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 |