US 10,985,559 B2 · Method and system for improved operation of power grid components in the presence of direct current (DC)

Abstract

Methods and systems for ensuring operation of one or more circuit breakers electrically connected on a phase of a multi-phase power line on a transformer electrically connected within a power grid at a substation are disclosed. The method includes detecting, at the transformer, a direct current component of a multi-phase power signal received at the transformer, the direct current component comprising a direct current received at a transformer neutral, the transformer neutral being electrically connected to a ground. The method further includes determining whether the direct current is above a predetermined threshold, the predetermined threshold being based on a determination that, above the predetermined threshold, at least one of the one or more circuit breakers is incapable of reliable operation. The method includes, in response to a determination that the direct current component is above the predetermined threshold, blocking the direct current between the transformer neutral and a ground.

Claims17

Dependent claims

A method of ensuring operation of one or more circuit breakers electrically connected on a phase of a multi-phase power line on a transformer electrically connected within a power grid at a substation, the method comprising:

detecting, at the transformer, a direct current component of a multi-phase power signal received at the transformer, the direct current component comprising a direct current received at a transformer neutral, the transformer neutral being electrically connected to a ground;
determining whether the direct current is above a predetermined threshold, the predetermined threshold being based on a determination that, above the predetermined threshold, at least one of the one or more circuit breakers electrically connected to at least one phase of the transformer is incapable of reliable operation;
in response to a determination that the direct current component is above the predetermined threshold, blocking the direct current with a direct current neutral blocking circuit between the transformer neutral and a ground.

An electrical protection system comprising:

a transformer included in a transformer assembly having a plurality of connections, each connection associated with a different power line phase of an alternating current power signal;
a direct current sensor to transmit a signal upon detection of a direct current in the neutral of the transformer;
at least one breaker electrically connected to a power line phase of the transformer;
a direct current neutral blocking circuit electrically connected between the transformer neutral and a ground;
a processor to receive the signal from the direct current sensor, the processor electrically connected to the at least one breaker and configured to open the at least one breaker electrically connected to the power line phase of the transformer upon receiving the signal from the direct current sensor in response to a determination at the processor that the direct current in the neutral is above a predetermined threshold,
wherein, above the predetermined threshold, at least one of the one or more circuit breakers electrically connected to at least one phase of the transformer is incapable of reliable operation.

3 more elements

Dependencies are inferred from the claim text.

Method and system for improved operation of power grid components in the presence of direct current (DC)

Life of this patent

Method and system for improved operation of power grid components in the presence of direct current (DC)

Life of this patent

Abstract

Claims17