Circuits, methods, and apparatus that may provide power supply voltages in a safe and reliable manner that meets safety and regulatory concerns and does not exceed physical limitations of cables and other circuits and components used to provide the power supply voltages. One example may provide a cable having a sufficient number of conductors to provide power without exceeding a maximum current density for the conductors. Another example may provide a cable having more than the sufficient number of conductors in order to provide an amount of redundancy. Current sense circuits may be included for one or more conductors. When an excess current is sensed, a power source in the power supply may be shut down, the power source may be disconnected from one or more conductors, or both events may occur.

Circuits, methods, and apparatus that may provide power supply voltages in a safe and reliable manner that meets safety and regulatory concerns and does not exceed physical limitations of cables and other circuits and components used to provide the power supply voltages. One example may provide a cable having a sufficient number of conductors to provide power without exceeding a maximum current density for the conductors. Another example may provide a cable having more than the sufficient number of conductors in order to provide an amount of redundancy. Current sense circuits may be included for one or more conductors. When an excess current is sensed, a power source in the power supply may be shut down, the power source may be disconnected from one or more conductors, or both events may occur.

A power supply with lightning protection includes a surge voltage suppression apparatus, an electromagnetic interference control circuit, a surge current bypass apparatus, an active bridge rectifier circuit, a power factor correction circuit, and a DC-to-DC conversion circuit. The surge voltage suppression apparatus is used to increase a tolerance of a surge voltage for the power supply. The electromagnetic interference control circuit is coupled to the surge voltage suppression apparatus. The surge current bypass apparatus is used to increase a tolerance of a surge current for the power supply. The active bridge rectifier circuit is used to rectify an input voltage. The power factor correction circuit is used to adjust the rectified input voltage to provide an adjusted input voltage on a bulk capacitor. The DC-to-DC conversion circuit is used to convert the adjusted input voltage into a DC output voltage.

A power device fault detection circuit includes a first fault detector configured to measure an output signal of at least one power device and output a first fault signal when a voltage of the output signal of the at least one power device exceeds a first voltage reference level after a first time period; and a second fault detector configured to measure an output signal of the at least one power device and output a second fault signal when a voltage of the output signal of the at least one power device exceeds a second voltage reference level after a second time period, where the first time period implemented by the first fault detector is shorter than the second time period implemented by the second fault detector.

Electric power is transferred to an electric load as alternating current over at least two incoming and outgoing lines. At least one line circuit manages at least one parameter of the transferred electric power. A central circuit exchanges data and/or commands with the at least one line circuit over a respective galvanically isolated communication interface, such that a reference potential of the central circuit is floating relative to an earth potential of the at least two incoming and outgoing lines. A respective surge protection capacitor is arranged in parallel with each galvanically isolated communication interface. The surge protection capacitors are configured to accumulate a respective fraction of an electric charge resulting from an undesired overvoltage on one of said incoming lines so as to split up the undesired overvoltage into two or more voltages over the galvanically isolated communication interfaces each of which voltage is smaller than the undesired overvoltage.

Electric power is transferred to an electric load as alternating current over at least two incoming and outgoing lines. At least one line circuit manages at least one parameter of the transferred electric power. A central circuit exchanges data and/or commands with the at least one line circuit over a respective galvanically isolated communication interface, such that a reference potential of the central circuit is floating relative to an earth potential of the at least two incoming and outgoing lines. A respective surge protection capacitor is arranged in parallel with each galvanically isolated communication interface. The surge protection capacitors are configured to accumulate a respective fraction of an electric charge resulting from an undesired overvoltage on one of said incoming lines so as to split up the undesired overvoltage into two or more voltages over the galvanically isolated communication interfaces each of which voltage is smaller than the undesired overvoltage.

A device includes a rectifier connected to a receiver coil, a first overvoltage protection apparatus connected between inputs of the rectifier and ground, and a second overvoltage protection apparatus connected between an output of the rectifier and ground, wherein in an overvoltage event, the first overvoltage protection apparatus and the second overvoltage protection apparatus are controlled based upon a comparison between a switching frequency of the device and a predetermine frequency threshold.

One general aspect includes methods, systems, and apparatus, including computer programs encoded on a computer storage medium, for fault protection of a bidirectional wireless power transfer system. The method includes the actions of detecting, by control circuitry of a wireless power transfer device, a fault for the bidirectional wireless power transfer system. Identifying an operating personality of the wireless power transfer device and a hardware configuration of the wireless power transfer device. Identifying, in response to detecting the fault and based on the operating personality and the hardware configuration, protection operations for protecting the wireless power transfer device from the fault. Controlling operations of the wireless power transfer device according to the protection operations. Other implementations of this aspect include corresponding systems, circuitry, controllers, apparatus, and computer programs, configured to perform the actions of the methods, encoded on computer storage devices.

In some examples, this disclosure describes a method for detecting a fault in an electrical power system comprising a bus connected between a first solid state power converter and a second solid state power converter. The method includes receiving, at a controller of the electrical power system, a first signal indicating a current at a source side of the first solid state power converter, wherein the source side of the first solid state power converter is connected to a power source of the electrical power system. The method also includes receiving, at the controller, a second signal indicating a current at the bus and determining, by the controller, that a fault occurred in the electrical power system based on the first signal and further based on the second signal. The method further includes controlling the first solid state power converter in response to determining that the fault occurred.

In some examples, this disclosure describes a method for detecting a fault in an electrical power system comprising a bus connected between a first solid state power converter and a second solid state power converter. The method includes receiving, at a controller of the electrical power system, a first signal indicating a current at a source side of the first solid state power converter, wherein the source side of the first solid state power converter is connected to a power source of the electrical power system. The method also includes receiving, at the controller, a second signal indicating a current at the bus and determining, by the controller, that a fault occurred in the electrical power system based on the first signal and further based on the second signal. The method further includes controlling the first solid state power converter in response to determining that the fault occurred.