JPH08289484A - Uninterruptible power supply system - Google Patents

Abstract

PURPOSE: To provide an uninterruptible power supply system which can feed power to an uninterruptible load system and an emergency load system even during power interruption without requiring any extra emergency power supply. CONSTITUTION: The uninterruptible power supply system comprises an emergency load system 4 to be connected with an AC power supply system, and an uninterruptible load system 5 to be connected with an uninterruptible power supply 25. The uninterruptible power supply 25 comprises a bilateral converting section 30 for A/D conversion and D/A conversion, a power storage unit 31 and a D/A converting section 32 for delivering power to the uninterruptible load system 5. When power supply from the AC power supply system is interrupted, the bilateral converting section 30 is switched to D/A conversion and AC power is fed therefrom to the emergency load system 4.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an uninterruptible power supply system having an emergency load system connected to an AC power supply system and an uninterruptible load system connected to an uninterruptible power supply.

[0002]

2. Description of the Related Art Conventionally, a large or small management system equipped with a computer has been adopted in many fields. For example,
Centralized management is performed by a computer in the management of each toll gate on the expressway, the disaster prevention management of tunnels, the disaster prevention management and crime prevention management system of underground malls, the parking of underground parking lots, and the entry / exit management system of vehicles. Also, in many buildings, a management system using a computer is constructed for office management and disaster prevention management. In general, a management system using these computers requires stable and reliable power supply. Therefore, an uninterruptible power supply is generally provided as a power supply for these management systems. As related to the management system that uses these computers, important devices associated with the computers are provided. In addition, important facilities such as disaster prevention facilities and crime prevention facilities are often installed in places where computers are installed. Such important equipment and facilities include, for example, auxiliary equipment for computers such as cooling devices, management terminal equipment such as terminal equipment at toll gates, disaster prevention equipment or emergency equipment in buildings and underground malls. These important devices and equipment are generally supplied with power from a commercial power supply.

FIG. 7 is an electric system diagram of an uninterruptible power supply system in a conventional management system using a computer. For example, a commercial AC power supply with a three-phase high voltage of 6.6 KV is converted into a predetermined three-phase low voltage by the power receiving facility 1 and supplied to the load bus 2.
A general load system 3, an emergency load system 4, and an uninterruptible load system 5 are branched from the load bus 2, and a breaker 6 and a protective relay 7 such as an overcurrent relay are provided in each system. These protective relays 7 are provided to open the circuit breaker of the system when a short circuit accident occurs in the system. The general load system 3 is connected to a general facility 8 such as lighting equipment in a computer room or an office, and the emergency load system 4 is connected.
Is connected to an important facility 9 such as a road management terminal facility, a computer auxiliary device, a disaster prevention facility or an emergency facility, and an uninterruptible load system 5 is connected to a computer facility 10.

An uninterruptible power supply 11 is provided in the uninterruptible load system 5, and AC power from the uninterruptible power supply 11 is supplied to the computer equipment 10. Although only one uninterruptible power supply 11 may be provided, it is often the case that a plurality of uninterruptible power supplies 11 are connected in parallel to increase reliability as shown in the drawing. The uninterruptible power supply device 11 includes an AC / DC converter 12 that converts AC into DC, a power storage device 13 connected to the output side of the AC / DC converter 12, and an orthogonal converter 14 that converts DC into AC. The AC-DC converter 12 is a diode or an IGBT (Insulated Gate Bipolar Transistor).
r) A converter including a module (hereinafter referred to as an IGBT) is used, and the orthogonal transformation unit 14 is an IGBT.
An inverter configured by T or the like is used, and the power storage device 13 is configured by connecting a required number of lead storage batteries or alkaline storage batteries in series.

[0005]

However, in the conventional uninterruptible power supply system as described above, since the power supply to the emergency load system is not taken into consideration at the time of power failure, for example, the cooling device of the computer is usually within 5 minutes. It is necessary to stop the computer unless operation is restarted, and the system itself stops if the management terminal equipment cannot operate normally.Even if the uninterruptible power supply continues to supply power to the computer. There was a problem of meaninglessness. In order to avoid such a problem, an emergency power supply facility may be provided, but such a facility poses a new problem that securing a place for installation and a large capital investment are required. Therefore, the present invention provides an uninterruptible power supply system that can supply power to an emergency load system even when power supply from an AC power supply system is stopped without providing special emergency power supply equipment. Is an issue.

[0006]

That is, an uninterruptible power supply system of the present invention comprises an emergency load system connected to an AC power supply system and an uninterruptible load system connected to an uninterruptible power supply. The power failure power supply device has a bidirectional converter, a power storage device, and a quadrature conversion unit. Has an output section. The bidirectional converter converts AC from the AC power supply system into DC and outputs from the DC side input / output section, and AC / DC conversion that converts DC stored in the power storage device into AC and outputs from the AC side input / output section. One of the orthogonal transforms can be switched.
Then, when the power supply from the AC power supply system is stopped, the bidirectional conversion unit is switched to orthogonal conversion, and the power supply to the emergency load system is supplied from the AC power supply system to the AC side input / output unit of the bidirectional conversion unit. The feature is that it can be switched. In a preferred embodiment of the above system, road management terminal equipment, computer auxiliary equipment, disaster prevention equipment or emergency equipment is connected to the emergency load system. In another preferred embodiment of the above system,
A commercial AC power supply and an in-house generated AC power supply are linked to the AC power supply system.

[0007]

In the uninterruptible power supply system of the present invention, when the power supply from the AC power supply system is stopped, the bidirectional converter provided in the uninterruptible power supply unit is switched to the orthogonal conversion, and the power supply to the emergency load system is provided. Since the supply can be switched from the AC power supply system to the AC side input / output unit of the bidirectional conversion unit, power can be continuously supplied from the uninterruptible power supply to the emergency load system as well as the uninterruptible load system. Therefore, even in the event of a power failure, it is possible to continue operating important equipment such as management systems that use computers and disaster prevention equipment. Moreover, since there is no need to install special emergency power supply equipment, there is no need to secure the installation site or capital investment.

[0008]

Embodiments of the present invention will now be described with reference to the drawings.
FIG. 1 is an electrical system diagram showing an example of the uninterruptible power supply system of the present invention, and the same devices and the like as those in FIG. 7 described above are designated by the same reference numerals. A general load system 3 branched from the load bus 2 supplies power to a general facility 8 such as a lighting device, and the general load system 3 is provided with a circuit breaker 6 that is opened by a protective relay 7. In the emergency load system 4 branched from the load bus 2, terminal equipment for road management, auxiliary equipment for computers,
A circuit breaker 2 to which an important equipment 9 such as a disaster prevention equipment or an emergency equipment is connected and which is opened by a protective relay 20.
1 is provided. The computer equipment 10 is connected to the uninterruptible load system 5 branched from the load bus 2, and the circuit breaker 23 opened by the protective relay 22 and the voltage rise at the time of orthogonal conversion of the bidirectional conversion unit described later are detected. A voltage detecting means 24 is provided for this purpose. As the voltage detecting means 24, for example, an overvoltage relay can be used. However, instead of providing the voltage detection means 24, a separate means may be provided in the uninterruptible power supply 25 for detecting the rise of the voltage at the time of orthogonal conversion of the bidirectional conversion section.

The computer equipment 10 is supplied with AC power from the output side of the uninterruptible power supply 25. However, if desired, a switching means 26 as shown in the figure is provided, and power is supplied to the computer equipment 10 from the input side (AC power system side) of the uninterruptible power supply 25 through the dotted line during normal operation.
The switching means 26 may be switched by the power failure signal to supply power from the output side of the uninterruptible power supply 25. The load bus 2 is provided with a power failure detecting means 27 for detecting a power failure. As the power failure detection means 27, for example, an undervoltage relay can be used. Instead of providing the power failure detection means 27 on the load bus 2, the power receiving equipment 1
It is also possible to provide a separate power failure detection means therein. The input side of the uninterruptible power supply 25, that is, the secondary side of the circuit breaker 23 and the secondary side of the circuit breaker 21 of the emergency load system 4 are connected by a communication line 29 provided with a circuit breaker 28. This communication line 2
9 is an uninterruptible power supply 25 to an emergency load system 4 in case of a power failure.
It is for supplying power to.

FIG. 2 shows the configuration of the uninterruptible power supply 25.
The uninterruptible power supply 25 includes a bidirectional converter 30, a power storage device 31 and an orthogonal converter 32 connected to the bidirectional converter 30. The bidirectional conversion unit 30 includes an AC side input / output unit 30a to which an AC power supply system is connected, a power storage device 31, and an orthogonal conversion unit 32.
Has a DC side input / output unit 30b connected to the DC side input / output unit 3b.
0b output from the AC / DC conversion, and the direct current stored in the power storage device 31 is converted into alternating current to output alternating current output on the alternating current side input / output unit 30.
Both orthogonal transforms output from a can be performed. That is, a diode bridge composed of six diodes 30c supplies 3 to the AC side input / output unit 30a.
The AC / DC conversion is the case where the AC power of the phase is converted to DC and output from the DC side input / output unit 30b.
The control switches 30d such as IGBTs connected in parallel to 0c are switched and controlled at the same frequency as the three-phase AC frequency of the AC power supply system to convert the DC stored in the power storage device 31 into AC and the AC side input / output unit 30a. Orthogonal transformation is the case where AC is output from.

The orthogonal transformation unit 32 can use an inverter similar to the conventional one, and its AC output is supplied to the computer equipment 10 through the uninterruptible power supply load system 5 in FIG. An uninterruptible power supply 25 connected in parallel in FIG.
Can be configured to have the bidirectional converter 30 as described above, but it is assumed that a part thereof has an AC / DC converter similar to the conventional uninterruptible power supply according to the capacity to be supplied with power at the time of power failure. It can also be configured. FIG. 3 shows the six control switches 30d of the bidirectional converter 30 shown in FIG.
FIG. 3 is a block diagram of a control circuit that controls ON / OFF of the. The control circuit 45 controls the oscillating unit 4 which is started by the start signal A.
5a and a control unit 45b that outputs a control pulse at a speed synchronized with the frequency. Since the control circuit 45 is basically the same as a normal inverter using an IGBT or the like, detailed description thereof will be omitted.

FIG. 4 shows a control circuit of the uninterruptible power supply system of FIG. In the figure, 24a is a contact which is turned on when the voltage detecting means 24 for detecting the rise of the voltage at the time of orthogonal conversion of the bidirectional converter is operated (a predetermined voltage is established), and 21a is opened when the breaker 21 is opened. A contact that is turned on, a contact 23a that is turned on when the circuit breaker 23 is opened, and a contact 27a that switches from the illustrated state to the opposite side (from b to a) when the power failure detection means 27 detects a power failure, 28a is a contact which is turned on when the circuit breaker 28 is opened, and 20a is a protective relay 20 provided in the emergency load system 4.
Is a contact which is turned on when is activated, and 22a is a contact which is turned on when the protective relay 22 provided in the uninterruptible load system 5 is activated. Further, 40 is an AND circuit, 41 is an OR circuit, 42 is a delay circuit (timer circuit), 43 is a flip-flop circuit, 44 is a drive circuit, and 45 is a control circuit of the bidirectional converter 30 described above.

Next, the operation of the uninterruptible power supply system of FIG. 1 will be described with reference to FIG. During normal times when AC power is supplied from the AC power system, the circuit breakers 6, 21 and 23 are closed and the circuit breaker 28 is open. When an abnormality such as a short circuit occurs in any of the load systems in this state, each protective relay operates to open the circuit breaker of the system, and an alarm is issued if necessary. When the power supply from the AC power supply system is stopped, that is, when a power failure occurs, the power failure detection means 27 operates and the contact point 27a thereof is switched from b to a. Then, the trip coils TC of the circuit breakers 21 and 23 are activated to immediately open the circuit breakers 21 and 23. When the circuit breakers 21 and 23 open, their contacts 21a, 23
A switching signal (start signal A) for switching to the orthogonal conversion is input to the control circuit 45 of the bidirectional conversion unit 30 according to the AND condition of a and the power failure signal.

When the bidirectional conversion unit 30 is switched to the orthogonal conversion, the direct current stored in the power storage device 31 in FIG. 2 is converted into the alternating current by the bidirectional conversion unit 30, and the alternating voltage is output from the alternating current side input / output unit 30a. To do. At that time, the direct current from the power storage device 31 is supplied to the orthogonal transformation unit 32, and the alternating current output keeps the power supply to the computer equipment 10. When the voltage at the AC side input / output section 30a of the bidirectional conversion section 30 rises to a predetermined value, the voltage detecting means 24 operates and the contact 24a thereof is turned on. On the other hand, the delay circuit 42 is activated by the AND condition of the contacts 21a and 23a and the power failure signal, and after the set time elapses, the flip-flop circuit 43 is set to the set state by the setup signal and the Q terminal is set to the high level (ON signal).

The closing coil CC of the circuit breaker 28 is activated by the operation of the voltage detecting means 24 and the AND condition of the ON signal from the Q terminal of the flip-flop circuit 43, and the circuit breaker 28 is activated.
Is closed. In this way, both the operation of the voltage detection means 24 for detecting the voltage rise in the AC side input / output unit 30a of the bidirectional conversion unit 30 and the signal from the delay circuit 42 activated by the AND condition of the contacts 21a and 23a and the power failure signal are both. The reason why the circuit breaker 28 is closed is for safety double check, and either of them may be omitted depending on the case. If the signal condition from the delay circuit 42 is omitted, the flip-flop circuit 43 can be omitted. When the circuit breaker 28 is closed, the AC output from the uninterruptible power supply 25 is supplied to the emergency load system 4 via the communication line 29. If a short circuit accident occurs in the emergency load system 4 in this state, the protective relay 20
Is activated, the trip coil TC of the circuit breaker 28 is activated by the contact 20a, and the circuit breaker 28 is opened. At the same time, an alarm is issued if necessary.

Next, when the power supply from the AC power supply system is started, that is, when there is a double power supply, the power failure detecting means 27 is deactivated and the contact point 27a thereof is restored from a to b. Then, the signal stops the switching signal for the orthogonal transformation, which has been input to the control circuit 45 of the bidirectional conversion section 30, and thereby the bidirectional conversion section 30 returns to the AC / DC conversion state. On the other hand, the delay circuit 42 is activated by the return of the contact 27a, and when the set time elapses, the setup signal resets the flip-flop circuit 43 to switch the Q'terminal to a high level (on signal) and the Q terminal to a low level (off signal). Replace The trip signal TC of the circuit breaker 28 is activated by the ON signal from the Q'terminal, and the circuit breaker 28 opens. The closing coil CC of the circuit breakers 21 and 23 is activated and the circuit breakers 21 and 23 are closed according to the AND condition of the contact 28a which is turned on when the circuit breaker 28 is opened and the ON signal from the Q'terminal. In this way, the uninterruptible power supply system returns to the normal state by shutting off and switching each circuit breaker, but the switching operation is not performed immediately by the power restoration signal,
The reason why the delay circuit 42 is performed after the lapse of the time set is to avoid unnecessary operation due to noise or the like.

FIG. 5 is an electric system diagram showing another example of the uninterruptible power supply system of the present invention, and the same components as those in FIG. 1 are designated by the same reference numerals. In this example, as an AC power supply system, an AC power supply from a power receiving facility 1 that receives a commercial AC power supply and converts it into a low voltage, and an AC power supply from a private power generation device 50 such as a diesel power generator or a fuel cell power generator are linked. There is. The AC power source from the power receiving equipment 1 is connected to the load bus 2 via a main line 51, and the main line 51 is provided with a protective relay 52 such as an overcurrent relay and a circuit breaker 53 which is opened by its operation. The AC power source from the private power generator 50 is connected to the load bus 2 via the main line 54, and the main line 54 is provided with a protective relay 55 such as an overcurrent relay and a circuit breaker 56 that is opened by its operation. By providing the private power generation device 50 in this manner, the power supply of the uninterruptible load system and the emergency load system can be continued by the private power generation device 50 when the commercial AC power supply is stopped, so that the stability of the system is further improved. You can

A general equipment 8 is connected to the general load system 3 branched from the load bus 2, and a circuit breaker 6 opened by a protective relay 7 is provided. An important equipment 9 is connected to the emergency load system 4 branched from the load bus 2, and a circuit breaker 21 that is opened by a protective relay 20 is provided. Further, the computer facility 10 is connected to the uninterruptible load system 5 branched from the load bus 2, and a circuit breaker 23 opened by a protective relay 22 is provided. A circuit breaker 57 is provided between the branch point of the general load system 3 and the branch point of the emergency load system 4 on the load bus 2, and the circuit breaker 57 is opened to open the general load system 3 to the emergency load system 4 and the uninterruptible load. It can be separated from lineage 5.

FIG. 6 shows a control circuit of the uninterruptible power supply system of FIG. In the figure, 53a is a contact that is turned on when the circuit breaker 53 is opened, 56a is a contact that is turned on when the circuit breaker 56 is opened, and 60 is a power failure state in both the power receiving facility 1 and the private power generation facility 50 At that time, a power failure detecting means for detecting that and switching the contact from b to a, 57a is a contact which is turned on when the circuit breaker 57 is opened, 52a is turned on when the protective relay 52 provided in the main line 51 is activated. , 55a is a protective relay 55 provided on the main line 54
Is a contact that is turned on when is activated, 58 is an emergency manual switch, and 59 is a push button switch for manually operating the circuit breaker 57. Other devices are the same as those in FIG. The manual switches and the like, current and voltage monitoring instruments, alarm devices, etc. are provided in a management device installed in a disaster prevention center (not shown).

Next, the operation of the uninterruptible power supply system of FIG. 5 will be described with reference to FIG. When AC power is supplied by at least one of the main lines 51 and 54, the circuit breakers 53 and / or 56 are closed, and the circuit breaker 57 is also closed. When the power supply from the AC power supply system is stopped, that is, when the power supply from both the main lines 51 and 54 is stopped and a power failure occurs, the power failure detection means 60 operates and its contact is switched from b to a. Replace Further, when the manual switch 58 is switched to the emergency side, the flip-flop circuit 43 is activated by the switching signal and the AND condition from the contact a, and the terminal Q thereof is at a high level (ON signal).
become. The ON signal from the terminal Q causes the circuit breakers 53, 56
And 57 are opened. Although the manual switch 58 is provided for safety confirmation, it may be omitted if desired. Further, depending on the ON signal from the terminal Q and the AND condition of the contacts 53a, 56a and 57a which are turned on by opening the circuit breakers 53, 56 and 57, the control circuit 45 of the bidirectional conversion unit 30 is switched to the orthogonal conversion. A signal (start signal A) is input, and the AC power supply is connected to the emergency load system 4 from the uninterruptible power supply 25 through the load bus 2.
Supplied to

Next, when the power supply from the AC power supply system is started, the power failure detecting means 60 is deactivated, and its contact point is restored from a to b. Further, when the manual switch 58 for safety confirmation is returned to the normal side, the setup signal is output when the delay circuit 42 is activated under those AND conditions and a set time elapses. The flip-flop circuit 43 is reset by this setup signal, its Q terminal becomes low level (off signal), and Q'terminal becomes high level (on signal). Then, the switching signal for the orthogonal transformation, which has been input to the control circuit 45 of the bidirectional conversion section 30, is stopped, whereby the bidirectional conversion section 30 returns to the AC / DC conversion state. Further, the closing coil CC of the circuit breakers 53 and 56 is activated by the ON signal from the Q'terminal, and the circuit breakers 53 and 56 are closed. On the other hand, closing coil CC of circuit breaker 57
Since the knot condition of the knotted element 61 is canceled by the OFF signal of the Q terminal, it can be operated by the operation of the push button of the push button switch 59 to close the circuit breaker 57. The circuit breaker 57 can be opened by operating the off button of the push button switch 59. By these operations, the uninterruptible power supply system returns to the normal state.

In the above description, the output frequency of the AC / DC converter 32 in the uninterruptible power supply 25 is the same as the frequency of the AC power supply system, but for a large computer, for example, 415 Hz.
Some are driven by a power source with a frequency such as. In such a case, the output frequency of the AC / DC converter 32 can be designed to match such a frequency. Furthermore, when the direct-current is converted into the alternating-current by the orthogonal conversion function of the bidirectional converter 30, the voltage can be controlled to gradually rise. By performing such control, there are advantages such as suppression of voltage fluctuation at the time of turning on.

[0023]

Since the present invention has the above-mentioned structure,
When the power supply from the AC power supply system is stopped, the bidirectional conversion unit provided in the uninterruptible power supply is switched to the orthogonal conversion, and the power supply to the emergency load system is supplied from the AC power supply system to the bidirectional conversion unit. Since the input / output unit can be switched to the AC side, the uninterruptible power supply can continue to supply power to the emergency load system as well as the uninterruptible load system. Therefore, even in the event of a power failure, it is possible to continue operating important equipment such as management systems that use computers and disaster prevention equipment. Moreover, since there is no need to install special emergency power supply equipment, there is no need to secure the installation site or capital investment.

[Brief description of drawings]

FIG. 1 is an electric system diagram showing an example of an uninterruptible power supply system of the present invention.

FIG. 2 is an electric circuit diagram showing a configuration of an uninterruptible power supply device 25 in FIG.

3 is a block diagram of a control circuit 45 that controls a bidirectional conversion unit 30 in FIG.

4 is an electric system diagram showing a control circuit of the uninterruptible power supply system of FIG.

FIG. 5 is an electric system diagram showing another example of the uninterruptible power supply system of the present invention.

6 is an electric system diagram showing a control circuit of the uninterruptible power supply system of FIG.

FIG. 7 is an electrical system diagram showing a conventional uninterruptible power supply system.

[Explanation of symbols]

 1 Power receiving equipment 2 Load busbar 3 General load system 4 Emergency load system 5 Uninterruptible load system 6 Circuit breaker 7 Protective relay 8 General equipment 9 Important equipment 10 Computer equipment 11 Uninterruptible power supply device 12 AC / DC converter 13 Power storage device 14 Orthogonal Converter 20 Protective relay 21 Circuit breaker 22 Protective relay 23 Circuit breaker 24 Voltage detection means 25 Uninterruptible power supply 26 Switching means 27 Power failure detection means 28 Circuit breaker 29 Communication line 30 Bidirectional converter 30a AC side input / output section 30b DC input Side output unit 30c Diode 30d Control switch 31 Power storage device 32 Quadrature conversion unit 40 AND circuit 41 OR circuit 42 Delay circuit 43 Flip-flop circuit 44 Drive circuit 45 Control circuit 45a Oscillation unit 45b Control unit 50 Private power generation device 51 Main line 52 Protective relay 53 Circuit breaker 54 Main line 55 Protective relay 5 Breaker 57 breaker 58 manual switch 59 push button switch 60 the power failure detection means 61 knots with element

Claims (3)

[Claims] 1. An uninterruptible power supply system comprising an emergency load system 4 connected to an AC power supply system and an uninterruptible load system 5 capable of supplying AC power from an uninterruptible power supply 25. The power supply device 25 is a bidirectional converter 3.
0, a power storage device 31, and a quadrature conversion unit 32. The bidirectional conversion unit 30 includes an AC side input / output unit 30a to which an AC power system is connected and a DC side to which the power storage device 31 and the quadrature conversion unit 32 are connected. The input / output unit 30b is provided, and the AC from the AC power supply system is further converted into DC to input / output unit 30b on the DC side.
The AC / DC conversion output from the AC power supply system 31 and the AC / DC conversion of the DC stored in the power storage device 31 to output the AC output from the AC side input / output unit 30a can be switched. When the power supply to the
The bidirectional conversion unit 30 is set to the orthogonal conversion state, and the power supply to the emergency load system 4 can be switched from the AC power system to the AC side input / output unit 30a of the bidirectional conversion unit 30. A featured uninterruptible power supply system. 2. The uninterruptible power supply system according to claim 1, wherein the emergency load system 4 is connected with road management terminal equipment, computer auxiliary equipment, disaster prevention equipment or emergency equipment. 3. The uninterruptible power supply system according to claim 1, wherein a commercial AC power supply and an in-house generated AC power supply are linked to the AC power supply system.