Circuit breaker with integrated control features

• US 5,875,087 A
• Filed: 08/08/1996
• Issued: 02/23/1999
• Est. Priority Date: 08/08/1996
• Status: Expired due to Term

• Current Assignee: GSK Technologies Incorporated
• Original Assignee: George A. Spencer
• Inventors: Clunn, Robert Henry, Blanton, LeRoy, Spencer, George Auther
• Primary Examiner(s): Medley, Sally C.
• Application Number:
  US08/695,076
• Time in Patent Office: 929 Days
• Field of Search: 368/85, 368/87, 368/93-98, 368/78
• US Class Current: 361/87
• CPC Class Codes: G01R 31/3277 of low voltage devices, e.g. domestic or industrial devices, such as motor protections, relays, rotation switches
• CPC Class Codes: H01H 2300/03 Application domotique, e.g. for house automation, bus connected switches, sensors, loads or intelligent wiring
• CPC Class Codes: H01H 9/56 for ensuring operation of the switch at a predetermined point in the ac cycle
• CPC Class Codes: H02H 1/043 to inrush currents H02H1/046 takes precedence; differential protection of transformers H02H7/045
• CPC Class Codes: H02H 1/06 Arrangements for supplying operative power power supply arrangements in general G05F, H02M
• CPC Class Codes: H02H 3/006 Calibration or setting of parameters
• CPC Class Codes: H02H 3/05 with means for increasing reliability, e.g. redundancy arrangements for logic circuits H03K19/003
• CPC Class Codes: H02H 3/0935 the timing being determined by numerical means
• CPC Class Codes: Y02B 70/30 Systems integrating technologies related to power network operation and communication or information technologies for improving the carbon footprint of the management of residential or tertiary loads, i.e. smart grids as climate change mitigation technology in the buildings sector, including also the last stages of power distribution and the control, monitoring or operating management systems at local level
• CPC Class Codes: Y04S 20/20 End-user application control systems

Abstract

A digitally controlled circuit breaker includes a conventional thermal circuit breaker (10) which is controlled by a solenoid (16) to override the thermal aspect thereof. The solenoid (16) is controlled by a digital processing section (20). The digital processing section (20) has a digital control module (22) with multiple profile tables associated therewith. The profile tables allow the digital control module (22) to compare a sensed current from a sensor (24) with a predetermined current value as a function of time and to generate the control signal for the solenoid (16) if the sensed current exceeds that in the profile. The profiles can optionally be downloaded to the module (22) through a serial communication port (36). The digital control module (22) is also operable to sense the voltage of the circuit breaker to determine zero crossing points and phase angle, which phase angle can be utilized to determine the type of load and, therefore, can alter the profile to be utilized. Display (30) provides a visual communication device for the control module (22). Various self-test features including generating a simulated current to the digital control module (22) and automatic recovery if the execution of the stored program in the digital control module (22) is disrupted.

Claims

1. An intelligent circuit breaker for controlling the current flow from an AC main to a load, which circuit breaker has a series breaker element that can be controlled by a generated control signal to control current flow to the load through the series breaker element, comprising:

a parameter sensor for sensing the parameters of the circuit breaker relating to current flowing through the circuit breaker from the AC main to the load;

a storage device for storing predetermined performance parameters for desired relationships between the current and the load that define acceptable operating current constraints of the load, wherein said acceptable operating current constraints vary with time according to the load that is associated with the series breaker element at a given time; and

a controller for comparing the sensed parameters detected by said parameter sensor to said stored predetermined performance parameters and generating said control signal when the sensed parameters fall outside of said acceptable operating current constraints.

2. The circuit breaker of claim 1, and further comprising an input/output port for communicating with said controller from an external location to said circuit breaker to allow information to be transmitted to said controller and information to be transmitted from said controller to said external location.

3. The circuit breaker of claim 2, wherein said controller is operable to receive from said input/output port new desired relationships for storage in said storage device.

4. The circuit breaker of claim 2, wherein command information is transmitted from said external location to said controller to override the operation of said controller and cause said controller to generate said control signal in response to receiving said command information.

5. The circuit breaker of claim 1, wherein said parameter sensor includes a current sensor for sensing the level of AC current supplied to the load.

6. The circuit breaker of claim 5, wherein the circuit breaker includes a bus line for carrying current from the series breaker element to the load and said current sensor comprises:

a toroidal core;

secondary winding wound on said toroidal core;

a primary winding wound on said toroidal core, said primary winding having two ends, said two ends disposed on the bus a predetermined distance apart, such that a portion of the current is routed through said primary winding; and

said secondary winding operable to translate the current level down to a measurable level, the current output thereof providing the sensed current.

7. The circuit breaker of claim 5, wherein the desired relationships include a maximum current level, such that whenever the sensed current exceeds the maximum current level, the control signal is immediately generated by said controller to interrupt current with the series breaker element.

8. The circuit breaker of claim 5, and further comprising a current zero crossing detector for determining when the sensed current makes a transition from a positive to a negative value and goes through a zero value.

9. The circuit breaker of claim 8, wherein said controller is operable to generate said control signal only when the current is determined to be proximate to a zero value.

10. The circuit breaker of claim 8, and further comprising a voltage sensor for sensing voltage on the load side of the series breaker element.

11. The circuit breaker of claim 10, and further comprising a voltage zero crossing detector for determining when the voltage passes from between positive and negative values and a substantially zero value and a phase detector for determining the phase angle between the sensed voltage at the zero crossing point thereof and the sensed current at the zero crossing point thereof.

12. The circuit breaker of claim 11, and further comprising a load detection device for determining the type of load that is present as a function of the determined phase angle.

13. The circuit breaker of claim 12, wherein said storage device is operable to store as the desired relationships a plurality of different, distinct, desired relationships and further comprising a selection device for selecting one of the desired and distinct relationships as a function of the type of determined load after determination thereof by said determination device.

14. The circuit breaker of claim 1, wherein said storage device is operable to store a plurality of predetermined performance parameters, each being distinct and associated with distinct ones of the desired relationships between the current and the load that define distinct, acceptable operating current constraints.

15. The circuit breaker of claim 14, wherein said plurality of predetermined performance parameters are each selectable.

16. The circuit breaker of claim 15, wherein said predetermined parameters are selectable by a user to effect operation of the circuit breaker.

17. The circuit breaker of claim 15, wherein each of said plurality of predetermined performance parameters are selectable as a function of parameters of the current flow to the load as determined by said parameter sensor.

18. The circuit breaker of claim 14, wherein said controller generates said control signal which is operable to cause the series breaker element to discontinue current to the load to thereby constitute a trip operation.

19. The circuit breaker of claim 18, wherein said parameter sensor includes a current sensor for sensing the current flow to the load from the series breaker element.

20. The circuit breaker of claim 19, wherein select ones of said plurality of parameters comprise a relationship of current versus time to define trip point constraints as a function of time that are points above which said controller will generate said control signal to trip said series breaker element, which relationships are defined as trip point profiles.

21. The circuit breaker of claim 20, wherein each of said trip point profiles are selectable with a selection device.

22. The circuit breaker of claim 21, wherein said trip point profiles are selectable by said selection device automatically as a function of parameters of the circuit breaker sensed by said parameter sensor.

23. The circuit breaker of claim 22, wherein said automatic sensing by said selection device is performed upon determining that a start-up condition has occurred, said selection occurring for a predetermined amount of time.

24. The circuit breaker of claim 21, wherein said selection device is operated by said user prior to installation of the circuit breaker.

25. The circuit breaker of claim 20, wherein each of said trip point profiles is a learned trip point profile and further comprising means for learning said trip point profiles.

26. The circuit breaker of claim 1, wherein said parameter sensor includes a voltage sensor for sensing the voltage on the load side of the series breaker element.

27. The circuit breaker of claim 26, wherein the series breaker element includes a series switch that can interrupt current flow from AC mains to the load, which said series switch is controlled by a solenoid, which said solenoid includes a solenoid switch for connecting a solenoid driving coil in said solenoid between the low side of said series switch and the neutral side of the AC mains, which solenoid switch is controlled by said generated control signal, and further comprising a solenoid voltage detector for detecting the voltage on the opposite side of said solenoid driving coil to the load side of said series switch, such that said voltage on the opposite side of said solenoid driving coil on said solenoid opposite to the low side of said series switch can be detected to determine if said solenoid driving coil is operating.

28. An intelligent circuit breaker for detecting arcs in a line, which circuit breaker is operable to modify the current supplied to the load in response to receiving a generated control signal, comprising:

a current sensor for detecting the AC current waveform for current flowing to a load disposed on the line;

a peak detector for measuring current at the substantially peak level thereof for a substantially complete cycle of the present AC waveform to provide a present detected value;

a comparator for comparing the present detected value with the detected value for the previous cycle and generating a true result when a predetermined number of comparisons exhibit a predetermined imbalance; and

a control circuit for generating the control signal when a true result is output by said comparator.

29. The circuit breaker of claim 28, wherein the circuit breaker is operable to interrupt current in response to generation of the control signal.

30. The circuit breaker of claim 28, wherein said predetermined imbalance occurs whenever the absolute difference of current magnitudes between adjacent cycles exceeds a predetermined value.

31. A method for controlling the current flow from an AC main to a load with a circuit breaker, the circuit breaker having a series breaker element associated therewith that can be controlled by a generated control signal to control current flow to the load through the breaker element, comprising the steps of:

sensing the parameters of the circuit breaker with a parameter sensor relating to current flowing through the circuit breaker from the AC main to the load;

storing in a storage device predetermined performance parameters for desired relationships between the current and the load that define acceptable operating current constraints of the load;

selecting various ones of the predetermined performance parameters for varying the operating current constraints of the load with time according to the load; and

comparing the sensed parameters sensed by the parameter sensor to the stored predetermined performance parameters and generating the control signal when the sensed parameters fall outside of the acceptable operating current constraints.

32. The method of claim 31, and further comprising the step of receiving from an input/output communication port new desired relationships for storage in the storage device in the step of storing.

33. The method of claim 31, and further comprising the step of receiving command information over a serial input/output communication link from an external location, which command information is utilized in the step of comparing to override the operation of generating the control signal to generate the control signal in response to receiving the command information.

34. The method of claim 31, wherein the step of sensing the parameters of the circuit breaker includes the step of sensing the level of AC current supplied to the load on the load side of the series breaker element.

35. The method of claim 34, wherein the desired relationship includes a maximum current level, such that whenever the sensed current sensed in the step of sensing exceeds the maximum current level, the step of generating is operable to immediately generate the control signal to interrupt current with the series breaker element.

36. The method of claim 34, and further comprising detecting the current zero crossing to determine when the sensed current makes the transition from a positive to a negative value and goes through a zero value.

37. The method of claim 36, wherein the step of generating the control signal is operable to generate the control signal only when the current is determined to be proximate to a zero value.

38. The method of claim 36, and further comprising the s step of sensing voltage on the load side of the series breaker element and then detecting a voltage zero crossing to determine when the voltage passes from between positive and negative values and at a substantially zero value and also the step of detecting the phase angle between the sensed voltage at the zero crossing point thereof and the sensed current at the zero crossing point thereof.

39. The method of claim 38, and further comprising the step of determining the type of load that is present as a function of the determined phase angle.

40. The method of claim 39, wherein the step of storing is operable to store as the desired relationships a plurality of different, distinct, desired relationships in the storage device and further comprising the step of selecting one of the desired and distinct relationships as a function of the type of determined load after determination thereof by the step of determining.

41. The method of claim 31, wherein the step of storing is operable to store a plurality of predetermined performance parameters, each being distinct and associated with distinct ones of the desired relationships between the current and the load that define distinct, acceptable operating current constraints.

42. The method of claim 41, wherein the plurality of predetermined performance parameters are each selectable as a function of the parameters of the current flow to the load as determined by the step of sensing the current parameters.

43. The method of claim 41, wherein the step of generating the control signal is operable to generate the control signal to cause the series breaker element to discontinue current to the load thereby constituting a trip operation.

44. The method of claim 43, wherein the step of sensing the parameters includes the step of sensing the current flow to the load from the series breaker element and wherein select ones of the plurality of parameters comprise a relationship of current versus time to define trip point constraints as a function of time that are points above which the step of generating the control signal will generate the control signal to trip the series breaker elements, which relationships are defined as trip point profiles.

45. The method of claim 44, wherein each of the trip point profiles are selectable.