Fault detection and monitoring methods for safe operation of a WEVC system

1. Base-side equipment of a wireless electric vehicle charging system, the base-side equipment comprising:

an inverter configured to provide a high frequency output;

tuning circuitry coupled to the inverter, the tuning circuitry configured to receive the high frequency output and provide an output power signal;

a coil coupled to the tuning circuitry, the coil configured to receive the output power signal and generate a magnetic field for delivery of power to vehicle-side equipment; and

monitoring circuitry between the inverter and the tuning circuitry, the monitoring circuitry configured to:

monitor voltage and current associated with operation of the base-side equipment; and

halt generation of the magnetic field in response to a change in the voltage, current, or voltage and current, that indicates a fault condition at the vehicle-side equipment.

2. The base-side equipment of claim 1 , wherein the fault condition is a loss of power or a disconnection of the vehicle-driving battery.

3. The base-side equipment of claim 1 , wherein the generation of the magnetic field is halted based on an interruption of the output power signal.

4. The base-side equipment of claim 1 , further comprising a power-factor-correction circuit coupled to a power source and configured to provide a direct current (DC) output to the inverter.

5. The base-side equipment of claim 1 , wherein:

the base-side equipment is configured to generate the magnetic field in response to power requests from the vehicle-side equipment; and

the monitoring circuitry is configured to compare a previous power request from the vehicle-side equipment with data representing present operation of the base-side equipment.

6. The base-side equipment of claim 1 , wherein:

the base-side equipment is configured to generate the magnetic field in response to power requests received from the vehicle-side equipment; and

the monitoring circuitry is further configured to:

determine a known performance value associated with the voltage, current, or voltage and current;

predict an expected value of a second voltage, a second current, or a second voltage and current associated with operation of the vehicle-side equipment based on a combination of a last received power request from the vehicle-side equipment and data representing operation of the base-side equipment; and

halt the generation of the magnetic field in response to a deviation in the known performance value from the expected value that exceeds a threshold value.

7. The base-side equipment of claim 1 , wherein:

the base-side equipment is configured to generate the magnetic field in response to power requests from the vehicle-side equipment; and

the monitoring circuitry is configured to compare a present power request from the vehicle-side equipment with a previous power request from the vehicle-side equipment.

8. The base-side equipment of claim 1 , wherein the monitoring circuitry is configured to determine the fault condition at the vehicle-side equipment based on a decrease in a value of the current.

9. The base-side equipment of claim 1 , wherein the monitoring circuitry is configured to determine the fault condition at the vehicle-side equipment based on a decrease in a value of the voltage.

10. The base-side equipment of claim 1 , wherein the monitoring circuitry is configured to determine the fault condition at the vehicle-side equipment based on a decrease in a first root mean square (RMS) value of the current and in a second RMS value of the voltage.

11. A method of controlling operation of a wireless electric vehicle charging system, the method comprising:

generating a magnetic field by base-side equipment of the wireless electric vehicle charging system to transfer power to vehicle-side equipment of the wireless electric vehicle charging system;

monitoring a voltage, a current, or a voltage and a current associated with operation of the base-side equipment between tuning circuitry of the base-side equipment and an inverter of the base-side equipment during power transfer from the base-side equipment to the vehicle-side equipment;

detecting a change in the voltage, the current, or the voltage and a current indicative of a fault condition in the vehicle-side equipment; and

halting generation of the magnetic field in response to detecting the change.

12. The method of claim 11 , wherein the fault condition is a loss of power or a disconnection of the vehicle-driving battery.

13. The method of claim 11 , wherein:

the magnetic field is generated by a coil driven by an alternating current; and

the halting comprises interrupting the alternating current to the coil.

14. The method of claim 11 , further comprising providing a direct current (DC) output to the inverter from a power-factor-correction circuit coupled to a power source.

15. The method of claim 11 , wherein:

the magnetic field is generated based on first data received from the vehicle-side equipment, the first data indicating a previous power measurement of the vehicle-side equipment; and

the method further comprises comparing the first data with second data representing present operation of the base-side equipment.

16. The method of claim 11 , wherein:

the magnetic field is generated based on first data received from the vehicle-side equipment, the first data indicating a power measurement of the vehicle-side equipment or a power request from the vehicle-side equipment; and

the method further comprises:

determining a known performance value based on the voltage, the current, or the voltage and current; and

predicting an expected value of a second voltage, a second current, or a second voltage and current associated with operation of the vehicle-side equipment based on a combination of the second data representing present operation of the base-side equipment and one of the power measurement of the vehicle-side equipment or the power request received from the vehicle-side equipment; and

halting generation of the magnetic field is performed in response to a deviation in a known performance value from the expected value that exceeds a threshold value.

17. The method of claim 11 , wherein:

the base-side equipment is configured to generate the magnetic field based on data received from the vehicle-side equipment that indicates vehicle-side power measurements; and

the method further comprises:

receiving first data indicating a first power measurement at the vehicle-side equipment;

subsequent to receiving the first data, receiving second data indicating a second power measurement at the vehicle-side equipment; and

comparing the second power measurement with the first power measurement to determine whether the fault condition has occurred at the vehicle-side equipment.

18. The method of claim 11 , further comprising determining the fault condition at the vehicle-side equipment based on a decrease in a value of the current.

19. The method of claim 11 , further comprising determining the fault condition at the vehicle-side equipment based on a decrease in a value of the voltage.

20. The method of claim 11 , further comprising determining the fault condition at the vehicle-side equipment based on a decrease in a first root mean square (RMS) value of the current and in a second RMS value of the voltage.