Digital line protection

• US 10,559,952 B2
• Filed: 08/11/2017
• Issued: 02/11/2020
• Est. Priority Date: 08/11/2017
• Status: Active Grant

• Current Assignee: Infineon Technologies AG
• Original Assignee: Infineon Technologies AG
• Inventors: Asam, Michael, Graf, Alfons
• Primary Examiner(s): Patel, Dharti H
• Application Number:
  US15/675,097
• Publication Number:
  US 20190052074A1
• Time in Patent Office: 914 Days
• Field of Search: 361 931- 939
• CPC Class Codes: G01R 19/0092 measuring current only all subgroups of G01R19/00 take precedence
• CPC Class Codes: G01R 19/16538 in AC or DC supplies G01R19/16519 and G01R19/16528 take precedence
• CPC Class Codes: G01R 19/2506 Arrangements for conditioning or analysing measured signals, e.g. for indicating peak values G01R19/003 takes precedence; Details concerning sampling, digitizing or waveform capturing displaying waveforms G01R13/00; analog sampling G01R19/0053
• CPC Class Codes: G01R 19/2513 Arrangements for monitoring electric power systems, e.g. power lines or loads; Logging
• CPC Class Codes: G01R 31/085 in power transmission or distribution lines, e.g. overhead
• CPC Class Codes: G01R 31/382 Arrangements for monitoring battery or accumulator variables, e.g. SoC
• CPC Class Codes: H02H 1/04 Arrangements for preventing response to transient abnormal conditions, e.g. to lightning or to short duration over voltage or oscillations; Damping the influence of dc component by short circuits in ac networks
• CPC Class Codes: H02H 3/08 responsive to excess current responsive to abnormal temperature caused by excess current H02H5/04
• CPC Class Codes: H02H 7/0844 Fail safe control, e.g. by comparing control signal and controlled current, isolating motor on commutation error
• CPC Class Codes: H02H 7/226 for wires or cables, e.g. heating wires

Abstract

A line protection device includes terminals to connect the line protection device in series with an electric line. A current sensor of the line protection device senses a value of electric current through the electric line. A digital filter circuit of the line protection device performs digital filtering of the value of electric current. Depending on the digitally filtered value of the electric current, a switch control circuit of the line protection device controls a switch to interrupt flow of the electric current through the line.

Claims

1. A line protection device comprising:

terminals adapted to couple the line protection device in series with an electric line;

a current sensor adapted to a sense a value of an electric current through the electric line;

a digital filter circuit adapted to perform digital filtering of the value of electric current, wherein the digital filter circuit is adapted to perform the digital filtering by calculating a polynomial function of the value of the electric current;

a switch control circuit adapted to control a switch to interrupt flow of the electric current through the electric line depending on the digitally filtered value of the electric current; and

a supply circuit adapted to power at least the digital filter circuit from at least one of the terminals.

2. The line protection device according to claim 1, wherein the digital filtering comprises low-pass filtering.

3. The line protection device according to claim 1, wherein the digital filtering comprises high-pass filtering.

4. The line protection device according to claim 1, wherein the digital filtering comprises low-pass filtering of the calculated polynomial function.

5. The line protection device according to claim 1, wherein the switch control circuit is adapted to control the switch depending on a comparison of the digitally filtered value of the electric current to a first threshold.

6. The line protection device according to claim 1, wherein the switch control circuit is adapted to control the switch depending on a comparison of the value of the electric current to a second threshold.

7. The line protection device according to claim 1, wherein the switch control circuit is adapted to control the switch depending on an input signal to interrupt the electric current independently of the value of the electric current.

8. The line protection device according to claim 1, wherein the digital filter circuit is adapted to operate on the basis of one or more configurable filter parameters.

9. The line protection device according to claim 1, wherein the switch control circuit is adapted to operate on the basis of one or more configurable control parameters.

10. The line protection device according to claim 1, wherein the line protection device comprises the switch.

11. A method of line protection, the method comprising:

coupling a line protection device in series with an electric line;

sensing a value of an electric current through the electric line by a current sensor of the line protection device;

digital filtering of the value of the electric current by a digital filter circuit of the line protection device, wherein digital filtering of the value of the electric current comprises calculating a polynomial function of the value of the electric current;

depending on the digitally filtered value of the electric current, controlling a switch to interrupt flow of the electric current through the electric line; and

powering the digital filter circuit from at least one terminal used to connect the line protection device in series with the electric line.

12. The method according to claim 11, wherein the digital filtering comprises low-pass filtering.

13. The method according to claim 11, wherein the digital filtering comprises high-pass filtering.

14. The method according to claim 11, wherein the digital filtering comprises low-pass filtering of the calculated polynomial function.

15. The method according to claim 11, further comprising

controlling the switch depending on a comparison of the digitally filtered value of the electric current to a first threshold.

16. The method according to claim 11, further comprising controlling the switch depending on a comparison of the value of the electric current to a second threshold.

17. The method according to claim 11, further comprising controlling the switch depending on an input signal to interrupt the current flow independently of the value of the electric current.

18. The method according to claim 11, further comprising performing the digital filtering on the basis of one or more configurable filter parameters.

19. The method according to claim 11, further comprising controlling the switch on the basis of one or more configurable control parameters.

21. The line protection device according to claim 19,

wherein the digital filter circuit is adapted to operate on the basis of a first set of one or more configurable filter parameters, or

wherein the switch control circuit is adapted to operate on the basis of a second set of one or more configurable control parameters.

20. A line protection device comprising:

terminals adapted to couple the line protection device in series with an electric line;

a current sensor adapted to a sense a value of an electric current through the electric line;

a digital filter circuit adapted to perform digital filtering of the value of electric current, wherein the digital filter circuit is adapted to perform the digital filtering by;

calculating a polynomial function of the value of the electric current;

low-pass filtering of the calculated polynomial function to generate a low-pass filtered value; and

high-pass filtering of the value of the electrical current to generate a high-pass filtered value;

a switch control circuit adapted to;

control the switch depending on a comparison of the low-pass filtered value to a first threshold;

control the switch depending on a comparison of the high-pass filtered value to a second threshold; and

control the switch depending on a comparison of the value of the electric current to a third threshold; and

a supply circuit adapted to power at least the digital filter circuit from at least one of the terminals.