WO2008133733A1 - Procédé et appareil destinés à la synchronisation d'actions dans un système d'alimentation sans coupure parallèle à l'aide d'un bus de communication série - Google Patents

Procédé et appareil destinés à la synchronisation d'actions dans un système d'alimentation sans coupure parallèle à l'aide d'un bus de communication série Download PDF

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Publication number
WO2008133733A1
WO2008133733A1 PCT/US2007/085228 US2007085228W WO2008133733A1 WO 2008133733 A1 WO2008133733 A1 WO 2008133733A1 US 2007085228 W US2007085228 W US 2007085228W WO 2008133733 A1 WO2008133733 A1 WO 2008133733A1
Authority
WO
WIPO (PCT)
Prior art keywords
ups
bus
request
units
output voltage
Prior art date
Application number
PCT/US2007/085228
Other languages
English (en)
Inventor
Mohammad Nanda Rahman Marwali
Kevin Kim Eschhofen
John Franz Christensen
Brian Paul Heber
Original Assignee
Liebert Corporation
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority claimed from US11/773,755 external-priority patent/US20090009001A1/en
Application filed by Liebert Corporation filed Critical Liebert Corporation
Publication of WO2008133733A1 publication Critical patent/WO2008133733A1/fr

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Classifications

    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J9/00—Circuit arrangements for emergency or stand-by power supply, e.g. for emergency lighting
    • H02J9/04—Circuit arrangements for emergency or stand-by power supply, e.g. for emergency lighting in which the distribution system is disconnected from the normal source and connected to a standby source
    • H02J9/06—Circuit arrangements for emergency or stand-by power supply, e.g. for emergency lighting in which the distribution system is disconnected from the normal source and connected to a standby source with automatic change-over, e.g. UPS systems
    • H02J9/062—Circuit arrangements for emergency or stand-by power supply, e.g. for emergency lighting in which the distribution system is disconnected from the normal source and connected to a standby source with automatic change-over, e.g. UPS systems for AC powered loads
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J3/00—Circuit arrangements for ac mains or ac distribution networks
    • H02J3/38—Arrangements for parallely feeding a single network by two or more generators, converters or transformers
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
    • H02M7/00—Conversion of ac power input into dc power output; Conversion of dc power input into ac power output
    • H02M7/42—Conversion of dc power input into ac power output without possibility of reversal
    • H02M7/44—Conversion of dc power input into ac power output without possibility of reversal by static converters
    • H02M7/48—Conversion of dc power input into ac power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode
    • H02M7/493—Conversion of dc power input into ac power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode the static converters being arranged for operation in parallel
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J9/00—Circuit arrangements for emergency or stand-by power supply, e.g. for emergency lighting
    • H02J9/04—Circuit arrangements for emergency or stand-by power supply, e.g. for emergency lighting in which the distribution system is disconnected from the normal source and connected to a standby source
    • H02J9/06—Circuit arrangements for emergency or stand-by power supply, e.g. for emergency lighting in which the distribution system is disconnected from the normal source and connected to a standby source with automatic change-over, e.g. UPS systems
    • H02J9/068—Electronic means for switching from one power supply to another power supply, e.g. to avoid parallel connection

Definitions

  • the present invention relates generally to uninterruptible power supply (UPS) systems, and more particularly to two or more UPS systems connected and operated in parallel wherein synchronization of actions between the UPS systems takes place using a serial communications bus.
  • UPS uninterruptible power supply
  • a UPS system is used in applications that require continuity of power, such that when the main power source fails, the UPS system provides power from a reserve energy stored system, typically in the form of a battery.
  • the UPS system monitors the main power source and controls the UPS components to provide continuous power to a critical load.
  • UPS units may be paralleled with other UPS units to form a redundant and scalable UPS system with a given multiplicity.
  • This system adds redundancy in that any UPS unit may be disconnected from the critical load for service or automatically by the UPS unit to isolate a faulty unit. The remaining unit(s) still provide power to the critical load.
  • this system allows flexibility in increasing the total power capacity of the system.
  • UPS units are paralleled, some unit-to-unit wiring is added to facilitate the sharing of power and the connection or disconnection of units.
  • Coordinated action taken by units in a UPS system with paralleled UPS units is vital to ensuring continuous, quality power is provided to the critical load.
  • This action includes requests to transfer power from the alternate AC source to the inverters of the UPS unit by closing the circuit breakers and turning off the static bypass switch (SBS).
  • SBS static bypass switch
  • These requests originate from a user pressing a button on the human-machine interface (HMI) of the system, or may result from an automatic request from the internal controller of the UPS unit to transfer the load back to the UPS unit at some period of time after an emergency transfer to bypass was executed.
  • HMI human-machine interface
  • These actions can tolerate some delay as to when they are accomplished, but all UPS units must perform the actions at the same instant of time in order to prevent improper load current sharing between inverters and the bypass source.
  • An additional action is a manual transfer to an SBS. This is a request from a user to transfer the power from the inverters to the bypass source by opening the output circuit breakers and turning on the SBS.
  • a further action that is required to be performed by all UPS units at virtually the same instant in time is an overload transfer to an SBS.
  • This action is a request determined by the controllers of the UPS units that an overload condition is detected at the load when powered by the inverters.
  • the UPS system may allow the conditions to last for relatively long periods of time before a transfer to an SBS is required. In this instance, some delay in performing the action can be tolerated, but still the actions are required to be performed synchronously.
  • a further action to be performed by all UPS units is a set point change. There are instances when the user desires to change the set points related to the inverter's output voltage generation, such as voltage amplitude and frequency.
  • a serial communications bus is utilized to send key action data between parallel UPS units.
  • the communications bus is used to transmit data at the zero crossing of the critical bus voltage.
  • Each UPS unit then takes action based upon the event data received at the next zero crossing of the critical bus voltage.
  • FIG. 1 illustrates a block diagram illustrating the present UPS system
  • FIGS. 2a, 2b and 2c illustrate wave forms illustrating operation of the present method
  • FIG. 3 illustrates a block diagram of an implementation of a controller for use with the present UPS system
  • FIG. 4 illustrates a computer flow chart illustrating a periodic timer interrupt service routine
  • FIG. 5 illustrates a computer flow chart illustrating a zero cross interrupt service routine.
  • UPS system 10 includes a UPS unit 12 and a UPS unit 14 connected in parallel to create UPS system 10. Although two UPS units 12 and 14 are illustrated in FIG. 1 , it should be understood that any number of UPS units may be connected in parallel, and units 12 and 14 are shown for illustrative purposes only.
  • the output of units 12 and 14 generate a critical bus voltage 16 (FIG. 2a) which is applied to a critical load 18.
  • UPS unit 12 includes a rectifier 20 that converts input power from an AC power source 22 to DC power.
  • AC power source 22 may be provided from utility power or another AC power source such as a generator.
  • Rectifier 20 is connected to a first power source, also referred to as an inverter 24 which converts the DC power to a regulated conditioned AC power.
  • a battery 26 provides reserved DC energy in the event that there is a utility power outage.
  • UPS unit 12 further includes a static bypass switch (SBS) 28 which connects an alternate AC source 30 to load 18 in the event that first power source 24 fails.
  • Alternative AC source 30 may optionally be connected to the same source as AC source 22 or it may be supplied from a separate AC source.
  • Devices suitable for static bypass switch 28 include SCRs, triac and IGBT, for example.
  • UPS unit 12 further includes a controller 32 which controls the operation of unit 12 including operation of rectifier 20, activation/deactivation of SBS 28, and controlling operation of inverter 24. Control of these components is through control and feedback signal measurements provided on bus 34.
  • the output voltage 36 of inverter 24 is normally part of the feedback signal measurement of bus 34, but is shown separately in FIG. 1 being applied to controller 32 to describe the present method.
  • a circuit breaker 38 is also provided within UPS unit 12. A request to transfer power from source 30 to inverter 24 is accomplished by closing circuit breaker 38 and turning off SBS 28.
  • UPS units such as
  • UPS unit 12 may be paralleled with additional UPS units such as second UPS unit 14.
  • UPS unit 14 has the same subsystems as UPS unit 12 including a rectifier 40, inverter 42, battery 44, SBS 46, controller 48, bus 50 and circuit breaker 52. The output voltage 54 of inverter 42 is applied to controller 48.
  • a plurality of UPS units 12 and 14 may be connected in parallel and controllers 32 and 48 in each unit is configured to operate in tandem with the other controller(s).
  • FIG. 2a illustrates the critical bus voltage 16 applied to critical load 18.
  • signaling on bus 60 occurs when a UPS unit detects a request to perform an action at time t 0 and immediately asserts the bus logic, and other UPS units take action at practically the same time.
  • Signaling on bus 60 is used for those actions that need to be implemented by all UPS units with minimum time delay. Such an action is in the event that critical bus voltage 16 fails when inverters 24 or 42 are powering load 18, UPS system 10 must transfer load 18 automatically to the alternate source 30 by turning on SBS 28 or 46 and opening circuit breakers 38 or 52. This action must be performed by all UPS units 12 and 14 at the same time and with minimum time delay in order to maintain continuity of power to load 18.
  • the present invention utilized serial communications bus 62 to transmit key event data between UPS units 12 and 14.
  • Bus 62 may comprise, for example, a controller area network (CAN), RS485 and other serial communications.
  • the present invention utilizes the output voltages 36 and 54 of units 12 and 14.
  • CAN controller area network
  • FIG. 2c when a UPS unit 12 or 14 detects a request to perform an action at time to, the UPS unit waits until time t] which is the next occurrence of a zero crossing of the voltage of the critical bus voltage 16 to broadcast the request to other UPS units through the serial communications bus 62. Since the command data is transmitted serially, there will be a finite time delay before the receiving UPS units receive the command. Once the serial data is fully received by all units at time t 2 , the receiving units wait until another voltage zero cross at time t 3 before performing the action.
  • t controller area network
  • bus 62 enables more than a single command to be decoded into one serial communication data stream, so only one serial bus wiring is necessary to accomplish many commands.
  • the present invention thereby eliminates numerous wires between UPS units in a parallel system.
  • the communication performed by bus 62 is not required to take place at an extremely high speed. So long as the transmit time, Vt 1 , is less than one line cycle period of the voltage, the distance between two positive zero crosses, then synchronization of UPS units 12 and 14 can be achieved. On average, there may be between, for example, 20 and 30 signals that are required to be communicated between UPS units 12 and 14.
  • the number of wired signals can be reduced to, for example, 3 or 4 utilizing bus 60, which results in a cost savings and reduces the complexity of the communications required between parallel units 12 and 14.
  • Those events that require immediate action are wired directly between units 12 and 14 utilizing bus 60 whereas those communications which can be slightly delayed, but which still must be synchronized, utilize bus 62 of the present invention.
  • FIG. 3 an example of a controller 32 or 48 within units 12 and 14 is illustrated.
  • the output voltage 36 (or 54) is applied to a zero cross detector 70 to generate a logic pulse at a zero cross of the output voltage. This logic pulse is used to generate an interrupt to a microprocessor system 72.
  • Microprocessor system 72 includes a serial communication controller 74 for transmitting and receiving data on serial bus 62.
  • FIGS. 4 and 5 illustrate the flow chart of the software which may be utilized to implement the controller functions shown in FIG. 3. Referring to FIG. 4, the periodic timer interrupt service routine begins at step 80.
  • each UPS unit checks to see if there is any request for an action at step 82. If there is a request for action, the system will set a software flag, True, at step 84 which indicates that the command is pending to be broadcast to other units. The actual command broadcast will be performed at the next occurrence of a voltage zero cross. If no requests for action are pending or if the command flag has been set True, the next step is to determine whether a new command has been received from a controller 32 or 48 at step 86. If a command has been received, a flag, True, indicating that action is pending is set at step 88. This action will be performed at the next occurrence of voltage zero cross.
  • the software to implement a zero cross interrupt service routine begins at step 92 when a zero cross interrupt occurs, the controller 32 or 48 checks at step 94 to determine if an action pending is to be performed. If a flag had previously been set at step 88, the pending flag is True and the action is performed at step 96. The pending flag will then be cleared at step 98 and set False to prevent multiple actions being performed for a single command.
  • the set actions pending flag may be set True at step 106, and the flow returns at step 108.

Landscapes

  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Business, Economics & Management (AREA)
  • Emergency Management (AREA)
  • Stand-By Power Supply Arrangements (AREA)
  • Supply And Distribution Of Alternating Current (AREA)

Abstract

L'invention concerne l'utilisation d'un bus de communication série (62) pour l'envoi de données d'actions principales entre des unités d'alimentation sans coupure (UPS) (12, 14). Le bus de communication (62) est utilisé pour transmettre des données au passage par zéro de la tension critique du bus. Chaque unité d'alimentation sans coupure (12, 14) agit ensuite sur la base des données d'événements reçues au passage par zéro suivant de la tension critique du bus.
PCT/US2007/085228 2007-04-27 2007-11-20 Procédé et appareil destinés à la synchronisation d'actions dans un système d'alimentation sans coupure parallèle à l'aide d'un bus de communication série WO2008133733A1 (fr)

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
US91459407P 2007-04-27 2007-04-27
US60/914,594 2007-04-27
US11/773,755 2007-07-05
US11/773,755 US20090009001A1 (en) 2007-07-05 2007-07-05 Method and apparatus for synchronization of actions in a parallel ups system using a serial communications bus

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WO2008133733A1 true WO2008133733A1 (fr) 2008-11-06

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TW (1) TW200843290A (fr)
WO (1) WO2008133733A1 (fr)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2010049231A3 (fr) * 2008-10-27 2010-07-01 Siemens Aktiengesellschaft Dispositif pour alimenter un réseau de consommateurs en énergie électrique fournie par un réseau d'alimentation
ITVI20090180A1 (it) * 2009-07-20 2011-01-21 Riccardo Novello Dispositivo per l'alimentazione di un carico elettrico, sistema di alimentazione o accoppiamento di una prima sorgente di potenza elettrica con una o più sorgenti di potenza elettrica ausiliarie e relativo metodo.
CN102593940A (zh) * 2012-01-19 2012-07-18 华为技术有限公司 不间断供电电源装置及其工作方法
WO2016094141A1 (fr) * 2014-12-10 2016-06-16 Eaton Corporation Appareil d'alimentation modulaire sans coupure et ses procédés de fonctionnement

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2224895A (en) * 1988-10-25 1990-05-16 Nishimu Denshi Kogyo Kk Parallel operation of triport uninterruptable power source devices
US6396170B1 (en) * 2000-03-29 2002-05-28 Powerware Corporation Method and apparatus for coordinating uninterruptible power supply modules to provide scalable, redundant power
US20030048006A1 (en) * 2000-10-27 2003-03-13 Liebert Corporation Uninterruptible power supply
US20050036253A1 (en) * 2003-08-13 2005-02-17 Shou-Long Tian Modular AC power supply system with fault bypass and method of switching output modes
US7038923B2 (en) * 2001-12-31 2006-05-02 Emerson Network Power Co., Ltd. Method of establishing a master & minus; host in modules connecting in parallel

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2224895A (en) * 1988-10-25 1990-05-16 Nishimu Denshi Kogyo Kk Parallel operation of triport uninterruptable power source devices
US6396170B1 (en) * 2000-03-29 2002-05-28 Powerware Corporation Method and apparatus for coordinating uninterruptible power supply modules to provide scalable, redundant power
US20030048006A1 (en) * 2000-10-27 2003-03-13 Liebert Corporation Uninterruptible power supply
US7038923B2 (en) * 2001-12-31 2006-05-02 Emerson Network Power Co., Ltd. Method of establishing a master & minus; host in modules connecting in parallel
US20050036253A1 (en) * 2003-08-13 2005-02-17 Shou-Long Tian Modular AC power supply system with fault bypass and method of switching output modes

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2010049231A3 (fr) * 2008-10-27 2010-07-01 Siemens Aktiengesellschaft Dispositif pour alimenter un réseau de consommateurs en énergie électrique fournie par un réseau d'alimentation
JP2012507253A (ja) * 2008-10-27 2012-03-22 シーメンス アクティエンゲゼルシャフト 供給ネットワークからの電力をコンシュマーネットワークに供給するためのデバイス
ITVI20090180A1 (it) * 2009-07-20 2011-01-21 Riccardo Novello Dispositivo per l'alimentazione di un carico elettrico, sistema di alimentazione o accoppiamento di una prima sorgente di potenza elettrica con una o più sorgenti di potenza elettrica ausiliarie e relativo metodo.
CN102593940A (zh) * 2012-01-19 2012-07-18 华为技术有限公司 不间断供电电源装置及其工作方法
WO2016094141A1 (fr) * 2014-12-10 2016-06-16 Eaton Corporation Appareil d'alimentation modulaire sans coupure et ses procédés de fonctionnement
US9769948B2 (en) 2014-12-10 2017-09-19 Eaton Corporation Modular uninterruptible power supply apparatus and methods of operating same
US10568232B2 (en) 2014-12-10 2020-02-18 Eaton Intelligent Power Limited Modular uninterruptible power supply apparatus and methods of operating same

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Publication number Publication date
TW200843290A (en) 2008-11-01

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