US 2014/0247528 A1 · METHOD AND DEVICE FOR DETERMINING DIRECTION OF CURRENT FLOWING THROUGH CIRCUIT BREAKER

Abstract

A method and device are disclosed for determining the direction of current flowing through a circuit breaker. An embodiment includes obtaining a sample value of current flowing through the circuit breaker and a differential value of current; obtaining a sample value of voltage at the circuit breaker; on the basis of a relationship between voltage and current in an equivalent circuit in which the circuit breaker lies at the present time and at a previous time, obtaining an equivalent resistance and an equivalent inductance in the equivalent circuit; if the equivalent resistance and equivalent inductance are both greater than zero, determining that the direction of current flowing through the circuit breaker is the same as the current reference direction, and if the equivalent resistance and equivalent inductance are both less than zero, determining that the direction of current flowing through the circuit breaker is opposite to the current reference direction.

Claims19

Dependent claims

A method for determining the direction of current flowing through a circuit breaker, wherein the circuit breaker has a current reference direction, the method comprising:

obtaining a sample value of current flowing through the circuit breaker and a differential value of current;
obtaining a sample value of voltage at the circuit breaker;
obtaining, on the basis of a relationship between voltage and current in an equivalent circuit in which the circuit breaker lies at the present time and at a previous time, an equivalent resistance and an equivalent inductance in the equivalent circuit;
determining, upon the equivalent resistance and equivalent inductance both being greater than zero, that the direction of current flowing through the circuit breaker is the same as the current reference direction, and determining, upon the equivalent resistance and equivalent inductance both being less than zero, that the direction of current flowing through the circuit breaker is opposite to the current reference direction.

1 more element

A device for determining a direction of current flowing through a circuit breaker, the device comprising:

a current acquisition unit, configured to obtain a sample value of current flowing through the circuit breaker and a differential value of current;
a voltage acquisition unit, configured to obtain a sample value of voltage at the circuit breaker;
an equivalent impedance calculation unit, configured to obtain an equivalent resistance and an equivalent inductance in an equivalent circuit in which the circuit breaker lies, on the basis of a relationship between voltage and current in the equivalent circuit at the present time and at a previous time;
and
a determining unit, configured to determine, upon the equivalent resistance and equivalent inductance both being greater than zero, that the direction of current flowing through the circuit breaker is the same as a current reference direction, and configured to determine, upon the equivalent resistance and equivalent inductance both being less than zero, that the direction of current flowing through the circuit breaker is opposite to the current reference direction.

2 more elements

Dependencies are inferred from the claim text.

Method and device for determining direction of current flowing through circuit breaker

Life of this patent

Method and device for determining direction of current flowing through circuit breaker

Life of this patent

Abstract

Claims19