Popis: |
Current and voltage instrument transformers are essential elements of the power system. They work like transformers but do not transmit power. Their task is to accurately transform currents or voltages during system operation, which are then used for measurement and protection. These devices are very precise, and their accuracy is defined by the IEC/CEN standards. Instrument transformers are located at all transformer stations, specialized high-voltage and high-power laboratories, and testing and teaching laboratories. Therefore, the design requirements are very different depending on their type (current, voltage, or combined), function (measuring, protection), and operating voltage (high, medium, and low). The requirements concern not only the operation but also the strength of the insulation system and, sometimes, the mechanical strength. |