Patent application number | Description | Published |
20090201703 | Systems and Methods for Uninterruptible Power Supply Control - Systems and methods are provided for distributing power to a load by controlling an uninterruptible power supply that has an inverter and a filter, where the filter has an inductor and a capacitor. The systems and methods apply a pulse width modulation control signal to the inverter, sample inverter inductor current and compare the inductor current to a reference current. A duty cycle of the pulse width modulation control signal is adjusted to drive the inductor current at a second sampling time to a value substantially equal to a reference current at a first sampling time. The systems and methods can filter harmonic distortion from output signals and control uninterruptible power supply output. | 08-13-2009 |
20090231892 | UNINTERRUPTIBLE POWER SUPPLY - An uninterruptible power supply (UPS) system includes an AC power input configured to receive AC power from a single-phase AC power source or a multi-phase AC power source, a DC power source, an output circuit including a power output, a controllable switch configured to selectively couple at least one of the AC power input and the DC power source to the output circuit, and a processor coupled and configured to affect operation of the output circuit depending upon which of single-phase and multi-phase operation of the UPS is indicated. | 09-17-2009 |
20090237963 | UPS FREQUENCY CONVERTER AND LINE CONDITIONER - Systems and methods disclosed herein monitor and control input to a converter in one or more of a UPS, a frequency converter, or a line conditioner. Distortion due at least in part to ripple voltage can be removed from a control signal that controls input current to the converter. The systems and methods described herein afford a simple and effective way to reduce or eliminate one or more of subharmonic oscillation and total harmonic distortion from a converter input current during synchronous and asynchronous modes of operation. The converter may include one or more of a rectifier and an inverter. | 09-24-2009 |
20100295374 | METHOD AND APPARATUS FOR PROVIDING UNINTERRUPTIBLE POWER - At least one aspect is directed to an uninterruptible power supply that includes a first input having an input line connection and an input neutral connection to receive a first input voltage from a first voltage source, a second input to receive a second input voltage from a second voltage source, and a boost circuit configured to provide a positive output DC voltage with respect to the input neutral connection and a negative output DC voltage with respect to the input neutral connection in both a line mode of operation and a backup mode of operation. The power supply also includes a first connection circuit to couple the first input to the boost circuit in the line mode of operation, and a second connection circuit to couple the second input to the boost circuit in the backup mode of operation, the second connection circuit being configured to isolate the second voltage source from the input neutral connection in the line mode of operation. | 11-25-2010 |
20100315849 | POWER SUPPLY CONTROL - Systems and methods for operating an uninterruptable power supply are provided. The uninterruptable power supply may include a rectifier that has a transistor and an inductor. The uninterruptable power supply may also include a controller. A current sensor can be configured to detect inductor current and to provide a detected inductor current value to the controller to generate a current error value based and to generate a pulse width modulation control signal based in part on the current error value. The controller can apply the pulse width modulation control signal to the transistor to adjust a switching frequency of the transistor. | 12-16-2010 |
20110043042 | UNINTERRUPTIBLE POWER SUPPLY - An uninterruptible power supply (UPS) system includes an AC power input configured to receive AC power from a single-phase AC power source or a multi-phase AC power source, a DC power source, an output circuit including a power output, a controllable switch configured to selectively couple at least one of the AC power input and the DC power source to the output circuit, and a processor coupled and configured to affect operation of the output circuit depending upon which of single-phase and multi-phase operation of the UPS is indicated. | 02-24-2011 |
20110278934 | DIGITAL CONTROL METHOD FOR OPERATING THE UPS SYSTEMS IN PARALLEL - Systems and methods of operating uninterruptible power supplies in parallel in a power distribution system to provide power to a load are provided. At least one uninterruptible power supply inverter provides power to the load. A communication interface provides a measured value of at least one of inverter output current of a first uninterruptible power supply and a measured value of the load current to a second uninterruptible power supply, and receives a measured value of at least one of inverter output current of the second uninterruptible power supply and the load current. A controller controls the uninterruptible power supplies to operate in one of a master state and a slave state. In the master state the uninterruptible power supply is configured to control the voltage to the load, and in the slave state the uninterruptible power supply is configured to determine a reference output current value based at least in part on at least one of the measured value of inverter output current of the second uninterruptible power supply and the measured value of the load current. The uninterruptible power supply in the slave state drives its inverter output current toward the reference output current value to provide its share of the load current. | 11-17-2011 |
20120112547 | SYSTEM AND METHOD FOR BIDIRECTIONAL DC-AC POWER CONVERSION - A power converter includes a power input configured to receive input power from an AC power source, a power output configured to provide output power to a load, a battery interface configured to exchange DC power with a battery, and power converter circuitry. The power converter circuitry is adapted to, in a first interconnection configuration, convert the input power into the DC power at the battery interface, and, in a second interconnection configuration, convert the DC power at the battery interface into the output power. The power converter circuitry has a power line, a transformer, a first connection node switchably connected to the power line in the first interconnection configuration and switchably connected to the transformer in the second interconnection configuration, and a second connection node switchably connected to the transformer in the first interconnection configuration and switchably connected to the power line in the second interconnection configuration. | 05-10-2012 |
20120175958 | METHOD AND APPARATUS FOR PROVIDING UNINTERRUPTIBLE POWER - At least one aspect of the invention is directed to an uninterruptible power supply. The uninterruptible power supply includes a first input having an input line connection and an input neutral connection to receive a first input voltage from a first voltage source, a second input having a positive input connection and a negative input connection to receive a second input voltage from a second voltage source, a boost circuit configured to provide a positive output DC voltage with respect to the input neutral connection and a negative output DC voltage with respect to the input neutral connection in both a line mode of operation and a backup mode of operation, a first connection circuit configured to couple the first input to the boost circuit in the line mode of operation, and configured to couple the second input to the boost circuit in the backup mode of operation, and a second connection circuit configured to couple a midpoint of the boost circuit to the input neutral connection in the line mode of operation and to couple the midpoint of the boost circuit to the positive input connection in battery mode of operation. | 07-12-2012 |
20120313438 | UNINTERRUPTIBLE POWER SUPPLY - An uninterruptible power supply (UPS) system includes an AC power input configured to receive AC power from a single-phase AC power source or a multi-phase AC power source, a DC power source, an output circuit including a power output, a controllable switch configured to selectively couple at least one of the AC power input and the DC power source to the output circuit, and a processor coupled and configured to affect operation of the output circuit depending upon which of single-phase and multi-phase operation of the UPS is indicated. | 12-13-2012 |
20130026835 | SINGLE-BATTERY POWER TOPOLOGIES FOR ONLINE UPS SYSTEMS - A power converter includes a first power input to receive AC input power, a second power input to receive backup power, a first DC bus configured to provide a positive DC output voltage, a second DC bus configured to provide a negative DC output voltage, and a power conversion circuit coupled to the first DC bus and the second DC bus. The power conversion circuit has an inductor, a first switch device coupled in series with the inductor, a second switch device coupled in series with the first switch device, and a bypass relay coupled in parallel with the second switch device. The power conversion circuit is switchably coupled to the first power input and the second power input, and is operable to charge the inductor and generate the positive and negative DC output voltages. | 01-31-2013 |
20130026836 | NON-ISOLATED AC-DC CONVERTER HAVING A POSITIVE OUTPUT BUCK-BOOST CONVERTER AND PFC AT INPUT SUPPLY - A power converter includes a battery having a positive terminal and a negative terminal, a first power input to receive AC input power, a second power input to receive DC input power from the battery, a first power output to charge the battery, a second power output to provide power to a load, a rectifier circuit coupled to the first power input, and a non-isolated single-stage power conversion circuit having an input and configured as a buck-boost converter. The power at the second power output is derived from the first power input and/or the second power input. The single-stage power conversion circuit is configured to convert an AC voltage to a DC voltage using a common energy storage element, and is coupled to the first power output and the rectifier circuit. | 01-31-2013 |
20130027126 | DUAL BOOST CONVERTER FOR UPS SYSTEM - A power converter includes a power conversion circuit switchably coupled to a first power input and a second power input. The power conversion circuit is operable to generate positive and negative DC output voltages and is configured such that, in a backup mode of operation, the negative DC output voltage is generated using backup power through a first current path of the power conversion circuit that includes a first diode coupled between the second power input and a second DC bus, and, in a line mode of operation, the negative DC output voltage is generated using AC input power through a second current path of the power conversion circuit that bypasses the first diode and includes a second diode coupled between the first power input and the second DC bus. | 01-31-2013 |
20140103725 | DIGITAL CONTROL METHOD FOR OPERATING UPS SYSTEMS IN PARALLEL - Systems and methods of operating uninterruptible power supplies in parallel in a power distribution system to provide power to a load are provided. At least one uninterruptible power supply inverter provides power to the load. A communication interface provides a measured value of at least one of inverter output current of a first uninterruptible power supply and a measured value of the load current to a second uninterruptible power supply, and receives a measured value of at least one of inverter output current of the second uninterruptible power supply and the load current. A controller controls the uninterruptible power supplies to operate in one of a master state and a slave state. In the master state the uninterruptible power supply is configured to control the voltage to the load, and in the slave state the uninterruptible power supply is configured to determine a reference output current value based at least in part on at least one of the measured value of inverter output current of the second uninterruptible power supply and the measured value of the load current. The uninterruptible power supply in the slave state drives its inverter output current toward the reference output current value to provide its share of the load current. | 04-17-2014 |
20150022003 | MODULAR THREE PHASE ON-LINE UPS - An uninterruptible power supply system (UPS) includes an interconnect circuit configured to receive three-phase AC input power from an AC power source and a plurality of UPS subsystems each coupled to the interconnect circuit. A first UPS subsystem includes first and second single-phase AC-to-DC converters. At least one second UPS subsystem includes third and fourth single-phase AC-to-DC converters. In a first mode of operation, the interconnect circuit is configured to conduct at least one phase of the AC input power to the first UPS subsystem and at least one phase of the AC input power to the second UPS subsystem, and, in a second mode of operation, to disconnect the AC input power from the first UPS subsystem and to conduct at least one phase of the AC input power to the second UPS subsystem. | 01-22-2015 |