Bidirectional operation of wireless power systems

A method for operating an inverter-rectifier of a bidirectional wireless power transmitter, the method comprising:

• determining a power flow direction of the bidirectional wireless power transmitter;
• controlling, in response to a determination that the power flow direction is a first power flow direction, the inverter-rectifier to operate in a rectifier mode;
• generating, during the rectifier mode, a zero-crossing signal representing one or more zero-crossings of a current at an input of the inverter-rectifier, wherein rising edges of the zero-crossing signal indicate zero-crossings corresponding to a rise in the current and falling edges of the zero-crossing signal indicate zero-crossings corresponding to a fall in the current;
• determining, during the rectifier mode, a first delay time based on at least one bidirectional wireless power transmitter parameter and the zero-crossing signal;
• generating, during the rectifier mode, first and second control signals for first and second switches of the inverter-rectifier, respectively, based on the first delay time and the rising and falling edges of the zero-crossing signal;
• and
• providing, during the rectifier mode, the first and second control signals to the first and second switches, respectively.

An inverter-rectifier of a bidirectional wireless power transmitter, the inverter-rectifier comprising:

• a first switch and a second switch coupled to at least one coil of the bidirectional wireless power transmitter;
• and
• a control system coupled to each of the first switch and the second switch, the control system configured to:
• determine a power flow direction of the bidirectional wireless power transmitter;
• control, in response to a determination that the power flow direction is a first power flow direction, the inverter-rectifier to operate in a rectifier mode;
• generate, during the rectifier mode, a zero-crossing signal representing one or more zero-crossings of a current at an input of the inverter-rectifier, wherein rising edges of the zero-crossing signal indicate zero-crossings corresponding to a rise in the current and falling edges of the zero-crossing signal indicate zero-crossings corresponding to a fall in the current;
• determine, during the rectifier mode, a first delay time based on at least one bidirectional wireless power transmitter parameter and the zero-crossing signal;
• generate, during the rectifier mode, first and second control signals for first and second switches of the inverter-rectifier, respectively, based on the first delay time and the rising and falling edges of the zero-crossing signal;
• and
• provide, during the rectifier mode, the first and second control signals to the first and second switches, respectively.