MEASUREMENT

Global Experience, Local Application

Deaf Measurement Devices
Today, many power quality measurements are usually carried out with devices that scan at a low resolution of 12.5kHz. In these devices, it analyzes up to the 50th harmonic, 2500Hz. However, as the IGBT technology becomes more widespread, the distortion goes far above the limit drawn with% THDi and becomes more dangerous. Located between 2500Hz and 170kHz for a true measurement
supraharmonics
must be analyzed.
In our fault-based analyzes, we increasingly encounter supraharmonics (high frequency network distortions) as the cause of problems or malfunctions in the system. Unfortunately, only a few - actually real - power quality analyzers offer the opportunity to make these distortions measurable.
Although the network standards (EN 61000-4-30 class A or other standards) do not set or suggest a limit for high frequency pollution above 2.5kHz, supraharmonics are now encountered in many parts of the industry and this high frequency pollution and causes malfunctions.

Even nowadays, one of the most important causes of failure is supraharmonics. As can be seen in the picture above, it shows the difference between the sampling rate of 40 kHz (generally there are 12.5kHz resolution devices in the market) and 1 MHz. Only with the higher sampling rate, ie resolution, supraharmonics up to 170 kHz become recognizable.

Very few power quality analyzers on the market allow permanent and accurate measurement of this frequency range from 2.5 to 170 kHz.

Being able to measure these frequencies is very important for power quality analysis. However, our customers do not have to worry about this. We have known this problem for a long time and we use the necessary measurement technology that is best for every situation.