JP4462230B2 - Uninterruptible power supply system - Google Patents

Description

  The present invention relates to a three-phase output uninterruptible power supply system that includes two sets of parallel redundant uninterruptible power supply devices, bypass switches, and power supply changeover switches, and supplies power to two sets of load systems.

  FIG. 4 is a circuit configuration diagram showing a conventional example of this type of uninterruptible power supply system. Reference numeral 10 denotes a first power system (hereinafter also referred to as an A system power system) composed of a commercial power system and private power generation equipment. 11 to 13 are uninterruptible power supply devices forming the first parallel redundant uninterruptible power supply device (hereinafter referred to as UPS 11 to 13 and also collectively referred to as A system UPS), and 15 is a thyristor switch, circuit breaker, A first bypass switch (hereinafter also referred to as A-system bypass SW) 16, 16 is a first power supply switching switch (hereinafter also referred to as A-system switch SW) including two sets of thyristor switches, and 20 is a commercial power system. And a second power system (hereinafter also referred to as a B system power system) 21-23 are uninterruptible power supply devices that form a second parallel redundant uninterruptible power supply device. Hereinafter, these are referred to as UPS 21 to 23 and also collectively referred to as B system UPS), 15 is a second bypass switch composed of a thyristor switch and a circuit breaker (hereinafter also referred to as B system bypass SW), and 26 are two sets. A second power supply changeover switch (hereinafter also referred to as a B system changeover SW), 31 is a system control circuit, 100 is a first load system (hereinafter also referred to as a load A), and 200 is a second load system (hereinafter referred to as a “system switch circuit”). And 11a to 13a, 14, 15a, 21a to 23a, 24, and 25a are circuit breakers.

  Note that the above-described UPSs 11 to 13, UPSs 21 to 23, A and B system bypass SWs, A and B system switching SWs, and the like are formed using a known technique.

  The operation of the conventional uninterruptible power supply system shown in FIG. 4 will be described below with reference to the chart shown in FIG. 5 for explaining the operation of the system control circuit 31.

  When both the A-system power system and the B-system power system are in a healthy state, both the A-system bypass SW and the A-system switch SW are turned off, and the circuit breaker 14 is first closed. 11a to 13a and 15a are closed, and each of the UPSs 11 to 13 is started. After the start is completed, the UPSs 11 to 13 are set in a parallel operation state. Similarly, the B system bypass SW and the B system switch SW are both turned off, the circuit breaker 24 is closed first, and the circuit breakers 21a to 23a and 25a are closed and the UPSs 21 to 23 are respectively closed. After the start is completed, the UPSs 21 to 23 are set in a parallel operation state.

  Next, the system control circuit 31 gives a control signal for setting the mode 1 or mode 2 shown in FIG. 5 to the A system UPS and the B system UPS. Both the output of the system UPS and the output of the B system UPS are in phase synchronization with the output of the system A power system, and the preparation for operation of the uninterruptible power supply system is completed.

  After that, the A system UPS side of the A system switching SW is turned on from the above-mentioned OFF state to start supplying power to the load A. Similarly, the B system UPS side of the B system switching SW is turned on from the above OFF state. The uninterruptible power supply system enters the normal operation state in the mode 1 state by starting the power supply to the load B by setting the state.

  If the A-system power system is lost for some reason during the normal operation state in the above-described mode 1, each of the UPSs 11 to 13 is in a power supply state from a storage battery facility (not shown) while continuing to supply power to the load A and the load B. At the same time, both the A-system UPS and the B-system UPS are in a self-running state, and thereafter, the system control circuit 31 sends a control signal for setting the mode 3 state shown in FIG. By supplying to the UPS, the output of the A-system UPS and the output of the B-system UPS are both in phase synchronization with the output of the B-system power system.

  In addition, if both the A-system power system and the B-system power system are lost for some reason during the normal operation state in the above-described mode 1, the power supply to the loads A and B is continued and the UPSs 11 to 13 and the UPSs 21 to 21 are continued. Each of the power supply units 23 is in a power supply state from a storage battery facility (not shown), and both the A-system UPS and the B-system UPS are once in a self-running state, and thereafter, from the system control circuit 31, the mode 5 or the mode 6 shown in FIG. For example, in the mode 5 state, the A system UPS is kept in a free-running state, and both outputs of the B system UPS are both in the A system. The phase is synchronized with the output of the UPS.

Each of the above-described phase synchronization methods is performed by a known technique.
JP 2005-269706 A

  FIG. 6 shows the behavior when the conventional uninterruptible power supply system shown in FIG. 4 is operating in the above-described mode 1 state, for example, when a short circuit accident or the like occurs in the load B and the overload state occurs. The following will be described with reference to the flowchart.

  When the uninterruptible power supply system shown in FIG. 4 is operating in the mode 1 state (step S1), the currents to the load A and the load B are monitored (step S2), and both are normal (specified values) in this step S2. If it is within the range, the process returns to step S1, and if abnormal (the B system load is overcurrent due to the above), then the voltage of the B system power system and the output voltage of the B system UPS are in an asynchronous state. Therefore, the B system UPS performs a current limiting operation as an overload protection operation, lowers its output voltage, detects this decrease, and the B system UPS side of the B system switching SW changes from the on state to the off state. At the same time, the A system UPS side changes from off to on (step S3), and therefore both the load A and the load B are supplied with power from the A system UPS. At this time, the A system UPS bears the overcurrent state of the load B. Next As a result, the A-system bypass SW is switched from OFF to ON (step S4), and each of the UPSs 11 to 13 is shut off by stopping the gate of the inverter circuit. Thereafter, both the load A and the load B are from the A-system power system. The power supply state is entered.

  That is, the power supply path of the load B is changed twice, voltage fluctuations accompanying this change occur, and after step S4, the power supply to both load systems is in the state from the A system power system, As a result, there has been a problem that the constant voltage characteristic for the load A and the load B is impaired.

  An object of the present invention is to provide an uninterruptible power supply system that solves the above problems.

  The uninterruptible power supply system according to the first aspect of the present invention is a first parallel redundant uninterruptible power supply having a first power system as an input AC power supply, and one end connected to the output end of the first uninterruptible power supply. A first bypass switch, a second parallel redundant uninterruptible power supply using a second power system as an input AC power supply, a second bypass switch having one end connected to the output end of the second uninterruptible power supply, A first power supply changeover switch installed between an output end of the first uninterruptible power supply and the second uninterruptible power supply output and the first load system; an output end of the first uninterruptible power supply; A second feed selector switch installed between each output terminal of the second uninterruptible power supply and the second load system; the other end of the first bypass switch; the other end of the second bypass switch; and the first power system. And the second power system Characterized in that a bypass power selection switch to be installed, and a system control circuit which performs system control of these component devices between.

  According to a second aspect of the present invention, in the uninterruptible power supply system according to the first aspect of the present invention, in the system control circuit, the first uninterruptible power supply and the first uninterruptible power supply when the bypass power selection switch selects the first power system. The outputs of the two uninterruptible power supply devices are phase-synchronized with the output of the first power system, and when the bypass power supply selection switch selects the second power system, the first uninterruptible power supply device and the second uninterruptible power supply device The output of each power failure power supply is phase-synchronized with the output of the second power system.

  Furthermore, a third invention is the uninterruptible power supply system according to the first or second invention, wherein in the system control circuit, when both the first power system and the second power system are lost, either one of the none A power failure power supply device is self-running, and the output of the other uninterruptible power supply device generates a control signal that is phase-synchronized with the output of the self-running uninterruptible power supply device.

  According to the uninterruptible power supply system of the present invention, either one of the first power system and the second power system is selected, and power is supplied as a bypass power source for the first bypass switch and the second bypass switch. By providing the bypass power source selection switch, the power supply reliability to the first load system and the second load system can be improved as will be described later.

  FIG. 1 is a circuit configuration diagram showing an embodiment of the uninterruptible power supply system of the present invention. In this figure, components having the same functions as those of the conventional configuration shown in FIG. Then, the explanation is omitted.

  In other words, the configuration shown in FIG. 1 is different from the configuration shown in FIG. 4 in that one of the first power system 10 and the second power system 20 is selected and the first bypass is selected. By providing a bypass power supply selection switch 32 (hereinafter also referred to as selection SW) for supplying power to the switch 15 and the second bypass switch 25, a part of the power supply path of the bypass power supply is changed, and conventional system control is performed. The circuit 31 is a new system control circuit 33.

  The operation of the uninterruptible power supply system of the present invention shown in FIG. 1 will be described below with reference to the chart shown in FIG. 2 for explaining the operation of the system control circuit 33.

  When both the A-system power system and the B-system power system are in a healthy state, both the A-system bypass SW and the A-system switch SW are turned off, and the circuit breaker 14 is first closed. 11a to 13a and 15a are closed, and each of the UPSs 11 to 13 is started. After the start is completed, the UPSs 11 to 13 are set in a parallel operation state. Similarly, the B system bypass SW and the B system switch SW are both turned off, the circuit breaker 24 is closed first, and the circuit breakers 21a to 23a and 25a are closed and the UPSs 21 to 23 are respectively closed. After the start is completed, the UPSs 21 to 23 are set in a parallel operation state.

  Next, the system control circuit 33 gives a control signal for setting the mode 11 or the mode 12 shown in FIG. 2 to the A system UPS and the B system UPS. The bypass power supply is set to the A system power system by SW, and the output of the A system UPS and the output of the B system UPS are both in phase synchronization with the output of the A system power system, and the uninterruptible power system is ready for operation. Complete.

  After that, the A system UPS side of the A system switching SW is turned on from the above-mentioned OFF state to start supplying power to the load A. Similarly, the B system UPS side of the B system switching SW is turned on from the above OFF state. The uninterruptible power supply system enters the normal operation state in the state of mode 11 by starting the power supply to the load B by setting the state.

  If the A-system power system is lost for some reason during the normal operation state in the mode 11 described above, the UPSs 11 to 13 are respectively in a power supply state from a storage battery facility (not shown) while continuing to supply power to the load A and the load B. At the same time, both the A-system UPS and the B-system UPS are once in a self-running state, and then the bypass power source is switched from the A-system power system to the B-system power system by the selection SW. By giving a control signal for switching to the mode 13 state to the A system UPS and the B system UPS, the output of the A system UPS and the output of the B system UPS are both in phase synchronization with the output of the B system power system. Become.

  Further, if both the A-system power system and the B-system power system are lost for some reason during the normal operation state in the above-described mode 11, the power supply to the load A and the load B is continued and the UPSs 11 to 13 and the UPSs 21 to 21 are continued. Each of the power supply units 23 is in a power supply state from a storage battery facility (not shown), and both the A-system UPS and the B-system UPS are once in a self-running state, and thereafter, from the system control circuit 33, the mode 15 or the mode 16 shown in FIG. For example, in the mode 15 state, the A system UPS is kept in a free-running state, and both B system UPS outputs are both in the A system. The phase is synchronized with the output of the UPS.

  FIG. 3 shows the behavior when the uninterruptible power supply system of the present invention shown in FIG. The following will be described with reference to the flowchart shown.

  While the uninterruptible power supply system shown in FIG. 1 is operating in the state of mode 11 (step S11), the currents to load A and load B are monitored (step S12), and both are normal (specified value) in step S12. If it is within the range, the process returns to step S11. If the load is abnormal (the B system load is overcurrent due to the above), at this time, the B system bypass SW is switched from OFF to ON (step S13). Each of the inverters 23 is shut off by shutting off the gate of the inverter circuit, and thereafter, the load B enters a power supply state from the A-system power system.

  That is, while the load A continues to supply power from the A system UPS, after step S13, only the power supply to the load B enters the state from the A system power system, and the power supply reliability as the whole uninterruptible system is improved. To do.

Circuit configuration diagram of an uninterruptible power supply system showing an embodiment of the present invention Chart for explaining the operation of FIG. Flowchart for explaining the operation of FIG. Circuit diagram of uninterruptible power supply system showing conventional example Chart for explaining the operation of FIG. Flowchart for explaining the operation of FIG.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... 1st electric power system, 11-13 ... Uninterruptible power supply, 14 ... Circuit breaker, 15 ... 1st bypass switch, 16 ... 1st electric power feeding switch, 20 ... 2nd electric power system, 21-23 ... Uninterruptible power supply Power supply device, 24 ... circuit breaker, 25 ... second bypass switch, 26 ... second power supply changeover switch, 31 ... system control circuit, 32 ... bypass power supply selection switch, 33 ... system control circuit, 100 ... first load system, 200: Second load system.

Claims (3)

  A first parallel redundant uninterruptible power supply using the first power system as an input AC power supply, a first bypass switch having one end connected to the output end of the first uninterruptible power supply, and a second power system as an input AC A second parallel redundant uninterruptible power supply as a power source, a second bypass switch having one end connected to the output end of the second uninterruptible power supply, the output end of the first uninterruptible power supply and the second A first feed selector switch installed between each uninterruptible power supply output terminal and the first load system; an output terminal of the first uninterruptible power supply; a second output terminal of the second uninterruptible power supply; A second power feeding changeover switch installed between the load system, the other end of the first bypass switch and the other end of the second bypass switch, and the first power system and the second power system. Bypass power supply selection Uninterruptible power supply system, characterized in that it comprises a pitch, and a system control circuit which performs system control of these configuration devices.   In the system control circuit, when the bypass power supply selection switch selects the first power system, the outputs of the first uninterruptible power supply and the second uninterruptible power supply are phase-synchronized with the outputs of the first power system. And when the bypass power supply selection switch selects the second power system, the outputs of the first uninterruptible power supply and the second uninterruptible power supply are phase-synchronized with the outputs of the second power system. The uninterruptible power supply system according to claim 1. In the system control circuit, when both the first power system and the second power system are lost, either one of the uninterruptible power supply devices is self-running, and the output of the other uninterruptible power supply device is self-running. 3. The uninterruptible power supply system according to claim 1, wherein a control signal that is phase-synchronized with an output of the uninterruptible power supply device is generated.

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