New input circuits used for parameters determination of circuit breaker voltage and current paths

Abstract

In the article new constructions of voltage and

current transducers have been presented that are used for

parameters determination of current and voltage signals in the

line protected by circuit breaker. These transducers are used

with protection relay that is also a subsystem of source data

acquisition for multi-criteria method of circuit breaker

diagnosis. Because of the multifunctionality of the device the

transducers have to work with, they have to be very accurate,

have wide bandwidth and be stable over varying environment

conditions like temperature and humidity. As current

transducers, Rogowski coils have been described. They have

been made with the use of multilayer PCB technology to

achieve very high repeatability of coils parameters, low labor

costs as well as high bandwidth and excellent linearity. The

designs of Rogowski coils have been presented together with

measurement results. As voltage transducers, new constructions

of reactance transducers, resistive transducers and air core

transformers have been presented. The main design effort has

been put into achieving wide bandwidth and good linearity. In

the paper input circuits adapted to new types of voltage

transducers have been described as well as measurement results.