Method for analyzing the contact assignment of a contact element of a cell module for a vehicle battery and module charger having a diagnosis function for the contact assignment of a contact element
A method for analyzing the contact assignment of a contact element of a cell module for a vehicle battery to charge or discharge individual cells. A module charger charges/discharges the cell module and includes a diagnosis function for the contact assignment of the contact element. A method is disclosed for operating a module charger, which allows for charging and discharging cells of different cell modules with different contact assignments and automatically prevents incorrect operation. The method includes connecting a contact element of a diagnosis unit corresponding to the contact element to establish an electrical connection with each contact. A voltage measurement is taken of a contact against all other individual contacts, and the voltage values assigned to the contacts are saved. Then, based on the assigned voltage values, the contact assignment with respect to the individual cells is determined and, finally, the cell module is charged or discharged.
1 . A method for analyzing the electrical contact assignment of a cell module contact system of a cell module for a vehicle battery in order to subsequently charge or discharge individual cells of the cell module by a module charger, comprising the following steps in the following order:
connecting a contact system to said cell module contact system,
performing at least one voltage measurement of a contact against all other individual contacts of the contact system and storing the voltage values assigned to the contacts,
wherein, when performing the at least one voltage measurement, each individual contact is measured against every further contact of the cell module contact system and the respective voltage difference between the two contacts measured in each case is stored for determining the electrical contact assignment,
determining the electrical contact assignment of the individual contacts of the contact system with respect to the connection to the individual cells of the cell module on the basis of the voltage values assigned to the respective contacts, and finally
charging or discharging the cell module.
2 . The method for analyzing the contact assignment according to claim 1 wherein, when performing the voltage measurement, firstly all further contacts are measured against a first individual contact in a respective first measurement and, subsequently, only the contacts for which a voltage of zero was measured in the first measurement are measured against a second individual contact in another measurement.
3 . The method for analyzing the contact assignment according to claim 1 , wherein the voltage values assigned to the contacts for determining the electrical contact assignment of the contact element are sorted according to their order of the absolute voltage values or according to the order of the smallest differential voltage that is not equal to zero with respect to one another, in order to thus identify the contacts in the order in which they are connected to the individual cells of the cell module arranged in series.
4 . The method for analyzing the contact assignment according to claim 1 , wherein, after the voltage measurement, a resistance measurement is also carried out for at least some of the contacts against every other contact, for which purpose a constant current is switched to each pair of contacts to be measured one against the other and, subsequently, the resistance between both contacts is measured.
5 . The method for analyzing the contact assignment according to claim 4 , wherein a resistance measurement is only carried out for contacts for which no voltage or rather a voltage of zero was measured during the previous voltage measurement.
6 . The method for analyzing the contact assignment according to claim 1 , wherein during the charging and/or discharging a further measurement of the voltage and/or resistance is performed, wherein only a measurement of the voltage and/or resistance of the contacts that are relevant to the cell being charged or discharged takes place.
7 . The method for analyzing the contact assignment according to claim 1 , wherein during the charging and/or discharging multiple power supplies and/or discharging units are switched on or off as required during the charging and/or discharging.
8 . A module charger for charging and discharging a cell module of a vehicle battery and having a diagnosis function for the electrical contact assignment of a cell module contact system of the cell module, comprising:
a contact system of the module charger corresponding to said cell module contact system for establishing an electrical connection with each of the contacts of the cell module, wherein
each contact is connected to two diagnosis lines of the module charger via one switch of an electronic switching unit in each case, such that each contact can be connected to the first or to the second diagnosis line via the two switches,
a voltage measuring unit for measuring the voltage difference between the individual contacts each connected to one of the diagnosis lines for subsequently saving the measured voltages of each contact,
a circuit configured to carry out the diagnosis function and to determine the electrical contact assignment of the contact system with respect to the connection to the individual cells of the cell module based on the measured voltages of each contact, and
a charging and/or discharging unit for adjusting the cell voltage of the cell module.
9 . The module charger for charging and discharging a cell module according to claim 8 , wherein the electronic switching unit is formed by an optoelectronically galvanically isolated switch.
10 . The module charger for charging and discharging a cell module according to claim 8 , wherein the electronic switching unit is designed and/or controlled such that activation of both switches simultaneously is excluded.