CONTROL CIRCUIT CONFIGURED TO DETERMINE WHEN A DIRECT CURRENT COMPONENT IN AN ALTERNATING CURRENT POWER LINE PASSES A DESIGNATED THRESHOLD

• US 20180062396A1
• Filed: 08/31/2016
• Published: 03/01/2018
• Est. Priority Date: 08/31/2016
• Status: Active Grant

• Current Assignee: TE Connectivity Solutions GmbH (TE Connectivity Ltd. (United Kingdom))
• Original Assignee: Tyco Electronics Corporation (TE Connectivity Ltd. (United Kingdom))
• Inventors: Mishrikey, Matthew
• Granted Patent: US 10,608,440 B2
• Time in Patent Office: Days
• CPC Class Codes: G01R 19/165 Indicating that current or voltage is either above or below a predetermined value or within or outside a predetermined range of values
• CPC Class Codes: H02H 3/332 with means responsive to dc component in the fault current
• CPC Class Codes: H02H 3/50 responsive to the appearance of abnormal wave forms, e.g. ac in dc installations
• CPC Class Codes: H02J 5/00 Circuit arrangements for transfer of electric power between ac networks and dc networks H02J3/36 takes precedence

Abstract

Control circuit includes a current sensor that is configured to detect alternating current transmitted through a power line. The alternating current includes an alternating current (AC) component and a direct current DC offset component. The control circuit also includes a filter sub-circuit that is configured to receive a sensor output from the current sensor that is representative of the AC component and the DC component. The AC component has a frequency higher than a frequency of the DC component. The filter sub-circuit is configured generate a DC output that is based on the DC component. The control circuit also includes an analysis sub-circuit that is configured to receive the DC output and determine that the DC output has passed a designated threshold. The analysis sub-circuit is configured to trip a relay or output a signal when the DC output passes the designated threshold.

Claims

1. A control circuit configured to monitor an alternating current power line, the control circuit comprising:

a current sensor configured to detect alternating current transmitted through a power line, wherein the alternating current of the power line includes an alternating current (AC) component and a direct current DC offset component;

a filter sub-circuit configured to receive a sensor output from the current sensor that is representative of the AC component and the DC component, the AC component having a frequency that is higher than a frequency of the DC component, the filter sub-circuit configured to block the AC component and generate a DC output that is based on the DC component; and

an analysis sub-circuit configured to receive the DC output from the filter sub-circuit and determine that the DC output from the filter sub-circuit has passed a designated threshold, the analysis sub-circuit configured to trip a relay or output a signal when the DC output from the filter sub-circuit passes the designated threshold.

2. The control circuit of claim 1, wherein the control circuit is configured to operate in a standard mode and in an emergency mode, the designated threshold being smaller for the standard mode than the emergency mode such that certain fault events are ignored when the control circuit is operating in the emergency mode.

3. The control circuit of claim 1, further comprising a reconditioning sub-circuit configured to modify the DC output from the filter sub-circuit prior to the DC output being received by the analysis sub-circuit.

4. The control circuit of claim 3, wherein the control circuit is configured to operate in a standard mode and in an emergency mode, the reconditioning sub-circuit modifying the DC output in a first manner during the standard mode and modifying the DC output in a second manner during the emergency mode, the DC output being modified in the emergency mode such that certain fault events are ignored when the control circuit is operating in the emergency mode.

5. The control circuit of claim 1, wherein the current sensor is a Hall sensor.

6. The control circuit of claim 1, wherein the analysis sub-circuit includes threshold detector.

7. The control circuit of claim 1, wherein the reconditioning sub-circuit offsets the value of the output from the filter sub-circuit by a predetermined amount.

8. The control circuit of claim 1, wherein the control circuit is configured to analyze the DC component to identify one or more fault events.

10. The control circuit of claim 1, wherein the control circuit is configured to operate in a standard mode and in an emergency mode, the designated threshold being smaller for the standard mode than the emergency mode such that certain fault events are ignored when the control circuit is operating in the emergency mode.

11. The control circuit of claim 1, further comprising a reconditioning sub-circuit configured to modify the DC output from the filter sub-circuit prior to the DC output being received by the analysis sub-circuit.

12. The control circuit of claim 3, wherein the control circuit is configured to operate in a standard mode and in an emergency mode, the reconditioning sub-circuit modifying the DC output in a first manner during the standard mode and modifying the DC output in a second manner during the emergency mode, the DC output being modified in the emergency mode such that certain fault events are ignored when the control circuit is operating in the emergency mode.

13. The control circuit of claim 1, wherein the current sensor is a Hall sensor.

14. The control circuit of claim 1, wherein the analysis sub-circuit includes threshold detector.

15. The control circuit of claim 1, wherein the reconditioning sub-circuit offsets the value of the output from the filter sub-circuit by a predetermined amount.

16. The control circuit of claim 1, wherein the control circuit is configured to analyze the DC component to identify one or more fault events.

9. A system comprising:

an alternating current power line that is configured to convey power from a power supply to a load;

a circuit breaker coupled to the power line; and

a control circuit configured to monitor the alternating current power line, the control circuit comprising;

a current sensor configured to detect alternating current transmitted through a power line, wherein the alternating current of the power line includes an alternating current (AC) component and a direct current DC offset component;

a filter sub-circuit configured to receive a sensor output from the current sensor that is representative of the AC component and the DC component, the AC component having a frequency that is higher than a frequency of the DC component, the filter sub-circuit configured to block the AC component and generate a DC output that is based on the DC component; and

an analysis sub-circuit configured to receive the DC output from the filter sub-circuit and determine that the DC output from the filter sub-circuit has passed a designated threshold, the analysis sub-circuit configured to activate a contactor of the circuit breaker or output a signal to an operator when the DC output from the filter sub-circuit passes the designated threshold.

17. A method comprising:

monitoring an alternating current power line that conveys power to a load;

detecting an alternating current (AC) component and a direct current (DC) offset component in the alternating current;

generating a sensor output that is representative of the AC component and the DC component, the AC component having a frequency that is higher than a frequency of the DC component;

filtering the sensor output by blocking the AC component and generating a DC output that is based on the DC component;

determining the DC output has passed a designated threshold; and

tripping a relay or outputting a signal when the DC output passes the designated threshold.

18. The method of claim 17, further comprising switching from a standard mode to an emergency mode, the designated threshold during the standard mode being smaller than the designated threshold during the emergency mode such that certain fault events are ignored in the emergency mode.

19. The method of claim 17, further comprising modifying the DC output prior to determining the DC output has passed the designated threshold.

20. The method of claim 19, further comprising switching from a standard mode to an emergency mode, the DC output being modified in a first manner during the standard mode and modified in a different second manner during the emergency mode, the DC output being modified in the emergency mode such that certain fault events are ignored when the control circuit is operating in the emergency mode.