Abstract: A system and method are provided for regulating voltage received from an electric utility grid. A unified power flow controller is provided at a point of power consumption and includes a terminal electrically coupled to a power source, which receives a grid alternating current and a grid alternating voltage from the electric utility grid. A power converter is electrically coupled to the terminal and includes an active rectifier that converts substantially all of the grid alternating current to a direct current and an inverter that converts the direct current to a load alternating current and a load alternating voltage, the load alternating voltage being less than the grid alternating voltage. A transformer is provided having first terminals electrically coupled to the power source and second terminals electrically coupled to an output of the inverter. The transformer injects the load alternating voltage in series with the grid alternating voltage.

Abstract: A method and system are provided for sourcing and sinking reactive power to an electric grid. The control system includes a terminal electrically coupled to a power source that originates from an electric utility grid. The terminal receives a grid alternating current having a real power component and a reactive power component. A power converter is electrically coupled to the terminal, the power converter includes an active rectifier that converts substantially all of the grid alternating current to a direct current and an energy storage device that stores energy supplied by the direct current. The active rectifier sources the reactive power component and the stored energy through the terminal to the electric utility grid. The power converter further includes an inverter that converts the direct current to a load alternating current having at least one of a load real power component and a load reactive power component.

Abstract: A system and method are provided for regulating voltage received from an electric utility grid. A unified power flow controller is provided at a point of power consumption and includes a terminal electrically coupled to a power source, which receives a grid alternating current and a grid alternating voltage from the electric utility grid. A power converter is electrically coupled to the terminal and includes an active rectifier that converts substantially all of the grid alternating current to a direct current and an inverter that converts the direct current to a load alternating current and a load alternating voltage, the load alternating voltage being less than the grid alternating voltage. A transformer is provided having first terminals electrically coupled to the power source and second terminals electrically coupled to an output of the inverter. The transformer injects the load alternating voltage in series with the grid alternating voltage.

Abstract: A method and system are provided for sourcing and sinking reactive power to an electric grid. The control system includes a terminal electrically coupled to a power source that originates from an electric utility grid. The terminal receives a grid alternating current having a real power component and a reactive power component. A power converter is electrically coupled to the terminal, the power converter includes an active rectifier that converts substantially all of the grid alternating current to a direct current and an energy storage device that stores energy supplied by the direct current. The active rectifier sources the reactive power component and the stored energy through the terminal to the electric utility grid. The power converter further includes an inverter that converts the direct current to a load alternating current having at least one of a load real power component and a load reactive power component.

Abstract: Systems, methods, and circuits are disclosed for detecting continuity of a fuse or other current protection device in a circuit. For example, a signal is generated and coupled onto a closed circuit in which the continuity of the fuse closes the circuit. The signal is then coupled from the closed circuit to a signal detector, which detects the presence of the signal and provides an output indicative of the presence of the signal. If the fuse blows, the circuit is opened, prohibiting the signal from being coupled to the signal detector, in which case the signal detector provides an output indicative of the absence of the signal. This example, however, are not exhaustive.

Abstract: Methods, apparatus and media for controlling a switching circuit controlling an amount of power drawn from an energy converter, to optimize the amount of power drawn from the energy converter. An output voltage and an output current of the energy converter are measured to produce signals representing converter output voltage and current. Converter power is calculated from the product of the converter output voltage and current. A perturb voltage is calculated as a decreasing nonlinear function of the converter power. A new reference voltage signal representing a desired converter output voltage is produced in response to a previous reference voltage signal and the perturb voltage. The reference voltage signal is used by the switching circuit to adjust the power drawn from the converter to achieve the desired converter output voltage.

Abstract: Systems, methods, and circuits are disclosed for detecting continuity of a fuse or other current protection device in a circuit. For example, a signal is generated and coupled onto a closed circuit in which the continuity of the fuse closes the circuit. The signal is then coupled from the closed circuit to a signal detector, which detects the presence of the signal and provides an output indicative of the presence of the signal. If the fuse blows, the circuit is opened, prohibiting the signal from being coupled to the signal detector, in which case the signal detector provides an output indicative of the absence of the signal. This example, however, are not exhaustive.

Abstract: A method of charging a battery in a system involving a renewable energy source and operable to supply at least some electrical energy from the renewable energy source to a third party involves causing a charge controller operably connected to the renewable energy source to receive the electrical energy from the renewable energy source and operably connected to the battery, to charge the battery, using only the electrical energy from the renewable energy source, according to a charging sequence. The charging sequence includes at least a bulk charge period wherein the battery is charged at a relatively constant charging current, an absorption period following the bulk charge period wherein the battery is charged in an absorption mode, and a float period following the absorption period wherein the battery is charged in a float charging mode.

Abstract: Methods, apparatus and media for controlling a switching circuit controlling an amount of power drawn from an energy converter, to optimize the amount of power drawn from the energy converter. An output voltage and an output current of the energy converter are measured to produce signals representing converter output voltage and current. Converter power is calculated from the product of the converter output voltage and current. A perturb voltage is calculated as a decreasing nonlinear function of the converter power. A new reference voltage signal representing a desired converter output voltage is produced in response to a previous reference voltage signal and the perturb voltage. The reference voltage signal is used by the switching circuit to adjust the power drawn from the converter to achieve the desired converter output voltage.

Abstract: A method of charging a battery in a system involving a renewable energy source and operable to supply at least some electrical energy from the renewable energy source to a third party involves causing a charge controller operably connected to the renewable energy source to receive the electrical energy from the renewable energy source and operably connected to the battery, to charge the battery, using only the electrical energy from the renewable energy source, according to a charging sequence. The charging sequence includes at least a bulk charge period wherein the battery is charged at a relatively constant charging current, an absorption period following the bulk charge period wherein the battery is charged in an absorption mode, and a float period following the absorption period wherein the battery is charged in a float charging mode.