JPH01311837A - Instantaneous interruption backup system, uninterruptible power system and nuclear-reactor protective system - Google Patents

Abstract

PURPOSE:To supply load with approximately several hundred ms-10s electric power at the time of service interruption by connecting an induction motor in parallel with load on the output side of a voltage type inverter, controlling frequency by the voltage type inverter at the time of service interruption and keeping the slip of the induction motor in a generator region. CONSTITUTION:An induction motor 1 is connected in parallel with load 3 on the output side of a voltage type inverter 4. When a host power supply 2 is interrupted, the induction motor 1 starts its generation by the energy of inertia of the induction motor. The frequency of the induction motor is controlled by operating the voltage type inverter 4 by an inverter controller 5 for another power supply, whereby the slip of the induction motor 1 is kept constant, and electrical energy is generated for a longer time. Accordingly, instantaneous service interruption can be backed up in approximately several hundredms-10s.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a power supply device, and particularly an instantaneous power failure backup method suitable for a power supply that supplies power to a load that requires a power failure backup of several looms to about 10 seconds, and the same. Regarding uninterruptible power supply systems and nuclear reactor protection methods using

[Conventional technology]

Conventional devices back up momentary power outages by connecting an induction motor and a capacitor in parallel, as described in Japanese Unexamined Patent Publication No. 56-66141.

This is shown in Fig. 7, where 17 is a thyristor and 16 is a gate control device.1 Normally, power is supplied to the gate control device 16 from the upper power supply 2, but at the same time power is also supplied to the induction motor 1 connected in parallel. , and a parallel-connected capacitor], 5. When the upper power supply 2 that constantly charges the 7 high-level power supply 2 has a power outage, the power supply to the induction motor 1- is stopped, but the induction motor 1 continues to rotate due to inertia. In addition, an exciting current is supplied to the induction motor j from the capacitor 15 that was being charged at the same time as the power outage occurs, so the induction motor 1 acts as a generator to generate electricity and feed its output to the gate control device 16. At this time, the directional relay 19 detects the reverse flow of power and opens the circuit breaker]0.

In this case, the time required for pulse processing to protect the thyristor is a short time of several ms to several tens of m5, so the backup method as described above was sufficient.

[Problem to be solved by the invention]

The above conventional technology is used to protect the thyristor.

Power is supplied to the gate control device that controls the thyristor for several ms.
~Number 1. ．． This is a backup method to extend the Om s, and because the backup time is short, no consideration is given to actively utilizing the inertial energy of the induction motor.
When a backup time of approximately 00 mg to 1.0 s is required, for example, when a voltage source inverter is used as the power source for driving the internal pump of a boiling water reactor, the inertia of the internal pump is small, making it easy to protect the reactor. There was a problem that it could not be used as a backup because the internal pump would be turbulent for several seconds after a power outage.

Furthermore, when configuring an uninterruptible @power supply system by combining multiple host power supplies and backup diesel generators, there are hundreds of times when switching power supplies or starting diesel generators is required.
There was a problem that it could not be applied as a backup for supplying power to a load for about ms to 10 seconds.

The first object of the present invention is to reduce the number of OOm s-・
The object of the present invention is to provide a momentary power outage backup method that can supply power to a load for about 10 seconds.

A second object of the present invention is to provide an uninterruptible power supply system using a backup method.

A third object of the present invention is to provide a nuclear reactor protection system that utilizes the aforementioned backup system and uninterruptible power supply system.

[Means to solve the problem]

1st. This objective is achieved by connecting an induction motor in parallel with the load on the output side of a voltage source inverter, and in the event of a power outage, controlling the frequency with the voltage source inverter to keep the slip of the induction motor within the generator range.

Furthermore, this can be achieved by connecting an MG Sera 1-, which is a combination of an induction motor and a synchronous generator, in parallel with the voltage type inverter, and switching from the voltage type inverter to the MG set in the event of a power outage.

Furthermore, this can be achieved by connecting a synchronous motor in parallel with the load and controlling the excitation of the synchronous motor by a separate power supply during a power outage to maintain the synchronous motor's full power in the generator area.

The second purpose is to connect multiple host power supplies in parallel via circuit breakers to the input side of a voltage source inverter, and connect an induction motor in parallel with the load on the output side of the voltage source inverter. This is achieved by quickly switching to another power source when one of the power sources is out of power, and supplying power through power generation from the inertia of the induction motor while switching.

In addition, a diesel generator is connected in parallel with the host power supply, and an induction motor is connected in parallel with the load on the output side of the voltage source inverter, and the diesel generator is started in the event of a power outage, and the diesel generator is started after the power outage. This can be achieved by supplying power through power generation from the inertia of an induction motor.

The third objective is achieved by using the means for solving objectives 1 and 2 as a power source for an internal pump or a recirculation pump of a nuclear reactor.

[Effect]

When an induction motor is connected in parallel with a load, power is supplied to the induction motor at the same time as the load from the host power supply, but even if the host power supply fails, the induction motor retains inertial energy. FIG. 8 shows the relationship between slip, torque, and current of an induction device, where 20 indicates slip, 21 indicates current, and 22 indicates torque. Since the slip Sl of the induction motor during a power outage is in the generator region, the induction motor operates as a generator. However, since the rotor of an induction motor only rotates due to inertia, if the frequency is not controlled, the slip will quickly approach -1 and the current will increase, making it impossible to generate electricity.However, by controlling the frequency with a voltage source inverter, Since the height is maintained at 81, the inertial energy of the induction motor can be effectively generated and power can be supplied to the load.

When a synchronous motor is connected in parallel with the load, the synchronous motor becomes a generator for the same reason as above, and the excitation is controlled to keep the slip of the synchronous motor at SL, effectively generating the inertial energy of the synchronous motor, and generating the load. can be powered.

When an MG set is connected in parallel with a voltage source inverter, if the host power supply fails, the power supply to the load is switched from the voltage source inverter to the MG set, and the MG set generates power by its inertia, so the load can be powered.

In the case of an uninterruptible power supply system that is combined with a plurality of host power supplies, when one of the host power supplies experiences a power outage, a circuit breaker performs a switching operation to another host power supply. During this switching operation, the load is not supplied with power from the host power source, but since the induction motor generates electricity due to inertia, power continues to be supplied to the load, so there can be no power outage.

In the case of an uninterruptible power supply system combined with a diesel generator, when the upper power source experiences a power outage, the diesel generator is started and supplies power to the load. Until the start-up of the diesel generator is completed, power continues to be supplied to the load through power generation by the inertia of the induction motor, allowing for uninterrupted power outages.

When the above power supply is applied to the internal pump or recirculation pump of a nuclear reactor, the power supply to the internal pump or recirculation pump will continue due to the above action even if the upper power supply fails, thereby cooling the reactor. Material supply can continue to facilitate reactor protection operations.

〔Example〕

Embodiments of the present invention will be described below with reference to FIGS. 1 to 6.

FIG. 1 is an embodiment of the present invention, and shows a single line diagram of a power supply device using an instantaneous power failure backup method.

In Figure 1, 1 is an induction motor, 2 is a host power supply, 3 is a load,
4 is a voltage source inverter, 5 is an inverter control device, 6 is a bus bar, 7a is an input transformer to the voltage source inverter 4, 7b
indicates an output transformer from voltage source inverter 4.

The load 3 and the induction motor 1 are connected to a host power source 2, a bus 6, an input transformer 7a, a voltage source inverter 4. Power is supplied via the output transformer 7b. When the upper power supply 2 has a power outage, the induction motor 1
starts generating electricity using its inertial energy. By controlling the frequency by operating the voltage source inverter 4 using the inverter control device 5 provided as a separate power source, and by keeping the current of the induction motor 1 constant, it is possible to generate electricity for a longer period of time.

According to this embodiment, the inertial energy of the induction motor is fully utilized, and there is an effect of providing a system for backing up instantaneous power outages of several 100 ms to 10 seconds.6 Figure 2 shows another embodiment of the present invention, other than the above. 8 is a synchronous motor, 9 is an excitation control device for the synchronous motor 8, and 10 is a circuit breaker.

Power is supplied to the load 3 and the synchronous motor 8 from the host power supply 2 via the bus 6 and the circuit breaker ]O. '' When the third power source 2 loses power, the circuit breaker 10 is opened to disconnect the upper power source and the load, and the synchronous motor 8 starts generating power because its inertial energy and excitation are performed by a separate power source. Further, the excitation control device 9 controls the synchronous motor 8 to maintain a constant level, thereby generating power for a longer period of time and backing up the load. According to this embodiment, the inertial energy of the synchronous motor is fully utilized, and there is an effect of providing a system for backing up momentary power outages by approximately 100 ms to 10 s.

FIG. 3 shows another embodiment of the present invention, in which 11 is M-
G-Sera I- is shown.

The load 3 is connected to the bus 6 from the upper power supply 2. The input transformer 7a, 1 is connected to the original inverter 4. Power is supplied via the output transformer 7b and the circuit breaker 10a. MG Sera 1-11 is connected to the bus 6 from the third power supply 2. Power is supplied via circuit breaker LOc. Circuit breaker]
0)) is open.

When the upper power supply 2 has a power outage, the circuit breakers 10a and 10e are opened,
The circuit breaker 10b is closed. Since the MG upper set 1 has its synchronous generator excited by a separate power source, it generates electricity using its inertial energy. Also, the excitation control device 9 controls the excitation of the synchronous generator.
By controlling this, the slip of the synchronous generator is kept constant, generating electricity for a longer period of time and increasing the load. According to this embodiment, the inertial energy of the M-G set is fully utilized,
This has the effect of providing a method for backing up momentary power outages once every few 100 m5 to 10 seconds.

FIG. 4 shows another embodiment of the present invention, in which 1.2 shows a diesel generator in addition to the above.

A circuit breaker 10 is connected to the load 3 and the induction motor 1 from the upper power supply 2.
Power is supplied via a in the same manner as in FIG.

The circuit breaker 10b is open. When the upper power supply 2 loses power, the circuit breaker 10a is opened. Power is supplied to the load 3 by the inertial power generation of the induction motor 1 in the same manner as in FIG. In addition, the diesel generator 12 is started, but when the start is completed, the circuit breaker 10b is closed and the diesel generator 12
breaker 10b.

Bus line 6. Power is supplied to the load 3 via an input transformer 7a, a voltage source inverter 4°, and an output transformer 7b. This embodiment has the effect of providing an uninterruptible power supply system.

FIG. 5 shows an uninterruptible power supply system that is an embodiment of the present invention. In FIG. 5, power is supplied to the load 3 and the induction motor 1 from the host power source 2a via the circuit breaker 10a in the same manner as in FIG. The circuit breaker 10b is open. When there is a power outage in the upper power supply 2a, the circuit breaker 1.0a is opened, and the circuit breaker]-0b is turned on, and the circuit breaker 1.0a is opened and the circuit breaker 1.0a is turned on and the circuit breaker 1.0a is opened and the circuit breaker 1.0a is turned on and the circuit breaker 1.0a is opened and the circuit breaker 1.0a is turned on and the circuit breaker 1.
Power is supplied to the load 3 via Ob in the same manner as in FIG.

During switching of the circuit breakers 10a and 10b, power is supplied to the load 3 by inertial power generation of the induction motor 1 in the same manner as shown in FIG. 1. According to this embodiment, an uninterruptible power supply system is provided.

FIG. 6 shows an internal pump power supply device for a nuclear reactor. In addition to the above, 13 indicates an internal pump, and 14 indicates a nuclear reactor.

To the internal pump 13 of the reactor 14, the third power source 2
Power is then supplied in the same manner as in FIG. When upper power supply 2 loses power, reactors 1-4 stop and their output decreases, but
Generates heat for a while. However, in the same way as shown in Fig. 1, the internal pump 1 is
3 is supplied with power for several seconds, and the internal pumps 1 and 3 are operated to supply coolant and remove the heat. According to this embodiment, it is possible to provide an internal pump power supply device for protecting a nuclear reactor.6 [Effects of the Invention] According to the present invention, the inertial energy of the induction motor and synchronous motor 2M=G set can be sufficiently Since power generation can be used, it is effective to supply a power supply device that can back up several looms to 10 seconds. Further, the combination of this backup power supply device and other power supply devices has the effect of supplying an uninterruptible power supply device.

Furthermore, by using this backup power supply for the internal pump or recirculation pump of a nuclear reactor, it is possible to supply coolant even when the reactor is shut down due to power loss, thereby protecting the reactor.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of an instantaneous power outage backup method which is an embodiment of the present invention, FIGS. 2 and 3 are block diagrams of a momentary power outage backup method which is another embodiment of the present invention, and FIGS. Figure 5 is a configuration diagram of an uninterruptible power supply system that is an embodiment of the present invention using a momentary power outage backup method, and Figure 6 is a diagram showing a nuclear reactor protection system that is an embodiment of the present invention that uses an instantaneous power outage backup method. , FIG. 7 is a block diagram showing a conventional instantaneous power failure backup system for thyristor protection, and FIG. 8 is a characteristic diagram showing the relationship between motor slip, current, and torque. 1...Induction motor, 2a, 2b...Upper power supply, 3.
...Load, 4...Voltage type inverter, 5...Inverter control device, 6...Bus bar, 7a...Input transformer,
7b...Output transformer, 8...Synchronous motor, 9...
Excitation control device. 10a, b-breaker, 11-MG set, 12...
Diesel generator, 13... Internal pump, 1
4... Nuclear reactor, 15... Capacitor, 16... Gate control device, 17... Thyristor, 18... Current transformer. 19... Directional relay, 20... Slip, 21...
Current, 22...torque. Figure 1, figure 2, figure 3, rate of sale, figure S, figure 6, figure I,

Claims (1)

[Claims] 1. In a system in which power is supplied to a load from an upper power source via a voltage source inverter, an induction motor is connected to the output side of the voltage source inverter in parallel with the load, and when the upper power source experiences a power outage, An instantaneous power outage backup method for a power supply device, characterized in that the voltage source inverter controls the frequency and supplies power generated by the inertial energy of the induction motor to the load. 2. In a system in which power is supplied to a load from an upper power source, a synchronous motor whose excitation is performed from a separate power source is installed in parallel with the load, and when the upper power source has a power outage, the excitation of the synchronous motor is controlled and the inertia of the synchronous motor is controlled. An instantaneous power outage backup method for a power supply device, characterized in that power generated by energy is supplied to the load. 3. In a system in which power is supplied from the upper power source to the load via the voltage source inverter, the M-G set is connected so as to bypass the voltage source inverter, and when the upper power source has a power outage, the power source of the load is switched to the voltage source. 1. An instantaneous power outage backup method for a power supply device, characterized in that the power supply unit switches from a type inverter to the M-G set, and supplies power generated by the inertial energy of the M-G set to the load. 4. A diesel generator is connected to the input side of the voltage source inverter, and when the upper power source has a power outage, the diesel generator is started, and from the time the upper power source loses power until the diesel generator is started. 2. The uninterruptible power supply system according to claim 1, wherein the power generation output generated by the inertial energy of the induction motor is supplied to the load. 5. A plurality of said upper power sources are provided, and when one upper power source has a power outage, it is promptly switched to another upper power source, and during the time required for this switching, the generated output from the inertial energy of the induction motor is supplied to the load. 1 uninterruptible power supply system. 6. The power supply device according to claim 1, 2, 3, 4 or 5 is used as the power supply for the internal pump or recirculation pump of the nuclear reactor, so that even when the upper power supply fails, coolant is supplied to the reactor and the nuclear A nuclear reactor protection method characterized by cooling the reactor.