System for contactless energy transfer, use of a system for contactless energy transfer and vehicle with a system for contactless energy transfer between a first vehicle component and a second vehicle component

A system for contactless energy transmission, comprising:

• a resonant transformer with a primary winding in a primary core, a secondary winding in a secondary core mechanically not connected to the primary core, and at least one capacitor with variable capacitance,
• a secondary control unit connected to the capacitor in a controlling manner, and
• a secondary measuring device connected to the secondary winding and to the secondary control unit for acquiring an electrical state variable in the secondary winding,
• wherein the secondary control unit is configured to provide a signal for a capacitance change in the capacitor, depending on the change in the electrical state variable.

A method for calibrating a system for contactless energy transmission, comprising the steps of:

• applying a primary voltage from a primary inverter to a primary winding,
• acquiring a state point in a secondary winding into which from the primary winding a voltage is induced, by measuring electrical state variables in the secondary winding,
• analyzing the state point for iterative optimization, and
• in the case of a deviation from an optimum operating point, transmitting a signal to a primary control unit connected to the primary winding and to the primary inverter, to change the frequency of the applied primary voltage.

A vehicle, comprising a system for wireless energy transmission, the system comprising:

• a resonant transformer with a primary winding in a primary core, a secondary winding in a secondary core mechanically not connected to the primary core, and at least one capacitor,
• a primary control unit,
• a secondary control unit,
• a measuring device connected to the secondary winding and to the secondary control unit for acquiring an electrical state variable in the secondary winding,
• a primary inverter, connected to the primary winding, with variable frequency, and
• a modulator-demodulator device for transmitting data between the primary control unit and the secondary control unit by way of the transformer,
• wherein the primary control unit is connected in a controlling manner to the primary inverter, and the primary control unit is configured to change the frequency of the primary inverter when the primary control unit receives a frequency change signal, and
• the secondary control unit is configured, depending on the change in the electrical state variable, to transmit a signal for a frequency change in the primary inverter to the primary control unit.