Abstract: A wireless charging system includes a transmitter with tunable reactive components (such as capacitance or inductance). A metric related to power transfer from the transmitter through a coil is used to determine an amount to modify a Parameter. One metric is equal to |Vs|·|Is|·cos(?)·(Vcoil_ref/Vcoil), where |Vs| is magnitude of the power source voltage, |Is| is magnitude of the power source current, ? is phase difference between the power source voltage and power source current, Vcoil_ref is a normalization value, and Vcoil is voltage across the coil. The transmitter can further include a phase tracking and adjustment loop (such as a phase-locked loop).

Abstract: A method for activating a local converter for one of a plurality of energy generating devices in an energy generating array is provided. The local converter includes a power stage and a local controller. The method includes comparing a device voltage for the energy generating device to a voltage activation level. The local converter is automatically activated when the device voltage exceeds the voltage activation level.

Abstract: An inductive structure includes a power coil and a data coil. The data coil is substantially centered within the power coil. A first portion of the data coil conducts current in a first direction. A second portion of the data coil conducts current in a second direction opposite the first direction. The first portion of the data coil is connected at a node to the second portion of the data coil. The node is coupled to a ground.

Abstract: A wireless energy transfer receiver includes an input configured to receive alternating current (AC) electric energy and an output configured to make available direct current (DC) electric energy. The receiver further includes a rectification component configured to convert the AC energy received at the input into DC energy available at the output, the DC energy made available as DC voltage; and a multiplication component configured to amplify a peak voltage of the AC energy received at the input, the DC voltage made available at the output correspondingly being higher than the peak voltage of the AC energy received at the input.

Abstract: A resonant power transfer system includes resonant circuitry (26) including an inductor coil (59) and a resonant capacitor (51) coupled to a first terminal (27) of the inductor coil, wherein the inductor coil and the resonant capacitor resonate to produce an excitation signal (IS) and a state variable signal (VCS1). Sub-sampling circuitry (30) samples first and second points of the state variable signal at a rate which is substantially less than the RF frequency of the state variable signal. Information recovery circuitry (32) produces a state variable parameter signal representing a parameter (A) of the state variable signal from information in the first and second sampled points. Control circuitry (38) produces a first control signal in response to the state variable parameter signal. Detection and optimization circuitry (41) produces a second control signal in response to the state variable parameter signal.

Abstract: A system configured to actively balance power among power cells such as batteries. The system includes a power module of series-coupled power cells, each exhibiting different charge levels during charging and discharging. A power module includes active cell balancing circuitry configured to substantially balance the charges of the power cells at least during charging. In one embodiment, the active cell balancing circuitry includes: (a) current source circuitry configured to supply extra charging current to a selected power cell; and (b) current source control circuitry configured to control the current source circuitry to supply extra charging current to the power cell with the lowest state of charge. In another embodiment, the system includes multiple power modules, each having multiple power cells coupled in series, and each having an active cell balancing circuit configured to substantially balance the charges of the power cells in an associated one of the power modules.

Abstract: A solar panel array for use in a solar cell power system is provided. The solar panel array includes a string of solar panels and multiple voltage converters. Each voltage converter is coupled to a corresponding solar panel in the string of solar panels. The solar panel array also includes multiple maximum power point tracking (MPPT) controllers. Each MPPT controller is coupled to a corresponding solar panel in the string of solar panels. Each MPPT controller is configured to sense an instantaneous power unbalance between the corresponding solar panel and an inverter.

Abstract: A sampling phase locked loop (PLL) circuit includes a pull-up/down buffer configured to convert an oscillator reference clock into a square wave sampling control signal input to a sampling phase detector. The buffer circuit is configured to reduce power by controlling the switching of the pull-up and pull-down transistors (and thereby the transitions of the sampling control signal) so that the transistors are not on at the same time.

Abstract: Control circuitry and method of controlling for a sampling phase lock loop (PLL). By controlling the duty cycle of one or more sampling control signals, power consumption by the reference signal buffer and spurious output signals from the sampling PLL being controlled can be reduced.

Abstract: A system includes a master device and multiple slave devices. The system also includes multiple bus interfaces forming a communication bus that couples the master and slave devices. Each bus interface includes a primary interface unit configured to communicate over first and second buses, where the first and second buses form a portion of the communication bus. Each bus interface also includes a secondary interface unit configured to communicate with the primary interface unit and to communicate with one of the slave devices over a third bus. Each bus interface further includes an isolator configured to electrically isolate the primary interface unit and the secondary interface unit. The primary interface unit is configured to receive multiple commands over the first bus, execute a first subset of commands, transmit a second subset of commands over the second bus, and transmit a third subset of commands over the third bus.

Abstract: Control circuitry and method of controlling for a sampling phase lock loop (PLL). By controlling the duty cycle of a sampling control signal, in accordance with the PLL reference and output signals, spurious output signals from the sampling PLL being controlled can be reduced.

Abstract: A method for providing a maximum power point tracking (MPPT) process for an energy generating device is provided. The method includes coupling a local converter to the energy generating device. A determination is made regarding whether the local converter is operating at or below a maximum acceptable temperature. A determination is made regarding whether at least one current associated with the local converter is acceptable. When the local converter is determined to be operating at or below the maximum acceptable temperature and when the at least one current associated with the local converter is determined to be acceptable, the MPPT process is enabled within the local converter.

Abstract: A transmitter includes an alternating current power source with tunable parameters. A tunable parameter may be capacitance, inductance, or frequency. A metric related to power transfer from the transmitter through a coil is used to determine an amount to modify a parameter. One metric is equal to |Vs|·|Is|·cos(?), where |Vs| is magnitude of the power source voltage, |Is| is magnitude of the power source current, and ? is phase difference between the power source voltage and power source current. Another metric is equal to |Vs|·|Is|·cos(?)·(Vcoil_ref/Vcoil), where |Vs| is magnitude of the power source voltage, |Is| is magnitude of the power source current, ? is phase difference between the power source voltage and power source current, Vcoil_ref is a normalization value, and Vcoil is voltage across the coil. The transmitter may further include a phase tracking and adjustment loop; for example, a phase-locked loop (PLL).

Abstract: In a wireless power transfer system with multiple receivers, receiver management may be necessary to effectively provide power to the multiple receivers. In one implementation, receiver management includes sweeping or stepping the transmitter resonant and/or operating frequency. In another implementation, receiver management includes receiver self-management, in which the receiver load current duty cycle is controlled to maintain receiver voltage even in the presence of multiple receivers. In another implementation, receiver management includes receiver self-management, in which one or more receivers use a time-sharing heuristic to identify when other receivers are charging and wait to begin receiving a transfer of power until another receiver has stopped receiving a transfer of power.

Abstract: A wireless power transfer system includes: a non-resonant transmitter, or a transmitter with a resonant circuit; and a non-resonant receiver, or a receiver with a resonant circuit. In some implementations, a transmitter with a resonant circuit is operated away from its resonance frequency. In some implementations, a receiver with a resonant circuit is operated away from the transmitter resonance frequency and/or the transmitter operating frequency. In some implementations, the selection of receiver resonance frequency is based on receiver power requirements. Thus, wireless power transfer may be accomplished by operating away from resonance in a quasi-resonant or non-resonant mode, and further may be accomplished using a non-resonant transmitter and/or a non-resonant receiver. Effective power transfer may also be achieved between a transmitter and multiple receivers. A combination of resonant and non-resonant transmitter and receiver(s) may be used for power transfer.

Abstract: A wireless energy transfer receiver includes an input configured to receive alternating current (AC) electric energy and an output configured to make available direct current (DC) electric energy. The receiver further includes a rectification component configured to convert the AC energy received at the input into DC energy available at the output, the DC energy made available as DC voltage; and a multiplication component configured to amplify a peak voltage of the AC energy received at the input, the DC voltage made available at the output correspondingly being higher than the peak voltage of the AC energy received at the input.

Abstract: Control circuitry and method of controlling for a sampling phase lock loop (PLL). By controlling the duty cycle of a sampling control signal, in accordance with the PLL reference and output signals, spurious output signals from the sampling PLL being controlled can be reduced.

Abstract: A system for integrating local maximum power point tracking (MPPT) into an energy generating system having centralized MPPT is provided. The system includes a system control loop and a plurality of local control loops. The system control loop comprises a system operating frequency, and each local control loop comprises a corresponding local operating frequency. Each of the local operating frequencies is spaced apart from the system operating frequency by at least a predefined distance. For a particular embodiment, a settling time corresponding to the local operating frequency of each local control loop is at least five times faster than a time constant corresponding to the system operating frequency.

Abstract: A system includes a master device and multiple slave devices. The system also includes multiple bus interfaces forming a communication bus that couples the master and slave devices. Each bus interface includes a primary interface unit configured to communicate over first and second buses, where the first and second buses form a portion of the communication bus. Each bus interface also includes a secondary interface unit configured to communicate with the primary interface unit and to communicate with one of the slave devices over a third bus. Each bus interface further includes an isolator configured to electrically isolate the primary interface unit and the secondary interface unit. The primary interface unit is configured to receive multiple commands over the first bus, execute a first subset of commands, transmit a second subset of commands over the second bus, and transmit a third subset of commands over the third bus.

Abstract: A method for selecting between centralized and distributed maximum power point tracking in an energy generating system is provided. The energy generating system includes a plurality of energy generating devices, each of which is coupled to a corresponding local converter that includes a local controller. The method includes determining whether there is at least a threshold amount of mismatch between operating characteristics of the energy generating devices. The energy generating system is placed in a centralized maximum power point tracking (CMPPT) mode when there is not at least the threshold amount of mismatch and is placed in a distributed maximum power point tracking (DMPPT) mode when there is at least the threshold amount of mismatch.