Wireless power transfer method, apparatus and system for low and medium power

A method of receiving power in a wireless manner from a wireless power transmitter using full and half-bridge inverter topologies, the method comprising:

• receiving a detection signal from the wireless power transmitter;
• transmitting at least one of an identification packet or configuration information to the wireless power transmitter;
• receiving a power signal controlled by a driving frequency from the half-bridge inverter to control an amount of power to be transferred;
• transmitting a control error packet from a wireless power receiver to the wireless power transmitter;
• and
• receiving a power signal controlled by at least one of the driving frequency or a duty cycle from the full-bridge inverter to control an amount of power to be transferred,
• wherein the inverter topology is changed from the half-bridge into the full-bridge after the control error packet is transmitted if the wireless power receiver is a medium power wireless receiver.

A wireless power transmitter using full and half-bridge inverter topologies, the wireless power transmitter configured to:

• detect whether or not a wireless power receiver is present;
• transmit a detection signal to the wireless power receiver;
• receive at least one of an identification packet or configuration information from the wireless power receiver;
• applying a power signal by controlling a driving frequency to the half-bridge inverter to control an amount of power to be transferred;
• receive a control error packet from the wireless power receiver;
• changing the inverter topology from the half-bridge into the full-bridge after receiving the control error packet if the wireless power receiver is a medium power wireless receiver;
• and
• applying a power signal by controlling at least one of the driving frequency or a duty cycle to the full bridge inverter to control an amount of power to be transferred.

A wireless charging system comprising:

• a wireless power transmitter configured to transmit power in a wireless manner;
• and
• a wireless power receiver configured to receive the power from the wireless power transmitter in the wireless manner,
• wherein a power transfer unit of the wireless power transmitter comprises an LC circuit configured to be switched between a full-bridge and a half-bridge,
• wherein the wireless power receiver further configured to:
• transmit a control error packet from the wireless power receiver to the wireless power transmitter;
• and
• receive a power signal controlled by at least one of the driving frequency or a duty cycle from the full-bridge inverter to control an amount of power to be transferred,
• wherein the inverter topology is changed from the half-bridge into the full-bridge after the control error packet is transmitted if the wireless power receiver is a medium power wireless receiver.