Patent application number | Description | Published |
20090213627 | POWER SUPPLY SYSTEM WITH ADAPTIVE BLOWN FUSE DETECTION USING NEGATIVE SEQUENCE COMPONENT - Existing measurements of an input component (such as voltage or current) in a three phase power supply system are decomposed into a negative sequence component. The negative sequence component, which is significantly higher when a rectifier fuse is blown, is compared to a threshold and a determination made that a rectifier fuse is blown when the negative component exceeds the threshold. In an aspect, an adaptive algorithm is used to make the detection work better in the range of the nominal frequency of the input voltage. In an aspect, the negative sequence is determined indirectly from the existing measurements. | 08-27-2009 |
20090251005 | UNDERVOLTAGE TRANSFER DETECTION - A method of increasing the reliability of an uninterruptible power supply (UPS) providing AC power to a load, comprising determining the magnitude and duration of an actual undervoltage event in a power output of the UPS; providing a predetermined undervoltage standard establishing at least a range of undervoltage events of acceptable magnitude and duration for the load; comparing the magnitude and duration of the actual undervoltage event with the predetermined standard; and causing the load to be transferred to an alternate source of AC power when the comparison of the actual undervoltage event with the predetermined standard reveals that the actual undervoltage event is not acceptable. | 10-08-2009 |
20100042344 | SYSTEM AND METHOD FOR DETECTING AN ELECTRICAL SHORT ACROSS A STATIC SWITCH OF AN UNINTERRUPTIBLE POWER SUPPLY - A monitoring system for detecting a short circuit condition in a switching subsystem of a bypass input of a power supply. The system may comprise a voltage monitoring subsystem for monitoring a voltage across at least one component of the switching subsystem and generating a first output signal in accordance therewith. A processor, responsive to the first output signal from the voltage monitoring subsystem, may be used to compare the first output signal with a predetermined threshold signal and to generate a second output signal based on the comparison. The processor may also be used to consider a state of a circuit breaker in communication with the switching subsystem and to use the state of the circuit breaker and the second output signal to determine whether at least one of a short circuit condition and an open circuit condition exists with respect to the switching subsystem. | 02-18-2010 |
20100067269 | INTELLIGENT SENSORLESS CONTROL OF A PHASE CONTROLLED RECTIFIER - An uninterruptible power supply (“UPS”) has a phase-controlled rectifier coupled to a source of AC power and having an output providing a DC bus, the output of the phase-controlled rectifier coupled to an inverter. A first controller generates a firing angle for the rectifier and a fuzzy logic controller generates a firing angle for the rectifier. In an aspect, the rectifier is controlled by the firing angle generated by the first controller during normal operating conditions of the UPS and the rectifier is controlled by the firing angle generated by the fuzzy logic controller during abnormal operating conditions of the UPS. The abnormal operating conditions can include loss of a direct DC bus voltage measurement and or a period of time after the UPS experiences a large load change. In an aspect, the firing angle generated by the first controller is compared to the firing angle generated by the fuzzy logic controller and a rectifier fault condition determined to exist when the two firing angles differ by at least a threshold amount. In an aspect, the first controller is a PI controller. | 03-18-2010 |
20100082173 | MAXIMIZED BATTERY RUN-TIME IN A PARALLEL UPS SYSTEM - An uninterruptible power supply (UPS) includes a plurality of UPS modules. Each of the UPS modules has a battery that provides power to a protected load in the event of a utility power failure. A plurality of controllers control how much power each of the batteries deliver to the protected load, and a communication bus allows the controllers to exchange information about the battery voltages. One of the controllers calculates the average battery voltage of the plurality of batteries and adjusts the amount of energy provided by an individual battery such that the battery voltage is about equal to the average battery voltage. | 04-01-2010 |
20140132074 | TECHNIQUES FOR IMPROVING OPERATION OF STATIC TRANSFER SWITCHES DURING VOLTAGE DISTURBANCES - When the preferred voltage source for a static transfer switch is a UPS, there can be a brief interruption in the voltage received from the UPS while the UPS is switching from economy mode to normal mode. Operation of the static transfer switch can be improved during such voltage disturbances. Specifically, the static transfer switch may be in data communication with the UPS and thereby made aware that the voltage disturbance is temporary. As a result, the static transfer switch can avoid an unnecessary transfer to an alternate voltage source. | 05-15-2014 |
20140139022 | Systems And Methods For Balancing UPS Output Voltages During Transitions Between Operating Modes - A UPS includes an input that receives first power from a utility source to power a load and receives second power from the utility source. The load is separate from the UPS. An inverter receives when in a first mode, the first and second power and when in a second mode, the second power and not the first power. The second power is used to power the inverter. A bypass circuit is connected to the input and bypasses the inverter to supply the first power to an output of the UPS when operating in the second mode. A control module detects a voltage at the output of the UPS, integrates the voltage to generate a first sum, and subsequent to completing a transition between the first and second modes, adjusts an output voltage of the inverter based on the first sum to balance the voltage of the UPS. | 05-22-2014 |
20140159493 | MULTIPLE UPS SYSTEM HAVING MULTI-WAY POWER TIE SYSTEM AND INTELLIGENT POWER SHARING CONTROL - A multiple UPS system includes a plurality of multi-module UPS subsystems coupled to a power tie cabinet, each multi-module UPS subsystem having a plurality of UPS modules. The power tie cabinet includes one or more controllers, collectively referred to as PTC (power tie cabinet) controls. The PTC controls periodically determine a power error message for each of the multi-module UPS subsystems and pass it to the respective multi-module UPS subsystem. A controller of the multi-module UPS subsystem uses the power error message to determine error data that is provided to a power average control loop used in control of power sharing among the UPS modules of the multi-module UPS subsystem. | 06-12-2014 |