A multi-stage electric voltage converter is disclosed. The converter comprises a voltage source and multiple stages. Each stage of the multiple stages comprises a first and a second and a third switch, and a capacitor, wherein the capacitor is coupled to the voltage source by the first and the second switches and each stage is coupled to a different stage or to an output of the multi-stage electric voltage converter by the third switch so as to allow the capacitor to be charged by the voltage source when the first and the second switches are closed and the third switch is open, and to allow the capacitor to be connected to the output of the multi-stage electric voltage converter when the first and the second switches are open and the third switch is closed.

A multi-stage electric voltage converter is disclosed. The converter comprises a voltage source and multiple stages. Each stage of the multiple stages comprises a first and a second and a third switch, and a capacitor, wherein the capacitor is coupled to the voltage source by the first and the second switches and each stage is coupled to a different stage or to an output of the multi-stage electric voltage converter by the third switch so as to allow the capacitor to be charged by the voltage source when the first and the second switches are closed and the third switch is open, and to allow the capacitor to be connected to the output of the multi-stage electric voltage converter when the first and the second switches are open and the third switch is closed.

A bidirectional power converter circuit is controlled via a hysteresis loop such that the bidirectional power converter circuit can compensate for variations and even changes in transmit and receive coil locations without damaging components of the system. Because the bidirectional power converter is capable of both transmitting and receiving power (at different times), one circuit and board may be used as the main component in multiple wireless power converter designs. A first bidirectional power converter is employed in a sealed battery unit having no external electrical contacts. A second bidirectional power converter is employed in a corresponding cart bidirectional power converter assembly. The battery unit and the cart bidirectional power converter assembly cooperate to wirelessly transmit power from the battery unit to a load of the cart bidirectional power converter assembly and from a power source to the battery unit via the cart bidirectional power converter assembly.

A bidirectional power converter circuit is controlled via a hysteresis loop such that the bidirectional power converter circuit can compensate for variations and even changes in transmit and receive coil locations without damaging components of the system. Because the bidirectional power converter is capable of both transmitting and receiving power (at different times), one circuit and board may be used as the main component in multiple wireless power converter designs. A first bidirectional power converter is employed in a sealed battery unit having no external electrical contacts. A second bidirectional power converter is employed in a corresponding cart bidirectional power converter assembly. The battery unit and the cart bidirectional power converter assembly cooperate to wirelessly transmit power from the battery unit to a load of the cart bidirectional power converter assembly and from a power source to the battery unit via the cart bidirectional power converter assembly.

A bidirectional power converter circuit is controlled via a hysteresis loop such that the bidirectional power converter circuit can compensate for variations and even changes in transmit and receive coil locations without damaging components of the system. Because the bidirectional power converter is capable of both transmitting and receiving power (at different times), one circuit and board may be used as the main component in multiple wireless power converter designs. A first bidirectional power converter is employed in a sealed battery unit having no external electrical contacts. A second bidirectional power converter is employed in a corresponding cart bidirectional power converter assembly. The battery unit and the cart bidirectional power converter assembly cooperate to wirelessly transmit power from the battery unit to a load of the cart bidirectional power converter assembly and from a power source to the battery unit via the cart bidirectional power converter assembly.

A bidirectional power converter circuit is controlled via a hysteresis loop such that the bidirectional power converter circuit can compensate for variations and even changes in transmit and receive coil locations without damaging components of the system. Because the bidirectional power converter is capable of both transmitting and receiving power (at different times), one circuit and board may be used as the main component in multiple wireless power converter designs. A first bidirectional power converter is employed in a sealed battery unit having no external electrical contacts. A second bidirectional power converter is employed in a corresponding cart bidirectional power converter assembly. The battery unit and the cart bidirectional power converter assembly cooperate to wirelessly transmit power from the battery unit to a load of the cart bidirectional power converter assembly and from a power source to the battery unit via the cart bidirectional power converter assembly.

Systems and methods for electrical power conversion include the provision of a full-bridge tunnel diode inverter topology which provides a balanced push-pull drive voltage and current across the entire transformer primary. Moreover, the full-bridge tunnel diode inverter may avoid operating its tunnel diodes in a high-current/high-voltage state at light loads, unlike a single-diode inverter. The disclosed principles also allow a full-bridge tunnel diode inverter topology that may avoid RF chirps in the tunnel diodes during rising or falling device ramp currents since the primary current passes through two tunnel diodes in series.

Aspects of interface converter common mode (CM) voltage control are described. In one embodiment, a bi-directional alternating current (AC) to direct current (DC) interface converter system includes an AC-DC converter between an AC power system and an interface link and a DC-DC converter between a DC power system and the interface link. The AC-DC converter can include a bridge converter having power switches, such as field-insulated gate bipolar transistors (IGBTs) or another power semiconductor device. The system also includes a control loop that generates control signals for switching the power switches of the AC-DC converter, and a CM control loop that injects a CM control signal into the control loop. By injecting the CM control signal into the control loop, low-frequency ripple and asymmetry between positive and negative output voltages of the DC power system can be reduced.

A bidirectional power converter circuit is controlled via a hysteresis loop such that the bidirectional power converter circuit can compensate in near real time for variations and even changes in transmit and receive coil locations without damaging components of the system. Because the bidirectional power converter is capable of both transmitting and receiving power (at different times), one circuit and board may be used as the main component in multiple wireless power converter designs.

A bidirectional power converter circuit is controlled via a hysteresis loop such that the bidirectional power converter circuit can compensate in near real time for variations and even changes in transmit and receive coil locations without damaging components of the system. Because the bidirectional power converter is capable of both transmitting and receiving power (at different times), one circuit and board may be used as the main component in multiple wireless power converter designs.