Back to results
US 8,618,789 B2Granted
Method and apparatus of offset error compensation for current measurement in phase lines of a multiphase current network
AssigneeRobert Bosch GmbH
InventorsSven Finke, Timo Kuehn
Life of this patent
Estimating the term…
Abstract
In a method for current measurement in a multiphase current network, a conductive connection is produced between a plurality of the phases of the multiphase current network such that the plurality of the phases is short-circuited with one another. At a detection time, a current value flowing between the conductive connection and a first voltage potential is detected.
Claims6
A method for current measurement in a multiphase current network, which has the following steps:
- detecting a first current value of a current flowing between a first phase of the multiphase current network and a first voltage potential at a first detection time;
- detecting a second current value of the current flowing between the first phase and the first voltage potential, at a second detection time, and the first detection time and the second detection time are selected such that the first current value and the second current value have different signs;
- and
- ascertaining a current value for the current from an average of the first current value and the second current value,
- wherein detection of the first current value and the second current value is done by means of a measuring device disposed between the first voltage potential and a plurality of first switches, and each phase of the multiphase current network is connected to the measuring device via a respective one of the plurality of first switches,
- wherein the measuring device includes a shunt resistor connected between the first voltage potential and the plurality of first switches through which the current flows,
- wherein each of the first switches is electrically connected to the shunt resistor, and
- wherein the first switch connected to the first phase is the only first switch closed at the first detection time such that the current flowing through the shunt resistor corresponds to the current flowing into the first phase and the first switch connected with the first phase is the only first switch opened at the second detection time such that the current flowing through the shunt resistor corresponds to the current flowing out of the first phase.
5 more elements
An apparatus for current measurement in a multiphase current network, the apparatus comprising:
- a shunt resistor via which the multiphase current network is connected to a first voltage potential;
- a plurality of first switches for connecting the multiphase current network to the shunt resistor, wherein each phase of the multiphase current network is connected to the shunt resistor via a respective one of the plurality of first switches;
- a measuring device for detecting a first current value of a current flowing between a first phase of the multiphase current network and the first voltage potential through the shunt resistor, at a first detection time and for detecting a second current value of the current, flowing between the first phase and the first voltage potential through the shunt resistor, at a second detection time, wherein the first detection time and the second detection time are selected such that the first current value and the second current value have different signs;
- and
- a device for ascertaining a current value for the current from an average of the first current value and the second current value,
- wherein the first switch connected to the first phase is the only first switch closed at the first detection time and the first switch connected with the first phase is the only first switch opened at the second detection time.
3 more elements
Dependencies are inferred from the claim text.