Mathematical models of the new remote transformer current transducers

Abstract

New designs of remote transformer current converters (RTCC) have been developed in this article. It is shown that an increase in sensitivity is achieved due to the implementation of the magnetic circuit in the form of a multiturn core with a common measuring winding, and the use of three identical RTCC installed to measure currents of all three phases with connected measuring windings according to open triangle circuit expands the functionality of device due to the simultaneous measurement of currents in three phases and unbalanced currents in a three-phase circuit. Generalized mathematical models of new RCTT have been developed taking into account the influence of magnetic fields of currents of neighboring buses for the most general case of their location in space in relation to the buses of a three-phase line. It is shown that for RTCC type TVM-P, in which the parallel rods are made in the form of a multi-turn core with a corresponding measuring winding, in order to reduce the effect on the readings of the current transducer installed to measure the current in phases A, the number of turns of the measuring winding located at a distance from of buses B and C, the multiturn core of the U-shaped magnetic circuit should be selected large in relation to the measuring winding placed on the multiturn core closest to the buses B and C.