Patent application number | Description | Published |
20090257256 | HIGH EFFICIENT INPUT CURRENT SHAPING FOR AC TO DC CONVERTERS WITH POWER FACTOR CORRECTION REQUIREMENT - A high efficient input current shaping AC to DC converter with PFC front end that reduces input current harmonics is provided. In one embodiment, an AC to DC converter connectable with an alternating current source and operable to output a direct current comprises a PFC front end followed by a DC/DC converter. The PFC front end reduces harmonic components present in an input current waveform received by the PFC front end from the alternating current source and includes current steering circuitry and, optionally, valley filling circuitry. The DC/DC converter comprises one that presents pure resistive input impedance to the PFC front end. The DC/DC converter outputs the direct current to a load connected thereto. | 10-15-2009 |
20090290385 | Resonant power factor correction converter - An AC-to-DC power converter configured to provide power factor correction and a single isolated low-voltage output. The power converter includes a single-stage resonant power converter including an isolation transformer, a resonant tank, a rectifier, and a bulk storage capacitor coupled to an output of the isolation transformer. In typical applications, at least one non-isolated power converter is coupled to the output of the single-stage isolated power factor correction converter. | 11-26-2009 |
20100182806 | Controller for a Power Converter - A controller for a power converter having a transformer T | 07-22-2010 |
20100188876 | Controller for a Power Converter - 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 SR. The controller also includes a discharge switch Q | 07-29-2010 |
20100315839 | ENERGY RECOVERY SNUBBER CIRCUIT FOR POWER CONVERTERS - An energy recovery snubber circuit for use in switching power converters. The power converters may include a switch network coupled to a primary winding of an isolation transformer, and rectification circuitry coupled to a secondary winding of the isolation transformer. The energy recovery snubber circuit may include clamping circuitry that is operative to clamp voltage spikes and/or ringing at the rectification circuitry. The clamped voltages may be captured by an energy capture module, such as a capacitor. Further, the energy recovery snubber circuitry may include control circuitry operative to return the energy captured by the energy capture module to the input of the power converter. To maintain electrical isolation between a primary side and a secondary side of the isolation transformer, a second isolation transformer may be provided to return the captured energy back to the input of the power converter. | 12-16-2010 |
20100321958 | Power Converter Employing a Variable Switching Frequency and a Magnetic Device with a Non-Uniform Gap - A power converter including a power switch, a controller for controlling a switching frequency thereof, and a magnetic device with a non-uniform gap. In one embodiment, the power converter includes a power switch and a magnetic device coupled to the power switch and having a non-uniform gap. The power converter also includes a controller having a detector configured to sense a condition representing an output power of the power converter. A control circuit of the controller is configured to control a switching frequency of the power switch as a function of the condition and control a duty cycle of the power switch to regulate an output characteristic of the power converter. | 12-23-2010 |
20100321964 | Power Adapter Employing a Power Reducer - A power adapter including a power reducer for no-load or light load applications and method of operating the same. In one embodiment, the power adapter includes a capacitor coupled to an input of the power adapter, and a bleeder switch coupled in parallel with the capacitor. The power adapter also includes a detection circuit configured to sense an ac mains voltage at the input of the power adapter and turn on the bleeder switch upon detection of a loss of the ac mains voltage. In addition to or in lieu of, the power adapter may include a power converter, and a disconnect switch configured to disconnect the ac mains voltage from the power converter in response to a signal from a load. | 12-23-2010 |
20110149607 | Controller for a Power Converter - A power converter employing a controller configured to increase a dead time between conduction periods of first and second power switches therein and method of operating the same. In one embodiment, the power converter includes first and second power switches coupled to an input thereof, and a sensor configured to provide a sensed signal representative of at least one of a current level and a power level of the power converter. The power converter also includes a controller configured to increase a dead time between conduction periods of the first and second power switches when the sensed signal indicates a decrease of at least one of the current level and the power level of the power converter. | 06-23-2011 |
20110305047 | Control System for a Power Converter and Method of Operating the Same - A power converter employing a control system configured to make multiple functional use of a circuit node therein and method of operating the same. In one embodiment, the power converter includes a power train including at least one power switch. The power converter also includes a control system including an opto-isolator circuit, including a resistor, configured to receive an output signal from the power converter and provide a feedback signal to a feedback node for the control system to provide a switch control signal for the at least one power switch. The control system also includes a current source configured to produce multiple voltage levels at the feedback node in accordance with the resistor, thereby enabling multiple functional uses of the feedback node. | 12-15-2011 |
20120057388 | Solar Photovoltaic Inverters - The invention relates to improved techniques for manufacturing power conditioning units (inverters) for use with photovoltaic (PV) modules, and to inverters manufactured by these techniques. We describe a solar photovoltaic inverter, comprising: a power conditioning circuit mounted on a circuit board, the power conditioning circuit having a dc power input to receive dc power from one or more photovoltaic panels and an ac power output to deliver ac power to an ac mains power supply; an electrically conductive shield enclosing said circuit board; and a plastic overmould over said conductive shield and said circuit board; wherein said electrically conductive shield has one or more holes to allow said plastic overmould to extend through said shield to cover said circuit board. | 03-08-2012 |
20120063177 | Solar Photovoltaic Power Conditioning Units - 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. | 03-15-2012 |
20120081204 | TRANSFORMER CONSTRUCTION - 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. | 04-05-2012 |
20120081933 | PHOTOVOLTAIC POWER CONDITIONING UNITS - We describe a photovoltaic (PV) panel power conditioning circuits, in particular for a PV panel with multiple sub-strings of connected solar cells. The power conditioning unit comprises a set of input power converters, one connected to each sub-string, a shared dc link to provide a common dc bus for the set of input power converters, and a common output power conversion stage coupled to the shared dc link to convert power from the shared dc link to ac power for a mains power supply output from the power conditioning unit. Local conversion of the sub-strings facilitates control of the power available from the panel and optimum energy harvesting, as well as local maximum power point tracking (MPPT) adjustment. | 04-05-2012 |
20120081934 | PHOTOVOLTAIC POWER CONDITIONING UNITS - 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. | 04-05-2012 |
20120098346 | Renewable Energy Power Generation Systems - 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. | 04-26-2012 |
20120262953 | MULTI-PHASE RESONANT CONVERTER - A resonant power converter draws current from a source that provides a supply current. Multiple quasi-resonant converters are interleaved and each quasi-resonant converter receives the supply current and forms a phase-shifted current according to drive signals supplied by a controller. Each phase-shifted current includes a dead-time delay and is phase-shifted relative to the other phase-shifted currents. The dead-time delay is determined as a time value within a calculated dead-time delay range having a dead-time delay minimum and a dead-time delay maximum. The outputs of each quasi-resonant converter are added together thereby reducing the AC components of current. Two, three, or four quasi-resonant power converters can be interleaved, each forming phase-shifted currents that are phase-shifted relative to the other phase-shifted currents. | 10-18-2012 |
20130229834 | Transformer Construction - 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. | 09-05-2013 |
20130229842 | Solar Photovoltaic Power Conditioning Units - 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. | 09-05-2013 |
20130257164 | Renewable Energy Power Generation Systems - 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. | 10-03-2013 |
20130294126 | Photovoltaic Power Conditioning Units - 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. | 11-07-2013 |
20140191583 | POWER BALANCING IN A MULTI-PHASE SYSTEM - 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. | 07-10-2014 |
20140301111 | CONTROL SYSTEM FOR A POWER CONVERTER AND METHOD OF OPERATING THE SAME - A power converter employing a control system configured to make multiple functional use of a circuit node therein and method of operating the same. In one embodiment, the power converter includes a power train including at least one power switch. The power converter also includes a control system including an opto-isolator circuit, including a resistor, configured to receive an output signal from the power converter and provide a feedback signal to a feedback node for the control system to provide a switch control signal for the at least one power switch. The control system also includes a current source configured to produce multiple voltage levels at the feedback node in accordance with the resistor, thereby enabling multiple functional uses of the feedback node. | 10-09-2014 |
20140306543 | Power Factor Adjustment in Multi-Phase Power System - A multi-phase power generation system for renewable energy, in which reactive elements (i.e., capacitors and/or inductors) can be selectively switched in and out in order to meet a particular power factor requirement, is provided. Each phase of the multi-phase power system receives generated powers from a set of inverters, and each phase has a set of switch reactive elements for making power factor adjustments to the power generated by the set of inverters. The power outputs of the set of inverters belonging to a particular phase are combined into a one combined ac power output, and the power factor adjustment for that particular phase is performed on the combined power output by the set of the switch reactive elements of that particular phase. In some embodiments, at least some of the inverters are micro-inverters that convert DC power from one or two solar panels to AC power. | 10-16-2014 |
20150022006 | RENEWABLE ENERGY POWER GENERATION SYSTEMS - 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. | 01-22-2015 |