Liebert Corporation

Vertiv Corporation

Delphi Technologies, Inc.

Brian Paul Heber

Terry Dwane Bush

Xian Chen

Mohammad Nanda Marwali

Kevin Kim Eschhofen

Russell Edward Shetler, Jr

Peter A Panfil

Paul Taylor

Mohammad Nanda Rahmana Marwali

William Charles Kruckemeyer

David Bernard Drennen

Michael Leslie Oliver

Richard Edward Longhouse

Gary Lee Johnston

Bo Dong Liu

Zhihua Wang

Suratkal Padmanabha Shenoy

Charles F Blair

Dangsheng Zhou

Andrew Karl Zup

Quanbo Xia

Edwin Shires

Scott Alan Horning

Jeffery Powell

Yihang Lu

Ramesh Subramanian

Nelson John Norris

Ronald Richard Rautenstrauch

Jon Ross Funk

Kevin Jay Bell

Steve Moran

Farzin Kafaipour

Chris Crawford

Andy Margraff

Jason D Peltier

Jr Russell E Shetler

Jr Russell E Shelter

The present disclosure relates to a system for controlling power walk-in for an uninterruptible power supply (UPS) being switched to receive AC power from an AC generator. The system may have a control system and a power walk-in (PWI) subsystem. The PWI subsystem may be controlled in part by the control system. The PWI subsystem may be configured to control at least one of an input current or an input power of an AC signal being provided by an AC generator during a power walk-in operation to attempt to maintain a minimum frequency of the AC signal from the AC generator during the power walk-in operation.

System and method for generator frequency control during UPS power walk-in

Effects of a surge in an AC input voltage to a UPS is mitigated. If the AC input voltage is overvoltage, the rectifier is operated using a DC bus target voltage for the DC bus voltage unless the rectifier reaches its current limit. If the rectifier reaches its current limit, the DC bus target voltage is increased by a predetermined amount which is used as a current DC bus target voltage unless the increased DC bus target voltage exceeds a maximum DC bus voltage limit in which case the current DC bus target voltage is set to the maximum DC bus voltage limit. The rectifier is then operated using the current DC bus target voltage until it reaches its current limit or the AC input voltage surge has passed. If the rectifier again reaches its current limit, the above steps starting with increasing the DC bus target voltage are repeated.

Method of mitigating effects of AC input voltage surge in a transformer-less rectifier uninterruptible power supply system

A common mode choke in a 3-wire transformer free UPS system with which different rectifier and bypass power sources are used is eliminated by using different types of PWM control depending on whether the inverter is paralleled with the bypass power source. When the inverter is paralleled with the bypass power source, a type of PWM control is used that does not have common mode voltage injection. When the inverter is not paralleled with the bypass power source, a type of PWM control is used that has common mode voltage injection. In an aspect, the PWM control that does not have common mode voltage injection is sine-triangle PWM and the PWM control that has common mode voltage injection is space-vector PWM.

3-wire transformer-free UPS system and method of control to reduce common mode current

A method is provided for balancing power amongst parallel connected power converters in an uninterruptible power supply (UPS). The method includes: applying a control signal to each of the parallel connected power converters, where the control signals applied to the parallel connected power converters are derived from a common control signal output by a centralized controller; receiving measurements of current being supplied by each power converter to the load; and adjusting phase of voltage applied to at least one of the power converters based on the received current measurements, such that the phase adjustment causes same magnitude of current to flow though each filter. Advancing phase angle of the voltage increases current supplied by the at least one power converter while retarding phase angle of the voltage decreases current supplied by the at least one power converter.

Method for balancing power in paralleled converters

A method is provided for detecting a failure of a rectifier or a rectifier source in context of an uninterruptible power supply. The method includes: measuring an input current into the rectifier from a primary power source; determining a rate of change in the measured current; determining a current difference between a reference current and the measured current; measuring voltage output by the rectifier; determining a voltage difference between a reference voltage and the measured voltage; and detecting a failure condition of the rectifier as a function of the measured input current, the rate of change in the measured current, the current difference, the measured voltage and the voltage difference. More specifically, a failure condition of the rectifier is identified when the input current is decreasing and the rate of change in the measured current is decreasing and the current difference is increasing and the voltage difference is increasing.

Method for detecting a failing rectifier or rectifier source

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.

Techniques for improving operation of static transfer switches during voltage disturbances

A multiple uninterruptible power supply system includes at least two uninterruptible power supply modules. Each uninterruptible power supply module has a control unit with the control unit coupled to a synchronization bus. The uninterruptible power supply module are synchronized to each other with one of the uninterruptible power supply modules being operated as a sync master UPS and its control unit sending synchronization signals on the synchronization bus that are received on the synchronization bus by control units of each of the other uninterruptible power supply module which are each operated as a slave UPS synchronized to the sync master UPS. When a bypass power source for the uninterruptible power supply module that is being operated as the sync master becomes unqualified, another one of the UPS modules is operated as the sync master and its control unit then sends out the synchronization signals.

Method to select optimal synchronization source in a multiple uninterruptible power supply system

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.

Systems and methods for balancing UPS output voltages during transitions between operating modes

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.

Multiple UPS system having multi-way power tie system and intelligent power sharing control

The present invention discloses a method for transmitting parallelization signals of uninterruptible power supplies, which firstly performs a serialization process on parallelization signals by a logic processing unit and then performs synchronous transmission of the parallelization signals of respective node units over a bus. The method for serial transmission of parallelization signals of uninterruptible power supplies according to the invention can be implemented with easy wiring and can achieve a strong anti-interference ability, ensure real time signal transmission over a guaranteed transmission distance and identify conveniently the failure of a parallelization line while satisfying fundamental transmission demands.

Method for transmitting parallelization signals of uninterruptible power supplies

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.

Maximized battery run-time in a parallel UPS system

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.

System and method for detecting an electrical short across a static switch of an uninterruptible power supply

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.

Power supply system with adaptive blown fuse detection using negative sequence component

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.

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Delaware, OH, United States of America

Brian Paul Heber