JPH10213696A - Station power facility of reactor power plant - Google Patents

Abstract

PROBLEM TO BE SOLVED: To simplify a station power facility of a reactor power plant and respond to a single failure and check of main transformer during operation. SOLUTION: During plant operation, station power is supplied from a main generator 5 through a direct transformer in the station 6 to a normal bus 7. In this time, a tap switcher 16 in load of site direct transformer 6 is controlled so that the secondary voltage of the station direct transformer 6 becomes rather low. In plant startup and shutdown on the other hand, the station power is supplied from the secondary side of the main transformer 3 to the normal bus 7. In this time, the on-load tap switcher 13 of main transformer 3 is controlled so that the secondary voltage of the main transformer 3 becomes rather high.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an in-plant power supply of a nuclear power plant for supplying power to various auxiliary machines of the nuclear power plant.

[0002]

2. Description of the Related Art For example, in a power plant in a boiling water nuclear power plant, when the plant is started or stopped, power cannot be obtained from a main generator via a directly connected transformer in the plant. Or when stopped,
The in-house power is supplied from a starting transformer circuit provided independently of the generator power transmission circuit.

FIG. 9 is a system diagram of such an in-house power supply facility. During operation of the plant, the electric power generated by the main generator 5 is transmitted to the switchyard bus 1 via the main transformer 3 and the main circuit breaker 2A. On the other hand, the power generated by the main generator 5 is also supplied to the in-house direct-coupled transformer 6 and supplied to the 6.9 KV service bus 7A via the circuit breaker 11A. In-house power is supplied from the service bus 7A to various auxiliary machines. As described above, during the operation of the plant, the in-house power is supplied from the generator transmission circuit including the main generator 5, the main transformer 3, and the main circuit breaker 2A. In this case, the generated voltage of the main generator 5 is directly applied to the primary side of the in-house transformer.
Basically, the generated voltage (power supply voltage) of the main generator 5 is fixed, so that the tap of the in-house direct-coupled transformer is fixed.

On the other hand, when the plant is started or stopped, the main generator 5 is stopped and power cannot be supplied through the in-house direct-coupled transformer 6, so that the working bus 7A is connected to the working bus 7A through the communication bus 10. Thus, the in-plant power is supplied from the 6.9 KV service bus 7B of the starting transformer circuit. That is, power is supplied from the switchyard bus 1 to the service bus 7B via the main transformer 2B and the starting transformer 12 provided independently of the generator transmission circuit, and the circuit breaker 11D, the communication bus 1
Power is supplied to the service bus 7A via the power supply 0 and the circuit breaker 11C. In this case, a power source switching operation is required,
Opening the circuit breaker 11A that has been turned on so far, turning on the circuit breaker 11C and the circuit breaker 11D, and receiving power supply through the switchyard bus 1, the starting transformer 12, the service bus 7B, and the communication bus 10. become.

A 6.9 KV emergency bus 8 is connected to the service bus 7B via a circuit breaker 11E, and the emergency generator 8 is connected to the emergency bus 8 via a circuit breaker 11F.
Is connected. This emergency generator 9 is driven by a diesel engine or a gas turbine.

[0006]

However, in such an in-house power supply system, when a failure related to the output of the main generator 5 occurs, the main circuit breaker 2A is opened regardless of the presence or absence of an electrical failure. In this case, switching of the in-house power supply bus always occurs.

FIG. 10 is a conventional interlock diagram. When the main circuit fault S1 of the generator transmission circuit or the generator fault S2 of the main generator 5 occurs, the generator protection lockout relay S3 operates to open the GIS S4 for opening the main circuit breaker 2A. And outputs the service bus 7
A to supply power from the start-up transformer circuit to circuit breaker 11
A is opened to output a bus switching command S5 for closing the circuit breakers 11C and 11D.

On the other hand, when a turbine failure (Tb failure) S6 occurs, the turbine protection lockout relay S7 operates to output a GIS open command S4 and also output a bus switching command S5. Similarly, when a reactor coolant loss accident (LOCA) S8 occurs, the GI
The main circuit breaker 2A is opened by outputting the S open command S4, and the bus switching command S5 is output to open the circuit breaker 11A to close the circuit breaker 11C and the circuit breaker 11D, and to the service bus 7A from the starting transformer circuit. Supply power.

As described above, conventionally, the main generator 5
When the failure related to the output of (1) occurs, the main circuit breaker 2A is opened, so that the plant is stopped, and the in-house power supply bus is switched. As described above, it is not possible to repair a failed portion while continuing the plant operation. For example, in the event of a failure or inspection of the main transformer 2A, the failed portion is repaired after the plant is stopped. After that, the plant was restarted.

[0010] Further, even in the event of a minor failure of the main transformer 2A, it is necessary to stop the plant in the same manner as in the above case. Power supply facilities are required.

In this case, not only the main generator 5 and the main transformer 2A can be simply separated from each other, but also it is possible to cope with various accidents required for the power supply equipment in the nuclear power plant, and to have high reliability. It is a prerequisite that the condition that satisfies the requirements is satisfied. In addition, it is necessary to provide an in-house power supply facility that can start repair work of the main transformer 2A while the operation is continued.

SUMMARY OF THE INVENTION It is an object of the present invention to simplify the power supply equipment in a nuclear power plant and to enable the power supply equipment in a nuclear power plant to respond to a failure or inspection of one of the main transformers during operation of the plant. Is to provide.

[0013]

According to the first aspect of the present invention, an in-plant power supply system for a nuclear power plant transmits power from a main generator to a switchyard bus via a main transformer and a main breaker during plant operation. An on-site power supply for a nuclear power plant that supplies on-site power from the main generator of the generator transmission circuit via an on-site direct-coupled transformer and supplies on-site power from the starting transformer circuit when the plant starts or stops. A service bus to which power is supplied to the station, an emergency bus to supply power in the station when the supply of power to the service bus is stopped, a secondary side of the transformer directly connected to the station, and an emergency bus. And a second connecting bus connecting the secondary side of the backup transformer of the starting transformer circuit and the service bus, and opening the main generator under a predetermined condition to connect the main transformer and From the in-house transformer A generator load switch to be separated, an on-load tap changer of the main transformer for adjusting the secondary voltage of the main transformer to be higher when the generator load switch is opened, and a generator load switch And a load tap changer for the on-site direct-coupled transformer, which adjusts so that the secondary voltage of the on-site direct-coupled transformer becomes lower when is closed.

In the power plant of a nuclear power plant according to the first aspect of the present invention, while the plant is operating, the power is supplied from the main generator to the service bus via the plant direct-connected transformer and the first communication bus is connected to the service bus. Power is supplied to the emergency bus via the office. At this time, the on-load tap changer of the in-house direct-coupled transformer adjusts the secondary-side voltage of the in-house direct-coupled transformer to be lower. On the other hand, when the generator load switch is opened under predetermined conditions and the main generator is disconnected from the main transformer and the in-house direct-connection transformer, the in-house power is supplied to the service bus from the secondary side of the main transformer. . In doing so, the on-load tap changer of the main transformer adjusts the secondary voltage of the main transformer to be higher. Then, when the supply of the in-house power to the service bus to which the in-plant power is supplied is stopped, the service is connected via the second communication bus from the secondary side of the backup transformer of the start-up transformer circuit connected to the emergency bus. Supply in-house power to the bus.

According to a second aspect of the present invention, there is provided an on-site power supply system for a nuclear power plant, comprising: a main power transmission circuit of a generator for transmitting power from a main generator to a switchyard bus via a main transformer and a main breaker during plant operation. An on-site power supply facility for a nuclear power plant that supplies on-site power from a generator via an on-site directly connected transformer and supplies on-site power from a startup transformer circuit when the plant starts or stops. A first connection for connecting an emergency bus to be used, an emergency bus for supplying an emergency internal power when the supply of the internal power to the service bus is stopped, and a secondary side of the internal direct-connected transformer and the emergency bus. And a second connecting bus connecting the secondary side of the auxiliary transformer of the starting transformer circuit to the service bus, and opening under predetermined conditions to disconnect the main generator from the main transformer and the on-site transformer. Generator negative And switch, in which a load tap changer of the main transformer to adjust so as to increase the secondary voltage of the main transformer when the generator load break switch is open.

In the power plant of a nuclear power plant according to the second aspect of the present invention, while the plant is operating, power is supplied from the main generator to the service bus via the plant direct-connected transformer, and the first connecting bus is connected to the service bus. Power is supplied to the emergency bus via the office. When the generator load switch is opened under predetermined conditions and the main generator is disconnected from the main transformer and the on-site direct-connection transformer, the on-site power is supplied to the service bus from the secondary side of the main transformer. In doing so, the on-load tap changer of the main transformer adjusts the secondary voltage of the main transformer to be higher. Then, when the supply of the in-house power to the service bus to which the in-plant power is supplied is stopped, the service is connected via the second communication bus from the secondary side of the backup transformer of the start-up transformer circuit connected to the emergency bus. Supply in-house power to the bus.

According to a third aspect of the present invention, there is provided an on-site power supply system for a nuclear power plant, comprising: a main power supply circuit of a generator transmission circuit for transmitting power from a main generator to a switchyard bus via a main transformer and a main breaker during plant operation. An on-site power supply facility for a nuclear power plant that supplies on-site power from a generator via an on-site directly connected transformer and supplies on-site power from a startup transformer circuit when the plant starts or stops. A first connection for connecting an emergency bus to be used, an emergency bus for supplying an emergency internal power when the supply of the internal power to the service bus is stopped, and a secondary side of the internal direct-connected transformer and the emergency bus. And a second connecting bus connecting the secondary side of the auxiliary transformer of the starting transformer circuit to the service bus, and opening under predetermined conditions to disconnect the main generator from the main transformer and the on-site transformer. Generator negative When the switch and the generator load switch are open, adjust the secondary side voltage of the in-house direct connection transformer to be higher. When the generator load switch is closed, the secondary side voltage of the in-house direct connection transformer And a tap changer at the time of load of an in-house direct-coupled transformer, which adjusts so as to be lower.

In the power supply system for a nuclear power plant according to the third aspect of the present invention, while the plant is in operation, the power supply is supplied from the main generator to the service bus via the direct connection transformer and the first communication bus is connected to the service bus. Power is supplied to the emergency bus via the office. At this time, the on-load tap changer of the in-house direct-coupled transformer adjusts the secondary-side voltage of the in-house direct-coupled transformer to be lower. On the other hand, when the generator load switch is opened under predetermined conditions and the main generator is disconnected from the main transformer and the in-house direct-connection transformer, the in-house power is supplied to the service bus from the secondary side of the main transformer. . At this time, the on-load tap changer of the in-house direct-coupled transformer adjusts the secondary-side voltage of the in-house direct-coupled transformer to be higher. Then, when the supply of the in-house power to the service bus to which the in-house power is supplied is stopped,
The local power is supplied from the secondary side of the backup transformer of the starting transformer circuit connected to the emergency bus to the service bus via the second communication bus.

According to a fourth aspect of the present invention, there is provided an on-site power supply system for a nuclear power plant, comprising: a main transformer and a main cutoff of a generator transmission circuit for transmitting power from a main generator to a switchyard bus via a main transformer and a main breaker. Two sets of generator load switches provided between the secondary side of each of the main transformers provided in parallel and the main generator and opened under predetermined conditions;
Two series of on-site direct-connection transformers connected between the secondary side of each main transformer and the generator load switch for supplying the on-site power, and each of the two series of generators during plant operation In-plant power is supplied to the two-service bus from the main generator through the load switch and the in-plant direct-connected transformer, and from one service bus to the other when the plant is started or stopped. It has a communication bus and an emergency bus that is connected to one of the two service buses and supplies an emergency power when the supply of the power to the other service bus stops.

According to the power supply system of the nuclear power plant according to the fourth aspect of the present invention, during the operation of the plant, two
Power is supplied from the main generator to each of the two service buses from the main generator via the generator load switch and the on-site direct-connection transformer. When one of the two sets of generator load switches is opened under predetermined conditions, the in-house power is supplied to the service bus from the closed generator load switch via the in-house transformer. The other service bus is supplied with in-house power via a connection bus. Then, when the supply of the in-house power to the service bus stops, the emergency in-house power is supplied to the service bus from the emergency bus.

According to a fifth aspect of the present invention, there is provided an on-site power supply system for a nuclear power plant, comprising: a main transformer and a main cutoff of a generator transmission circuit for transmitting power from a main generator to a switchyard bus via a main transformer and a main breaker. Two sets of generator load switches provided between the secondary side of each of the main transformers provided in parallel and the main generator and opened under predetermined conditions;
Two series of on-site transformers connected between the secondary side of each main transformer and the generator load switch for supplying in-house power, and two series of on-site transformers during plant operation During the operation of the plant, the on-site power supply is supplied from one side, and the on-site power supply is supplied from the other of the two series of on-site power transformers during plant operation. The emergency bus to be supplied and the first connecting the secondary side of one of the in-house direct-coupled transformers to the emergency bus
, And a second communication bus connecting the secondary side of the other in-house direct-coupled transformer and the service bus.

In the power plant of a nuclear power plant according to the present invention, power is supplied to the service bus from one of the two series of direct-connected transformers during operation of the plant,
In addition, in-house power is supplied to the emergency bus from the other of the two series of in-house transformers. When one of the two sets of generator load switches is opened under predetermined conditions, power is supplied from the closed generator load switch to the service bus or emergency bus from the closed generator load switch via the in-house transformer. Then, the in-house power is supplied from the service bus to the emergency bus via the first communication bus, and the in-house power is supplied from the emergency bus to the service bus via the second communication bus.

According to a sixth aspect of the present invention, there is provided an on-site power supply system for a nuclear power plant, comprising: a main transformer and a main cutoff of a generator transmission circuit for transmitting power from a main generator to a switchyard bus via a main transformer and a main breaker. And a plurality of series generator load switches which are provided between the secondary side of each main transformer provided in parallel and the generator and are opened under predetermined conditions, Two series of on-site transformers connected between the secondary side of two main transformers of the transformers and the generator load switch for supplying the on-site power; The in-house power is supplied to the service bus through which the in-house power is supplied from the main generator via the generator load switch and the in-house transformer connected to each of the two systems, and the service bus through the communication bus when the plant is started or stopped. Startup change to supply It is obtained by a vessel circuit.

According to the power supply system of the nuclear power plant according to the invention of claim 6, the power supply of the nuclear power plant can be operated while the plant is operating.
Power is supplied from the main generator to the service bus from the main generator via the generator load switch and the on-site transformer connected to each of the series. When one of the two sets of generator load switches is opened under predetermined conditions, the in-house power is supplied to the service bus from the closed generator load switch side. When the plant is started or stopped, the in-house power is supplied from the starting transformer circuit to the service bus via the communication bus.

According to a seventh aspect of the present invention, there is provided an on-site power supply system for a nuclear power plant, wherein the generator load switch is a main generator accident, a turbine failure or a loss of reactor coolant. It is designed to be opened when one of the accidents occurs.

According to the seventh aspect of the present invention, in the power supply system for a nuclear power plant, in addition to the effects of the first to sixth aspects, any one of a main generator accident, a turbine failure, and a reactor coolant loss accident may occur. When the alarm occurs, the generator load switch is opened.

According to the invention of claim 8, the on-site power supply system of the nuclear power plant is characterized in that, in the invention of claims 1 to 6, the generator load switch is configured to detect any one of a turbine failure and a reactor coolant loss accident. It is designed to be released when it occurs.

[0028] In the power supply system for a nuclear power plant according to the invention of claim 8, the generator according to any of claims 1 to 6, when any of a turbine failure or a reactor coolant loss accident occurs. Open the load switch.

[0029]

Embodiments of the present invention will be described below. FIG. 1 is a configuration diagram showing a first embodiment of the present invention. This first embodiment is different from the conventional example shown in FIG. 9 in that the service bus 7B of the start-up transformer circuit is deleted and the connecting bus 10 is replaced with the secondary side of the in-house direct-coupled transformer 6. A first connecting bus 14 connecting the service bus 8 and a second connecting bus 15 connecting the secondary side of the auxiliary transformer 12A of the start-up transformer circuit and the service bus 7; And a generator load switch 4 for separating the main generator 5 from the main transformer 2A and the in-house direct-coupled transformer 6, and the secondary voltage of the main transformer 3 becomes higher when the generator load switch 4 is opened. Tap changer 1 under load of main transformer 3
3, when the generator load switch 4 is closed, an in-house direct connection transformer 6
And an on-load tap changer 16 of the in-house direct-coupled transformer 6 for adjusting the secondary side voltage to be lower.
The other configuration is the same as that of the conventional example shown in FIG. 9, so that the same components are denoted by the same reference numerals and description thereof will be omitted.

In FIG. 1, during plant operation, the generator load switch 4 is closed and power generated by the main generator 5 is transmitted to the switchyard bus 1 via the main transformer 3 and the main breaker 2A. Have been. On the other hand, in-plant power is supplied from the main generator 5 to the service bus 7 via the in-plant direct-connection transformer 6 and the circuit breaker 11A. The secondary side of the in-house direct connection transformer 6 is branched, and the in-house power is supplied to the emergency bus 8 via the first connecting bus 14 and the circuit breaker 11C. Here, during the operation of the plant, the generated voltage of the main generator 5 is directly applied to the primary side of the in-house direct-coupled transformer 6, so that a relatively high in-house power supply voltage is obtained as it is. Accordingly, the secondary tap voltage of the in-house direct-coupled transformer 6 is induced to a lower voltage by the on-load tap changer 16 of the in-house direct-coupled transformer 6.

On the other hand, when the plant is started / stopped, the generator load switch 4 is in an open state, and the main generator 5 is disconnected from the main transformer 3 and the on-site directly connected transformer 6.
In this state, in-house power is supplied to the service bus 7 from the secondary side of the main transformer 3. Here, when the plant is started / stopped, the power supplied via the main transformer 3 is located at the end of the power transmission circuit, so that a relatively low local power supply voltage is obtained as it is. Therefore, the secondary tap voltage of the main transformer is induced to a higher voltage by the tap changer 13 at the time of load of the main transformer 3.

Then, the regular bus 7 to which the in-house power is supplied
When the power supply to the office stops, the emergency bus 8
Is supplied to the service bus 7 from the secondary side of the backup transformer 12A of the starting transformer circuit connected to the service bus 7 via the second connection bus 15.

Accordingly, in the normal operation range, the start-up transformer circuit is not required, and from the viewpoint of securing an emergency power supply,
The capacity can be selected by positioning as A, and the equipment capacity can be reduced. In addition, by installing the generator load switch 4, applying the on-load tap changer 16 to the in-house transformer 6, and applying the on-load tap changer 13 to the main transformer 3, the power supply equipment capacity in the office can be reduced. In addition to this, the fluctuation range of the in-house power supply voltage can be suppressed.

As described above, according to the first embodiment, the on / off operation of the generator load switch 4 allows the power supply from the main generator to be supplied from the main generator transmission circuit even when the plant is started or stopped. it can. Therefore, it is possible to provide a backup small-capacity backup circuit in place of the starting transformer circuit. In particular, the switching station bus 1
Is a power transmitting end during plant operation and a power receiving end when the plant is started and stopped. Therefore, depending on the operation mode, the fluctuation range of the power supply voltage is increased. Hour tap changer 13, 1
By providing 6, the fluctuation range of the in-house power supply voltage can be reduced.

Next, a second embodiment of the present invention will be described. FIG. 2 is a configuration diagram showing a second embodiment of the present invention. This second embodiment is different from the first embodiment shown in FIG. 1 in that the on-load tap changer 16 of the in-house direct-coupled transformer 6 is omitted. Other configurations are the same as those of the first embodiment shown in FIG. 1, and therefore, the same components are denoted by the same reference symbols and description thereof will be omitted.

In FIG. 2, during plant operation, the generator load switch 4 is in a closed state, and in-house power is supplied from the main generator 5 to the service bus 7 via the in-house transformer 6 and the circuit breaker 11A. I do. At the same time, power is supplied to the emergency bus 8 via the first connecting bus 14 and the circuit breaker 11C.

On the other hand, when the plant is started and stopped, the generator load switch 4 is in an open state, and the main generator 5 is disconnected from the main transformer 3 and the on-site transformer 6.
In this state, in-house power is supplied to the service bus 7 from the secondary side of the main transformer 3. Here, when the plant is started / stopped, the power supplied via the main transformer 3 is located at the end of the power transmission circuit, so that a relatively low local power supply voltage is obtained as it is. Therefore, the secondary tap voltage of the main transformer is induced to a higher voltage by the tap changer 13 at the time of load of the main transformer 3.

Then, the regular bus 7 to which the in-house power is supplied
When the power supply to the office stops, the emergency bus 8
Is supplied to the service bus 7 from the secondary side of the backup transformer 12A of the starting transformer circuit connected to the service bus 7 via the second connection bus 15.

As described above, in the second embodiment,
In the first embodiment, the on-load tap changer 16 of the in-house direct connection transformer 6 is omitted, and the in-house power supply equipment is simplified. That is, the generator load switch 4 is introduced, and the tap transformer 13 at the time of load is provided in the main transformer 3 so as to reduce the capacity of the facility power supply and to suppress the fluctuation range of the facility power supply voltage. In this case, during the operation of the plant, the voltage generated by the main generator 5 is directly connected to the in-house transformer 6.
, And a relatively high local power supply voltage is obtained.

Next, a third embodiment of the present invention will be described. FIG. 3 is a configuration diagram showing a third embodiment of the present invention. This third embodiment is different from the first embodiment shown in FIG. 1 in that the on-load tap changer 1 of the main transformer 3 is provided.
3 is omitted. Other configurations are the same as those of the first embodiment shown in FIG. 1, and therefore, the same components are denoted by the same reference symbols and description thereof will be omitted.

In FIG. 3, the generator load switch 4 is closed, and the power generated by the main generator 5 is transmitted to the switchyard bus 1 via the main transformer 3 and the main circuit breaker 2A. On the other hand, in-plant power is supplied from the main generator 5 to the service bus 7 via the in-plant direct-connection transformer 6 and the circuit breaker 11A. The secondary side of the in-house direct connection transformer 6 is branched, and the in-house power is supplied to the emergency bus 8 via the first connecting bus 14 and the circuit breaker 11C. Here, during the operation of the plant, the generated voltage of the main generator 5 is directly applied to the primary side of the in-house direct-coupled transformer 6, so that a relatively high in-house power supply voltage is obtained as it is. Accordingly, the secondary tap voltage of the in-house direct-coupled transformer 6 is induced to a lower voltage by the on-load tap changer 16 of the in-house direct-coupled transformer 6.

On the other hand, when the plant is started / stopped, the generator load switch 4 is in an open state, and the main generator 5 is disconnected from the main transformer 3 and the on-site directly connected transformer 6.
In this state, in-house power is supplied to the service bus 7 from the secondary side of the main transformer 3. Here, when the plant is started / stopped, the power supplied via the main transformer 3 is located at the end of the power transmission circuit, so that a relatively low local power supply voltage is obtained as it is. Therefore, the secondary tap voltage of the main transformer 6 is induced to a higher voltage by the on-load tap changer 16 of the in-house direct-coupled transformer 6.

Then, the regular bus 7 to which the in-house power is supplied
When the power supply to the office stops, the emergency bus 8
Is supplied to the service bus 7 from the secondary side of the backup transformer 12A of the starting transformer circuit connected to the service bus 7 via the second connection bus 15.

As described above, in the third embodiment,
The first embodiment is different from the first embodiment in that the on-load tap changer 13 of the main transformer 3 is omitted to simplify the in-house power supply equipment. That is, the generator load switch 4 is introduced and the on-site direct-connection transformer 6 is provided with the on-load tap changer 16 to reduce the on-site power supply equipment capacity as in the first embodiment and to reduce the in-station power supply voltage. The fluctuation range is also suppressed.

Next, a fourth embodiment of the present invention will be described. FIG. 4 is a configuration diagram showing a fourth embodiment of the present invention. In the fourth embodiment, the main transformer 3 and the main circuit breaker 2 of the generator transmission circuit for transmitting power from the main generator 5 to the switchyard bus 1 via the main transformer 3 and the main circuit breaker 2 are connected in parallel. The two sets of generator load switches 4 are provided between the secondary side of each of the main transformers 3 provided in parallel and the main generator 5, and are opened under predetermined conditions. Between the secondary side of the power generator and the generator load switch 4 for supplying power in the office, two series of direct-connected transformers 6 are provided. And two sets of service buses 7 each of which is supplied with in-house power from the main generator 5 via an in-house direct-coupled transformer 6,
At the time of starting or stopping the plant, there is provided a communication bus 10 for supplying the internal power from one service bus 7 to the other service bus 7, and the power supply to the other service bus 7 is provided to one of the two series of service buses 7. An emergency bus 8 is provided for supplying an emergency power supply when the supply is stopped.

In FIG. 4, during operation of the plant, electric power is supplied from the two generator load switches 4 to the switch bus 1 via the main transformer 3 and the main circuit breaker 2, respectively. In addition, the main power generator 5 is connected to each of the two generators via the generator load switch 4 and the on-site direct-coupled transformer 6 and the on-site power supply via the on-site direct-coupled transformer 6 and the circuit breakers 11A and 11B. Is supplied to the service bus 7 of the common bus.

Each of the service buses 7 is connected by a communication bus 10 via a circuit breaker 11C and a circuit breaker 11D.
The emergency bus 8 is connected to one service bus via a circuit breaker 11E. An emergency generator 9 is connected to the emergency bus 8 via a circuit breaker 11F.

When one of the two sets of generator load switches is opened under predetermined conditions, the generator bus is closed from the generator load switch 4 side to the service bus 7 via the in-house direct connection transformer 6. Power is supplied to the site. An in-house power is supplied to the other service bus 7 via a communication bus 10. On the other hand, when the supply of the in-house power to the service bus 7 is stopped, the emergency in-house power is supplied to the service bus 7 from the emergency bus 8.

Now, it is assumed that one of the two main transformers 3 fails during the operation of the plant. In this case, the main circuit breaker 2 and the generator load switch 4 on the main transformer 3 side are opened. As a result, the failed main transformer 3 is brought into a no-voltage state, so that a repair work can be performed. On the other hand, the output of the main generator 5 is output to the switchyard bus 1 via the other sound main transformer 3, so that it is not necessary to stop the main generator 5 and the plant can be operated continuously.

In the case of an accident, the following measures are taken. In the case where the power supply of the service bus 7 is lost due to a failure of one system of the in-house direct-connection transformer 6, the power is supplied to the other service bus 7 by the communication bus 10. If the main generator 5 fails, the generator load switch 4 is opened,
This corresponds to supplying power in the office from the switch bus 1. In the case where the power supply in the office is cut off due to multiple failures or the like, the emergency power generator 9 is started and the internal power supply is supplied from the emergency bus 8 to cope with the situation.

As described above, in the fourth embodiment, by preparing two main circuit breakers 2, two main transformers 3, and two generator load switches 4, each one of the main transformers 3 can be broken or inspected. It is possible to respond to. That is, when one of the main transformers fails during the operation of the plant or during inspection, the generator load switch 4 on the failure / inspection side and the main circuit breaker 2 are opened, and the main transformer 3 is connected to the main transformer 3. The output from the generator 5 is stopped, and the other generator load switch 4
Power is supplied to the in-house transformer 6 through

Therefore, even if the main transformer 3 fails during the operation of the plant, the output of the main generator 5 can be transmitted from the other main transformer 3 to the switching station bus 1, so that if the plant is stopped, In addition, since the generator load switch 4 downstream of the main transformer 3 and the main circuit breaker 2 upstream can be opened, the main transformer 3 can be repaired. As a result, the power supply structure can cope with various accidents required for the power supply equipment in the nuclear power plant.

Next, a fifth embodiment of the present invention will be described. FIG. 5 is a configuration diagram showing a fifth embodiment of the present invention. In the fifth embodiment, the main transformer 3 and the main circuit breaker 2 of the generator transmission circuit for transmitting power from the main generator 5 to the switchyard bus 1 via the main transformer 3 and the main circuit breaker 2 are connected in parallel. A two-series generator load switch, which is opened under predetermined conditions, is provided between the secondary side of each main transformer 3 and the main generator 5 provided in parallel. Between the secondary side and the generator load switch 4, there are provided two series of in-house direct-coupled transformers 6 for supplying in-house power, respectively. Is provided, and during the operation of the plant, the in-house power is supplied from the other of the two series of in-house direct-coupled transformers 6 and the emergency in-house power is stopped when the in-house power supply to the working bus 7 is stopped. An emergency bus 8 to be supplied is provided, and the emergency bus 8 is connected to the secondary side of one A first contact bus 14 for connecting the bus 8 is provided, is provided with a second contact bus 15 that connects the secondary side of the other house direct transformer 6 and a common bus 7.

In FIG. 5, during operation of the plant, power is supplied from each of the two generator load switches 4 to the switch bus 1 via the main transformer 3 and the main circuit breaker 2, respectively. In addition, power from the main generator 5 is supplied to the service bus 7 from one of the two series of direct connection transformers 6 via the generator load switch 4 to the service bus 7 via the circuit breaker 11A. In-house power is supplied to the emergency bus 8 from the other of the series-connected in-house transformers 6 via the circuit breaker 11B. The secondary side of the in-house direct connection transformer 6 is branched. That is, the in-house power is supplied to the emergency bus 8 via the first communication bus 14 and the circuit breaker 11C, while the service bus 7 is supplied via the second communication bus 15 and the circuit breaker 11D. Power is supplied to the office. An emergency generator 9 is connected to the emergency bus 8 via a circuit breaker 11E.

When any one of the two sets of generator load switches 4 is opened under predetermined conditions, the service bus 7 is connected from the closed generator load switch 4 via the in-house direct-coupled transformer 6. Alternatively, the internal power is supplied to the emergency bus 8, the internal power is supplied from the service bus 7 via the first connecting bus 14 to the emergency bus 8, and the emergency bus 8 is supplied from the emergency bus 8 via the second connecting bus 15. The internal power is supplied to the service bus 7.

Now, it is assumed that one of the two main transformers 3 fails during the operation of the plant. In this case, the main circuit breaker 2 and the generator load switch 4 on the side of the main transformer 3 are opened, and the main transformer 3 is in a no-voltage state, so that a repair work can be performed. On the other hand, since the output of the main generator 5 is output to the switching station bus (transmission system) 1 via the other main transformer 3, it is not necessary to stop the main generator 5 and the plant can be operated continuously. Become.

In the event of an accident, the following measures are taken. If the power supply of the service bus 7 is lost due to a failure of one of the transformers 6 in the station, the power is supplied to the other emergency bus 8 through the communication bus 10. When the main generator 5 fails, the generator load switch 4 is opened, and power is supplied from the switch station bus (power transmission system) 1 to the power station. In the case where the power supply in the office is cut off due to multiple failures or the like, the internal power supply is supplied from the emergency power generator 9 to the emergency bus 8 to cope with the situation.

As described above, in the fifth embodiment, one system of the service bus 7 can be reduced, and one system of the power system for the service system is reduced. ing.

Next, a sixth embodiment of the present invention will be described. FIG. 6 is a configuration diagram showing a sixth embodiment of the present invention. In the sixth embodiment, a plurality of main transformers and main breakers of a generator transmission circuit for transmitting power from a main generator to a switchyard bus via a main transformer and a main breaker are provided in parallel, and a plurality of series are provided. A plurality of generator load switches which are opened under predetermined conditions are provided between the secondary side of each of the provided main transformers and the generator, and two main transformers of each of the main transformers are provided. Two sets of in-house direct-connected transformers for supplying in-house power are provided between the secondary side of the power generator and its generator load switch, respectively. A service bus to which power is supplied from the main generator via the direct-connected transformer is provided, and a start-up transformer circuit for supplying the power to the service bus via the communication bus when the plant is started or stopped is provided. Things.

In FIG. 6, during operation of the plant, power from the main generator is transmitted to the switchyard bus 1 via the generator load switchgear 4, the main transformer 3 and the main breaker 2 of each system. I do. In addition, the in-plant power supply from the main generator 5 to the service bus 7A via the generator load switches 4A and 4B, the in-station direct-coupled transformers 6A and 6B, and the circuit breakers 11A and 11B in each of two of the plurality of systems. Supplied. The service bus 7A is connected to the other service bus 7B via a circuit breaker 11D and a circuit breaker 11E via a connecting bus 10, and the other service bus 7B is connected to the switchboard bus 1 from the main circuit breaker 2
Z, power is supplied via the auxiliary transformer 12A and the circuit breaker 11C.

A circuit breaker 11 is connected to the other service bus 7B.
An emergency bus 8 is connected via F, and an emergency generator 9 is connected to the emergency bus 8 via a circuit breaker 11G. During normal operation, the circuit breaker 11D and the circuit breaker 11
E is open.

When any one of the two sets of generator load switches 4 is opened under predetermined conditions, the in-house power is supplied to the service bus 7A from the closed generator load switch 4 side. When the plant is started or stopped, the in-house power is supplied from the starting transformer circuit to the service bus 7A via the communication bus 10.

If one of the main transformers 3 in a plurality of systems fails during the operation of the plant, in this case, the main breaker 2 and the generator load switch 4 on the main transformer 3 side are opened. Then, the failed main transformer 3 is brought into a non-voltage state, so that a repair work can be performed. On the other hand, since the output of the main generator 5 is output to the switchyard bus (power transmission system) 1 via the other main transformer 3, it is not necessary to stop the main generator 5 and the plant operation can be continued. .

In the event of an accident, the following measures are taken. In the case where one system of the in-house direct connection transformer 6 fails, the in-house power supply is supplied from the normal in-house direct connection transformer 6 to the service bus 7A. When both the transformers 6A and 6B in the office are out of order and the power supply of the service bus 7A is lost, the power is supplied from the other service bus 7B at the communication bus 10 to cope with the situation. When the main generator 5 is out of order, all the generator load switches 4 are opened, and the power is supplied from the switch bus 1 to the power station.

Further, since the power transmission circuit is divided into a plurality of systems, the reliability for one failure is increased. For example, if n generator load switches 4 and main transformers 3 are provided and the installed capacity per unit is 100% / (n-1), 100% power transmission is always possible even in the case of one failure. Becomes In a plant having a 33% turbine bypass capacity, three generator load switches 4 and a main transformer 3 are provided to reduce the installed capacity per unit to 100% /
Even if it is 3 ≒ 33%, continuous operation of the plant is possible. Furthermore, by dividing into n units, the rated capacity of the generator load switch 4 per unit can be reduced, and a system configuration that can cope with an increase in the power generation output of the plant in the future can be constructed. In the case where the power supply in the station is cut off due to multiple failures, the power is supplied from the emergency generator 9 to the emergency bus 8 and further supplied to the service buses 7A and 7B.

As described above, in the sixth embodiment, by preparing three or more main transformers 3 and three or more generator load switches 4, each of the main transformers 3 can cope with failure or inspection. It is possible. That is, when the main transformer 3 and the generator load switch 4 are three or more systems, and one of the main transformers 3 fails during the plant operation, the main transformer 3 is connected to the failed generator load switch 4. The output of the main generator 5 is stopped, and the internal load is supplied to the internal transformer 6 via the other generator load switch 4. Therefore, it becomes possible to expand the applicable range of operation of the in-house power supply equipment.

Next, an example of the interlock of the in-house power supply equipment of the present invention is shown in FIG. FIG. 7 shows an interlock diagram relating to the operation of the in-house power supply equipment in which the generator load switch 4 is provided between the main generator 5 and the main transformer 3.

When the main circuit fault S1 of the generator power transmission circuit occurs, the generator protection lockout relay S3 operates, and the main circuit breaker 2 of the generator power transmission circuit in which the fault has occurred.
GIS open command S4 for releasing the command is output. At the same time, a circuit breaker 11
A bus switching command S5 for performing the above operation is output.

On the other hand, when the generator accident S2 of the main generator 5 occurs, the generator load switch lockout relay S
9 operates and outputs a GLS opening command S10 for opening the generator load switch 4. Similarly, when a turbine failure (Tb failure) S6 occurs, the turbine protection lockout relay S7 operates to output a GLS open command S10 for opening the generator load switch 4. Similarly, when the coolant loss accident (LOCA) S8 of the reactor occurs, the GLS opening command S1 for opening the generator load switch 4 is similarly obtained.
Outputs 0.

As described above, by treating the generator load switch 4 as a circuit breaker, in addition to the turbine protection lockout relay-86TG operation and the LOCA occurrence condition, the generator electrical failure and power generation except for the main circuit-related electrical failure are generated. The generator load switch lockout relay 86
The generator load switch 4 is opened by the GLS, and the main circuit breaker 2 is not opened, so that the in-plant power source can be secured through the main transformer 3 and the in-station direct-coupled transformer 6.

As a result, it is possible to reduce the frequency of switching the bus in the office, reduce the frequency of fluctuations in the in-house power supply system, and reduce the stress on the load side. Therefore, an improvement in the reliability of the in-house power supply system can be expected. .

Next, another example of the interlock of the in-house power supply equipment of the present invention is shown in FIG. This is an interlock that enables the generator load switch 4 to handle all requests related to main circuit-related failures and shutdowns from the main generator 5 other than electrical failures. By reducing the frequency, it is possible to rationalize backup power supply equipment.

When the main circuit fault S1 or the generator fault S2 of the generator power transmission circuit occurs, the generator protection lockout relay S3 operates, and the main circuit breaker 2 of the generator power transmission circuit in which the fault has occurred is activated. The GIS opening command S4 for opening is output. At the same time, a bus switching command S5 for operating the circuit breaker 11 to supply the in-house power to the service bus 7
Is output. On the other hand, when a turbine failure (Tb failure) S6 occurs, the turbine protection lockout relay S7 operates to output a GLS open command S10 for opening the generator load switch 4. In addition, the loss of coolant at the reactor (L
Similarly, when the OCA S8 occurs, the GLS opening command S10 for opening the generator load switch 4 is output.

As described above, by treating the generator load switch 4 as a switch, in the event of a failure other than an electrical failure around the generator, the generator protection switch-out relay-86TG operation and LOCA generation conditions cause The load switch 4 is opened and the main circuit breaker 2 is not opened, so that the in-house power supply can be secured through the main transformer 3 and the in-house direct-coupled transformer 6. In the case of an electrical failure, opening the main circuit breaker 2 uniformly will cause switching of the in-house bus. However, as compared with the conventional interlock, a relatively simple interlock is used without adding a lockout relay. With the configuration, it is possible to reduce the frequency of in-house bus switching. As a result, the frequency of fluctuation of the power supply system in the office can be reduced, and the stress on the load side can be reduced, so that the reliability of the power supply system in the office can be expected to be improved.

[0075]

As described above, according to the present invention, in an in-house power supply system of a nuclear power plant, an independent circuit (start-up transformer circuit) for starting and stopping the plant is basically unnecessary, and Equipment capacity and the amount of material in the configuration can be reduced. In addition, one of the main transformers of nuclear power plants
Even during failures and inspections, repair work can be performed while plant operation is continued, and the plant operation rate can be improved.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of an on-site power supply facility of a nuclear power plant according to a first embodiment of the present invention.

FIG. 2 is a configuration diagram of an in-house power supply facility of a nuclear power plant according to a second embodiment of the present invention.

FIG. 3 is a configuration diagram of an on-site power supply facility of a nuclear power plant according to a third embodiment of the present invention.

FIG. 4 is a configuration diagram of an in-house power supply facility of a nuclear power plant according to a fourth embodiment of the present invention.

FIG. 5 is a configuration diagram of an in-house power supply system of a nuclear power plant according to a fifth embodiment of the present invention.

FIG. 6 is a configuration diagram of an in-house power supply facility of a nuclear power plant according to a sixth embodiment of the present invention.

FIG. 7 is an interlock diagram showing an example of an interlock of an in-house power supply facility in the boiling water nuclear power plant according to the present invention.

FIG. 8 is an interlock diagram showing another example of the interlock of the in-house power supply equipment in the boiling water nuclear power plant of the present invention.

FIG. 9 is a system diagram of an in-house power supply system of a conventional boiling water nuclear power plant.

FIG. 10 is an interlock diagram of an in-house power supply facility in a conventional boiling water nuclear power plant.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Switch station bus 2 Main circuit breaker 3 Main transformer 4 Generator load switch 5 Main generator 6 Directly connected transformer 7 Service bus 8 Emergency bus 9 Emergency generator 10 Communication bus 11 Circuit breaker 12 Starting transformer 12A Auxiliary transformer 13 Main transformer load tap changer 14 First connection bus 15 Second connection bus 16 Directly connected transformer load tap changer

Claims (8)

[Claims] 1. During plant operation, power is supplied from a main generator via a main transformer to a switchyard bus via a main transformer and a main circuit breaker. In the on-site power supply facility of a nuclear power plant, which supplies on-site power from a starting transformer circuit at the time of plant start-up and shutdown, a service bus to which the on-site power is supplied, and an in-house power supply to the service bus An emergency bus for supplying emergency local power when the supply is stopped, a first connecting bus connecting the secondary side of the local direct-connected transformer and the emergency bus, and a start-up transformer circuit. A second connecting the secondary side of the backup transformer and the service bus
A connection bus, a generator load switch that opens under predetermined conditions and disconnects the main generator from the main transformer and the on-site direct-coupled transformer, and two of the main transformer when the generator load switch is opened. An on-load tap changer for the main transformer for adjusting the secondary side voltage to be higher, and an adjustment for lowering the secondary side voltage of the in-house direct connection transformer when the generator load switch is closed. And a tap changer at the time of loading of the in-house direct-coupled transformer. 2. During plant operation, power is supplied from the main generator via a main transformer to a switchyard bus via a main transformer and a main circuit breaker. In the on-site power supply facility of a nuclear power plant, which supplies on-site power from a starting transformer circuit at the time of plant start-up and shutdown, a service bus to which the on-site power is supplied, and an in-house power supply to the service bus An emergency bus for supplying emergency local power when the supply is stopped, a first connecting bus connecting the secondary side of the local direct-connected transformer and the emergency bus, and a start-up transformer circuit. A second connecting the secondary side of the backup transformer and the service bus
A connection bus, a generator load switch that opens under predetermined conditions and disconnects the main generator from the main transformer and the on-site direct-coupled transformer, and two of the main transformer when the generator load switch is opened. An on-site power supply facility for a nuclear power plant, comprising: a tap changer at load of the main transformer, which adjusts the secondary side voltage to be higher. 3. During plant operation, power is supplied from the main generator via a main transformer to the switchyard bus via a main transformer and a main circuit breaker. In the on-site power supply facility of a nuclear power plant, which supplies on-site power from a starting transformer circuit at the time of plant start-up and shutdown, a service bus to which the on-site power is supplied, and an in-house power supply to the service bus An emergency bus for supplying emergency local power when the supply is stopped, a first connecting bus connecting the secondary side of the local direct-connected transformer and the emergency bus, and a start-up transformer circuit. A second connecting the secondary side of the backup transformer and the service bus
A connection bus, a generator load switch that opens under predetermined conditions and disconnects the main generator from the main transformer and the in-plant direct-connect transformer, and the in-plant direct-connect transformer when the generator load switch opens. When the generator load switch is closed, the secondary voltage of the in-house direct-coupled transformer is adjusted to be lower when the in-house direct-coupled transformer is loaded. An on-site power supply facility for a nuclear power plant, comprising a tap changer. 4. The main transformer and the main circuit breaker of the generator transmission circuit for transmitting power from the main generator to the switchyard bus via the main transformer and the main circuit breaker are provided in parallel, and each provided in parallel. A two-series generator load switch, which is provided between the secondary side of the main transformer and the main generator and opens under predetermined conditions, the secondary side of each of the main transformers and the generator load Two series of on-site direct-connection transformers connected between the switch and the respective on-site power supply and, during plant operation, mainly connected via the two series of generator load switches and on-site direct-connection transformers. Any one of two series buses, each of which is supplied with in-house power from a generator, a communication bus that supplies in-house power from one service bus to the other service bus when the plant is started or stopped, and the two-system service bus Connected to one or the other An on-site power supply facility for a nuclear power plant, comprising: an emergency bus for supplying emergency on-site power when supply of on-site power to the bus is stopped. 5. The main transformer and the main circuit breaker of a generator transmission circuit for transmitting power from a main generator to a switchyard bus via a main transformer and a main circuit breaker, wherein the main transformer and the main circuit breaker are provided in parallel. A two-series generator load switch, which is provided between the secondary side of the main transformer and the main generator and opens under predetermined conditions, the secondary side of each of the main transformers and the generator load A two-line in-house direct-connection transformer connected between a switch and each of which supplies in-house power; and a service bus to which the in-house power is supplied from one of the two lines of the in-house power transformer during plant operation. An emergency bus that supplies emergency power when the power is supplied from the other of the two series of direct-connected transformers during the operation of the plant and power supply to the service bus is stopped. The secondary side of the in-house direct-coupled transformer and the A nuclear power plant, comprising: a first connecting bus connecting a service bus; and a second connecting bus connecting the secondary side of the other in-house direct-coupled transformer and the service bus. On-site power supply equipment. 6. A plurality of said main transformers and said main circuit breakers of a generator transmission circuit for transmitting power from a main generator to a switchyard bus via a main transformer and a main circuit breaker are provided in parallel and provided in parallel. A plurality of series generator load switches provided between the secondary side of each main transformer and the generator and opened under predetermined conditions, and two main transformers of the main transformers Two series of on-site transformers connected between the secondary side of the unit and its generator load switch for supplying in-house power, and each of the two series of generator load switching during plant operation A service bus to which in-house power is supplied from a main generator via a unit and an in-house direct-coupled transformer, and a start-up transformer circuit for supplying the in-house power to the service bus via a communication bus when the plant is started or stopped. Characterized by having Power supply facilities for nuclear power plants. 7. The generator load switch according to claim 1, wherein the generator load switch is opened when any of a main generator accident, a turbine failure, and a reactor coolant loss accident occurs. An in-house power supply facility for a nuclear power plant according to claim 6. 8. The generator load switch according to claim 1, wherein the generator load switch is opened when one of a turbine failure and a reactor coolant loss accident occurs. Power supply facilities for nuclear power plants in Japan.