Magnetic flux cancellation for power line communications

Patent metadata

Field	Value
Publication number	US-12412690-B2
Application number	US-202418761753-A
Country	US
Kind code	B2
Filing date	Jul 2, 2024
Priority date	Sep 30, 2019
Publication date	Sep 9, 2025
Grant date	Sep 9, 2025

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

The invention claimed is:

1. An apparatus comprising:
a core;
a plurality of first windings inductively coupled with the core, wherein the plurality of first windings are each configured to connect to a power line of a power generation system;
a second winding inductively coupled with the core;
a sensor configured to measure a current produced in the power line; and
a circuit connected to the second winding and the sensor, wherein the circuit is configured to monitor a sensor value of the sensor and apply, based on comparing a monitored sensor value to a reference value, a current to the second winding, wherein the current to the second winding is configured to produce a cancelling magnetic flux that cancels at least in part a magnetic flux produced in the core by the plurality of first windings, wherein each of the plurality of first windings apply the magnetic flux to the core in a same orientation.

2. The apparatus of claim 1 , wherein the plurality of first windings and the core are configured to filter a signal on the power line.

3. The apparatus of claim 2 , wherein the circuit is configured to:
in response to the power line being active, compute, using the sensor value, a value of the magnetic flux;
compare the value of the magnetic flux to a second reference value; and
apply the cancelling magnetic flux in a reverse orientation, that is opposite to an orientation of the plurality of first windings, based on the comparison of the value of the magnetic flux to the second reference value.

4. The apparatus of claim 1 , wherein the 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 core greater than the magnetic flux saturation limit.

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

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

7. The apparatus of claim 1 , further comprising a third winding configured to measure the magnetic flux in the core.

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

9. The apparatus of claim 1 , wherein the 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.

10. The apparatus of claim 9 , wherein the at least one component comprises at least one analog electrical component.

11. The apparatus of claim 1 , wherein the circuit comprises at least one processor and a memory storing program code configured for implementing component functions using at the at least one processor.

12. A method comprising:
monitoring a sensor value of a power line, wherein the sensor value represents a current in the power line, and wherein a magnetic flux is induced in a same orientation in a core by a plurality of first windings connected to the power line and inductively coupled with the core;
applying, using a second winding inductively coupled with the core, a cancelling magnetic flux based on a comparison of the sensor value to a reference value, wherein the second winding inductively coupled with the core generates the cancelling magnetic flux to cancel at least in part the magnetic flux in the core induced by the plurality of first windings; and
adjusting, based on the comparison of the sensor value to the reference value, a flux cancelling current applied to the second winding inductively coupled with the core.

13. The method of claim 12 , wherein the 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 core greater than the magnetic flux saturation limit.

14. A method comprising:
disabling a power line current in a power line inductively coupled to a core, wherein the power line current comprises a direct current;
sending a signal over the power line;
computing a sensor signal value associated with the signal;
storing the sensor signal value as a reference value;
retrieving the reference value; and
generating a cancelling magnetic flux in the core, using a current flowing through a plurality of first windings inductively coupled to the core, wherein the current is based on a comparison of a new signal value to the reference value, wherein each of the plurality of first windings apply the cancelling magnetic flux to the core in a same orientation.

15. The method of claim 14 , wherein the power line is connected to a plurality of second windings inductively coupled to the core in a same orientation.

16. The method of claim 15 , wherein the plurality of second windings and the core are configured to filter the signal on the power line.

17. The method of claim 14 , wherein the plurality of first windings generate in the core the cancelling magnetic flux in the core in an opposite orientation of a magnetic flux in the core generated by the power line.

18. The method of claim 16 , wherein the 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 a magnetic flux in the core greater than the magnetic flux saturation limit.

19. The method of claim 12 , wherein the power line is connected to a plurality of second windings inductively coupled to the core in a same orientation.

20. The method of claim 12 , wherein the plurality of first windings on the core generates the magnetic flux in an opposite orientation of a magnetic flux generated by the power line.

Assignees

• Solaredge Technologies Ltd

Inventors

• Manelis Michael
• Litmanovitch Gil
• Braginsky David

Classifications

• H02P9/02

  Details {of the control} · CPC title

• H01F27/28

  Coils; Windings; Conductive connections · CPC title

• H01F27/24

  Magnetic cores · CPC title

• H04B2203/5483

  using coupling circuits · CPC title

• H04B2203/547

  via DC power distribution · CPC title