Magnetic flux cancellation for power line communications

Patent metadata

Field	Value
Publication number	US-11705261-B2
Application number	US-202017036449-A
Country	US
Kind code	B2
Filing date	Sep 29, 2020
Priority date	Sep 30, 2019
Publication date	Jul 18, 2023
Grant date	Jul 18, 2023

Abstract

An apparatus comprising a signal transformer coupled to a power line and a signal transmission, reception, or detection circuit. A sensor is configured to be responsive to the power line current or magnetic flux generated in a ferrite core of the signal transformer. When the sensor indicates that the flux generated by the power line current mat cause an attenuation of the signal strength, a second circuit generates a current through a flux cancelling winding that cancels at least some of the flux generated by the power line current.

First claim

What is claimed is:

1. An apparatus comprising:
a ferrite core;
a first winding inductively coupled with the ferrite core, wherein the first winding is configured to connect to a power generation system using a power line;
a second winding configured to transmit or receive a signal on the power line using the ferrite core, wherein the second winding is inductively coupled with the ferrite core and is connected to a first circuit;
a third winding inductively coupled with the ferrite core;
a sensor comprising a fourth winding configured to measure a magnetic flux produced in the ferrite core by the first winding, and
a second circuit connected to the third winding and the sensor, wherein the second circuit and the third winding are configured to produce a cancelling magnetic flux that cancels at least in part the magnetic flux produced in the ferrite core by the first winding.

2. The apparatus of claim 1 , wherein the signal comprises an electrical arc generated noise, and wherein the first circuit comprises an arc detection circuit.

3. The apparatus of claim 1 , wherein the sensor comprises a current sensor, and wherein the second circuit is configured to:
monitor sensor values;
compute, based on the sensor values, a current value of the power line;
compare the current value to a reference value; and
apply the cancelling magnetic flux based on the comparison of the current value to the reference value.

4. The apparatus of claim 1 , wherein the signal comprises a communication signal, and wherein the first circuit comprises a communication circuit.

5. The apparatus of claim 4 , wherein the second circuit is configured to:
in response to the communication circuit being active, monitor sensor values;
compute, using the sensor values, a signal value of the communication signal;
compare the signal value to a reference value; and
apply the cancelling magnetic flux in a reverse orientation, that is opposite to an orientation of the first winding, based on the comparison of the signal value to the reference value.

6. The apparatus of claim 1 , wherein the ferrite core comprises a magnetic flux saturation limit, and wherein a maximum current of the power line, when the cancelling magnetic flux is not applied, produces the magnetic flux in the ferrite core greater than the magnetic flux saturation limit.

7. The apparatus of claim 1 , wherein the second circuit comprises analog components.

8. The apparatus of claim 1 , wherein the second circuit comprises at least one digital component.

9. The apparatus of claim 1 , further comprising a current sensor configured to measure a current in the power line.

10. The apparatus of claim 1 , further comprising a pulse width modulation (PWM) sensor configured to measure a value associated with a current in the power line.

11. The apparatus of claim 1 , wherein the second circuit comprises at least one component from the group consisting of a band pass filter, a frequency mixer, a peak detector, a signal averaging component, a signal median component, a comparator, a PWM generator, and a current driver.

12. The apparatus of claim 11 , wherein the at least one component is at least one analog electrical component.

13. The apparatus of claim 11 , wherein the at least one component is a software component comprising program code configured for implementing component functions using at least one processor.

14. A method comprising:
monitoring sensor values;
computing, using the sensor values, a current value or a signal value of a power line, wherein the current value or the signal value represents a magnetic flux in a ferrite core;
comparing the current value or the signal value to a reference value; and
applying, using a winding on the ferrite core, a cancelling magnetic flux based on the comparison of the current value or the signal value to the reference value, wherein the ferrite core is inductively coupled to the power line, and wherein the winding on the ferrite core generates the cancelling magnetic flux in an opposite orientation to the magnetic flux in the ferrite core; and
adjusting based on the comparison of the current value or the signal value to the reference value, a flux cancelling current applied to the winding on the ferrite core.

15. A method comprising:
disabling a power line current in a power line, wherein the power line current comprises a direct current or an alternating current;
sending a signal, using a signal transformer, over the power line;
monitoring sensor values associated with the signal;
computing, using the sensor values, a signal value of the power line; and
storing the signal value as a reference value for later retrieval in generating a cancelling magnetic flux in the signal transformer based on a comparison of a new signal value to the reference value.

16. The method of claim 15 , wherein the signal comprises one or more of an electrical arc generated noise or a communication signal.

17. The method of claim 15 , wherein the generating the cancelling magnetic flux comprises:
applying a flux cancelling current to a winding on a ferrite core, wherein the ferrite core is inductively coupled to the power line, and wherein the winding on the ferrite core generates the cancelling magnetic flux in an opposite orientation of a magnetic flux generated by the power line.

18. The method of claim 15 , wherein the alternating current has a frequency below 1,000 hertz.

19. The method of claim 14 , wherein the ferrite core comprises a magnetic flux saturation limit, and wherein a maximum current of the power line, when the cancelling magnetic flux is not applied, produces the magnetic flux in the ferrite core greater than the magnetic flux saturation limit.

20. The method of claim 14 , wherein the current value or the signal value indicates an electrical arc generated noise or a communication signal.

Assignees

• Solaredge Technologies Ltd

Inventors

• Manelis Michael
• Litmanovitch Gil
• Braginsky David

Classifications

• H01F7/064 Primary

  Circuit arrangements for actuating electromagnets (circuit arrangements for obtaining special operating characteristics H01F7/18; driving circuits for electromagnets making use of a switching regulator H01H47/325) · CPC title

• H01F27/24

  Magnetic cores · CPC title

• H01F27/28

  Coils; Windings; Conductive connections · CPC title

• H02P9/02

  Details {of the control} · CPC title

• G01R19/0092 Primary

  Measuring current only · CPC title