JP5401235B2 - Uninterruptible power supply system - Google Patents

Description

  The present invention relates to an uninterruptible power supply system of a parallel redundant system capable of operating at least three uninterruptible power supply apparatuses in parallel.

  Patent Document 1 discloses an uninterruptible power supply that can recover power supply in a short time even if the uninterruptible power supply fails, and can reduce the risk of a load stoppage due to a power failure of the bypass power supply within the time required for repair of the uninterruptible power supply. A power supply system is disclosed. It opens and closes two uninterruptible power supplies that output uninterruptible AC power, two sets of switching circuits that switch to a bypass power supply in the event of a failure of the uninterruptible power supply, and two sets of switching circuits. It has 4 switches, and these switches allow you to select the connection between 2 sets of switching circuits and 2 sets of loads, and also have a switch that opens and closes the outputs of 2 uninterruptible power supplies. It is configured so that either single-unit operation or parallel operation of the apparatus can be selected.

  Patent Document 2 discloses an uninterruptible power supply system that can reliably supply power even when a failure occurs in one of the backup power supplies or during a maintenance test. This is because when a failure occurs in one of the first or second uninterruptible power supply devices connected in parallel to the bus board that performs AC output, the failure occurs by the first or second switching control circuit. The uninterruptible switching operation of the first or second uninterruptible switching circuit on the side is stopped, the uninterruptible switching circuit on the side where no failure has occurred is switched to the direct power feeding side, and the first or second If an overcurrent occurs in any one of the uninterruptible power supply units, switch to direct-line power supply, and also during the maintenance test, either during the maintenance test of either the first or second uninterruptible power supply unit, the other Backup power supply from the uninterruptible power supply.

FIG. 6 differs from Patent Documents 1 and 2 described above in that it is a parallel redundant system in which three uninterruptible power supply devices are connected in parallel, and schematically shows a conventional uninterruptible power supply system having a maintenance circuit. FIG.

  The AC input power supply 2 and the commercial power supply 3 are connected in parallel to the input sides of a plurality of uninterruptible power supply devices 1a, 1b, 1c, respectively, and the uninterruptible power supply devices 1a, 1b, 1c (collectively referred to as 1). Are connected to the load 10 at the same time.

  The uninterruptible power supply 1a inputs the alternating current from the alternating current input power source 2 to the converter 5a via the alternating current input circuit breaker 4a, converts it into direct current by the converter 5a, and inputs the converted direct current to the inverter 7a. The inverter 7a converts it to alternating current, and the converted alternating current is supplied to the load 10 via the inverter side contact side contactor 8a. Further, the uninterruptible power supply 1a includes a commercial power source 3, a commercial power source circuit breaker 13a connected in series between the connection points of the output side of the inverter contact side contactor 8a and the load 10, and a commercial power source circuit breaker 13a. Are connected in series with a commercial power supply side contactor 12a and a semiconductor switch 11a connected in parallel with the commercial power supply side contactor 12a.

  The uninterruptible power supply 1b inputs alternating current from the alternating current input power supply 2 to the converter 5b via the alternating current input circuit breaker 4b, converts it into direct current by the converter 5b, and inputs the converted direct current to the inverter 7b. The inverter 7b converts it into alternating current, and the converted alternating current is supplied to the load 10 via the inverter side contact side contactor 8b. Further, the uninterruptible power supply 1b includes a commercial power source 3, a commercial power source circuit breaker 13b connected in series between the connection points of the output side of the inverter side contactor contactor 8b and the load 10, and a commercial power source circuit breaker 13b. Are connected in series with a commercial power supply side contactor 12b, and a semiconductor switch 11b connected in parallel with the commercial power supply side contactor 12b.

  The uninterruptible power supply 1c inputs the alternating current from the alternating current input power source 2 to the converter 5c via the alternating current input circuit breaker 4c, converts it into direct current by the converter 5c, and inputs the converted direct current to the inverter 7b. The inverter 7b converts it into alternating current, and the converted alternating current is supplied to the load 10 via the inverter side contact side contactor 8b. Further, the uninterruptible power supply 1c includes a commercial power source 3, a commercial power source circuit breaker 13c connected in series between the connection points of the output side of the inverter contact side contactor 8c and the load 10, and a commercial power source circuit breaker 13c. Are connected in series with a commercial power supply side contactor 12c, and a semiconductor switch 11c connected in parallel with the commercial power supply side contactor 12c.

  Between each converter 5a, 5b, 5c (collectively 5) and the inverter 7a, 7b, 7c (collectively 7) and the ground, power storage means such as storage batteries 6a, 6b, 6c (collectively named) 6) is connected.

  Specifically, the storage battery 6a is connected between the connection point between the commercial power source 3, the converter 5a and the inverter 7a and the ground, the storage battery 6b is connected between the connection point between the converter 5b and the inverter 7b and the ground, and the converter 5c and the inverter. The storage battery 6c is connected between the connection point 7c and the ground. Further, the output side contactor 9 constituting the maintenance circuit 27 is connected between the common connection point of the load 10 and each uninterruptible power supply 1.

  In addition, a maintenance maintenance bypass circuit 15 is connected in parallel to each uninterruptible power supply 1 and connected to a connection point between the output side contactor 9 on the output side of the commercial power supply 3 and the input side of the load 10. The maintenance breaker 14 constituting the maintenance circuit 27 is connected to a part of 15. As described above, since the maintenance and maintenance bypass circuit 15 and the maintenance and maintenance circuit breaker 14 are added, when a maintenance check including the common parts of the uninterruptible power supply devices 1a, 1b and 1c is performed, the load from the commercial power source 3 is applied. 10 can be fed.

JP 2002-27684 A JP 2000-201440 A

  Hereinafter, problems in the conventional uninterruptible power supply system of FIG. 6 will be described with reference to FIG. 7, FIG. 8, FIG. 9, and FIG. As shown in FIG. 7, when the uninterruptible power supply system is normal, as shown in FIG. 7A, each uninterruptible power supply 1 is normally an AC input circuit breaker (closed state) with an AC input power supply 2 as an input. ) 4 and the converter 5 are used to convert alternating current into direct current, to charge the storage battery 6 and to supply power to the inverter 7. The inverter 7 is connected to the inverter side contactor (closed state) 8 and the output side contactor ( Power is supplied to the load 10 via the closed circuit state 9.

  In this state, when the AC input power supply 2 fails, the converter 5 stops (gate block), DC power from the storage battery 6 is input to the inverter 7, and the AC converted in the inverter 7 is the inverter side contactor 8. Power is supplied to the load 10 via the output side contactor 9. As a result, AC power is continuously supplied to the load 10.

  Then, from the state where each uninterruptible power supply 1 is operating normally as shown in FIG. 7 (a), bypass power feeding, specifically, commercial power supply 3 and commercial power supply side cutoff as shown in FIG. 7 (b). Power is supplied to the load 10 via the output side contactor (closed state) 9 or any one of the switch 13, the semiconductor switch (closed state) 11 and the commercial power supply side contactor (closed state) 12 constituting the switching device.

  As described above, the uninterruptible power supply devices 1a, 1b and 1c are either one of the two systems of the AC input power supply 2 via the inverters 7a, 7b and 7c and the power supply system via the commercial power supply 3 with respect to the load 10. I am trying to supply power. Now, as shown in FIG. 7A, when the uninterruptible power supply devices 1a, 1b and 1c are supplying power to the load 10 via the power supply system via the inverters 7a, 7b and 7c, for example, the uninterruptible power supply device 1c. If a failure occurs, the inverter-side contactor 8c is turned off, and the uninterruptible power supply 1a and 1b supplies power to the load 10.

  Further, when the uninterruptible power supply 1b fails from the state where the uninterruptible power supply 1c has failed, the inverter-side contactor 8b is turned off to supply power to the load 10 only by the uninterruptible power supply 1a. Furthermore, when the uninterruptible power supply 1a fails from the state where both the uninterruptible power supplies 1c and 1b fail, the inverter side contactor 8a is turned off, the semiconductor switches 11a, 11b and 11c, the commercial power supply side contactor 12a, By supplying power to the load 10 from the power supply system via the commercial power source 3 and the commercial circuit breaker 13 by turning on 12b and 12c, the power supply to the load 10 can be continued.

  However, in the conventional uninterruptible power supply system, bypass power supply (power is supplied through the path of the storage battery 6 or the AC input power supply 2 and the circuit breaker 4-inverter 7-contactor 8, 9) by failure switching or the like ( When switching the power supply to the commercial power source 3-the circuit breaker 13-the power supply via the switchers 12 and 11), two of the three uninterruptible power supply devices 1 (the semiconductor switch 11 and the contactor 12). May be unable to switch to bypass power supply.

  Here, specifically, in FIG. 9B, a case where the semiconductor switches 11b and 12b and / or the semiconductor switches 12b and 12c constituting the switching device become abnormal is considered. For example, a case where an uninterruptible power supply system of 1000 kVA is constructed as a parallel redundant system, and a case where it is configured by 500 kVA × 3 uninterruptible power supply devices 1a, 1b, and 1c is assumed.

  As shown in FIG. 8B, for example, even when the switching units 11c and 12c of one uninterruptible power supply 1c become abnormal and cannot be switched by bypass power feeding, the remaining two uninterruptible power supplies that can operate normally. Power supply to the load 10 can be continued by operating the devices 1a and 1b.

  However, as shown in FIG. 9B, for example, when the switches 11b, 12b and 11c, 12c of the two uninterruptible power supply devices 1b, 1c become abnormal, as shown in FIG. The uninterruptible power supply 1a will bear a power supply capacity of, for example, 1000 kVA, which far exceeds the rated capacity of the equipment, so that the circuit breaker 13a trips due to an overload and feeds the load 10 Until it stopped.

  8A and 9A show a state in which the uninterruptible power supply devices 1a, 1b, and 1c are operating normally as in FIG. 7A.

  The present invention has been made to solve the above-described problems, and even when a plurality of uninterruptible power supply switching devices become abnormal, load power feeding can be continued without stopping load power feeding. The purpose is to provide an uninterruptible power supply system.

In order to achieve the above object, an invention corresponding to claim 1 inputs DC power from power storage means, converts this into AC power, and supplies the converted AC power to a load;
Voltage control means for generating an output voltage command for the inverter so that the AC output voltage of the inverter matches a voltage reference, and gates of switching elements constituting the inverter based on the inverter output voltage command from the voltage control means. A gate control circuit to be controlled; an AC power supply path that supplies AC power from a commercial AC power supply to the load separately from a power supply path from the inverter; and the AC power supply path that supplies the AC power And an uninterruptible power supply device comprising: a semiconductor switch that constitutes a switching device by cutting off and a contactor that is connected in parallel to the semiconductor switch and constitutes the switching device; and at least three uninterruptible power supply devices in parallel A maintenance circuit breaker that is connected and connected in parallel to each uninterruptible power supply, and that is protected by overcurrent during maintenance. A maintenance bypass circuit including an output contactor that closing operation to the opening operation to and during non-maintenance maintenance, the uninterruptible power supply system having a,
A switching device abnormality detecting circuit for detecting that the switching device having the respective uninterruptible power supply is turned on each abnormality, closed path the maintenance breaker of the maintenance bypass circuit based on an output of the respective switching device abnormality detection circuit An uninterruptible power supply system including a determination circuit for setting a state.

In order to achieve the above object, the invention corresponding to claim 2 is an inverter that inputs DC power from the power storage means, converts it to AC power, and supplies the converted AC power to a load;
An inverter-side contactor provided in an electric circuit between the output side of the inverter and the load; and voltage control means for generating an output voltage command of the inverter so that an AC output voltage of the inverter matches a voltage reference; A gate control circuit that controls the gate of a switching element that constitutes the inverter based on an inverter output voltage command from the voltage control means, AC power from a commercial AC power source, and a power supply path from the inverter to the load Separately supplied AC power supply path, provided in the AC power supply path, a semiconductor switch that supplies and cuts off the AC power to form a switch, and a commercial switch that is connected in parallel with the semiconductor switch to form the switch an AC power source side contact unit, and an uninterruptible power supply having a well as three parallel connecting the uninterruptible power supply, wherein the uninterruptible power In an uninterruptible power supply system comprising a maintenance circuit breaker that is connected in parallel to the device and that is protected by overcurrent during maintenance, and a maintenance bypass circuit that includes an output contactor that is opened during maintenance and closed during non-maintenance An inverter side detection circuit for detecting a closed state of the inverter side contactor included in each uninterruptible power supply, a commercial AC power source side detection circuit for detecting a closed state of the switch, and the commercial AC power source side contactor The maintenance circuit breaker of the maintenance bypass circuit is closed based on a power supply command for switching to one of the inverter side contactor, the output of the inverter side detection circuit, and the output of the commercial AC power supply side detection circuit. And outputting the switch abnormality signal based on the power supply command and the output of the commercial AC power supply side detection circuit. And the constant circuit,
Is an uninterruptible power supply system.

In order to achieve the above object, the invention corresponding to claim 3 is an inverter that inputs DC power from the power storage means, converts it to AC power, and supplies the converted AC power to a load;
Voltage control means for generating an output voltage command for the inverter so that the AC output voltage of the inverter matches a voltage reference, and gates of switching elements constituting the inverter based on the inverter output voltage command from the voltage control means. A gate control circuit to be controlled; an AC power supply path that supplies AC power from a commercial AC power supply to the load separately from a power supply path from the inverter; and the AC power supply path that supplies the AC power And an uninterruptible power supply device comprising: a semiconductor switch that constitutes a switching device by cutting off and a contactor that is connected in parallel to the semiconductor switch and constitutes the switching device; and at least three uninterruptible power supply devices in parallel A maintenance circuit breaker that is connected and connected in parallel to each uninterruptible power supply, and that is protected by overcurrent during maintenance. A maintenance bypass circuit including an output contactor that is opened during maintenance and closed during non-maintenance, and the switching unit included in each of the uninterruptible power supply devices is abnormal. Switch abnormality detection circuit to detect, overload detection circuit for detecting current flowing in the load and detecting an overload state based on the detected current, output of each switch abnormality detection circuit, and overload detection circuit of the maintenance breaker of the maintenance bypass circuit based on an output a uninterruptible power supply system comprising a determination circuit, a to a closed circuit condition.

  According to the present invention, it is possible to provide an uninterruptible power supply system capable of continuing load power feeding without stopping load power feeding even if a plurality of uninterruptible power supply switching devices become abnormal.

BRIEF DESCRIPTION OF THE DRAWINGS The schematic block diagram for demonstrating 1st Embodiment of the uninterruptible power supply system by this invention. The schematic block diagram for demonstrating 2nd Embodiment of the uninterruptible power supply system by this invention. The state transition diagram for demonstrating operation | movement of the switching device abnormality detection circuit of FIG. The time chart for demonstrating operation | movement of the switch abnormality detection circuit of FIG. The schematic block diagram for demonstrating 3rd Embodiment of the uninterruptible power supply system by this invention. The schematic block diagram for demonstrating an example of the conventional uninterruptible power supply system. The schematic block diagram for demonstrating operation | movement of the conventional uninterruptible power supply system. The schematic block diagram for demonstrating operation | movement of the conventional uninterruptible power supply system. The schematic block diagram for demonstrating operation | movement of the conventional uninterruptible power supply system. The schematic block diagram for demonstrating the problem of the conventional uninterruptible power supply system.

[First Embodiment]
(Constitution)
Hereinafter, a first embodiment of an uninterruptible power supply system of the present invention will be described with reference to FIGS. 1 and 2. 6 is different from the conventional example of FIG. 6 in that a switching device abnormality detection circuit 26a, 26b, 26c, and a determination circuit 22 including AND circuits 22a, 22b, 22c and an OR circuit 22d are provided. The configuration other than this is the same as that of FIG. 6, and the uninterruptible power supply devices 1 a, 1 b, and 1 c are exemplified here, but the number of units is not limited to this and may be more than three.

  The switching device abnormality detection circuit 26a detects abnormality by each abnormality, for example, answerback, of the switching device including the semiconductor switch 11a included in the uninterruptible power supply 1a and the commercial power supply side contactor 12a connected in parallel to the semiconductor switch 11a. The switch abnormal (bypass) signal 21a is output. Further, the switching device abnormality detection circuit 26b is abnormal due to each abnormality of the switching device including the semiconductor switch 11b included in the uninterruptible power supply 1b and the commercial power supply side contactor 12b connected in parallel to the semiconductor switch 11b, for example, an answerback. Is detected, and a switch abnormality (bypass) signal 21b is output. Further, the switching device abnormality detection circuit 26c is abnormal due to each abnormality of the switching device including the semiconductor switch 11c included in the uninterruptible power supply 1c and the commercial power supply side contactor 12c connected in parallel to the semiconductor switch 11c, for example, an answer back. Is detected, and a switch abnormality (bypass) signal 21c is output.

  The switch abnormality signals 21a and 21b are input to the input terminal of the logical product circuit 22a of the determination circuit 22, the switch abnormality signals 21a and 21c are input to the input terminal of the logical product circuit 22b of the determination circuit 22, and The switch abnormality signals 21c and 21b are input to the input terminal of the AND circuit 22c of the determination circuit 22.

The outputs of the logical product circuits 22a, 22b, and 22c are respectively input to the logical sum circuit 22d.
The output of the OR circuit 22d, that is, the output of the determination circuit 22 (maintenance maintenance bypass circuit operation signal) 25 is given to the maintenance circuit breaker 14, and the output of the OR circuit 22d is “1”.
At this time, the circuit breaker 14 is automatically closed.

  The present embodiment is an example in which a 1000 kVA uninterruptible power supply system is constructed as a parallel redundant system with 500 kVA × 3 uninterruptible power supplies, and the logic circuit of the determination circuit 22 in this case is a logical product. The number of circuits is three and the number of OR circuits is one, but it depends on the number of redundant or parallel operation units of the uninterruptible power supply system.

(Function)
The determination circuit 22 including the AND circuits 22a, 22b, and 22c and the OR circuit 22d in FIG. 1 receives the abnormality detection signals from the switching device abnormality detectors of the uninterruptible power supply devices 1a, 1b, and 1c as input. By determining that the abnormality detection signal is lower than the capacity of the uninterruptible power supply system, the maintenance bypass circuit 27 can be operated. Specifically, even when the state shown in FIG. 10A is reached, the maintenance circuit breaker 14 is automatically closed as shown in FIG. 10B. FIGS. 10 (a) and 10 (b) both show the configuration of a conventional uninterruptible power supply system, but only FIG. 10 is used here to facilitate the explanation of the present invention. Absent.

(effect)
As a result, in the uninterruptible power supply system provided with at least three uninterruptible power supplies, for example, the switch composed of the semiconductor switch 11 and the contactor 12 of the two uninterruptible power supplies becomes abnormal and the remaining healthy Even when it can be determined that the bypass circuit of the uninterruptible power supply apparatus is in an overload state, power supply to the load 10 can be continued by securing a route for load power supply from the maintenance bypass circuit.

[Second Embodiment]
(Constitution)
FIG. 2 is a schematic circuit diagram showing only a part of the second embodiment of the present invention. The commercial power supply side contactor 12 and the semiconductor switch 11 of the switch of the uninterruptible power supply are respectively connected to a control device (not shown). When the power supply command 32 is given via the inverting circuit 30 and “0” is given as the power supply command 32, both the commercial power supply side contactor 12 and the semiconductor switch 11 on the inverter side are closed, and the power supply command 32 When “1” is given, the commercial power supply side contactor 12 and the semiconductor switch 11 on the inverter side are both in an open circuit state. When both the commercial power supply side contactor 12 and the semiconductor switch 11 are in the open state, the inverter side contactor 8 is in the closed state.

  When the commercial power supply side contactor 12 and the semiconductor switch 11 are in a closed state, this is detected and an on detection signal (bypass side) 34 is output, and the on detection signal 34 is input to a switch abnormality detection circuit 31 described later. It has become. Further, when the inverter side contactor 8 is in a closed state, this is detected, an on detection signal (inverter side) 33 is output, and the on detection signal 33 is input to the switch abnormality detection circuit 31 described later. .

  The switch abnormality detection circuit 31 includes an AND circuit 31a, AND circuits 31b and 31c with one input inverting terminal, a AND circuit (NOR circuit) 31d with two input inverting terminals, and OR circuits 31e, 31f, and 31g. The power supply command is input to one of the input terminals of the AND circuit 31a, the inverting input terminal of 31b, the one of the input terminals of 31c, and one of the inverting input terminals of 31d, and the input terminal of the AND circuit 31a. The ON detection signal 34 is input to the other input terminal and the other inverting input terminal of 31d, and the ON detection signal 33 is input to the other input terminal 31b and the inverting input terminal of 31c. The outputs of the AND circuits 31a and 31b are respectively input to the OR circuit 31e, the outputs of the AND circuits 31c and 31d are respectively input to the OR circuit 31f, and the outputs of the OR circuits 31e and 31f are respectively the OR circuit 31g. The switch abnormality signal 35 is output from the output side of the logical sum circuit 31g, and the switch abnormality signal (bypass) from the connection point between the output terminal of the logical product circuit 31d and the input terminal of the logical sum circuit 31f. Side) 36 is output.

  The state transition diagram of the switch failure detection circuit 31 in FIG. The AND circuit 31d of No. 1 and No. 3 is a case where there is no ON detection signal 34 for the commercial power supply command output. No. 2 shows a case where commercial power feeding is normally performed, and No. 7 shows a case where inverter power feeding is normally performed.

  FIG. 4 is a time chart for explaining the operation of FIG. 2, and FIG. 4 (a) shows a case where the inverter side operation is switched to the commercial power source side operation by manual switching (No. 2 in the state transition diagram of FIG. 3). 4 (b) shows the case where the operation is switched from the commercial power supply side operation to the inverter side operation by automatic switching (the state No. 7 in the state transition diagram of FIG. 3), and FIG. ) Is when all uninterruptible power supplies (UPS) stop abnormally and switch from inverter side operation to commercial power source side operation (state No. 2 in the state transition diagram of FIG. 3). Indicates asynchronous time.

  As described above, the switch abnormality detection circuit 31 in FIG. 2 has the power supply command 32 and the detection signal 33 for detecting that the inverter-side contactor 8 is closed (turned on) and the bypass-side contactor 12 are closed. A detection signal 34 for detecting the state (turned on) is input. When the detection signals 33 and 34 do not match the power supply command 32, it is determined that the contactor 8 or 11 is abnormal, and the switch abnormal signal 35 is output. In FIG. 4, 33AX indicates an answerback signal of the detection signal 33, and 34AX indicates an answerback signal of the detection signal 34.

  In the embodiment of FIG. 2, since it is desired to detect only when the power supply command 32 is on the bypass side and the bypass side contactor 12 is not turned on, the switch abnormality signal (bypass) 36 is output. .

  The embodiment of FIG. 2 determines that the power supply cannot be performed by a sound uninterruptible power supply from the switch abnormality signal 36 from each uninterruptible power supply and the current capacity of the uninterruptible power supply system. 27 maintenance circuit breakers 14 can be closed.

[Third Embodiment]
(Constitution)
FIG. 5 is a schematic configuration diagram for explaining a third embodiment of the uninterruptible power supply system of the present invention. A logical product circuit 22e and a current detection circuit are newly added to the determination circuit 22 of the first embodiment. 22f, a setting circuit 22g, and a comparison circuit 22h are added, and a current detector 41 is added to the first embodiment described above. Other configurations are the same as those in the embodiment of FIG. 1, and the same parts are denoted by the same reference numerals and description thereof is omitted.

  The current detector 41 detects the current flowing from the uninterruptible power supply system to the load 10 and takes it into the current detection circuit 22f, where it is used as a predetermined level of current detection value, and this current detection value is input to one of the comparison circuits 22h. The current setting value set by the setting circuit 22g is taken into the other input terminal of the comparison circuit 22h, and an overload state in which the current detection value exceeds the current setting value is detected by the comparison circuit 22h. When the overload detection signal detected at 22h and the output of the logical sum circuit 22d are input to the logical product circuit 22e, and the logical product of the overload detection signal and the output of the logical sum circuit 22d is established, the maintenance of the maintenance circuit 27 is maintained. A maintenance maintenance bypass circuit operation signal is given to the maintenance circuit breaker 14, and the circuit breaker 14 is closed.

(Function and effect)
As a result, according to the third embodiment described above, the switching circuits of the plurality of uninterruptible power supply units constituting the uninterruptible power supply system become abnormal, and the uninterruptible power supply is sound from the detected current of the uninterruptible power supply system. Even in an assembly where it can be determined that the device has become overloaded, power supply to the load 10 can be continued by securing a path for load power supply from the maintenance bypass circuit 27.

[Modification]
In the embodiment of FIG. 1 described above, the case where the maintenance maintenance circuit breaker 14 is automatically closed when the maintenance maintenance bypass circuit operation signal 25 from the determination circuit 22 is supplied to the maintenance maintenance circuit breaker 14 has been described. The maintenance maintenance bypass circuit operation signal 25 may be configured to be notified to the maintenance inspector in some form, and the maintenance maintenance circuit breaker 14 may be closed by the recognition of the maintenance inspector.

  In the embodiment of FIG. 2, the case where the maintenance maintenance circuit breaker 14 is automatically closed by the switcher abnormality detection signal 35 from the switcher abnormality detection circuit 31 has been described. It may be configured to notify the maintenance inspector in some form, and the maintenance maintenance circuit breaker 14 may be closed by the recognition of the maintenance inspector.

  Furthermore, in the embodiment of FIG. 5, the case has been described in which the maintenance maintenance circuit breaker 14 is automatically closed when the maintenance maintenance bypass circuit operation signal 25 from the determination circuit 22 is given to the maintenance maintenance circuit breaker 14. The maintenance maintenance bypass circuit operation signal 25 may be configured to be notified to the maintenance inspector in some form, and the maintenance maintenance circuit breaker 14 may be closed by the recognition of the maintenance inspector.

  In the above-described embodiment, the description of the control device that controls the entire uninterruptible power supply system is omitted, but actually, the power supply command 32, the AC input circuit breaker 4 open / close command, the inverter contactor 8 open / close command, and the output A control device for outputting a switching command for the side contactor 9, a switching command for the semiconductor switch 11, a switching command for the commercial power supply side contactor 12, a switching command for the commercial power supply circuit breaker 13, a switching command for the maintenance maintenance circuit breaker 14, etc. It goes without saying that it is prepared.

DESCRIPTION OF SYMBOLS 1 (1a, 1b, 1c) ... Uninterruptible power supply device, 2 ... AC input power supply, 3 ... Commercial power supply, 4 (4a, 4b, 4c) ... AC input circuit breaker, 5 (5a, 5b, 5c) ... Converter, 6 (6a, 6b, 6c) ... accumulator, 7 (7a, 7b, 7c) ... inverter, 8 (8a, 8b, 8c) ... inverter side contactor, 9 ... output side contactor, 10 ... load, 11 (11a) , 11b, 11c)
... Semiconductor switch, 12 (12a, 12b, 12c) ... Commercial power supply side contactor, 13 (13a, 13b, 13c) ... Commercial power supply side circuit breaker, 14 ... Maintenance and maintenance circuit breaker, 21 (21a, 21b, 21c) ... Switching device abnormality (bypass) detection signal, 22 ... determination circuit, 22a, 22b, 22c, 22d, 22e ... AND circuit, 22d ... OR circuit, 22f ... current detection circuit, 22g ... setting circuit, 22h ... comparison circuit 25 ... Maintenance bypass circuit operation signal, 26a, 26b, 26c ... Switcher abnormality detection circuit, 31 ... Switcher abnormality detection circuit, 32 ... Power supply command, 33 ... On detection signal (inverter), 34 ... On detection signal (bypass) 35 ... Switcher abnormality signal, 36 ... Switcher abnormality signal (bypass), 41 ... Current detector.

Claims (3)

An inverter that inputs DC power from the power storage means, converts it into AC power, and supplies the converted AC power to a load;
Voltage control means for generating an output voltage command of the inverter so that the AC output voltage of the inverter matches a voltage reference;
A gate control circuit for controlling a gate of a switching element constituting the inverter based on an inverter output voltage command from the voltage control means;
AC power supply path for supplying AC power from a commercial AC power supply to the load separately from the power supply path from the inverter;
A semiconductor switch that is provided in the AC power supply path and that constitutes a switch by supplying and cutting off the AC power;
A contactor connected in parallel with the semiconductor switch and constituting the switch;
An uninterruptible power supply with
Connect at least three uninterruptible power supplies in parallel, connect them in parallel to the uninterruptible power supplies, and perform a protective operation with overcurrent during maintenance, etc., and open when maintenance and close when not maintenance A maintenance bypass circuit including an output contactor, and an uninterruptible power supply system comprising:
A switch abnormality detecting circuit for detecting that each of the uninterruptible power supply units has an abnormality, and
A determination circuit for closing the maintenance circuit breaker of the maintenance bypass circuit based on the output of each switch abnormality detection circuit;
An uninterruptible power supply system characterized by comprising: An inverter that inputs DC power from the power storage means, converts it into AC power, and supplies the converted AC power to a load;
An inverter-side contactor provided in an electrical path between the output side of the inverter and the load;
Voltage control means for generating an output voltage command of the inverter so that the AC output voltage of the inverter matches a voltage reference;
A gate control circuit for controlling a gate of a switching element constituting the inverter based on an inverter output voltage command from the voltage control means;
AC power supply path for supplying AC power from a commercial AC power supply to the load separately from the power supply path from the inverter;
A semiconductor switch that is provided in the AC power supply path and that constitutes a switch by supplying and cutting off the AC power;
A commercial AC power supply side contactor that is connected in parallel with the semiconductor switch and constitutes the switching device,
An uninterruptible power supply with
Three uninterruptible power supply units are connected in parallel, a maintenance circuit breaker that is connected in parallel to each uninterruptible power supply unit and that is protected by overcurrent during maintenance, etc., and is opened during maintenance and closed during non-maintenance. In an uninterruptible power supply system comprising a maintenance bypass circuit including an output contactor,
An inverter-side detection circuit that detects a closed state of the inverter-side contactor in each uninterruptible power supply;
A commercial AC power supply side detection circuit for detecting a closed state of the switch;
Based on the power supply command for switching to either the commercial AC power supply side contactor or the inverter side contactor , the output of the inverter side detection circuit, and the output of the commercial AC power supply side detection circuit, the maintenance bypass circuit A determination circuit that puts the maintenance circuit breaker in a closed state and outputs the switch abnormality signal based on the power supply command and the output of the commercial AC power supply side detection circuit;
An uninterruptible power supply system characterized by comprising: An inverter that inputs DC power from the power storage means, converts it into AC power, and supplies the converted AC power to a load;
Voltage control means for generating an output voltage command of the inverter so that the AC output voltage of the inverter matches a voltage reference;
A gate control circuit for controlling a gate of a switching element constituting the inverter based on an inverter output voltage command from the voltage control means;
AC power supply path for supplying AC power from a commercial AC power supply to the load separately from the power supply path from the inverter;
A semiconductor switch that is provided in the AC power supply path and that constitutes a switch by supplying and cutting off the AC power;
A contactor connected in parallel with the semiconductor switch and constituting the switch;
An uninterruptible power supply with
Connect at least three uninterruptible power supplies in parallel, connect them in parallel to the uninterruptible power supplies, and perform a protective operation with overcurrent during maintenance, etc., and open when maintenance and close when not maintenance A maintenance bypass circuit including an output contactor, and an uninterruptible power supply system comprising:
A switch abnormality detecting circuit for detecting that each of the uninterruptible power supply units has an abnormality, and
An overload detection circuit that detects a current flowing through the load and detects an overload state based on the detected current;
A judging circuit for the closed circuit condition the maintenance breaker of the maintenance bypass circuit based on the output of the output and the overload detection circuit of each switching device abnormality detection circuit,
An uninterruptible power supply system characterized by comprising:

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