Granted Patent B2

US 12,573,840 · App. 18/504,573 · Granted Mar 10, 2026

Inventors: Govind S. Chavan (Garner, NC); Chunmeng Xu (Raleigh, NC); Zhou Dong (Raleigh, NC); Pietro Cairoli (Cary, NC)

Assignee: ABB Schweiz AG

H02H7/268G01R15/181G01R15/202H02H1/0007

Abstract

Claims (30)

1 . An electrical circuit for detecting short circuit faults with a solid-state circuit breaker (SSCB), comprising:

a first sensor configured to detect a fault current of an electrical system, wherein the first sensor is configured for installation on a main current path of an SSCB pole;

a second sensor configured to detect a derivative of the fault current of the electrical system with respect to time, wherein the second sensor is configured for installation on the main current path of the SSCB pole; and

an analog circuit, wherein an output of the first sensor and an output of the second sensor are connected to the analog circuit.

2 . The electrical circuit of claim 1 , wherein the second sensor is a Rogowski coil current sensor.

3 . The electrical circuit of claim 2 , wherein the Rogowski coil current sensor is designed as a printed circuit board (PCB), and wherein the PCB comprises a window, which the main current path of the SSCB pole passes through.

4 . The electrical circuit of claim 1 , wherein the second sensor is an inductor.

5 . The electrical circuit of claim 1 , wherein the first sensor is a Hall-effect current sensor.

6 . The electrical circuit of claim 1 , wherein the analog circuit comprises a subtractor and/or an adder that combines the output of the first sensor, the output of the second sensor, and a trip current threshold to evaluate whether a sum of the outputs of the first and second sensors exceeds the trip current threshold.

7 . The electrical circuit of claim 6 , wherein an output of the subtractor and/or the adder delivers an adjusted trip current threshold based on the derivative of the fault current with respect to time.

8 . The electrical circuit of claim 7 , wherein the analog circuit further comprises a comparator that determines whether the fault current exceeds the adjusted trip current threshold, based on which a decision to trip the SSCB is made.

9 . The electrical circuit of claim 1 , wherein the analog circuit further comprises an instrumentation amplifier, wherein a gain of the instrumentation amplifier is adjusted based on the derivative of the fault current with respect to time to increase or decrease a compensation for the derivative of the fault current with respect to time.

10 . An electrical circuit on a printed circuit board (PCB) for detecting short circuit faults with a solid-state circuit breaker (SSCB), wherein the electrical circuit is configured for connection to a first sensor configured to detect a fault current of an electrical system, comprising:

a second sensor configured to detect a derivative of the fault current with respect to time of the electrical system, wherein the second sensor is connected to a main current path of an SSCB pole; and

an analog circuit, wherein an output of the first sensor and an output of the second sensor are connected to the analog circuit.

11 . The electrical circuit on the PCB of claim 10 , wherein the second sensor is a Rogowski coil current sensor.

12 . The electrical circuit on the PCB of claim 11 , wherein the Rogowski coil current sensor is designed as a PCB-based Rogowski coil current sensor, and embedded into the electrical circuit on the PCB, and wherein the PCB-based Rogowski coil current sensor is customized to detect a derivative of a secondary fault current output of the first sensor with respect to time.

13 . The electrical circuit on the PCB of claim 11 , wherein the Rogowski coil current sensor is a planar Rogowski coil current sensor.

14 . The electrical circuit on the PCB of claim 10 , wherein the first sensor is a Hall-effect current sensor.

15 . The electrical circuit on the PCB of claim 10 , wherein the analog circuit comprises a subtractor and/or an adder that combines the output of the first sensor, the output of the second sensor, and a trip current threshold to evaluate whether a sum of the outputs of the first and second sensors exceeds the trip current threshold.

16 . The electrical circuit on the PCB of claim 15 , wherein an output of the subtractor and/or the adder delivers an adjusted trip current threshold based on the derivative of the fault current with respect to time.

17 . The electrical circuit on the PCB of claim 16 , wherein the analog circuit further comprises a comparator that determines whether the fault current exceeds the adjusted trip current threshold, based on which a decision to trip the SSCB is made.

18 . The electrical circuit on the PCB of claim 10 , wherein the analog circuit further comprises an instrumentation amplifier, wherein a gain of the instrumentation amplifier is adjusted based on the derivative of the fault current with respect to time to increase or decrease a compensation for the derivative of the fault current with respect to time.

19 . The electrical circuit on the PCB of claim 10 , further comprising an integrator that accumulates the derivative of the fault current with respect to time detected by the second sensor over a defined time and produces a representative output as a backup current for the fault current detected by the first sensor.

20 . A method for adjusting a trip current threshold for an electrical circuit for detecting short circuit faults with a solid-state circuit breaker (SSCB), comprising:

detecting a fault current using a first sensor;

detecting a derivative of the fault current with respect to time using a second sensor;

evaluating whether a sum of the detected fault current and the detected derivative of the fault current with respect to time exceeds the trip current threshold to obtain an adjusted trip current threshold;

comparing the detected fault current with the adjusted trip current threshold; and

making a tripping decision for the SSCB based on a result of the comparison.

Assignments (1)

Continuity (1)

References Cited (23)