Impact of MV sensors on differential protection performance

摘要

Differential protection provides basic protection for power transformers, motors, generators, overhead lines, cables and other important equipment used in Medium Voltage (MV) systems. The main advantages of differential protection are selectivity and fast operation. However for proper operation differential protection needs to receive reliable information about primary currents. Therefore differential protection places special requirements on current transformers (CTs). Consequently CTs generally need to be designed with very high parameters that are not practical to achieve in all cases. MV sensors represent an alternative way for measuring currents and voltages in MV networks. Due to their linear characteristics, sensors are very accurate across the whole operating range and in particular do not have a problem with saturation. The paper introduces the latest development in sensors used for differential protection applications and offers new views on how sensors could improve differential protection performance.%Zabezpieczenia różnicowe mogą wprowadzać ograniczenia. Dlatego w artykule przedstawiono czujniki określające precyzyjnie prąd I napięcie w sieci, bez ryzyka nasycenia.