Device and method for detecting a polarity reversal on a low voltage side of a DC voltage transformer in a dual-voltage vehicle electrical system

• US 9,287,704 B2
• Filed: 11/12/2010
• Issued: 03/15/2016
• Est. Priority Date: 12/28/2009
• Status: Active Grant

• Current Assignee: Robert Bosch GmbH
• Original Assignee: Robert Bosch GmbH
• Inventors: Pushkolli, Beqir, Knorpp, Thomas, Ruffer, Michael, Scheidle, Alexander
• Primary Examiner(s): Nguyen, Tung X
• Assistant Examiner(s): Le, Thang
• Application Number:
  US13/519,503
• Publication Number:
  US 20130021019A1
• Time in Patent Office: 1,950 Days
• Field of Search: 324/133, 324/120, 324/126, 324/127, 324/117.R, 324/444
• US Class Current: 1/1
• CPC Class Codes: B60L 3/003 relating to inverters
• CPC Class Codes: B60L 58/20 having different nominal voltages
• CPC Class Codes: H02J 1/08 Three-wire systems; Systems having more than three wires
• CPC Class Codes: H02J 1/082 Plural DC voltage, e.g. DC supply voltage with at least two different DC voltage levels
• CPC Class Codes: H02J 7/0034 using reverse polarity correcting or protecting circuits mechanical means of polarity protection H02J7/0045
• CPC Class Codes: Y02T 10/70 Energy storage systems for electromobility, e.g. batteries

Abstract

A device and a method for detecting a polarity reversal on a low voltage side of a DC voltage transformer in a dual-voltage vehicle electrical system, particularly in a motor vehicle. A current flow is enabled, in this instance, in a connecting line on the low voltage side of the DC voltage transformer by a controllable switching element, a current is detected in a connecting line on the low voltage side of the DC voltage transformer, with the aid of a current sensor system, the direction of the detected current is evaluated by an evaluation unit and a polarity reversal is detected if the direction of the detected current differs from an expected current direction.

Claims

1. A device for detecting a polarity reversal on a low voltage side of a DC voltage transformer in a dual-voltage vehicle electrical system, comprising:

a controllable switching element for selectively enabling and interrupting a current flow in a connecting line on the low voltage side of the DC voltage transformer;

a current sensor system for detecting the current in the connecting line on the low voltage side of the DC voltage transformer; and

an evaluation unit for evaluating the direction of the detected current and for detecting a polarity reversal if the direction of the detected current deviates from an expected current direction;

wherein, in a standby mode of the DC voltage transformer, the switching element is closed by the control unit at regular time intervals.

2. The device of claim 1, wherein, after the closing of the switching element, the evaluation unit compares a sign of the detected current to an expected sign and detects a polarity reversal if the signs deviate from each other.

3. The device of claim 1, wherein, upon activation of the DC voltage transformer, the switching element is closed by a control unit.

4. A method for detecting a polarity reversal on a low voltage side of a DC voltage transformer in a dual-voltage vehicle electrical system, the method comprising:

enabling a current flow in a connecting line on the low voltage side of the DC voltage transformer by a controllable switching element;

detecting the current in the connecting line on the low voltage side of the DC voltage transformer;

evaluating the direction of the detected current; and

detecting a polarity reversal if the direction of the detected current deviates from an expected current direction;

wherein, in a standby mode of the DC voltage transformer, the switching element is closed at regular time intervals.

5. The method of claim 4, wherein a sign of the detected current is compared to an expected sign, and a polarity reversal is detected if the signs deviate from each other.

6. The method of claim 4, wherein, upon activation of the DC voltage transformer, the switching element is closed.