Intelligent leakage current detection and interruption device for power cord

Patent metadata

Field	Value
Publication number	US-11258245-B2
Application number	US-202017013610-A
Country	US
Kind code	B2
Filing date	Sep 6, 2020
Priority date	Sep 28, 2017
Publication date	Feb 22, 2022
Grant date	Feb 22, 2022

Abstract

An intelligent leakage current detection and interruption device for a power cord, including a switch module for controlling electrical connection of two power lines between input and output ends; a leakage current detection module, including two leakage current detection lines and a signal feedback line, one end of the parallelly coupled two leakage current detection lines being coupled via the signal feedback line to a point between the two power lines, for respectively detecting a leakage current on the two power lines; a detection monitoring module, coupled to the leakage current detection module, for detecting open circuit conditions in the two leakage current detection lines; and a drive module, coupled to the switch module, the leakage current detection module and the detection monitoring module, for driving the switch module to disconnect power to the output end in response to any detected leakage current or open circuit condition.

First claim

What is claimed is:

1. An intelligent leakage current detection and interruption device for a power cord, comprising:
a first power line and a second power line, each having a power input end and a power output end;
a switch module, configured to control an electrical connection of the first and second power lines between the power input end and the power output end;
a leakage current detection module, including a first leakage current detection line, a second leakage current detection line, and a signal feedback line, wherein the first and second leakage current detection lines are coupled in parallel, one end of the parallelly coupled first and second leakage current detection lines is coupled via the signal feedback line to a point between the first and second power lines, wherein the first and second leakage current detection lines are configured to detect whether a leakage current is present on the first power line and the second power line, respectively;
a detection monitoring module, coupled to the leakage current detection module, and configured to detect whether an open circuit condition is present in the first or second leakage current detection line; and
a drive module, coupled to the switch module, the leakage current detection module and the detection monitoring module, and configured to drive the switch module to cut off power to the power output end in response to any detected leakage current or open circuit condition.

2. The intelligent leakage current detection and interruption device of claim 1 , wherein the detection monitoring module includes at least three resistors and at least one diode.

3. The intelligent leakage current detection and interruption device of claim 1 , wherein the detection monitoring module includes a first resistor, a second resistor, a third resistor, and a first diode.

4. The intelligent leakage current detection and interruption device of claim 3 , wherein the first resistor is coupled in series with the first leakage current detection line and coupled to a first common point, the second resistor is coupled in series with the second leakage current detection line and coupled to the first common point, the first diode is coupled between the first common point and one of the first and second power lines, a second common point of the first and second leakage current detection lines is coupled via the signal feedback line to a first end of the third resistor, and a second end of the third resistor is coupled via the drive module to another one of the first and second power lines.

5. The intelligent leakage current detection and interruption device of claim 3 , wherein the first resistor is coupled in series with the first leakage current detection line and coupled to a first common point, the second resistor is coupled in series with the second leakage current detection line and coupled to the first common point, the first common point is coupled via the first diode to one of the first and second power lines, a second common point of the first and second leakage current detection lines is coupled via the signal feedback line to a first end of the third resistor, and a second end of the third resistor is coupled via the drive module to another one of the first and second power lines, and wherein the first diode is shared by the detection monitoring module and the drive module.

6. The intelligent leakage current detection and interruption device of claim 1 , further comprising a test module which includes a test switch, wherein the test switch is coupled between the first leakage current detection line and one of the first and second power lines, and wherein when the test switch is closed and no open circuit condition is present on the first and second leakage current detection lines, the drive module drives the switch module to disconnect power to the output end.

7. The intelligent leakage current detection and interruption device of claim 1 , wherein the drive module includes a semiconductor switch having a current path and a control gate, a resistor coupled to the control gate of the semiconductor switch, and an actuator coupled to the current path of the semiconductor switch, the actuator being mechanically coupled to the switch module.

8. The intelligent leakage current detection and interruption device of claim 1 , wherein the first and second leakage current detection lines are first and second shield lines respectively covering the first and second power lines.

9. The intelligent leakage current detection and interruption device of claim 1 , wherein the signal feedback line is a conductor individually covered by an insulating layer.

10. The intelligent leakage current detection and interruption device of claim 1 , wherein the signal feedback line is insulated from the first and second leakage current detection lines except for the coupling at the one end of the first and second leakage current detection lines.

Assignees

• Li Chengli

Inventors

• Li Chengli
• Chen Long

Classifications

• G01R31/58

  Testing of lines, cables or conductors (testing of electric windings G01R31/72) · CPC title

• H02H3/16 Primary

  responsive to fault current to earth, frame or mass (with balanced or differential arrangement H02H3/26 {; monitoring earth connection H02H5/105}) · CPC title

• G01R31/008

  on air- or spacecraft, railway rolling stock or sea-going vessels · CPC title

• H02H3/17

  by means of an auxiliary voltage injected into the installation to be protected {(using summation current transformers H02H3/33)} · CPC title

• H02H9/08

  Limitation or suppression of earth fault currents, e.g. Petersen coil · CPC title