CURRENT SENSOR

Abstract

A battery sensor for detecting a current flowing through an electrical conductor, wherein the battery sensor has at least two mutually independent measuring devices for detecting the current flowing through the electrical conductor. The measuring devices are structurally and/or electrically completely isolated from one another.

Claims

1. A battery sensor for detecting a current flowing through an electrical conductor, the battery sensor comprising: a first measuring device configured to detect the current flowing through the electrical conductor; and a second measuring device configured to detect the current flowing through the electrical conductor, wherein the first measuring device and the second measuring device are structurally and electrically isolated from each other.

2. The battery sensor as claimed in claim 1, further comprising: a first printed circuit board, wherein the first measuring device is disposed on the first printed circuit board; and a second printed circuit board, wherein the second measuring device is disposed on the second printed circuit board.

3. The battery sensor as claimed in claim 2, further comprising: a first power supply electrically coupled to the first measuring device and configured to provide power to the first measuring device; and a second power supply electrically coupled to the second measuring device and configured to provide power to the second measuring device.

4. The battery sensor as claimed in claim 3, wherein the first measuring device comprises a first signal input and a first signal output and the second measuring device comprises a second signal input and a second signal output.

5. (canceled)

6. The battery sensor as claimed in claim 1, wherein at least one of the first measuring device and the second measuring device functions according to a magnetic measuring principle, and wherein the at least one of the first measuring device and the second measuring device comprises a Hall sensor.

7. The battery sensor as claimed in claim 1, wherein the first measuring device comprises a measuring resistor and a voltage detection device for detecting a voltage drop across the measuring resistor.

8. The battery sensor as claimed in claim 7, wherein the second measuring device comprises a circuit configured to electrically isolate the second measuring device from signal inputs or signal outputs of the first measuring device.

9. The battery sensor as claimed in claim 8, wherein the circuit comprises at least one transformer.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Further advantages and features are found in the following description in conjunction with the accompanying drawings, in which:

[0017] FIG. 1 shows a schematic illustration of a battery sensor;

[0018] FIG. 2 shows a second schematic illustration of a battery sensor; and

[0019] FIG. 3 shows a perspective view of a battery sensor.

DETAILED DESCRIPTION

[0020] The current sensor has an electrical conductor (busbar 800V) which is arranged in the high-voltage circuit and through which the battery current therefore flows. The current sensor is preferably used in vehicles with an electric drive or hybrid drive in order to measure the high currents provided by the vehicle battery or the high currents applied during charging.

[0021] A first measuring device is provided on a first section of the electrical conductor, in which a contactless current measurement is performed using a magnetic measuring principle by way of a Hall sensor (contactless ASIC or open loop HALL). The Hall sensor is supplied with power by a low-voltage circuit with 5V (power supply 2), for example by a vehicle battery (12V). Furthermore, the Hall sensor has a signal output (analog out) for outputting the measured values. The Hall sensor itself is not connected to the electrical conductor and therefore has no electrical contact with the high-voltage side (HV). The Hall sensor is therefore located entirely on the low-voltage side (LV).

[0022] A second measuring device is provided on a second section, having a measuring resistor (shunt) and a measuring apparatus (shunt Quibz+Z), which makes contact with the electrical conductor in each case upstream and downstream of the measuring resistor. The measuring device can measure the voltage upstream and downstream of the measuring resistor and thus the voltage drop across the measuring resistor. The current flowing via the measuring resistor can be calculated from the voltage difference and the known electrical resistance of the measuring resistor by way of Ohms law.

[0023] The second measuring device also has a low-voltage power connection with 5 V or 12 V (power supply 1) and a signal output (CAN out) for outputting the measured values.

[0024] As can be seen in particular in FIG. 1, the second measuring device is connected to the high-voltage circuit via the connections upstream and downstream of the measuring resistor. The isolation between the high-voltage side and the low-voltage side takes place here in the power supply (DC/DC) or in the correspondingly isolated signal output (isolated CAN driver). On the printed circuit board of the second measuring device, for example, the power supply and the signal output are isolated via a transformer that isolates the high-voltage side and the low-voltage side from one another.

[0025] Alternatively, other apparatuses of the design measures can be provided, which enable signal transmission or power supply but reliably exclude a voltage.

[0026] In order to ensure that the Hall sensor and the shunt measurement are completely independent of each other, they are arranged on different sections of the electrical conductor.

[0027] Furthermore, the power supply for both measuring devices is independent of each other, that is to say errors within the power supply only affect the respective measuring device and not both measuring devices.

[0028] In addition, as can be seen in FIG. 3, separate printed circuit boards (PCB1, PCB2) are provided for both measuring devices. This ensures that the measuring devices are completely isolated from each other and cannot influence each other. In particular, the measuring devices can be spatially positioned relative to one another in any way. In addition, different printed circuit boards can be selected, for example, in order to minimize production influences, for example.

[0029] In addition, design measures for isolating the printed circuit boards may be provided in order to exclude any mutual dismissal. For example, a galvanic isolation or decoupling can be provided.