Current sensing system for protection of high power frequency converters
Data
2013Autorius
Šimkevičius, Česlovas
Žurauskienė, Nerija
Balevičius, Saulius
Stankevič, Voitech
Baškys, Algirdas
Keršulis, Skirmantas
Metaduomenys
Rodyti detalų aprašąSantrauka
The design and test results of a current-sensing system used for the protection of frequency converters, which are used for controlling the speeds of ac induction motors, are presented. The proposed pulse current-sensing system consists of a magnetic field sensor, which is made of thin polycrystalline La-Sr-Mn-O manganite film exhibiting the colossal magnetoresistance (CMR) effect, and a microcontroller with a 12-bit A/D converter that is used for recording the fault current signal. The magnetic field generated by the high power current cable is fed using a flux concentrator to the manganite magnetic field sensor (CMR-resistor). The design of the contactless current sensor, consisting of two manganite resistors, is developed and investigated. The system is tested in the ambient temperature range of 0–45 °C. The possibilities of using this method in other pulsed power systems are discussed.