Patent application number | Description | Published |
20080219036 | CLEAN INPUT UPS WITH FAST RECTIFIER CONTROL AND IMPROVED BATTERY LIFE - The present invention relates to the control of active rectifiers for UPS systems. Aspects of the present invention relate to a control algorithm that is implemented to realize a fast rectifier control operation that results in the improved life of a battery that is linked to the active rectifier of the UPS system. Within aspects of the present invention under unbalanced load conditions, it is possible to select (he desired behavior between the two possible extreme conditions, i.e. implement a clean power input that results in the reduced life of the battery or implement a non-clean power input resulting in the improved life of the battery. Additionally, the present invention utilizes fast rectifier control and specific feed-forward action to make it possible to obtain the very rigid control of a dc link voltage, even under extreme step load variations. | 09-11-2008 |
20110141783 | CONTROL OF FOUR-LEG TRANSFORMERLESS UNINTERRUPTIBLE POWER SUPPLY - A system and method for managing a 4 leg transformerless Uninterrupted Power Supply is disclosed. The system comprises a 3 leg inverter modulation signal generator that applies signals to a modulation circuit that generates a 4 | 06-16-2011 |
20120026764 | CONTROL SYSTEM FOR HIGH-EFFICIENCY OPERATION IN PARALLEL INVERTER INSTALLATIONS - A control system for parallel connected inverter legs energized by a power source and configured for servicing a load is disclosed. The invention facilitates the number of running inverter legs to adaptively react to changes in the load by dynamically switching various inverter legs “on” or “off” in response to variations in load demand, while continuing magnetization of an output transformer connected with an “off” inverter leg via a back-feed from another output transformer of an “on” inverter leg, greatly improving the dynamic response to load changes. This design enables a fast reaction to load changes with “off” inverter legs transitioning to on-line operation instantaneously. | 02-02-2012 |
20130181528 | REDUNDANT CONTROL SYSTEMS, METHODS, AND DEVICES FOR PARALLEL INVERTER INSTALLATIONS - Systems, methods, and devices are provided for redundant control of parallel inverter installations. In one example, a parallel uninterruptible power supply (UPS) system may include several inverter feed paths and several UPS controllers. The inverter feed paths may supply double-conversion power to a load. The UPS controllers may be communicatively coupled to one another via at least two redundant data busses. The UPS controllers may operate in conjunction with one another to control the plurality of feed paths. | 07-18-2013 |
20130193760 | CONTROL SYSTEM FOR UNINTERRUPTIBLE POWER SUPPLIES - Systems and methods for controlling uninterruptible power supplies (UPSs) are provided. In one example, a system may include an inverter feed path to supply a first amount of power to a load and a bypass feed path to supply a second amount of power to the load. A controller may generate command the inverter feed path and the bypass feed path to vary the first amount of power and the second amount of power based at least in part on an occurrence of a power supply disturbance and a type or severity, or both, of the power supply disturbance. | 08-01-2013 |
20130193761 | SYSTEMS, METHODS, AND DEVICES FOR CONTROL OF PARALLEL UNINTERRUPTIBLE POWER SUPPLIES - Systems, methods, and devices for controlling parallel uninterruptible power supplies (UPSs) are provided. One example of a parallel UPS system may include several UPS modules to supply power to a load and at least one controller. At least some of the UPS modules may include a bypass feed path that can be switched on or off via a static switch module (SSM). The controller may adaptively control which of the bypass feed paths are switched on and off based on the load and respective capacity ratings of the UPS modules. The controller may also determine when an SSM of one of the bypass feed paths is likely to have failed. | 08-01-2013 |
20130258725 | Systems and Methods for Balancing UPS Source Currents During Unbalanced Load Transient Conditions - Systems and methods for balancing current from an AC source. The method includes determining a difference between a DC voltage output by a rectifier in an uninterruptible power supply (UPS) to a DC reference voltage. The method also includes determining an error between the DC voltage and the DC reference voltage based at least in part on the difference. After determining the error, the method includes filtering a second order harmonic from the error thereby generating a filtered error. The method may then include determining one or more switching signals for one or more switching components in the rectifier based at least in part on the filtered error and sending the switching signals to the rectifier. | 10-03-2013 |
20140012522 | SYSTEMS, METHODS, AND DEVICES FOR CAPACITANCE ESTIMATION OF POWER CAPACITORS - Systems, methods, and devices are provided for estimating when preventive maintenance of power capacitors is called for. Such a system may include, for example, a voltage sensor, a current sensor, and data processing circuitry. The voltage sensor may measure a voltage difference across a phase of a power capacitor. The current sensor may measure a current across the phase of the power capacitor. The data processing circuitry to determine a first instantaneous indication of a difference between a nominal capacitance of the power capacitor and an actual value of the power capacitor based at least in part on the measured first voltage difference and first current. | 01-09-2014 |
20140036555 | Intelligent Level Transition Systems and Methods for Transformerless Uninterruptible Power Supply - Systems and methods are provided for controlling an uninterruptible power supply (UPS) to transition between three- or higher-level operation and two-level operation in a neutral-point-clamped (NPC) inverter. In an example, a UPS system includes an NPC inverter and a controller. The NPC inverter may supply power to a load. The controller may control the inverter to operate in a three-level mode or higher when the load is substantially balanced and to operate in a two-level mode when the load is substantially unbalanced. | 02-06-2014 |
20140152109 | MEDIUM VOLTAGE UNINTERRUPTIBLE POWER SUPPLY - A medium voltage uninterruptible power supply system is presented. The system includes a first power converter coupled between a first bus and a second bus. Furthermore, a second power converter operatively coupled to the first power converter via the first bus and the second bus, where the second power converter includes at least three legs, where the at least three legs include a plurality of switching units, and where the plurality of switching units includes at least two semiconductor switches and an energy storage device. Additionally, system includes a direct current link coupled between the first bus and the second bus. Also, system includes an energy source coupled to the second power converter, the direct current link, or a combination thereof via one or more of a third power converter, a transformer, and a fourth power converter. Method of operating a medium voltage uninterruptible power supply system is also presented. | 06-05-2014 |
20140368043 | SYSTEMS AND METHODS FOR GRID INTERACTIVE UPS - A grid interactive uninterruptible power supply (UPS) is provided. The grid interactive UPS includes a first path including a rectifier, an inverter coupled in series with the rectifier, and a battery coupled in parallel with the inverter. The grid interactive UPS further includes a second path in parallel with the first path, wherein the grid interactive UPS is operable to supply power from the battery to a grid coupled to an input of the grid interactive UPS. | 12-18-2014 |
20150131349 | SYSTEM AND METHOD FOR BALANCING MULTILEVEL POWER CONVERTERS - A system including a multi-level power converter is provided. The system also includes a plurality of DC link capacitors and a balancing circuit coupled to the multi-level power converter. The balancing circuit further includes two sets of interface branches. Each set includes a plurality of interface branches and a plurality of switching elements. The balancing circuit also includes a battery coupled to one or more inductors across the two sets of interface branches and a controller for controlling switching operations of the plurality of switching elements for modifying a voltage of the battery to balance voltages of the plurality of DC link capacitors. | 05-14-2015 |
20150162782 | METHOD AND SYSTEM FOR A DUAL CONVERSION UNINTERRUPTIBLE POWER SUPPLY - A method and system for an uninterruptible power supply (UPS) are provided. The UPS includes a three-phase high power transformer, an active or passive-rectifier configured to generate and regulate a set of DC link voltages, and a set of cascaded inverters configured to generate an AC voltage using the DC link voltages. The UPS also includes a set of bi-directional battery converters configured to charge a bank of backup batteries when power is available from an AC mains source and discharge the bank of backup batteries to generate a three-phase AC voltage when the AC mains source voltage falls outside a predetermined range. The UPS further includes a bypass switch configured to electrically couple the AC mains source directly to a load when the UPS is in a bypass mode of operation and electrically couple the bank of backup batteries to the load through the set of bi-directional battery converters and the transformer. | 06-11-2015 |
20150263566 | REDUNDANT UNINTERRUPTIBLE POWER SUPPLY SYSTEMS - A system is provided. The system includes a utility, a plurality of uninterruptible power supplies (UPSs), a ring bus, at least one load electrically coupled to the plurality of UPSs and the ring bus, and a controller communicatively coupled to the plurality of UPSs, the controller configured to determine a common reference angle while the utility is disconnected from at least one UPS of the plurality of UPSs, calculate a phase angle for each UPS of the plurality of UPSs, wherein the phase angle for each UPS is calculated relative to the common reference angle, and control operation of each UPS based on the respective calculated phase angles. | 09-17-2015 |
20150263567 | REDUNDANT UNINTERRUPTIBLE POWER SUPPLY SYSTEMS - A system is provided. The system includes a plurality of uninterruptible power supplies (UPSs), a ring bus, at least one load electrically coupled to the plurality of UPSs and the ring bus, and a controller communicatively coupled to the plurality of UPSs. The controller is configured to calculate an output voltage frequency for each UPS of the plurality of UPSs, and control operation of each UPS based on the respective calculated output voltage frequencies. | 09-17-2015 |
20150263568 | Systems and Methods for Providing Increased Fault Current Capability in Uninterruptible Power Supply Systems - A system is provided. The system includes a ring bus, at least one voltage source, and a plurality of uninterruptible power supplies (UPSs) electrically coupled between the at least one voltage source and the ring bus, wherein at least one UPS of the plurality of UPSs includes an input, an output, a rectifier having a rectifier input and a rectifier output, an inverter having an inverter input and an inverter output, wherein the rectifier output is electrically coupled to the inverter input, and a bypass switch electrically coupled between the rectifier input and the inverter output, the bypass switch configured to close in response to detection of a fault on the ring bus. | 09-17-2015 |
20150318737 | SYSTEM AND METHOD FOR CONTROLLING DYNAMIC OUTPUT IMPEDANCE OF AN INVERTER - A control circuit is described herein. The control circuit includes an oscillator and a processor. The oscillator is configured to generate a reference signal. The processor is coupled to the oscillator. The processor is configured to receive a first output current sample, a second output current sample, and a third output current sample, all of an output current. The first output current sample is first-in-time, the second output current sample is second-in-time, and the third output current sample is third-in-time. The processor is further configured to compute a time-derivative of the output current. The processor is further configured to compute a command variable based on the reference signal, a time-derivative of the reference signal, the third output current sample, and the time-derivative of the output current. | 11-05-2015 |
20160036216 | SYSTEMS AND METHODS FOR EXPLOITING CURRENT CAPABILITY IN STATIC UPS - A system is provided. The system includes a plurality of uninterruptible power supplies (UPSs), each UPS of the plurality of UPSs including an inverter, a ring bus, and at least one controller communicatively coupled to the plurality of UPSs, the at least one controller configured to control at least one bridge current in each UPS, the at least one bridge current controlled such that the inverter of each UPS operates in a partial current limiting regime between a full current limiting regime and a linear mode. | 02-04-2016 |