Primary Unit for an Inductive Charging System and Method for Operating a Primary Unit

A primary unit for an inductive charging system configured to transfer energy from the primary unit to a secondary unit via a magnetic field, comprising:

• a primary coil configured to generate the magnetic field in response to a coil current through the primary coil;
• a first inverter coupled to the primary coil via a first capacitor and configured to charge or discharge the first capacitor based on a first input voltage;
• a second inverter coupled to the primary coil via a second capacitor and configured to charge or discharge the second capacitor based on a second input voltage;
• and
• a control unit configured to:
• ascertain a capacitance information item with respect to an effective capacitance of a primary resonant circuit of the primary unit, wherein the primary resonant circuit comprises the primary coil;
• and
• drive the first inverter and the second inverter based on the capacitance information item in order to bring about the coil current through the primary coil.

A method for operating a primary unit of an inductive charging system configured to transfer energy from the primary unit to a secondary unit via a magnetic field;

• wherein
• the primary unit comprises a primary coil configured to generate the magnetic field in response to a coil current through the primary coil;
• the primary unit comprises a first inverter coupled to the primary coil by a first capacitor and configured to charge or discharge the first capacitor based on a first input voltage;
• and
• the primary unit comprises a second inverter coupled to the primary coil via a second capacitor and configured to charge or discharge the second capacitor based on a second input voltage;
• the method comprising:
• ascertaining a capacitance information item in relation to an effective capacitance of a primary resonant circuit of the primary unit, wherein the primary resonant circuit comprises the primary coil;
• and
• driving the first inverter and the second inverter based on the capacitance information item in order to bring about the coil current through the primary coil.