JP3597757B2 - Parallel operation system of uninterruptible power supply - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a parallel operation system of an uninterruptible power supply.
[0002]
[Prior art]
FIG. 7 is a rewriting of the basic configuration of the uninterruptible power supply shown in FIG. 2 on page 1312 of "IEEJ Transactions on Industrial Applications D, Journal of Industrial Applications, Vol. 107, November 1987", in the same form as the present invention. FIG. 1 is a conventional block diagram, in which 101 and 102 are MCCBs (main circuit breakers), 1 is an uninterruptible power supply, and symbols in the tens are constituent elements of the uninterruptible power supply. Reference numerals 11, 14, and 16 denote switches, 12 a converter for converting AC power to DC power, 13 a battery, 15 an inverter for converting DC power to AC power, and 17 an AC switch.
[0003]
Next, the operation will be described. When the input power supply is normal, converter 12 converts AC power to DC power via MCCB 102 and switch 11, and supplies DC power to inverter 15 while charging battery 13 via switch 14. . Inverter 15 outputs AC power via switch 16. This case is the power supply mode of the inverter power supply. When the input power supply is interrupted, converter 12 stops, and inverter 15 outputs AC power using the power of battery 13. The AC switch 17 is turned on when the inverter is normally stopped, overloaded, or stopped, and supplies bypass power to the load. As shown in FIG. 8, the AC switch is configured to input an inverter power supply stop signal of the sequence control circuit 1002 to the switch drive circuit 1001 so that the AC switch 17 is turned on when the inverter power supply is stopped. Thus, even when the inverter fails, power can be continuously supplied to the load.
[0004]
In order to improve the power supply reliability of such an uninterruptible power supply, parallel redundant operation may be performed, and the configuration shown in FIG. 9 is often employed. In FIG. 9, 4 and 5 are parallel uninterruptible power supplies. For example, when the load is within 100 kVA, at least one of the parallel uninterruptible power supplies 4 and 5 is operated by setting the rated capacity to 100 kVA. If this is the case, a redundant configuration that can supply uninterruptible power to the load is provided. The difference between the uninterruptible power supply 1 of FIG. 7 and the uninterruptible power supply for parallel use 4 and 5 is that the uninterruptible power supply 1 has a bypass power supply as an input and an AC switch 17 for supplying bypass power to a load when the inverter power supply is stopped. In contrast, the parallel uninterruptible power supplies 4 and 5 have no bypass input and no AC switch.
[0005]
In the configuration shown in FIG. 9, a switching panel 6 is provided which receives the outputs of the uninterruptible power supply units 4 and 5 and the bypass power supply as inputs. Is supplied to the load. Inside the switchboard 6, the outputs of the parallel uninterruptible power supplies 4 and 5 are connected to form a parallel bus, and the output of the parallel uninterruptible power supply is normally supplied to the load via the switch 31. If neither of the parallel uninterruptible power supplies 4 and 5 can supply power, the switch 31 is turned off, and the semiconductor switch 33 and 34 and the switch 32 supply bypass power to the load. In FIG. 9, reference numeral 104 denotes an MCCB.
[0006]
[Problems to be solved by the invention]
In the conventional parallel operation system of the uninterruptible power supply with improved power supply reliability, the uninterruptible power supply (4, 5 in FIG. 9) and the switchboard 6 which do not have a bypass circuit for parallel redundancy are used. The configuration of the uninterruptible power supply (4, 5 in FIG. 9) is different from that of the uninterruptible power supply (1 in FIG. 7) having a built-in bypass circuit used in a single system of the uninterruptible power supply.
[0007]
On the other hand, in the block diagram which forms a part of the present invention shown in FIG. 1, the uninterruptible power supply of a type having a built-in bypass circuit used in a single-unit system is configured to perform a parallel redundant operation. Each of the uninterruptible power supply devices 1 and 2 has two power supply modes of power supply by an inverter and power supply by a bypass power supply as a single unit (each unit). By connecting these in parallel, two bypass power supply circuits are provided. In addition, the number of inverters becomes two, and redundancy can be provided not only during inverter power supply but also during bypass power supply.
[0008]
In the configuration of FIG. 1, the uninterruptible power supplies 1 and 2 each receive inverter power supply or bypass power supply due to overload, operation by an operator, failure, or the like. The power supply device 2 may have different power supply modes, such as inverter power supply. In this case, the inverter needs to be capable of supplying power in parallel with the bypass power supply, and there is a problem that the control circuit becomes complicated.
[0009]
Therefore, the present invention has been made to further solve the above-described problem, and has an uninterruptible power supply in which a power supply mode of each unit of an uninterruptible power supply having a built-in bypass circuit is different so that power is not supplied to a load. The object is to obtain a parallel operation system of the devices.
[0010]
[Means for Solving the Problems]
The parallel operation system of the uninterruptible power supply according to the present invention has two power supply modes: an inverter power supply in which power is supplied by an inverter, and a bypass power supply in which AC power is directly transmitted via an AC switch when the inverter stops. The own power unit and the other power unit of the power failure power supply device are operated in parallel, and the drive command of the AC switch of the own power unit is opened when the other power unit is supplying power to the inverter.
[0011]
In addition, each output of the uninterruptible power supply with its own power supply and other power supplies has two power supply modes: an inverter power supply in which power is supplied by an inverter, and a bypass power supply in which AC power is directly transmitted via an AC switch when the inverter stops. Are connected via switches, and are operated in parallel, wherein the drive command of the AC switch of the own unit is provided in the power supply mode of the inverter power supply and the switch provided in the output of the other unit. Is closed and opened.
[0012]
Further, an AND condition signal of a power supply mode signal of the inverter power supply of another unit and a closing signal of a switch provided at the output of the other unit is transmitted from the other unit to the own unit.
[0013]
In addition, each output of the uninterruptible power supply with its own power supply and other power supplies has two power supply modes: an inverter power supply in which power is supplied by an inverter, and a bypass power supply in which AC power is directly transmitted via an AC switch when the inverter stops. Are connected via switches, respectively, and are operated in parallel, and the drive command of the AC switch of the own unit is supplied to the output of the other unit in the power supply mode of the inverter supply in the other unit. Are closed and the switch provided at the output of the own machine is closed and opened.
[0014]
Also, an AND condition signal of the power supply mode signal of the inverter power supply of the other unit and the close signal of the switch provided at the output of the other unit is transmitted from the other unit to the own unit, and provided at the output of the own unit at the own unit. In this case, an AND condition signal with the switch closing signal is generated.
[0015]
BEST MODE FOR CARRYING OUT THE INVENTION
Embodiment 1 FIG.
Hereinafter, a first embodiment of the present invention will be described with reference to the drawings. In FIG. 1, reference numerals 101, 102, 103, 104, 105, and 106 denote MCCBs, reference numerals 1 and 2 denote an uninterruptible power supply, reference numerals in the tens are constituent elements of the uninterruptible power supply 1, and reference numerals in the twentieth are uninterruptible power supplies. It is a component of the power supply device 2. 11, 14, 16, 21, 24, 26 are switches; 12, 22 are converters for converting AC power to DC power; 13, 23 are batteries; 15, 25 are inverters for converting DC power to AC power; , 27 are AC switches. The operations of the input power supply 1, the uninterruptible power supply 1, and the bypass power supply, and the operations of the input power supply 2, the uninterruptible power supply 2, and the bypass power supply are respectively independent operations. Since the operation is the same as that of the bypass power supply, the description is omitted.
[0016]
FIG. 2 is a block diagram of a part that drives the AC switches 17 and 27 that are turned on at the time of bypass power supply, which are built in the uninterruptible power supplies 1 and 2. Symbols in the 2000s are constituent elements of the uninterruptible power supply 2. 1002 and 2002 are sequence control circuits, 1003 and 2003 are AND circuits, and 1004, 1005, 2004 and 2005 are inversion circuits.
[0017]
The operation will be described with reference to FIG. The AC switch 17 in the uninterruptible power supply (own unit) 1 must be turned on when the inverter 15 is stopped or the switch 16 is turned off during single operation and the inverter power supply to the load is stopped. . However, at the time of the parallel redundant operation, even if the inverter power supply is stopped, if the inverter power supply is performed by another uninterruptible power supply (other unit) 2, the AC switch 17 is turned off, and the other uninterruptible power supply 2 Also, the AC switch 17 may be turned on only when the inverter power supply is stopped. As a circuit for realizing this, the signal of “No. 1 INV power supply stop” of the own unit is input to the AND circuit 1003 from the sequence control circuit 1002, and the “No. 2 INV power supply” signal of the other unit is input to the sequence control circuit of the other unit. From 2002, the signal is input to the inversion circuit 1004 of the own device via the inversion circuit 2005, and the output of the inversion circuit 1004 is input to the AND circuit 1003. Thus, the “No. 2 INV power supply” signal of the other unit can be used as a signal for interlocking the ON of the AC switch 17.
[0018]
In this case, the signal exchanged between boards is only the "INV power supply" signal. Even if this signal cannot be transmitted correctly to another unit, it is a signal that interlocks the ON of the AC switch. To the power supply.
[0019]
As described above, by setting the “INV power supply” signal of the other unit to a signal for interlocking the ON of the AC switch of the own unit, the respective power supply modes in the parallel operation system of the uninterruptible power supply with a built-in bypass circuit are provided. Can be different.
[0020]
Embodiment 2 FIG.
In the first embodiment, the “INV power supply” signal of the other unit is used as the interlock signal for turning on the AC switch of the own unit. In the second embodiment, the MCCB 105 provided at the output of the uninterruptible power supply is used. , 106 are also added to the interlock signal.
[0021]
Hereinafter, a second embodiment of the present invention will be described with reference to FIGS. The parts added to FIG. 2 will be described below. 3, reference numeral 2008 denotes an auxiliary contact of the MCCB 106, and reference numeral 1008 denotes an auxiliary contact of the MCCB 105, which turns on / off according to the on / off operation of the MCCB. 1007 and 2007 are contact input circuits, and 1006 and 2006 are AND circuits.
[0022]
An object of the present invention is to check the uninterruptible power supply units 1 and 2 while checking the uninterruptible power supply units, that is, to interrupt the uninterruptible power supply unit supplying power to the load to the AC switch on. It is to output a lock signal appropriately. For example, in FIG. 1, it is assumed that the uninterruptible power supply 1 (own unit) is operating, the MCCB 105 is on, the uninterruptible power supply 2 (other unit) is under inspection, and the MCCB 106 is off. At this time, if the uninterruptible power supply 2 is set to the power supply mode of the inverter power supply for inspection, the "No. 2 INV power supply" signal is generated from the uninterruptible power supply 2 and the AC switch in the first embodiment. 17 is interlocked, there is a problem that when the inverter of the uninterruptible power supply 1 stops due to a failure or the like, bypass power supply cannot be performed.
[0023]
Therefore, in the second embodiment, the interlock signal for turning on the AC switch is output only when the other unit is in the power supply mode of the inverter power supply and the output MCCB of the other unit is on. As a circuit for realizing this, when explaining on the uninterruptible power supply 1 side, the auxiliary contact of the output MCCB 106 of the other unit is input to the contact input circuit 1007, and the output “MCCB 106 ON” signal and the signal from the other unit are output. The “No. 2 INV power supply” signal is input to the AND circuit 1006. By inputting the output of the AND circuit 1006 to the inverting circuit 1004 and inputting the output of the inverting circuit 1004 to the AND circuit 1003, a signal for interlocking the “No. can do.
[0024]
By configuring as above, in the parallel operation system of uninterruptible power supply with built-in bypass circuit, when checking other units, interlock signal to AC switch on of own unit is not output In this case, the power supply modes may be differently supplied to the load.
[0025]
Embodiment 3 FIG.
In the second embodiment, the "INV power supply" signal of the other unit and the output MCCB auxiliary contact of the other unit are input, and an interlock signal for turning on the AC switch is created. It is a simple way of doing.
[0026]
Hereinafter, a third embodiment of the present invention will be described with reference to FIGS. The parts changed from FIG. 3 are that the MCCB auxiliary contact input to each uninterruptible power supply is the MCCB of the own unit output, and the state of the MCCB auxiliary contact is added to the signal exchanged between panels. It is a point.
[0027]
The purpose of the present invention is the same as that of the second embodiment. In the third embodiment, the wiring is simplified. In the description of the uninterruptible power supply 1 side, the auxiliary contact of the output MCCB 106 of the other unit is input to the contact input circuit 2007 of the other unit, and the output “MCCB 106 ON” signal and the “No. A signal is input to the AND circuit 2006 on the unit side, and a signal of “No. 2 INV power supply” and “MCCB106 ON” is transmitted from another unit to the own unit, and this signal is used to interlock the ON of the AC switch 17 of the own unit. And
[0028]
By configuring as above, in the parallel operation system of uninterruptible power supply with built-in bypass circuit, when checking other units, the interlock signal to the own unit AC switch ON is not output. In addition to being able to prevent power from being supplied differently in each power supply mode, the wiring of the auxiliary contacts of the MCCB is compatible with the own machine, so that the wiring is simplified.
[0029]
Embodiment 4 FIG.
In the second and third embodiments, the "INV power supply" signal of the other unit and the output MCCB auxiliary contact signal of the other unit are input to create an interlock signal for AC switch-on. However, the difference is that the output MCCB auxiliary contact signal of the own machine is also used for creating the interlock.
[0030]
Hereinafter, a fourth embodiment of the present invention will be described with reference to FIGS. The part added to FIG. 4 is that the contact input circuits 1007 and 2007 receive the auxiliary contact 1008 of the MCCB 105 and the auxiliary contact 2008 of the MCCB 106 as inputs, respectively, and the AND circuits 1006 and 2006 as three inputs. The point is that the auxiliary contact signal is input to each AND circuit.
[0031]
An object of the present invention is to provide a power supply mode for inverter power supply and bypass power supply for any of the unchecked power supply units 1 and 2 irrespective of the other units when checking any one of the uninterruptible power supply apparatuses 1 and 2. It was constructed so that it could be done and checked. For example, in FIG. 1, it is assumed that the uninterruptible power supply 1 is operating, the MCCB 105 is on, the uninterruptible power supply 2 is under inspection, and the MCCB 106 is off. At this time, even if the uninterruptible power supply 2 is set to the power supply mode of the bypass power supply for inspection, if the uninterruptible power supply 1 is supplied with the inverter power supply, the uninterruptible power supply 1 is still in the third embodiment. Since the “No. 1 INV power supply” signal is generated and the ON of the AC switch 27 of the other unit is interlocked, there is a problem that the uninterruptible power supply device 2 cannot be set to the power supply mode of the bypass power supply for inspection.
[0032]
Therefore, in the fourth embodiment, in addition to the interlock conditions of the third embodiment, an interlock signal of an AC switch on to another unit is output only when the output MCCB of the other unit is ON. are doing. As a circuit for realizing this, when describing the uninterruptible power supply 1 side, the auxiliary contact signal of the output MCCB 106 of the other unit is input to the contact input circuit 1007, and the output of the auxiliary contact signal is “MCCB 106 ON” and “MCCB 105 ON”. ”Signal and the“ No. 1 INV power supply ”signal from the own device are input to the AND circuit 1006. By inputting the output of the AND circuit 1006 to the inverting circuit 2004 and inputting the output of the inverting circuit 2004 to the AND circuit 2003, the "No. 1 INV power supply", the "MCCB105 ON" and the "MCCB106 ON" are switched to the AC switch of another machine. 27 can be used as a signal to interlock.
[0033]
By configuring as above, in the parallel operation system of uninterruptible power supply with built-in bypass circuit, when checking other units, interlock signal to AC switch on of own unit is not output The power supply mode can be changed differently so that the load is not supplied to the load differently, and the car being inspected can freely change the power supply mode.
[0034]
Embodiment 5 FIG.
In the fourth embodiment, the inverter power supply signal of the other unit and the output MCCB auxiliary contact signal of the own unit and the other unit are input and the interlock signal of the AC switch on of the own unit is created. In the form 5, the wiring is simplified.
[0035]
Hereinafter, a fifth embodiment of the present invention will be described with reference to FIGS. The part changed from FIG. 5 is that the MCCB auxiliary contact signal input to each uninterruptible power supply is only the MCCB output from the own unit, and the other An AND condition signal of the other unit output MCCB signal and the other unit's inverter power supply signal is created in the unit, transmitted from the other unit to the own unit, and the own unit output MCCB signal is added in the own unit. .
[0036]
Explaining on the uninterruptible power supply 1 side, the auxiliary contact signal of the output MCCB 106 of the other unit is input to the contact input circuit 2007 of the other unit, and the "MCCB 106 ON" signal and the "No. The other device inputs to the AND circuit 2006 and transmits the signal of “No. 2 INV power supply” and “MCCB106 ON” from the other device to the own device. On the other hand, the auxiliary contact signal of the output MCCB 105 is input to the contact input circuit 1007 of the own device in the own device, and the output “MCCB 105 ON” signal is input to the AND circuit 1009. A signal transmitted from another unit is also input to the AND circuit 1009, and the output is used as an interlock signal for turning on the AC switch 17.
[0037]
By configuring as above, in the parallel operation system of uninterruptible power supply with built-in bypass circuit, when checking other units, interlock signal to AC switch on of own unit is not output The power supply mode can be changed differently so that the load is not supplied to the load differently. Because it is compatible with the unit, wiring is simplified.
[0038]
【The invention's effect】
As described above, according to the parallel operation system of the uninterruptible power supply of the present invention, the inverter power supply that supplies power by the inverter and the bypass power supply that directly supplies the AC power supply via the AC switch when the inverter stops. The own unit and the other unit of the uninterruptible power supply having two power supply modes are operated in parallel, and the drive command of the AC switch of the own unit is opened when the other unit is supplying inverter power. Therefore, it is possible to prevent the power supply modes of the own device and the other devices from being different.
[0039]
In addition, each output of the uninterruptible power supply with its own power supply and other power supplies has two power supply modes: an inverter power supply in which power is supplied by an inverter, and a bypass power supply in which AC power is directly transmitted via an AC switch when the inverter stops. Are connected via switches, and are operated in parallel, wherein the drive command of the AC switch of the own unit is provided in the power supply mode of the inverter power supply and the switch provided in the output of the other unit. Is closed and open, it is possible to prevent the power supply modes of the own unit and the other units from being differently supplied to the load.
[0040]
In addition, since the AND condition signal of the power supply mode signal of the inverter power supply of the other unit and the closing signal of the switch provided at the output of the other unit is transmitted from the other unit to the own unit, wiring is simplified. .
[0041]
In addition, each output of the uninterruptible power supply with its own power supply and other power supplies has two power supply modes: an inverter power supply in which power is supplied by an inverter, and a bypass power supply in which AC power is directly transmitted via an AC switch when the inverter stops. Are connected via switches, respectively, and are operated in parallel, and the drive command of the AC switch of the own unit is supplied to the output of the other unit in the power supply mode of the inverter supply in the other unit. Is closed and the switch provided at the output of the own unit is closed and open, so that the power supply modes of the own unit and the other units are different, so that power cannot be supplied to the load. No. can change the power supply mode freely.
[0042]
Also, an AND condition signal of the power supply mode signal of the inverter power supply of the other unit and the close signal of the switch provided at the output of the other unit is transmitted from the other unit to the own unit, and provided at the output of the own unit at the own unit. Since the AND condition signal with the switch closing signal is generated, the wiring is simplified.
[Brief description of the drawings]
FIG. 1 is a block diagram showing a part of an embodiment of the present invention.
FIG. 2 is a block diagram which constitutes Embodiment 1 of the present invention together with FIG.
FIG. 3 is a block diagram which constitutes Embodiment 2 of the present invention together with FIG. 1;
FIG. 4 is a block diagram which constitutes Embodiment 3 of the present invention together with FIG. 1;
FIG. 5 is a block diagram which constitutes Embodiment 4 of the present invention together with FIG. 1;
FIG. 6 is a block diagram constituting a fifth embodiment of the present invention together with FIG. 1;
FIG. 7 is a block diagram showing a conventional uninterruptible power supply.
FIG. 8 is a block diagram related to AC switch driving of a conventional uninterruptible power supply.
FIG. 9 is a block diagram showing a conventional parallel redundant operation system of an uninterruptible power supply.
[Explanation of symbols]
1, 2 uninterruptible power supply 12, 22 converter 13, 23 battery 11, 14, 16, 21, 24, 26 switch 15, 25 inverter 17, 27 AC switch 101, 102, 103, 104, 105, 106 MCCB
1001, 2001 Switch driving circuit 1002, 2002 Sequence control circuit 1003, 2003 AND circuit 1004, 1005, 2004, 2005 Inverting circuit 1006, 2006 AND circuit 1007, 2007 Contact input circuit 1008 The auxiliary contact 2008 of the MCCB 105 is the auxiliary contact of the MCCB 106.

Claims (5)

The own unit and other units of the uninterruptible power supply unit have two power supply modes: an inverter power supply that supplies power using an inverter, and a bypass power supply that sends AC power directly through an AC switch when the inverter stops. A parallel operation system for an uninterruptible power supply, characterized in that a drive command for an AC switch of the own unit is opened when another unit is supplying inverter power. Each output of the uninterruptible power supply with its own power supply and other power supplies has two power supply modes: an inverter power supply that supplies power using an inverter, and a bypass power supply that sends AC power directly through an AC switch when the inverter stops. Connected via a switch and operated in parallel, the drive command of the AC switch of the own unit is controlled by the other unit in the power supply mode of the inverter power supply and the switch provided at the output of the other unit is closed. A parallel operation system for an uninterruptible power supply, characterized by being opened. 3. The uninterruptible power supply according to claim 2, wherein an AND condition signal of a power supply mode signal for inverter power supply of another unit and a closing signal of a switch provided at an output of the other unit is transmitted from the other unit to the own unit. Parallel operation system. Each output of the uninterruptible power supply with its own power supply and other power supplies has two power supply modes: an inverter power supply that supplies power using an inverter, and a bypass power supply that sends AC power directly through an AC switch when the inverter stops. Connected via a switch and operated in parallel, the drive command of the AC switch of the own unit is controlled by the other unit in the power supply mode of the inverter power supply, and the switch provided at the output of the other unit is closed. Wherein the switch provided at the output of the own machine is closed and opened. An AND condition signal of the power supply mode signal of the other unit's inverter power supply and the close signal of the switch provided at the output of the other unit is transmitted from the other unit to the own unit, and the switching provided at the output of the own unit at the own unit 5. The parallel operation system for an uninterruptible power supply according to claim 4, wherein an AND condition signal is generated with a closing signal of the switch.

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