Method and apparatus for contactless voltage and current estimation through measurements of electric and magnetic fields with redundant sensor arrays

Patent metadata

Field	Value
Publication number	US-12085591-B2
Application number	US-202318150032-A
Country	US
Kind code	B2
Filing date	Jan 4, 2023
Priority date	Dec 5, 2019
Publication date	Sep 10, 2024
Grant date	Sep 10, 2024

Abstract

A multi-sensor, real-time, in-process current and voltage estimation system is disclosed including sensors, affiliated hardware, and data processing algorithms that allow accurate estimation of currents and voltages from magnetic and electric field measurements, respectively. Aspects of the system may be embodied in a detector that is readily attachable to conductors of an energized system for contactless current and/or voltage sensing of the conductors without requiring the conductors to be disconnected from the energized system.

First claim

The invention claimed is:

1. A detector system for contactless current sensing, the detector system comprising:
a frame having conductor receiving locations configured to receive a plurality of current carrying conductors and to support the conductors in a fixed arrangement relative to the frame;
a plurality of magnetic field sensors supported by the frame in a redundant array in a fixed relationship with respect to the conductor receiving locations to sense a magnetic field in a vicinity of the conductors during operation; and
a computing system communicatively coupled to the magnetic field sensors, the computing system configured to receive magnetic field data from the redundant array of magnetic field sensors and to generate an estimated current by utilizing an estimator algorithm that accounts for external magnetic field disturbances on the magnetic field in the vicinity of the conductors to enhance the accuracy of the contactless current sensing of the detector system.

2. The detector system of claim 1 , wherein each magnetic field sensor is configured to output a voltage linearly proportional to a component of a magnetic field along an axis of sensitivity of the magnetic field sensor.

3. The detector system of claim 2 , wherein the axis of sensitivity of each magnetic field sensor is fixed in an orthogonal direction relative to a direction of current flow through the conductors.

4. The detector system of claim 2 , wherein the axis of sensitivity of at least one of the magnetic field sensors is perpendicular to the axis of sensitivity of at least one other one of the magnetic field sensors.

5. The detector system of claim 1 , wherein the redundant array of magnetic field sensors includes a plurality of overlapping subsets of the magnetic field sensors, each overlapping subset encircling a respective one of the conductors.

6. The detector system of claim 1 , wherein the magnetic field sensors are arranged in a plane transverse to a direction of current flow through the conductors.

7. The detector system of claim 1 , wherein at least some of the magnetic field sensors are arranged between the conductor receiving locations.

8. The detector system of claim 1 , wherein a number of the magnetic field sensors is at least three times a number of the current carrying conductors to be sensed.

9. The detector system of claim 1 , wherein the detector system is devoid of electromagnetic shielding around the redundant array of magnetic field sensors.

10. The detector system of claim 1 , wherein the estimator algorithm comprises one of the following:
an Ordinary Least Squares estimator technique;
an Ampere's Law estimator technique;
a Non-linear Model estimator technique;
a Linear Model estimator technique;
a Spatial Harmonics estimator technique;
a Best Linear Unbiased estimator technique;
a Machine Learning estimator technique; and
a Regression estimator technique.

11. The detector system of claim 1 , wherein the estimator algorithm is based on a Best Linear Unbiased estimator technique.

12. The detector system of claim 1 , wherein the computing system is configured to generate the estimated current without employing frequency filtering of a frequency of an energized system to which the conductors belong.

13. The detector system of claim 1 , wherein the frame is configured to be removably secured to the conductors without disconnecting the conductors from an energized system to which the conductors belong.

14. The detector system of claim 1 , wherein the detector system is further configured for contactless voltage sensing and further comprises, for each of at least two of the conductors, a voltage sensing arrangement comprising:
a capacitive sensing electrode with an active shield provided at a first location along a length of a conductor passage for the conductor; and
a capacitive calibration electrode with an active shield provided at a second location offset from the first location along the length of the conductor passage for the conductor, and
wherein the computing system is communicatively coupled to the voltage sensing arrangement and configured to receive calibration data from the voltage sensing arrangement and to generate an estimated capacitance value of the capacitive sensing electrode based in part on said calibration data.

15. The detector system of claim 14 , wherein the computing system is further configured to generate an estimated voltage differential between the two conductors based in part on the estimated capacitance values of the capacitive sensing electrodes.

16. The detector system of claim 14 , wherein the capacitive sensing electrode includes a measurement electrode, a shielding electrode, a dielectric substrate between the measurement electrode and the shielding electrode to isolate the measurement electrode from the shielding electrode, an operational amplifier coupled to the measurement electrode and the shielding electrode, and a bypass resistor between the measurement electrode and ground.

17. A method of estimating current in a plurality of current carrying conductors of an energized system, the method comprising:
obtaining magnetic field data from a redundant array of magnetic field sensors of a detector unit that is secured to the conductors within an environment subjected to external magnetic field disturbances, the detector unit supporting the magnetic field sensors in a fixed relationship to the conductors without electromagnetic shielding; and
generating an estimated current by utilizing an estimator algorithm that accounts for said external magnetic field disturbances on the magnetic field in the vicinity of the conductors to enhance the accuracy of the estimated current.

18. The method of claim 17 wherein the estimator algorithm comprises one of the following:
an Ordinary Least Squares estimator technique;
an Ampere's Law estimator technique;
a Non-linear Model estimator technique;
a Linear Model estimator technique;
a Spatial Harmonics estimator technique;
a Best Linear Unbiased estimator technique;
a Machine Learning estimator technique; and
a Regression estimator technique.

19. The method of claim 17 wherein the estimator algorithm is based on a Best Linear Unbiased estimator technique.

20. The method of claim 17 , further comprising:
obtaining voltage data via a respective voltage sensing arrangement provided in the detector unit for each of the conductors, each voltage sensing arrangement including a capacitive sensing electrode having a measurement electrode, a shielding electrode, a dielectric substrate between the measurement electrode and the shielding electrode to isolate the measurement electrode from the shielding electrode, an operational amplifier coupled to the measurement electrode and the shielding electrode, and a bypass resistor between the measurement electrode and ground; and
calculating a voltage differential between two of the conductors based on said voltage data.

Assignees

• Harting Electric Gmbh & Co Kg
• The Massachusetts Institute Of Tech
• Harting Electric Stiftung & Co Kg

Inventors

• Dave Vivek R
• Loske Felix
• Knop Enger
• Tröger Lutz
• Casallas Alan E
• Lang Jeffrey H

Classifications

• G01R33/06 Primary

  using galvano-magnetic devices · CPC title

• G01R33/0029

  Treating the measured signals, e.g. removing offset or noise · CPC title

• G01R33/0082

  Compensation, e.g. compensating for temperature changes · CPC title

• G01R15/142

  Arrangements for simultaneous measurements of several parameters employing techniques covered by groups G01R15/14 - G01R15/26 · CPC title

• G01R33/0094

  Sensor arrays · CPC title