s first climatic test chamber for energized medium voltage (MV) switchgear (investing €700,000 for its creation) with a press release titled, in part, “ABB’s MV switchgear testing goes extreme.” EE Power wanted the inside scoop for its readers on what exactly this means, so we tapped into Zdenek Kutalek, ABB Brno Laboratory Manager and Michal Bernard, ABB Technology Centre Manager, to find out.
The climatic test chamber. Image used courtesy of ABB
The chamber will be able to simulate the harshest climatic conditions from lows of 50°C below zero to highs of 80°C, as well as pollution. As humidity and water condensation can cause faster aging and degradation of switchgear, the climate chamber will also test for that. These tests are intended to reveal any limits of the switchgear beyond the current industry standard to enhance grid resilience.
EE Power: How does the chamber actually work?
Zdenek Kutalek/Michal Bernard: The testing room for tests, according to IEC 62271-304, is created by an MV voltage source testing area and the climatic chamber itself. The test object is placed inside the climatic chamber and energized using MV cables leading from the MV source to cable connections of the switchgear through bushings in the wall of the climatic chamber. The requested climatic conditions (temperature, humidity and pollution) are set up in requested cycles.
Where the test object is able to withstand defined environmental conditions under rated voltage, the MV switchgear is subjected to further mandatory voltage tests defined in applicable standards and additional tests required by the customer to clarify if the test in the climatic chamber was satisfactory.
UniGear switchgear located in the climatic chamber. Image used courtesy of ABB
EE Power: The press release headline reads, in part, “ABB’s MV switchgear testing goes extreme.” In real terms, what does this mean?
Zdenek Kutalek/Michal Bernard: MV switchgear for inside use is usually placed in an operation room where environmental conditions are considered to be normal service conditions. In this case, switchgear does not require any special testing apart from standard testing.
However, in some cases, environmental conditions in certain operating rooms do not fulfill normal operation conditions. Different environmental conditions are usually caused by higher humidity, with more water condensation than is allowed, higher or lower temperatures, higher pollution and so on. When severe climatic conditions arise inside an operation room, it is necessary to perform additional tests in a climatic chamber, according to IEC TS 62271-304.
EE Power: What is new and different about this switchgear testing? How is it a game changer?
Zdenek Kutalek/Michal Bernard: Such tests are usually performed in climatic chambers where it is possible to simulate environmental conditions through two basic parameters: temperature and humidity. The climatic chamber in ABB Brno (ABB’s Distribution Solutions business line in Brno, Czech Republic and where the climatic test chamber is located) allows the simulation of environmental conditions using three parameters: temperature, humidity and pollution. The pollution is simulated by employing salted fog with different conductivity of water needed for salted fog preparation.
The combination of the three parameters (humidity, temperature and pollution) in this climatic chamber creates an environment much closer to the harsh environmental conditions found in places like the Arctic or the Sahara. The ability to create real environmental conditions in ABB’s climatic chamber is the major change compared with commonly used climatic chambers where it is only possible to change two parameters.
MV voltage part–equipped with voltage source for energizing the test object inside of the climatic chamber. Image used courtesy of ABB
EE Power: What makes this testing facility stand out in the industry?
Zdenek Kutalek/Michal Bernard: We can better understand and evaluate the behavior of MV switchgear in severe climatic conditions and use this knowledge to reduce failures and unplanned downtime at customer sites, and enhance product reliability and grid resilience to help our customers to keep the power supply on 24/7.
EE Power: How will ABB utilize the results of the testing?
Zdenek Kutalek/Michal Bernard: The results of these tests performed in more real conditions allow us to understand switchgear behavior and its aging during the lifetime of the switchgear in severe climatic conditions. Having this knowledge allows our designers to better understand all aspects and circumstances which need to be taken into consideration during the development process.