Resonance converter for wireless charger and method for implementing the same

A resonance converter for a wireless charger, comprising:

• a full bridge inverter connected to an input power source that supplies an input voltage and having first to fourth switches;
• a resonance tank comprising,
• a primary resonance tank comprising at least one first resonator and configured to receive the input voltage from the full bridge inverter and at least one first intermediate resonator loosely coupled to the at least one first resonator, and
• a secondary resonance tank comprising at least one second resonator and coupled to a rectification bridge and at least one second intermediate resonator loosely coupled to the at least one second resonator;
• and
• the rectification bridge configured to rectify an output voltage sent from the secondary resonance tank and transfer the rectified output voltage to a battery.

A resonance converter for a wireless charger, comprising:

• a full bridge inverter connected to an input power source that supplies an input voltage and having first to fourth switches;
• a resonance tank comprising,
• a primary resonance tank comprising at least one first resonator and configured to receive the input voltage from the full bridge inverter and at least one first intermediate resonator loosely coupled to the at least one first resonator, and
• a secondary resonance tank comprising at least one second resonator and coupled to a rectification bridge and at least one second intermediate resonator loosely coupled to the at least one second resonator;
• the rectification bridge configured to rectify an output voltage sent from the resonance tank and transfer the rectified output voltage to a battery;
• and
• a control circuit configured to control the full bridge inverter and a sufficient phase margin is provided at a crossover frequency of a constant-current mode for constant-current charging of the battery and a constant-voltage mode for constant-voltage charging of the battery.

A method for implementing a resonance converter for a wireless charger, wherein the resonance converter performs voltage conversion in an inductive power transfer manner between a primary resonance tank having at least one first resonator and at least one first intermediate resonator loosely coupled to the at least on first resonator and at least one secondary resonance tank having a second resonator and at least one second intermediate resonator loosely coupled to the at least one second resonator, to transfer a voltage of an input terminal connected to the primary resonance tank to an output terminal connected to the secondary resonance tank, the method comprising:

• setting self-inductance of a first coil included in the at least one first resonator and a fourth coil included in the at least one second resonator to maximize a coupling coefficient between the first coil and the fourth coil;
• calculating the number of turns of a second coil included in the at least one first intermediate resonator and a third coil included in the at least one second intermediate resonator and the second coil and the third coil respectively have a maximum quality recognition value;
• setting resonance frequencies of the first to fourth coils;
• and
• calculating capacitance of first to fourth capacitors connected to the first to fourth coils in series depending on the inductance and the resonance frequency of the first to fourth coils, thereby implementing the resonance tank.