System for inductively transmitting power from a primary device to a secondary device, primary device, and method for operating such a system

A primary device for inductively transmitting power from the primary device to a secondary device, comprising:

• a control unit and a primary device interface;
• wherein the control unit is designed to record a frequency parameter of the primary device and to record, via the primary device interface, secondary power data of a secondary device coupled to the primary device for inductively transmitting power;
• wherein the control unit is designed to determine an actual distance between the primary device and the secondary device using a distance characteristic field, the recorded secondary power data and the recorded frequency parameter;
• and
• wherein the distance characteristic field includes reference secondary power data as a function of reference frequency parameters and as a function of reference distances.

A method for operating a system for inductively transmitting power from a primary device to a secondary device;

• comprising:
• recording a frequency parameter of the primary device and secondary power data of the secondary device during power transmission;
• and
• determining an actual distance between the primary device and the secondary device using a distance characteristic field, the recorded secondary power data and the frequency parameter;
• wherein the distance characteristic field includes reference secondary power data as a function of reference frequency parameters and as a function of reference distances.