Method for measuring phase currents of a device under test, in particular of an inverter

1. A method for measuring phase currents of a device under test in which a sensor arrangement is arranged in a region of the device under test, the method comprising:

using the sensor arrangement to detect a magnetic field formed by a vector of a plurality of magnetic fields, each magnetic field of the plurality magnetic fields induced by a corresponding phase current of a plurality of phase currents of the device under test;

determining the vector of the plurality of magnetic fields based on the detected magnetic field; and

calculating a vector for each phase current of the plurality of phase currents based on the determined vector of the plurality of magnetic fields and a coefficient matrix,

wherein the sensor arrangement includes a component comprising a crystal lattice with at least one defect configured to generate an output corresponding to the detected magnetic field,

wherein the device under test is a three-phase inverter,

wherein the three-phase inverter is operably connected to an electric motor, and

wherein the three-phase inverter is operated based on the calculated vector for each phase current in order control a drive torque of the electric motor.

2. A sensor arrangement for measuring phase currents of a device under test, the sensor arrangement comprising:

a component defining a crystal lattice with at least one defect, the component arranged in a region of the device under test; and

a processor operably connected to the component, the processor configured to (i) detect a magnetic field formed by a vector of a plurality of magnetic fields, each magnetic field of the plurality of magnetic fields induced by a corresponding phase current of a plurality of phase currents of the device under test, (ii) determine the vector of the plurality of magnetic fields based on the detected magnetic field, and (iii) calculate a vector for each phase current of the plurality of phase currents based on the determined vector of the plurality of magnetic fields and a coefficient matrix,

wherein the at least one defect is configured to generate an output corresponding to the detected magnetic field,

wherein the device under test is a three-phase inverter,

wherein the three-phase inverter is operably connected to an electric motor, and

wherein the three-phase inverter is operated based on the calculated vector for each phase current in order control a drive torque of the electric motor.

3. The method as claimed in claim 1 , wherein the plurality of phase currents includes three phases and the method further comprises:

positioning the sensor arrangement at approximately the same distance to each of the three phases of the device under test.

4. The method as claimed in claim 1 , wherein the output of the at least one defect has a fluorescent effect and the method further comprises:

detecting the magnetic field using an optically detected magnetic resonance (“ODMR”).

5. The method as claimed in claim 1 , wherein the output of the at least one defect induces a magnetic resonance and the method further comprises:

detecting the magnetic field using a photoelectric detection of the magnetic resonance (“PDMR”) measurement.

6. The method as claimed in claim 1 , further comprising:

determining the coefficient matrix using a calibration.

7. The method as claimed in claim 1 , further comprising:

determining the coefficient matrix using a trained neural network.

8. The sensor arrangement as claimed in claim 2 , wherein the crystal lattice is a diamond.

9. The sensor arrangement as claimed in claim 8 , wherein the at least one defect is formed as a nitrogen defect or a nitrogen-vacancy center (“NV center”).

10. The sensor arrangement as claimed in claim 2 , further comprising:

at least one microwave source.