JP2003319571A - Electric power system for plant equipment - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain an electric power system for a plant equipment using an AC motor as a load necessary for its operation even in an emergency so as to simplify the plant equipment by eliminating the necessity for a DC motor and a DC power circuit for its use. <P>SOLUTION: An AC power unit 1 performing ordinary operation of a load 3 of electric motors necessary for the operation of plant equipment and an uninterruptive electric power unit 6 operated by an electric power unit 2 for emergency at power interruption of the AC power unit 1 to supply AC power to the load 3 of the electric motors to have a power/reactive power compensating means are provided, the uninterruptive electric power unit 6 supplies the AC power to the load 3 of the electric motors in response to power interruption of the AC power unit 1 so as to continue the operation of the plant equipment by driving the load 3 of the electric motors. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power supply system for plant equipment, and more particularly to a power supply system for plant equipment equipped with an uninterruptible power supply.

[0002]

2. Description of the Related Art As shown in FIG. 8, in a conventional power supply system such as a thermal power plant, an important electric motor such as an electric motor for driving an emergency bearing pump of a turbine or a generator or a drain valve of a steam system. The important device is the same electric motor
There are AC and DC devices, the AC power supply circuit has an AC motor and an AC device as loads, and the DC power supply circuit has a DC motor and a DC device as loads, which are duplicated with separate power supply buses. .

In FIG. 8, 1 is an AC power source, 2 is a DC power source device, 3a is an AC motor as a small capacity AC load, 3
Reference numeral b is an AC device power supply, and 4 is a DC motor.

Since an electric motor causes a voltage drop and reactive power due to an inrush current at the time of starting the electric motor, the capacity of the power supply device to be supplied to the electric motor requires a power supply capacity larger than that output by the electric motor. The diesel engine generator to be supplied needs a generator capacity sufficiently larger than the load output by the AC motor in order to compensate the reactive power.

The conventional uninterruptible power supply cannot cope with a large overcurrent such as a starting current and cannot cope with a load such as an electric motor.

[0006]

In plant equipment such as a thermal power plant, an electric motor of an important auxiliary machine necessary for operating the plant equipment is duplexed by an AC electric motor and a DC electric motor as shown in FIG. . This is because the auxiliary equipment, which must always be operated during plant operation, is operated with an AC power supply or a DC power supply. In addition, an uninterruptible power supply consisting of an alternating-current power supply 3b capable of constantly outputting alternating-current power by matching an alternating-current power supply and a direct-current power supply is installed in the plant equipment, but the conventional uninterruptible power supply has an excessive current such as a starting current. Therefore, there is a problem that an electric motor having a large starting current cannot be used as a load of an uninterruptible power supply because it cannot withstand the load, and it has been used only for a load having a very small required capacity such as a computer. Therefore,
In order to duplicate the motor power source, it was necessary to install an AC power circuit and an AC motor, and a DC power circuit and a DC motor, respectively.

If the uninterruptible power supply can have an AC motor as a load, it is possible to duplicate the AC and DC power supplies by the uninterruptible power supply, and the DC motor need not be installed. You can Further, in the AC electric motor, a voltage drop and reactive power are generated due to a rush current at the time of starting the electric motor. Therefore, the capacity of the power supply device supplied to the electric motor needs to be larger than the electric power output by the electric motor. Therefore, it is necessary to select the capacity of the AC power source in consideration of the starting current of the AC motor in order to suppress the voltage drop of the motor. Had to be selected. Therefore, in the case of supplying an emergency AC power source with an emergency diesel generator or the like, the load that can be used as the emergency AC power source is greatly limited because the diesel generator does not have a large capacity.

The present invention has been made to solve the above problems, and by using an AC motor as a load necessary for operating plant equipment even in an emergency, a DC motor and a DC power source for the DC motor are provided. The objective is to obtain a power supply system for plant equipment that does not require a circuit and can simplify the plant equipment.

[0009]

In the power supply system for plant equipment according to the first aspect of the present invention, an AC power supply for performing a normal operation of a motor load necessary for operating the plant equipment and an emergency power supply when the AC power supply fails An uninterruptible power supply that operates and supplies AC power to the motor load, the uninterruptible power supply supplies AC power to the motor load in response to a power failure of the AC power supply, and supplies the motor load. It is designed to continue operation of the plant equipment by driving.

In the power supply system for plant equipment according to the second aspect of the present invention, an AC power supply for performing a normal operation of a motor load necessary for operating the plant equipment and a device load necessary for operating the plant equipment other than the motor load, An uninterruptible power supply that operates by an emergency power supply when the AC power supply fails and supplies AC power to the motor load and the device load, the uninterruptible power supply responding to a power failure of the AC power supply, AC power is supplied to the electric motor load and the device load to continue the operation of the plant equipment.

In a power supply system for plant equipment according to a third invention, in the first or second invention, reactive power compensating means is provided in the uninterruptible power supply.

In a power supply system for plant equipment according to a fourth aspect of the present invention, in the third aspect of the present invention, the uninterruptible power supply device is provided with control means for selecting a load to supply AC power.

In a power supply system for plant equipment according to a fifth aspect of the present invention, in the third aspect of the present invention, there is provided control means for selecting a load to which the uninterruptible power supply supplies AC power and controlling the order of applying the load. It is provided.

In a power supply system for plant equipment according to a sixth aspect of the present invention, in the third to fifth aspects, a transformer provided in the AC power supply circuit is provided, and reactive power compensation provided in the uninterruptible power supply device. By supplying the reactive power by the means, the power factor of the motor load is improved to reduce the required capacity of the transformer.

In a power supply system for plant equipment according to a seventh invention, in the first to sixth inventions, a changeover switch for switching between the AC power supply and the uninterruptible power supply is provided for overcurrent of the AC power supply circuit. The thyristor element has a corresponding overcurrent protection function.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiment 1. The first embodiment according to the present invention will be described with reference to FIG. FIG. 1 is a block diagram showing the circuit configuration of the power supply system according to the first embodiment.

In FIG. 1, 1 is an AC power supply, 2 is an emergency DC power supply, 3 is an AC motor load, 5 is a power / reactive power compensator, and 6 is an uninterruptible power supply. The AC motor load 3 constitutes an important auxiliary machine that is necessary for operation of plant equipment such as an electric motor that drives an emergency bearing pump of a turbine or a generator or a drain valve of a steam system, and is essential for continuous operation of the plant equipment. To do.

There is a power supply circuit composed of an AC power supply 1, a DC power supply 2, an AC motor 3, and an uninterruptible power supply 6 having a power / reactive power compensator 5. Supply electric power to the electric motor 3.
At the time of starting and normal operation, the normal power supply 1 is directly connected to the AC motor 3
Therefore, it is possible to have the AC motor 3 as an uninterruptible power supply load. When the AC power supply 1 fails, the DC power supply 2 converts the AC power to AC power through the power / reactive power compensator 5 and supplies the AC motor 3 with AC power.

In the prior art, an electric motor as an important auxiliary device is a dual AC power source and a DC power source as shown by an AC motor 3a and a DC motor 4 in FIG. 8, and therefore two AC motors and a DC motor are used. However, if the AC motor 3 is duplicated with the AC power supply 1 and the DC power supply 2 by using the uninterruptible power supply 6 as shown in FIG. 1 in the first embodiment, the DC power supply and the DC motor can be installed. Is unnecessary,
The internal circuit as shown in FIG. 1 can be composed of only the AC power supply system.

That is, in the configuration of the first embodiment shown in FIG. 1, the following operation is performed. During normal operation, AC power is supplied to the AC electric motor 3 by the AC power supply 1 composed of a commercial power supply or the like, and the AC electric motor 3 is started and the normal operation is performed. When driven, the AC motor 3 serves as an important auxiliary device that drives an emergency bearing pump of a turbine or a generator or a drain valve of a steam system. When the AC power supply 1 is in a power failure state, the uninterruptible power supply device 6 responds to the power failure of the AC power supply 1 to convert the DC power from the emergency DC power supply 2 into AC power, and converts the DC power via the power / reactive power compensator 5 into AC power. AC power is supplied to the electric motor 3. The AC motor 3 continues to be driven by the supply of the AC power, and continues to perform the role of the important auxiliary machine described above. As a result, the operation of plant equipment such as a thermal power plant can be continued without any hindrance, and the influence of the power failure of the AC power supply 1 can be avoided.

According to the first embodiment of the present invention, the AC power source 1 for performing the normal operation of the motor load 3 which is necessary for the operation of the plant equipment and is essential for the continued operation of the plant equipment, and the An uninterruptible power supply 6 having an electric power / reactive power compensating means for operating with the power supply 2 for power supply and supplying AC power to the motor load 3, and the uninterruptible power supply 6 operates in case of a power failure of the AC power supply 1. In response to this, AC power is supplied to all of the motor loads 3,
Since it was designed to continue operating the plant equipment by using the AC motor as a load necessary for the operation of the plant equipment and indispensable for continuous operation of the plant equipment, the DC motor and the DC A power supply system for plant equipment that does not require a power supply circuit and can simplify plant equipment can be obtained.

Embodiment 2. A second embodiment according to the present invention will be described based on FIG. FIG. 2 is a block diagram showing the circuit configuration of the power supply system according to the second embodiment.
In the second embodiment, the configuration other than the unique configuration described here has the same configuration as that of the first embodiment described above, and has the same operation. In the drawings, the same reference numerals indicate the same or corresponding parts.

In FIG. 2, 1 is an AC power supply, 2 is a DC power supply, 3 is an AC motor load, 5 is a power / reactive power compensator, 6 is an uninterruptible power supply, and 7 is a device circuit load.
The AC motor load 3 constitutes an important auxiliary machine that is necessary for operation of plant equipment such as an electric motor that drives an emergency bearing pump of a turbine or a generator or a drain valve of a steam system, and is essential for continuous operation of the plant equipment. To do. The device circuit load 7 constitutes an important auxiliary device that is necessary for operation of plant equipment such as control operation circuits for display, alarm, circuit breaker control, solenoid valve, etc. and is essential for continuous operation of plant equipment. .

That is, in the configuration of the second embodiment shown in FIG. 2, the following operation is performed. During normal operation, AC power is supplied to the AC motor 3 and the apparatus circuit load 7 by the AC power supply 1 configured by a commercial power supply or the like, and the AC motor 3 is started and the normal operation is performed.
When driven, the AC motor 3 serves as an important auxiliary device that drives an emergency bearing pump of a turbine or a generator or a drain valve of a steam system. When the device circuit load 7 is supplied with AC power, it performs a function as an important auxiliary device such as a control operation for display, alarm, circuit breaker control, solenoid valve, and the like. When the AC power supply 1 is in a power failure state, the uninterruptible power supply device 6 responds to the power failure of the AC power supply 1 to convert the DC power from the emergency DC power supply 2 into AC power, and converts the DC power via the power / reactive power compensator 5 into AC power. AC power is supplied to the electric motor 3 and the device circuit load 7. The AC motor 3 and the device circuit load 7 continue the driving state and the control operation by the supply of the AC power, and continuously perform the role as the important auxiliary machine described above. As a result, the operation of plant equipment such as a thermal power plant can be continued without any hindrance, and the influence of the power failure of the AC power supply 1 can be avoided.

In the first embodiment, only the motor load is connected to the uninterruptible power supply, but if all the circuits that were conventionally DC power supplies are AC power supplies as in the second embodiment, the plant equipment can be The DC power supply circuit can be erased.

According to the second embodiment of the present invention, it is necessary to operate the plant load other than the motor load 3 and the motor load 3 necessary for operating the plant facility and indispensable for the operation. An AC power supply 1 that performs the normal operation of the indispensable device load 7, and an emergency power supply 2 that operates when the AC power supply 1 fails to supply AC power to the motor load 3 The uninterruptible power supply device 6 includes an uninterruptible power supply device 6, and the uninterruptible power supply device 6 supplies alternating current power to all of the motor load 3 and the device load 7 in response to a power failure of the alternating current power supply 1 to continue operation of plant equipment. Therefore, by using the AC motor and AC device load even in an emergency as a load necessary for the operation of the plant equipment and indispensable for the continued operation of the plant equipment, the DC motor The DC power supply circuit for fine DC motor is not necessary, it is possible to obtain a power supply system of the plant equipment which can simplify the plant equipment.

Embodiment 3. The third embodiment according to the present invention will be described with reference to FIG. FIG. 3 is a block diagram showing the circuit configuration of the power supply system according to the third embodiment.
In the third embodiment, the configuration other than the unique configuration described here has the same configuration as the first and second embodiments described above, and has the same operation. In the drawings, the same reference numerals indicate the same or corresponding parts.

In FIG. 3, 1 is an AC power supply, 2 is a DC power supply, 3 is an AC motor load, 5 is a power / reactive power compensator, 6 is an uninterruptible power supply, 7 is a device circuit load, and 8 is a thyristor element. Is a high-speed changeover switch configured by.

The AC motor load 3 in FIG. 3 is supplied with power from the AC power supply 1 at the time of starting. The AC power from the AC power supply 1 is supplied to the AC motor 3 through a high-speed changeover switch 8 that can handle overcurrent, and also passes through an uninterruptible power supply 6 having a power / reactive power compensator 5. The AC motor 3 generates a starting current larger than the rated current at the time of starting, but the starting current can be suppressed by the power / reactive power compensator 5 performing power compensation. For this reason, the capacity of the AC power supply 1 had a large starting current in the past, so it was necessary to plan a power supply capacity sufficiently larger than the rated load capacity, but the power supply capacity can be planned with a smaller capacity than before. . Examples of the AC power supply device include power supply devices such as a diesel engine generator, a gas turbine engine generator, and a solar power generator.

According to the third embodiment of the present invention, the AC power supply 1 for performing the normal operation of the motor load 3 necessary for the operation of the plant equipment and indispensable for the operation, and the AC power supply circuit for the AC power supply 1 And a high speed changeover switch 8 composed of a thyristor element capable of performing a protection operation in response to an overcurrent and an emergency power supply 2 when the AC power supply 1 fails to supply AC power to the motor load 3. And an uninterruptible power supply 6 having a reactive power compensator, the uninterruptible power supply 6 supplies AC power to all of the motor loads 3 in response to a power failure of the AC power supply 1,
Since the electric motor load 3 is driven to continue the operation of the plant equipment, the AC electric motor is used even in an emergency as a load necessary for the operation of the plant equipment and indispensable for continuing the operation of the plant equipment. It is possible to obtain a power supply system for plant equipment that does not require a DC power supply circuit for a DC motor, can simplify plant equipment, and can suppress the influence of a starting current of an AC motor load.

Fourth Embodiment A fourth embodiment according to the present invention will be described with reference to FIGS. FIG. 4 is a block diagram showing the circuit configuration of the power supply system according to the fourth embodiment. FIG. 5 is a characteristic curve diagram showing the relationship between load and time in the fourth embodiment. In the fourth embodiment, for configurations other than the specific configuration described here,
It has the same configuration as that of the first to third embodiments described above and has the same operation. In the drawings, the same reference numerals indicate the same or corresponding parts.

In FIG. 4, 1 is an AC power supply, 2 is a DC power supply, 3 is an AC motor load, 5 is a power / reactive power compensator, 6 is an uninterruptible power supply, 7 is a device circuit load, and 8 is a thyristor element. Is a high-speed changeover switch, and 9 is a control device.

FIG. 4 shows a power supply system diagram of the fourth embodiment.
In contrast to the third embodiment, the AC power supply fails and the DC power supply 2
When the electric motor 3 and the device circuit 7 are operated in step 2, the capacity of the DC power supply 2 needs to be extremely large in order to continue the operation of all the AC electric motors 3 and the device circuits 7. Therefore, by using the control device 9 to select the operating load so that only the minimum required load is operated during AC power supply operation, it is possible to reduce the capacity of the DC power supply device during AC power failure.

FIG. 5 shows the relationship between the capacity and load capacity of a conventional power supply device. As shown in FIG. 5, since the capacity of the power supply device is determined by the capacity of the starting current of the load, it is larger than the rated load. Therefore, if the uninterruptible power supply as in Embodiment 4 is added to the circuit in which the conventional power supply equipment is installed, the load that can be added to the uninterruptible power supply can be increased.
This is because the number of electric motors and devices that are currently operating in an emergency can be changed by changing the power supply system according to the fourth embodiment when an AC power source such as an emergency diesel engine is installed in a hospital or the like. However, the quantity is less limited, and the capacity of the load that can be supplied by the power supply device driven by the emergency diesel engine can be increased.

According to the fourth embodiment of the present invention, in the configuration of the first to third embodiments, the uninterruptible power supply 6 selects a load for supplying AC power, and the load sequence is the same. Since the control means composed of the control device 9 for controlling the DC motor is provided, the DC motor and the DC power source for the DC motor can be used by using the AC motor even in an emergency as a load necessary for the operation of the plant equipment and indispensable for continuing the operation. It is possible to obtain a power supply system for plant equipment that does not require a circuit, can simplify the plant equipment, and can reduce the capacity of the emergency DC power supply device.

Embodiment 5. A fifth embodiment according to the present invention will be described with reference to FIG. FIG. 6 is a block diagram showing the circuit configuration of the power supply system according to the fifth embodiment. In the fifth embodiment, the configuration other than the peculiar configuration described here has the same configuration as the first to fourth embodiments described above, and has the same operation. In the drawings, the same reference numerals indicate the same or corresponding parts.

In the figure, 1 is an AC power supply, 2 is a DC power supply, 3 is an AC motor load, 5 is a power / reactive power compensator, 6 is an uninterruptible power supply, 7 is a device circuit load, and 8 is a thyristor element. The configured high-speed changeover switch, 10 is a transformer, 11 is a common busbar, 12 is an individual busbar, and 13 is a circuit breaker.

As shown in FIG. 6 showing a power supply configuration diagram, in a circuit in which a common bus 11 is received from a high-voltage to low-voltage transformer 10 and each individual bus 12 has a motor load, between the common bus and each individual bus. In addition, if the uninterruptible power supply 6 used in the first to fourth embodiments is used, and if the electric power / reactive power compensation function 5 allows the electric motor 3 to have a high power factor, the transformer 10 and the common busbar. The capacity required by 11 can be made a sufficiently small value as compared with a circuit in which the uninterruptible power supply 6 is not installed, and the% Z, that is, the% impedance of the transformer can be reliably determined at the initial stage of the plant planning. It will be possible.

According to the fifth embodiment of the present invention, in the configurations of the first to fourth embodiments,
A transformer 10 provided in the AC power supply circuit is provided, and the power factor of the electric motor load is improved by supplying reactive power by the reactive power compensating means 5 provided in the uninterruptible power supply 6. Since the required capacity has been reduced, the DC motor and DC power supply circuit for the DC motor are not required by using the AC motor in an emergency as a load necessary for the operation of the plant equipment and indispensable for continuous operation of the plant equipment. A plant power supply system that can simplify the plant equipment, reduce the capacity of the transformer installed in the AC power supply circuit, and reliably determine the% impedance of the transformer at the initial stage of plant planning be able to.

Sixth Embodiment A sixth embodiment according to the present invention will be described with reference to FIG. FIG. 7 is a block diagram showing the circuit configuration of the power supply system according to the sixth embodiment. The sixth embodiment has the same structure as the first to fifth embodiments described above, except for the specific structure described here, and has the same operation. In the drawings, the same reference numerals indicate the same or corresponding parts.

In the figure, 1 is an AC power supply, 2 is a DC power supply, 3 is an AC motor load, 5 is a power / reactive power compensator, 6 is an uninterruptible power supply, 7 is a device circuit load, and 8 is a thyristor element. The configured high-speed changeover switch, 10 is a transformer, 11 is a common busbar, and 12 is an individual busbar.

A power supply configuration diagram is shown in FIG. Since the uninterruptible power supply 6 can be separated from the lower order by the upper order power supply and the high-speed changeover switch 8, the uninterruptible power supply 6 shown in FIG.
It becomes possible to eliminate the circuit breaker 13 between the common busbar 11 and the individual busbars 12 as shown in FIG.

According to the sixth embodiment of the present invention, in the configurations of the first to fifth embodiments,
By configuring the changeover switch for switching between the AC power supply 1 and the uninterruptible power supply 6 by a high-speed changeover switch 8 including a thyristor element having an overcurrent protection function for overcurrent of the AC power supply circuit, Since the circuit breaker that protects the AC power supply circuit from overcurrent is not required, the DC motor and the DC motor can be used by using the AC motor as a load necessary for the operation of plant equipment and indispensable for continuing the operation. The DC power supply circuit for the electric motor is unnecessary, and the plant equipment can be simplified,
It is possible to obtain a power supply system for plant equipment in which a circuit breaker for protecting an AC power supply circuit from overcurrent can be omitted.

[0044]

According to the first aspect of the present invention, an AC power source for performing a normal operation of an electric motor load necessary for operating plant equipment and an emergency power source when the AC power source fails to operate, and an AC electric power is supplied to the electric motor load. And an uninterruptible power supply device for supplying power to the uninterruptible power supply, which supplies AC power to the motor load in response to a power failure of the AC power supply and drives the motor load to continue operating plant equipment. Therefore, by using the AC motor as a load necessary for operating the plant equipment even in an emergency, the DC motor and the DC power supply circuit for the DC motor are not required, and the power supply system of the plant equipment can be simplified. Obtainable.

According to the second aspect of the invention, the AC power supply for performing the normal operation of the motor load necessary for operating the plant equipment and the device load necessary for operating the plant equipment other than the motor load, and when the AC power supply fails, An uninterruptible power supply that operates by an emergency power supply and supplies AC power to the motor load and the device load, the uninterruptible power supply responding to a power failure of the AC power supply, the motor load and the device. Since AC power is supplied to the load and the plant equipment continues to operate, the DC motor and the DC power supply circuit for the DC motor are unnecessary by using the AC motor as a load necessary for operating the plant equipment even in an emergency. As a result, it is possible to obtain a power supply system for plant equipment that can simplify the plant equipment.

According to the third invention, in the first or second invention, since the reactive power compensating means is provided in the uninterruptible power supply, the AC motor is used as a load necessary for operating the plant equipment even in an emergency. By using the DC motor and the DC power supply circuit for the DC motor, the plant equipment can be simplified, and the power supply system of the plant equipment that can suppress the influence of the starting current of the AC motor load can be obtained.

According to the fourth aspect of the present invention, in the third aspect of the present invention, the uninterruptible power supply has a control means for selecting a load for supplying AC power. By using the AC motor, the DC motor and the DC power supply circuit for the DC motor are not required, the plant equipment can be simplified, and the power supply system of the plant equipment that can reduce the capacity of the emergency DC power supply can be obtained.

According to a fifth aspect of the present invention, in the third aspect of the present invention, the uninterruptible power supply unit is provided with a control means for selecting a load for supplying AC power and controlling the loading sequence of the load. By using the AC motor as a load necessary for operating the facility even in an emergency, the DC motor and the DC power supply circuit for the DC motor are unnecessary, the plant equipment can be simplified, and the capacity of the emergency DC power supply device can be further reduced. A power supply system for plant equipment can be obtained.

According to a sixth aspect of the present invention, in any of the third to fifth aspects of the present invention, a transformer provided in the AC power supply circuit is provided, and Since the required capacity of the transformer is reduced by improving the power factor of the electric motor load by the supply, by using the AC electric motor even in an emergency as the load necessary for operating the plant equipment, the DC electric motor and the DC electric motor It is possible to obtain a power supply system for plant equipment that does not require a DC power supply circuit for an electric motor, can simplify plant equipment, and can reduce the capacity of a transformer provided in an AC power supply circuit.

According to a seventh invention, in the first to sixth inventions, a changeover switch for switching between the AC power supply and the uninterruptible power supply is provided with an overcurrent protection circuit against an overcurrent of the AC power supply circuit. Since it is configured with a thyristor element having a function, the DC motor and DC power supply circuit for the DC motor are not needed by using the AC motor as a load necessary for operating the plant equipment in an emergency, and the plant equipment is simplified. In addition, it is possible to obtain a power supply system for plant equipment in which a circuit breaker for protecting the AC power supply circuit from overcurrent can be omitted.

[Brief description of drawings]

FIG. 1 is a block diagram showing a circuit configuration of a power supply system according to a first embodiment of the present invention.

FIG. 2 is a block diagram showing a circuit configuration of a power supply system according to a second embodiment of the present invention.

FIG. 3 is a block diagram showing a circuit configuration of a power supply system according to a third embodiment of the present invention.

FIG. 4 is a block diagram showing a circuit configuration of a power supply system according to a fourth embodiment of the present invention.

FIG. 5 is a characteristic curve diagram showing a relationship between load and time in the fourth embodiment according to the present invention.

FIG. 6 is a block diagram showing a circuit configuration of a power supply system according to a fifth embodiment of the present invention.

FIG. 7 is a block diagram showing a circuit configuration of a power supply system according to a sixth embodiment of the present invention.

FIG. 8 is a block diagram showing a circuit configuration of a power supply system according to a conventional technique.

[Explanation of symbols]

1 AC power supply, 2 DC power supply, 3 AC motor, 4 DC motor, 5 power / reactive power compensator, 6 uninterruptible power supply, 7 AC device power supply, 8 high-speed changeover switch, 9
Control device, 10 transformers, 11 common busbars, 12 individual busbars, 13 circuit breakers.

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Atsushi Oda             2-3 2-3 Marunouchi, Chiyoda-ku, Tokyo             Inside Ryo Electric Co., Ltd. F-term (reference) 5G015 FA10 GA11 HA04 JA01 JA09                       JA11 JA48 JA52                 5G066 FA01 FB03 FB11 HA19 HA22                       HB09

Claims (7)

[Claims] 1. An AC power supply for performing a normal operation of an electric motor load necessary for operating plant equipment, and an uninterruptible power supply device which is operated by an emergency power supply when the AC power supply fails and supplies AC power to the electric motor load. Wherein the uninterruptible power supply supplies AC power to the electric motor load in response to a power failure of the AC power supply, and drives the electric motor load to continue operation of the plant facility. Power supply system for plant equipment. 2. An AC power supply for performing a normal operation of an electric motor load necessary for operating the plant equipment and an equipment load necessary for operating the plant equipment other than the electric motor load, and an emergency power supply that operates when the AC power supply fails. An uninterruptible power supply that supplies AC power to the motor load and the device load, the uninterruptible power supply supplying AC power to the motor load and the device load in response to a power failure of the AC power supply. The power supply system for plant equipment is characterized in that the operation of the plant equipment is continued. 3. The power supply system for plant equipment according to claim 1, wherein the uninterruptible power supply is provided with a reactive power compensator. 4. The power supply system for plant equipment according to claim 3, wherein the uninterruptible power supply includes control means for selecting a load that supplies AC power. 5. The power supply for plant equipment according to claim 3, wherein the uninterruptible power supply unit is provided with a control unit that selects a load that supplies AC power and controls the loading sequence of the load. system. 6. A transformer provided in the AC power supply circuit, wherein the transformer is provided by improving the power factor of the motor load by supplying reactive power by reactive power compensating means provided in the uninterruptible power supply. 6. The device according to claim 3, wherein the required capacity of the container is reduced.
The power supply system for plant equipment described in any one of 1. 7. A thyristor element having an overcurrent protection function for overcurrent of the AC power supply circuit, wherein the changeover switch for switching between the AC power supply and the uninterruptible power supply is configured. A power supply system for plant equipment according to any one of claims 1 to 6.