Device for monitoring an operation of an inductive element

• US 10,175,285 B2
• Filed: 11/04/2014
• Issued: 01/08/2019
• Est. Priority Date: 11/05/2013
• Status: Active Grant

• Current Assignee: Robert Bosch GmbH
• Original Assignee: Robert Bosch GmbH
• Inventors: Martini, Marco, Mueller, Bernd, Guenther, Uwe, Meli, Bertrand Eric, Henkel, Frank
• Primary Examiner(s): Le, Son
• Assistant Examiner(s): Zakaria, Akm
• Application Number:
  US14/532,286
• Publication Number:
  US 20150123675A1
• Time in Patent Office: 1,526 Days
• Field of Search: 324546
• CPC Class Codes: G01R 31/72 Testing of electric windings testing of transformers G01R31/62

Abstract

A device for monitoring an operation of an inductive element, includes a current-measuring device is switched in series with the inductive element. The device is configured to ascertain a first time-discrete and value-discrete signal, which characterizes a current flowing through the current-measuring device; to ascertain a second time-discrete and value-discrete signal, which characterizes a current flowing through the current-measuring device and has a predefinable time shift in relation to the first signal; and to infer the presence of a shunt from a comparison of the first signal with the second signal. Also described is a method for monitoring the operation of the inductive element.

Claims

1. A device for monitoring an operation of an inductive element, comprising:

a current-measuring device connected in series with the inductive element;

a determining arrangement to ascertain a first time-discrete and value-discrete signal, which characterizes a current flowing through the current-measuring device, to ascertain a second time-discrete and value-discrete signal, which characterizes a current flowing through the current-measuring device and has a predefinable time shift in relation to the first signal, and to infer the presence of an undesired shunt from a comparison of the first signal with the second signal, wherein the determining arrangement is configured to obtain the second signal from the first signal through a delay operation;

a switch arrangement coupled to a first terminal of the current-measuring device, wherein a second terminal of the current-measuring device is coupled to a terminal of the inductive element; and

a control and driving arrangement coupled to the determining arrangement and coupled to the switch arrangement to control and drive the switch arrangement;

wherein the determining arrangement is configured to ascertain the first signal in that a voltage drop that arises in the current-measuring device and characterizes the current flowing through the current-measuring device, is ascertained and converted into the first signal by an A/D converter,

wherein one of (i) and (ii) is satisfied;

(i) the determining arrangement is configured to perform the following within the framework of the comparison;

forming a signal that characterizes a difference between the first signal and the second signal; and

comparing the signal that characterizes the difference between the at least one of the first signal and the second signal or a signal derived therefrom, with a corresponding predefinable threshold value, and

wherein the determining arrangement is configured to subject the signal that characterizes the difference between the at least one of the first signal and the second signal or a signal derived therefrom to at least one of filtering, decimation, and a sampling-rate reduction, and

(ii) the determining arrangement is configured to perform the following within the framework of the comparison;

subjecting the at least one of the first signal and the second signal to an adaptive process to obtain an adapted first signal and an adapted second signal;

determining a difference between the adapted first signal and the adapted second signal to obtain a signal that characterizes the difference between the adapted first signal and the adapted second signal; and

comparing the signal that characterizes the difference between the adapted first signal and the adapted second signal with a corresponding predefinable threshold value;

wherein at least one of (i) the adapted first signal, (ii) the adapted second signal, and (iii) the signal that characterizes the difference between the adapted first signal and the adapted second signal, has a different sampling rate than the at least one of the first signal and the second signal.

2. The device of claim 1, wherein the determining arrangement is configured to perform the following within the framework of the comparison:

subjecting the at least one of the first signal and the second signal to at least one of filtering, decimation, and a sampling-rate reduction to obtain at least one of a filtered first signal and a sampling-rate-reduced first signal and at least one of a filtered second signal and a sampling-rate-reduced second signal;

determining a difference between the at least one of the filtered first signal and a sampling-rate-reduced first signal and the at least one of the filtered second signal and the sampling-rate-reduced second signal, through a difference calculation, to obtain a signal that characterizes the difference between the at least one of the filtered first signal, the sampling-rate-reduced first signal and the at least one of the filtered second signal and the scanning-rate reduced second signal; and

comparing the signal that characterizes the difference between the at least one of the filtered first signal and the sampling-rate-reduced first signal and the at least one of the filtered second signal and the sampling-rate-reduced second signal or a signal derived therefrom, with a corresponding predefinable threshold value.

9. The device of claim 1, wherein the determining arrangement is configured to ascertain the first signal in that a voltage drop that arises in the current-measuring device and characterizes the current flowing through the current-measuring device, is ascertained and converted into the first signal by a sigma-delta A/D converter.

10. The device of claim 1, wherein the determining arrangement is configured to perform the following within the framework of the comparison:

determining a signal that characterizes a difference between the first signal and the second signal, by a difference calculation of the signals; and

comparing the signal that characterizes the difference between the first signal and the second signal or a signal derived therefrom, with a corresponding predefinable threshold value.

11. The device of claim 1, wherein the determining arrangement is configured to perform the following within the framework of the comparison:

subjecting the at least one of the first signal and the second signal to an adaptive process to obtain an adapted first signal and an adapted second signal;

determining a difference between the adapted first signal and the adapted second signal to obtain a signal that characterizes the difference between the adapted first signal and the adapted second signal; and

comparing the signal that characterizes the difference between the adapted first signal and the adapted second signal with a corresponding predefinable threshold value;

wherein at least one of (i) the adapted first signal, (ii) the adapted second signal, and (iii) the signal that characterizes the difference between the adapted first signal and the adapted second signal, has a different sampling rate than the at least one of the first signal and the second signal.

12. The device of claim 1, wherein the different sampling rate is lower than the at least one of the first signal and the second signal.

3. A device for monitoring an operation of an inductive element, a current-measuring device being connected in series with the inductive element, comprising:

a determining arrangement to ascertain a first time-discrete and value-discrete signal, which characterizes a current flowing through the current-measuring device, to ascertain a second time-discrete and value-discrete signal, which characterizes a current flowing through the current-measuring device and has a predefinable time shift in relation to the first signal, and to infer the presence of an undesired shunt from a comparison of the first signal with the second signal;

wherein the determining arrangement is configured to obtain the second signal from the first signal through a delay operation,

wherein the determining arrangement is configured to perform the following within the framework of the comparison;

subjecting the at least one of the first signal and the second signal to at least one of filtering, decimation, and a sampling-rate reduction to obtain at least one of a filtered first signal and a sampling-rate-reduced first signal and at least one of a filtered second signal and a sampling-rate-reduced second signal;

determining a difference between the at least one of the filtered first signal and a sampling-rate-reduced first signal and the at least one of the filtered second signal and the sampling-rate-reduced second signal, through a difference calculation, to obtain a signal that characterizes the difference between the at least one of the filtered first signal, the sampling-rate-reduced first signal and the at least one of the filtered second signal and the scanning-rate reduced second signal; and

comparing the signal that characterizes the difference between the at least one of the filtered first signal and the sampling-rate-reduced first signal and the at least one of the filtered second signal and the sampling-rate-reduced second signal or a signal derived therefrom, with a corresponding predefinable threshold value, and

wherein at least one of (i) the at least one of the filtered first signal and the sampling-rate-reduced first signal, (ii) the at least one of the filtered second signal and the sampling-rate-reduced second signal, and (iii) the signal that characterizes the difference between the at least one of the filtered first signal and the sampling-rate-reduced first signal and the at least one of the filtered second signal and the sampling-rate-reduced second signal, has a lower sampling rate than the at least one of the first signal and the second signal.

4. A method for monitoring an operation of an inductive element, a current-measuring device being connected in series with the inductive element, the method comprising:

ascertaining, via a determining arrangement, a first time-discrete and value-discrete signal, which characterizes a current flowing through the current measuring device;

ascertaining, via the determining arrangement, a second time-discrete and value-discrete signal, which characterizes a current flowing through the current-measuring device and which has a predefinable time shift in relation to the first signal; and

comparing the first signal with the second signal to infer the presence of an undesired shunt;

wherein the second signal is formed from the first signal through a delay operation

wherein a switch arrangement is coupled to a first terminal of the current-measuring device, and wherein a second terminal of the current-measuring device is coupled to a terminal of the inductive element,

wherein a control and driving arrangement is coupled to the determining arrangement and coupled to the switch arrangement to control and drive the switch arrangement,

wherein the determining arrangement is configured to ascertain the first signal in that a voltage drop that arises in the current-measuring device and characterizes the current flowing through the current-measuring device, is ascertained and converted into the first signal by an A/D converter,

wherein one of (i) and (ii) is satisfied;

(i) the determining arrangement is configured to perform the following within the framework of the comparison;

forming a signal that characterizes a difference between the first signal and the second signal; and

comparing the signal that characterizes the difference between the at least one of the first signal and the second signal or a signal derived therefrom, with a corresponding predefinable threshold value, and

wherein the determining arrangement is configured to subject the signal that characterizes the difference between the at least one of the first signal and the second signal or a signal derived therefrom to at least one of filtering, decimation, and a sampling-rate reduction, and

(ii) the determining arrangement is configured to perform the following within the framework of the comparison;

subjecting the at least one of the first signal and the second signal to an adaptive process to obtain an adapted first signal and an adapted second signal;

determining a difference between the adapted first signal and the adapted second signal to obtain a signal that characterizes the difference between the adapted first signal and the adapted second signal; and

comparing the signal that characterizes the difference between the adapted first signal and the adapted second signal with a corresponding predefinable threshold value;

wherein at least one of (i) the adapted first signal, (ii) the adapted second signal, and (iii) the signal that characterizes the difference between the adapted first signal and the adapted second signal, has a different sampling rate than the at least one of the first signal and the second signal.

5. The method of claim 4, wherein the following are performed within the framework of the comparison:

subjecting at least one of the first signal and the second signal to at least one of filtering, decimation and a sampling-rate reduction to obtain at least one of a filtered first signal and the sampling-rate-reduced first signal and at least one of a filtered second signal and the sampling-rate-reduced second signal;

calculating a difference between the at least one of the filtered first signal and the sampling-rate-reduced first signal and the at least one of the filtered second signal and the sampling-rate-reduced second signal, by subtraction, to obtain a signal that characterizes the difference between the at least one of the filtered first signal and sampling-rate-reduced first signal and the filtered or sampling-rate-reduced second signal; and

comparing the signal that characterizes the difference between the filtered or sampling-rate-reduced first signal and the at least one of the filtered second signal and the sampling-rate-reduced second signal or a signal derived therefrom, with a corresponding predefinable threshold value.

7. The method of claim 4, wherein the first signal is ascertained in that a voltage drop that arises in the current-measuring device and characterizes the current flowing through the current-measuring device is ascertained and converted into the first signal by a sigma-delta A/D converter.

8. The method of claim 4, wherein the following are performed within the framework of the comparison:

forming a signal that characterizes a difference between the first signal and the second signal, by a difference calculation of the signals; and

comparing the signal that characterizes the difference between the first signal and the second signal or a signal derived therefrom, with a corresponding predefinable threshold value.

13. The method of claim 4, wherein the following are performed within the framework of the comparison:

subjecting the at least one of the first signal and the second signal to an adaptive process to obtain an adapted first signal and an adapted second signal;

determining a difference between the adapted first signal and the adapted second signal to obtain a signal that characterizes the difference between the adapted first signal and the adapted second signal; and

comparing the signal that characterizes the difference between the adapted first signal and the adapted second signal with a corresponding predefinable threshold value;

wherein at least one of (i) the adapted first signal, (ii) the adapted second signal, and (iii) the signal that characterizes the difference between the adapted first signal and the adapted second signal, has a different sampling rate than the at least one of the first signal and the second signal.

14. The method of claim 13, wherein the different sampling rate is lower than the at least one of the first signal and the second signal.

6. A method for monitoring an operation of an inductive element, a current-measuring device being connected in series with the inductive element, the method comprising:

ascertaining a first time-discrete and value-discrete signal, which characterizes a current flowing through the current measuring device;

ascertaining a second time-discrete and value-discrete signal, which characterizes a current flowing through the current-measuring device and which has a predefinable time shift in relation to the first signal; and

comparing the first signal with the second signal to infer the presence of an undesired shunt;

wherein the second signal is formed from the first signal through a delay operation,

wherein the following are performed within the framework of the comparison;

subjecting at least one of the first signal and the second signal to at least one of filtering, decimation and a sampling-rate reduction to obtain at least one of a filtered first signal and the sampling-rate-reduced first signal and at least one of a filtered second signal and the sampling-rate-reduced second signal;

calculating a difference between the at least one of the filtered first signal and the sampling-rate-reduced first signal and the at least one of the filtered second signal and the sampling-rate-reduced second signal, by subtraction, to obtain a signal that characterizes the difference between the at least one of the filtered first signal and sampling-rate-reduced first signal and the filtered or sampling-rate-reduced second signal; and

comparing the signal that characterizes the difference between the filtered or sampling-rate-reduced first signal and the at least one of the filtered second signal and the sampling-rate-reduced second signal or a signal derived therefrom, with a corresponding predefinable threshold value, and

wherein at least one of;

(i) the at least one of the filtered first signal and the sampling-rate-reduced first signal, (ii) the at least one of the filtered second signal and the sampling-rate-reduced second signal, and (iii) the signal that characterizes the difference between the at least one of the filtered first signal and the sampling-rate-reduced first signal and the at least one of the filtered second signal and the sampling-rate-reduced second signal, has a lower sampling rate than the first signal or the second signal.