Abstract: We describe a photovoltaic power conditioning unit comprising: both dc and ac power inputs; a dc link; at least one dc-to-dc converter coupled between dc input and dc link; and a dc-to-ac converter coupled between dc link and ac output. The dc-to-dc converter comprises: a transformer having input and output windings; an input dc-to-ac converter coupled between dc input and input winding; and an ac-to-dc converter coupled between output winding the dc link. The output winding has a winding tap between the first and second portions. The ac-to-dc converter comprises: first and second rectifiers, each connected to a respective first and second portion of the output winding, to the dc link and winding tap; and a series inductor connected to the winding tap. Rectifiers are connected to the winding tap of the output winding via the series inductor wherein the series inductor is shared between the first and second rectifiers.

Abstract: Tracking tags for attachment to an object or animal. The tracking tags may include low-power long-range transmitters drawing power from a battery or a renewable energy source. The tracking tags may also each include a microcontroller having a sleep-mode module enabling nearly no quiescent current to be drawn when the microcontroller is in a sleep-mode. The microcontroller may enter into a sleep-mode for long periods of time following a short period of sending data to the low-power long-range transmitter. The short period of sending data may be approximately one-twentieth of the long sleep-mode period. The tracking tags may also include sensors for determining an ambient temperature or biometric data about an animal to which the tracking tag is attached. Locations of the tracking tags may be determined using signal trilateration and/or signal triangulation.

Abstract: An uninterruptible power supply (UPS) and method for managing power flow in a grid-tied photovoltaic system, wherein the UPS provides grid-tie, backup power, voltage-frequency relay, power factor control, and load-leveling functions. The UPS includes a bi-directional power converter, a switch, and a controller. The converter converts between AC power and DC power, and includes ports which are connectable to a battery, a plurality of current-source inverters, a load, and an electric utility grid. The switch selectively connects and disconnects the converter from the grid. The controller monitors the voltage and current associated with the grid, and based thereon, controls the switch and the bi-directional power converter to manage power flow in the grid-tied photovoltaic system. The controller also manages the power factor of the current flowing into or out of the grid by introducing appropriate distortion or displacement current.

Abstract: An LED driver having an input to receive AC power from an AC power source, a semiconductor switch and an inductor controlled to produce a sinusoidal current drawn from the AC power source, and a large non-electrolytic (e.g. film) capacitor energy storage component. The semiconductor switch operates with a varying pulse-width-modulation frequency to regulate the voltage across the non-electrolytic capacitor energy storage component in such a way that a ripple current through the inductor is substantially smaller than a pulse-width-modulation cycle average current through the inductor. A DC-to-DC converter couples the energy from the non-electrolytic energy-storage capacitor to an LED string. A feedback loop allows the LED string to be regulated in either constant current mode or constant power mode and information for the feedback regulation is fed back across a high-voltage boundary using a low-cost signal transformer.

Abstract: The invention provides a screening method for identifying an insect-specific TRPA1 modulator by comparing modulation of an insect TRPA1 and a mammalian TRPA1. The invention further provides method of insect control by applying to an insect a insect-specific TRPA1 modulator identified by the screening method.

Abstract: A DC-to-AC power converter is disclosed. The power converter has a DC input to receive DC power from a photovoltaic device, an AC output configured for direct connection to an AC mains power supply line, six semiconductor switches, one isolated high-frequency power transformer, two high-frequency inductors, a small resonant capacitor, and a large non-electrolytic (e.g. film) capacitor energy storage component. One of the semiconductor switches located on the primary side of the transformer operates to regulate the voltage across the non-electrolytic capacitor energy storage component. A second semiconductor switch located on the primary side of the transformer provides a resonant reset for the energy stored in the transformer and allows the first semiconductor switch to operate with nearly zero-voltage-switching.

Abstract: We describe a photovoltaic (PV) panel system comprising a PV panel with multiple sub-strings of connected solar cells in combination with a power conditioning unit (microinverter). The power conditioning unit comprises a set of input power converters, one connected to each sub-string, and a common output power conversion stage, to provide power to an ac mains power supply output. Integration of the micro-inverter into the solar PV module in this way provides many advantages, including greater efficiency and reliability. Additionally, embodiments of the invention avoid the need for bypass diodes, a component with a high failure rate in PV panels, providing lower power loss and higher reliability.

Abstract: The invention provides a screening method for identifying an insect-specific TRPA1 modulator by comparing modulation of an insect TRPA1 and a mammalian TRPA1. The invention further provides method of insect control by applying to an insect a insect-specific TRPA1 modulator identified by the screening method.

Abstract: Some embodiments of the invention provide a method for balancing the power output to each phase of a set of micro-inverters. The method of some embodiments is performed by a gateway, which receives output messages from a plurality of micro-inverters. The gateway identifies the phase of each micro-inverter and calculates the output of the plurality of micro-inverters to each power line of a multi-phase system. The gateway then sends control signals to the micro-inverters to control the output of each micro-inverter to maintain a balanced aggregate power output to each phase of the power grid.

Abstract: We describe a modular adjustable power factor renewable energy inverter system. The system comprises a plurality of inverter modules having a switched capacitor across its ac power output, a power measurement system coupled to a communication interface, and a power factor controller to control switching of the capacitor. A system controller receives power data from each inverter module, sums the net level of ac power from each inverter, determines a number of said capacitors to switch based on the sum, and sends control data to an appropriate number of the inverter modules to switch the determined number of capacitors into/out of said parallel connection across their respective ac power outputs.

Abstract: Some embodiments of the invention provide a method for balancing the power output to each phase of a set of micro-inverters. The method of some embodiments is performed by a gateway, which receives output messages from a plurality of micro-inverters. The gateway identifies the phase of each micro-inverter and calculates the output of the plurality of micro-inverters to each power line of a multi-phase system. The gateway then sends control signals to the micro-inverters to control the output of each micro-inverter to maintain a balanced aggregate power output to each phase of the power grid.

Abstract: We describe a modular adjustable power factor renewable energy inverter system. The system comprises a plurality of inverter modules having a switched capacitor across its ac power output, a power measurement system coupled to a communication interface, and a power factor controller to control switching of the capacitor. A system controller receives power data from each inverter module, sums the net level of ac power from each inverter, determines a number of said capacitors to switch based on the sum, and sends control data to an appropriate number of the inverter modules to switch the determined number of capacitors into/out of said parallel connection across their respective ac power outputs.

Abstract: We describe a photovoltaic power conditioning unit comprising: both dc and ac power inputs; a dc link; at least one dc-to-dc converter coupled between dc input and dc link; and a dc-to-ac converter coupled between dc link and ac output. The dc-to-dc converter comprises: a transformer having input and output windings; an input dc-to-ac converter coupled between dc input and input winding; and an ac-to-dc converter coupled between output winding the dc link. The output winding has a winding tap between the first and second portions. The ac-to-dc converter comprises: first and second rectifiers, each connected to a respective first and second portion of the output winding, to the dc link and winding tap; and a series inductor connected to the winding tap. Rectifiers are connected to the winding tap of the output winding via the series inductor wherein the series inductor is shared between the first and second rectifiers.

Abstract: The invention relates to a transformer construction comprising a plurality of transformer cores configured to share magnetic flux paths and, as a result, at least one of the cores comprises a post and an associated sidewall having an effective cross-sectional area which is less than that of the post. Such a construction may be employed in a power conditioning unit, for example, for a photovoltaic module, which is configured to operate the cores out of phase from each other. Also described is a transformer winding comprising a longitudinal spine having a first turn emanating from a first portion of the spine in a first transverse direction and a second turn emanating from a second portion of the spine in a second transverse direction, wherein the second transverse direction is opposite to the first transverse direction.

Abstract: A controller for a power converter and method of operating the same employable with a bridge rectifier having first and second synchronous rectifier switches. In one embodiment, the controller includes an amplifier configured to enable a turn-on delay for the first synchronous rectifier switch. The controller also includes a discharge switch having first and second switched terminals coupled to gate and source terminals, respectively, of the first synchronous rectifier switch and configured to discharge a gate-to-source capacitance of the first synchronous rectifier switch to enable a turn off thereof.

Abstract: An LED driver having an input to receive AC power from an AC power source, a semiconductor switch and an inductor controlled to produce a sinusoidal current drawn from the AC power source, and a large non-electrolytic (e.g. film) capacitor energy storage component. The semiconductor switch operates with a varying pulse-width-modulation frequency to regulate the voltage across the non-electrolytic capacitor energy storage component in such a way that a ripple current through the inductor is substantially smaller than a pulse-width-modulation cycle average current through the inductor. A DC-to-DC converter couples the energy from the non-electrolytic energy-storage capacitor to an LED string. A feedback loop allows the LED string to be regulated in either constant current mode or constant power mode and information for the feedback regulation is fed back across a high-voltage boundary using a low-cost signal transformer.

Abstract: A DC-to-AC power converter is disclosed. The power converter has a DC input to receive DC power from a photovoltaic device, an AC output configured for direct connection to an AC mains power supply line, six semiconductor switches, one isolated high-frequency power transformer, two high-frequency inductors, a small resonant capacitor, and a large non-electrolytic (e.g. film) capacitor energy storage component. One of the semiconductor switches located on the primary side of the transformer operates to regulate the voltage across the non-electrolytic capacitor energy storage component. A second semiconductor switch located on the primary side of the transformer provides a resonant reset for the energy stored in the transformer and allows the first semiconductor switch to operate with nearly zero-voltage-switching.

Abstract: We describe a modular adjustable power factor renewable energy inverter system. The system comprises a plurality of inverter modules having a switched capacitor across its ac power output, a power measurement system coupled to a communication interface, and a power factor controller to control switching of the capacitor. A system controller receives power data from each inverter module, sums the net level of ac power from each inverter, determines a number of said capacitors to switch based on the sum, and sends control data to an appropriate number of the inverter modules to switch the determined number of capacitors into/out of said parallel connection across their respective ac power outputs.

Abstract: We describe a photovoltaic power conditioning unit comprising: both dc and ac power inputs; a dc link; at least one dc-to-dc converter coupled between dc input and dc link; and a dc-to-ac converter coupled between dc link and ac output. The dc-to-dc converter comprises: a transformer having input and output windings; an input dc-to-ac converter coupled between dc input and input winding; and an ac-to-dc converter coupled between output winding the dc link. The output winding has a winding tap between the first and second portions. The ac-to-dc converter comprises: first and second rectifiers, each connected to a respective first and second portion of the output winding, to the dc link and winding tap; and a series inductor connected to the winding tap. Rectifiers are connected to the winding tap of the output winding via the series inductor wherein the series inductor is shared between the first and second rectifiers.

Abstract: The invention relates to a transformer construction comprising a plurality of transformer cores configured to share magnetic flux paths and, as a result, at least one of the cores comprises a post and an associated sidewall having an effective cross-sectional area which is less than that of the post. Such a construction may be employed in a power conditioning unit, for example, for a photovoltaic module, which is configured to operate the cores out of phase from each other. Also described is a transformer winding comprising a longitudinal spine having a first turn emanating from a first portion of the spine in a first transverse direction and a second turn emanating from a second portion of the spine in a second transverse direction, wherein the second transverse direction is opposite to the first transverse direction.