Electrical link comprising an electrical protection device—current bias

Patent metadata

Field	Value
Publication number	US-10938201-B2
Application number	US-201815967953-A
Country	US
Kind code	B2
Filing date	May 1, 2018
Priority date	May 3, 2017
Publication date	Mar 2, 2021
Grant date	Mar 2, 2021

Abstract

An electrical link ( 8 ) between a DC high-voltage power source ( 2 ) and a user apparatus ( 5 ) including: an electrical conductor ( 4 ) surrounded by an insulating cover ( 4 a ), and an electrical protection device ( 3 ) that includes a conductive sleeve ( 7 ) arranged around the insulating cover ( 4 a ), a current generator ( 10 ) connected to a current injection point ( 30 ) of the conductive sleeve ( 7 ), a circuit breaker ( 9 ) arranged on the conductor and configured to cut off a current transiting through the conductor ( 4 ), and a detection module ( 11 ) connected to a current tap-off point ( 31 ) of the conductive sleeve ( 7 ) and to the circuit breaker ( 9 ) and configured to detect a current leak out of the conductor ( 4 ) and command the circuit breaker ( 9 ).

First claim

The invention claimed is:

1. An electrical link configured to link a DC high-voltage power source to a user apparatus, the electrical link comprising:
an electrical conductor surrounded by an insulating cover, wherein the electrical conductor is connectable to the DC high-voltage source, and
an electrical protection device comprising:
a conductive sleeve arranged around the insulating cover,
a current generator generating a direct current and connected to a current injection point of the conductive sleeve, wherein the direct current is applied as a biasing current to the conductive sleeve;
a circuit breaker in series with the electrical conductor and configured to interrupt current through the conductor, and
a detection module connected to a current tap-off point of the conductive sleeve and to the circuit breaker, and the detection module is configured to (i) detect current flowing through the conductive sleeve, (ii) compare the current flowing through conductive sleeve to a predetermined current level greater than the biasing current, and (iii) command the circuit breaker to interrupt the current in the conductor if the current flowing through the conductive sleeve is at least at the predetermined current level.

2. The electrical link according to claim 1 , wherein the detection module comprises:
a shunt having a first terminal connected to the tap-off point and a second terminal connected to a ground;
a comparator including a first input connected to the first terminal of the shunt via a detection line, and a second input connected to a DC voltage generator supplying a reference voltage (Vref); and
a microcontroller receiving output signals from the comparator and generating a command signal to cause the circuit breaker to interrupt the current to the conductor, wherein the microcontroller is configured to issue the command signal to the circuit breaker in response to a certain output signal received from the comparator.

3. The electrical link according to claim 2 , further comprising a test module including a central unit connected to a first switch and a second switch, wherein the central unit is configured to command the switching of the first and second switches;
wherein the first switch is connected to the injection point and is configured to switch between a first non-connected terminal and a second terminal linked to a current generator supplying a DC test current; and
wherein the second switch is connected to the output of the microcontroller and is configured to switch between a third terminal linked to the central unit such that only the central unit receives the command signal from the microcontroller, and a fourth terminal linked to the circuit breaker such that only the circuit breaker receives the command signal from the microcontroller.

4. The electrical link according to claim 2 , wherein the detection module comprises a low-pass filter in series with the detection line.

5. The electrical link according to claim 2 , wherein an insulating cover surrounds the conductive sleeve.

6. The electrical link of claim 1 , wherein the current generator is conductively connected to the conductive sleeve and is not conductively coupled to the electrical conductor.

7. The electrical link of claim 1 , wherein the current generator applies a voltage level no greater than fifty volts to the conductive sleeve and the voltage source applies a voltage of at least 270 volts to the electrical conductor.

8. A method to provide a secure supply of electric power to a user apparatus in a vehicle via an electrical link connecting the user apparatus and a power source supplying a DC voltage to the electrical link, wherein the vehicle includes a conductive structure forming a ground and the electrical link includes:
an electrical conductor surrounded by an insulating cover;
an electrical protection device including a conductive sleeve arranged around the insulating cover;
a current generator connected to a current injection point of the conductive sleeve;
a circuit breaker in series with the electrical conductor and configured to interrupt current transiting in the electrical conductor; and
a detection module comprising a shunt including a first terminal connected to a current tap-off point of the conductive sleeve and a second terminal connected to ground, a comparator including a first input connected to the first terminal of the shunt via a detection line and a second input connected to a DC voltage generator supplying a reference voltage (Vref), and a microcontroller connected between an output of the comparator and the circuit breaker,
wherein the method comprises:
injection by the current generator of a direct biasing current (Ig) at the current injection point;
measurement of a magnitude of a current (Ir) via the shunt tapped off at the current tap-off point;
comparison, by the comparator, of a voltage (Ur) on the detection line and the reference voltage (Vref), wherein the voltage (Ur) is determined from the current (Ir) and the comparator generates of a first output signal indicative of the comparison if the current (Ir) is below a predetermined current level higher than the direct biasing current (Ig) and generates a second output signal if the current (Ir) is above the predetermined current level;
monitoring by the microcontroller of the output signal of the comparator and determining if the output signal is the first or second output signal; and
activation, by the microcontroller, of the circuit breaker to interrupt the current in the electrical conductor in response to the output signal of the comparator being the second output signal.

9. The method according to claim 8 , wherein the detection module includes a test module and the test module includes a central unit coupled to a first switch and a second switch;
wherein the central unit commands switching of the first and second switches;
wherein the first switch is connected to the current injection point and switches between a first non-connected terminal and a second terminal linked to a current generator supplying a DC test current, wherein a current of the DC test current and the direct current while applied to the comparator causes the comparator to output an output signal indicative of a current leak;
the second switch is connected to the output of the microcontroller and switches between a third terminal linked to the central unit such that only said central unit receives the command signal from the microcontroller and a fourth terminal linked to the circuit breaker such that only the circuit breaker receives the command signal from the microcontroller;
wherein the method further comprises a test step during which the central unit commands the first switch to switch to the second terminal and commands the second switch to switch to the third terminal and thereafter the central unit monitors a change of the command signal from the microcontroller; and
in response to an end of the test step, the central unit commands the first switch to switch to the first terminal and commands the second switch to switch to fourth terminal.

10. An electrical link system comprising:
a conductor configured to connect to a DC voltage power source and to an electrically powered user apparatus;
an insulating cover surrounding the conductor;
a conductive sleeve around the insulating cover;
a current generator generating a direct current and connected to a current injection point of the conductive sleeve, wherein the current generator applies a the direct current to the conductive sleeve;
a circuit breaker in series with the conductor and configured to interrupt current through the conductor;
a shunt resistor having a first terminal connected to

Assignees

• Airbus Operations Sas

Inventors

• Oms Patrick

Classifications

• H02H3/32 Primary

  involving comparison of the voltage or current values at corresponding points in different conductors of a single system, e.g. of currents in go and return conductors · CPC title

• H03K5/24

  the characteristic being amplitude · CPC title

• H02H1/0007

  concerning the detecting means (in general G01R or other subclasses of G01; reed switches H01H71/2445) · CPC title

• H02H3/202 Primary

  for DC systems · CPC title

• H02H7/228

  for covered wires or cables · CPC title