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US 11,430,624 B2Granted
Current sensor output converter for circuit breakers that are configured for Rogowski coils
AssigneeEaton Intelligent Power Limited
InventorsTheodore J. Miller, David R. Olenak, Zachary Mueller
Life of this patent
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Abstract
In a circuit breaker arrangement, this disclosure describes a method and circuit design enables a current transformer to be used to detect ground faults in circuit breakers (such as a main-tie-main circuit breakers) that have been designed to receive signals from Rogowski coils.
Claims22
An electrical system comprising:
- a first power source;
- a first circuit breaker that is electrically connected to an output of the first power source;
- a first trip unit for the first circuit breaker;
- a first current transformer that is positioned to detect current passing through a neutral line that extends from the first power source;
- and
- a first converter circuit that is positioned to:
- receive a signal from an output of the first current transformer,
- convert the received signal to a first voltage signal, and
- send the first voltage signal to the first trip unit,
- wherein during operation the first voltage signal will have a voltage that is proportional to a time rate of change of the received signal,
- wherein the system is a main-tie-main system that also comprises:
- a second power source;
- a second circuit breaker that is electrically connected to an output of the second power source;
- a second trip unit for the second circuit breaker;
- a second current transformer that is positioned to detect current passing through a neutral line that extends from the second power source, and that has an output that is electrically connected to the second trip unit;
- a second converter circuit that is positioned to:
- receive a signal from the output of the second current transformer,
- convert the signal received from the output of the second current transformer to a second voltage signal, and
- send the second voltage signal to the second trip unit;
- and
- a third circuit breaker that is electrically connected to both the first power source and the second power source.
18 more elements
A converter circuit for receiving signals from one or more current transformers and outputting a signal to a circuit breaker trip unit, the converter circuit comprising:
- an input component that is electrically connected to receive an output signal from each of one or more current transformers of a circuit breaker;
- a burden resistor that is electrically connected across a coil of the input component;
- a passive differentiator that is electrically connected across the burden resistor, wherein the passive differentiator comprises a resistor and a capacitor;
- and
- an output that is configured to deliver, from the passive differentiator during operation, a converted output voltage that is proportional to a time rate of change of a signal that is received by the input component, such that the converted output voltage does not need to be processed by an integrated circuit in order for the trip unit to make a determination to output a trip signal.
2 more elements
An electrical system having a main-tie-main configuration, the system comprising:
- a first power source;
- a first circuit breaker that is electrically connected to an output of the first power source;
- a first trip unit for the first circuit breaker;
- a first current transformer that is positioned to detect current passing through a neutral line that extends from the first power source;
- a second power source;
- a second circuit breaker that is electrically connected to an output of the second power source;
- a second trip unit for the second circuit breaker;
- a second current transformer that is positioned to detect current passing through a neutral line that extends from the second power source, and that has an output that is electrically connected to the second trip unit;
- a third circuit breaker that is electrically connected to both the first power source and the second power source;
- a first converter circuit that is positioned to:
- receive signals from the first and second current transformers,
- sum and convert the signals received from the output of the first and second current transformers to a first voltage signal, and
- send the first voltage signal to the first trip unit, wherein during operation the first voltage signal will have a rate of change that is proportional to a rate of change of the signals received by the first converter circuit;
- and
- a second converter circuit that is positioned to:
- receive signals from the first and second current transformers,
- sum and convert the signals received from the output of the first and second current transformers to a second voltage signal, and
- send the second higher voltage signal to the second trip unit, wherein during operation the second voltage signal will have a rate of change that is proportional to a rate of change of the signals received by the second converter circuit.
15 more elements
A converter for receiving signals from one or more current transformers and outputting a signal to a circuit breaker trip unit, the converter comprising:
- an input component that is electrically connected to receive an output signal from each of one or more current transformers of a circuit breaker;
- and
- an inductor that is electrically connected across a coil of the input component;
- wherein the converter is configured to deliver, during operation, a converted output voltage that is proportional to time rate of change of current that is received by the input component, such that the converted output voltage does not need to be processed by an integrated circuit in order for the trip unit to make a determination to output a trip signal.
1 more element
Dependencies are inferred from the claim text.