JP2004093577A - Control rod controller system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce a deviations in positions of control rods during a drive and at a stop when the control rods are gang-driven in the case wherein induction motors are driven by on/off control to drive the control rods. <P>SOLUTION: A plurality of the control rods 6 are installed in a nuclear reactor 5, which is an object to be controlled in a system. Each drive source of the control rods 6 is connected to the induction motor 7. The position of the control rod is controlled by a semiconductor switching element 13B of a control rod drive assisting board 3 for controlling a power supply to an electromagnetic brake 15 and the induction motor 7. When the position of the control rod reaches a specified value designating a position before a target position, the power supply to the motor 7 and the brake 15 is cut off by the switching element 13B to activate the brake 15. <P>COPYRIGHT: (C)2004,JPO

Description

The present invention relates to a control rod control device, and more particularly to a control rod control device used for a boiling water reactor.

(4) Output control of the improved boiling water nuclear power plant (ABWR) is performed by operating control rods with an electrically driven control rod drive device. The electric drive type control rod driving device includes a step motor, a ball screw screw connected to the step motor, a ball nut meshing with the ball screw screw, and a connection rod attached to the ball nut and extending in the axial direction. Fine drive is possible. This control rod driving device has an electromagnetic brake connected to a step motor rotation shaft. A connecting rod is connected to a control rod in the reactor. Reactor power is controlled by moving control rods into and out of the reactor core. One of the control requests for the reactor power is to stop the control rods with as little delay time as possible based on a control rod stop request from an operator.

The operation of the control rods is performed based on the control rod operation procedure in response to an operation command from the control rod operation monitoring panel of the central control room. The step motor operates by a pulse signal from a speed control circuit. The speed control of the step motor is performed by changing the frequency of the pulse current. When the control rod is stopped, a pulse signal having a low frequency is output from the speed control circuit to reduce the number of rotations in order to reduce the rotation of the step motor. When the step motor finally stops, the electromagnetic brake operates. The electromagnetic brake does not operate at the same time while the control rod is being driven, and does not operate during the step motor stop control. The operation of the electromagnetic brake prevents the control rod from moving due to its own weight after the step motor is stopped. In addition, as a technique related to the control rod operation by the step motor, there are techniques described in Japanese Patent Application Laid-Open Nos. 55-143604 and 57-208880.

場合 If the control rods can be finely driven by the step motor, many step motor power panels and laid cables are required. For this reason, application of an induction motor instead of a step motor is being studied. The induction motor includes a primary-side stator and a secondary-side rotor. The secondary winding receives electric energy from the stator by electromagnetic induction, converts the electric energy into mechanical energy through an air gap, rotates the rotor, and generates mechanical power.

誘導 This induction motor has a different principle from a step motor, and cannot control the number of revolutions with a pulse signal like a step motor. Further, the detent torque of the induction motor is substantially equal to 0, and the rotor rotates even if the current on the stator side is set to 0. Therefore, in order to stop the induction motor, a braking brake that is externally stopped by friction or the like or a braking mechanism that dynamically controls the phase of the exciting current to perform braking is required. A technique related to control rod drive by an induction motor is disclosed in Japanese Patent Application Laid-Open No. 61-59287. This is to control the phase of the exciting current of the induction motor to apply dynamic braking to improve the positioning accuracy when stopping.

JP-A-6-300878

ギ ャ A gang operation that operates multiple control rods simultaneously has been considered in order to reduce the start-up time and power control time of the reactor. Since the stepping motor rotates by an amount corresponding to the number of pulses to be added, when the stepping motor is used, the control rod can be accurately moved to the target position by controlling the number of pulses. Therefore, during the gang operation, the plurality of control rods can be simultaneously moved to the same target position.

When an induction motor is applied, if the control rod is driven by driving the induction motor by on / off control, the power converter and the speed control device required in the case of the step motor become unnecessary, and the equipment can be simplified and reduced. . However, the position of the induction motor is maintained by the braking force of the electromagnetic brake, and this braking force must be released when the induction motor is started. If the start timing of each induction motor and the operation timing of the electromagnetic brake deviate at the start of the gang operation, the process of increasing the rotation speed at the start of each induction motor differs. For this reason, the positions of the respective control rods being driven are shifted. Furthermore, since the stop position is determined depending on the braking performance at the time of stopping, if the operation timing of each electromagnetic brake is shifted, the position of each control rod at the time of stopping will be different. That is, when an induction motor is applied to the control rod drive source, there is a possibility that a deviation occurs in the position of each control rod during driving and during stoppage in the gang operation. If there is a deviation in the position of each control rod, the symmetry of the power distribution may be broken and thermal stress may be applied to the fuel. Conventionally, no consideration has been given to this point.

An object of the present invention is to provide a control rod control device that can reduce a deviation of a stop position of each control rod during a gang operation when an induction motor is applied to the control rod drive device.

A feature of the first invention for achieving the above object is that a plurality of control rod driving devices connected to control rods and driven by the induction motor are provided for each of the control rod driving devices, and the induction motor is provided by stopping supply of power. An electromagnetic brake for stopping rotation, control rod operation command output means for outputting operation commands to a plurality of control rods to be gang operated, and the operation from the control rod operation command output means provided for each control rod drive device A power cutoff determining means for inputting a command and outputting the control command and stopping the output based on the control rod operation target position and the measured control rod position included in the operation command; and The power supply to the induction motor and the electromagnetic brake is turned on based on the output operation command, and the power cutoff determination unit stops outputting the operation command, and Induction motor and having a semiconductor switching element to turn off the power supply to the electromagnetic brake, in that a power control unit provided for each of the control rod drive.

Since the operation delay of the semiconductor switching element is extremely short and its variation is small, the semiconductor switching element is used to turn on and off the power supply to the induction motor and the electromagnetic brake, thereby starting the induction motor for gang operation and starting the electromagnetic brake. The difference between the timing of the braking force release and the timing of the stop of the rotation of the induction motor due to the actuation of the braking force of the electromagnetic brake is reduced in each control rod performing the gang operation. For this reason, when the induction motor is applied to the control rod driving device, the deviation of the stop position of each control rod during the gang operation can be reduced. For this reason, the reactor power at the position of each control rod that has been gang operated in the horizontal cross section of the core can be made substantially uniform, and the core operation management in consideration of the thermal limit value and the like can be easily performed.

The feature of the second invention for achieving the above object is that the operation command from the control rod operation command output means is provided for each control rod driving device, and the control rod operation target position and the control rod operation target position included in the operation command are input. When the measured control rod position reaches a power cutoff position set based on the position of the control rod at the head position among the plurality of gang operated control rods, outputting the input operation command And a power cutoff determining means for stopping the operation.

When the measured control rod position reaches the power cutoff position set based on the control rod operation target position and the position of the control rod at the head position, the output of the input operation command is stopped. Even if there is a difference in the movement of the control rod by each control rod driving device that operates each control rod (for example, the degree of engagement with the ball screw nut in the control rod driving device, drive history, aging, etc.) ), The difference in the stop position between the control rods during the gang operation can be significantly reduced.

A feature of a third invention for achieving the above object is that the power cutoff position is a movement amount of the control rod from the control rod operation target position to a stop of power supply to the induction motor to a stop of rotation of the induction motor. Is set to a value obtained by subtracting.

制 御 The control rod moves slightly from the stop of the power supply to the induction motor to the stop of the rotation of the induction motor. For this reason, when the output of the operation command input when the measured control rod position reaches the control rod operation target position is stopped, the control rod stops beyond the control rod operation target position. By setting the power cutoff position to a value obtained by subtracting the amount of control rod movement from the stop of power supply to the induction motor to the stop of rotation of the induction motor from the control rod operation target position, the control rod operates at the control rod operation target. Stopping beyond the position can be prevented, and each control rod performing a gang operation can be accurately stopped at the control rod operation target position.

A feature of the fourth invention for achieving the above object is that the operation command from the control rod operation command output means is provided for each control rod driving device, and the control rod operation target position included in the operation command is The first control rod setting position set based on the second control rod setting position set based on the position of the control rod at the leading position among the plurality of control rods to be gang operated, When the measured control rod position coincides with the first control rod setting position or the second control rod setting position, there is provided a power cutoff determining means for stopping the output of the input operation command. The fourth invention has the same function and effect as the second invention.

A feature of a fifth invention for achieving the above object is that the power cutoff determining means is configured to control the first control rod operation based on a control rod operation target position included in the operation command input from the control rod operation command output means. Means for setting a set position, means for determining the position of the control rod at the leading position among the plurality of control rods to be gang operated, and greater than the obtained position of the control rod at the leading position. Means for setting the second control rod setting position, means for holding the second control rod setting position when the first control rod setting position coincides with the second control rod setting position, And a means for stopping the output of the input operation command when the measured control rod position matches the second control rod set position.

Means for setting a second control rod setting position larger than the obtained position of the control rod at the leading position, and a second control rod when the first control rod setting position matches the second control rod setting position It has means for holding the set position, and when the measured control rod position matches the held second control rod set position, the output of the input operation command is stopped. Since the target value during the movement of the control rod does not deviate significantly from the current position of the moving control rod until the second control rod set position coincides, a control rod stop command is input by a manual command of the operator. At this time, the control rod can be stopped without causing an overrun from the control rod position at the time when the control rod stop command is input. As an example in which an operator inputs a control rod stop command by a manual command, for example, there is a case where a neutron flux rapidly rises.

A feature of a sixth invention for achieving the above object is that the first control rod setting position is such that the control rod is set from the control rod operation target position to a stop of power supply to the induction motor to a stop of rotation of the induction motor. And the second control rod setting position is set to a value obtained by adding a control rod movement amount equal to or greater than the control rod movement amount to the position of the control rod at the leading position. It is in.

By setting the power cutoff position to a value obtained by subtracting the amount of movement of the control rod from the stop of power supply to the induction motor to the stop of rotation of the induction motor from the control rod operation target position, as in the third invention, Each of the control rods performing the gang operation can be accurately stopped at the control rod operation target position. Further, since the second control rod setting position is set to a value obtained by adding the control rod movement amount equal to or more than the control rod movement amount to the position of the control rod at the leading position, a control rod stop command is input by a manual command. In this case, the control rod can be stopped by significantly reducing the amount of overrun from the control rod position at the time when the control rod stop command is input.

A feature of the seventh invention for achieving the above object is that the operation command from the control rod operation command output means is provided for each control rod driving device, and the control rod operation target position and the control rod operation target position included in the operation command are input. Power cutoff determining means for outputting the control command and stopping the output based on the measured control rod position; and turning on power supply to the induction motor based on the operation command output from the power cutoff determining means. And a first power control means provided for each control rod driving device, comprising: a first semiconductor switching element for turning off power supply to the induction motor when the output of the operation command is stopped by the power cutoff determination means. A rectifier connected to an AC power supply for converting AC to DC, and power supply from the rectifier to the electromagnetic brake by stopping output of the control command by the power cutoff determining means. A second semiconductor switching element is turned off, in that a second power control means provided for each of the control rod drive.

(4) Since a direct current is supplied to the electromagnetic brake via the second semiconductor switching element with the rectifying device, the time from the activation of the electromagnetic brake to the stop of the induction motor is shorter. As a result, the moving distance from the time when the electromagnetic brake is actuated to the time when the control rod stops is shortened, so that the influence of the load fluctuation of the control rod driving device is hardly affected, and the positioning accuracy of the control rod to the control rod operation target position is reduced. Is further improved.

The feature of the eighth invention for achieving the above object is that the operation command from the control rod operation command output means is provided for each control rod driving device, and the control rod operation target position and the control rod operation target position included in the operation command are input. When the measured control rod position reaches a power cutoff position set based on the position of the control rod at the head position among the plurality of gang operated control rods, outputting the input operation command And a power cutoff determining means for stopping the operation. The eighth invention produces the function and effect obtained by the features of the second invention.

A feature of a ninth aspect of the present invention that achieves the above object is that the power cutoff position is a movement amount of the control rod from the control rod operation target position to a stop of power supply to the induction motor to a stop of rotation of the induction motor. Is a value obtained by subtracting The ninth aspect of the invention has the effect obtained by the features of the third aspect of the invention.

A feature of the tenth invention for achieving the above object is that the operation command from the control rod operation command output means is provided for each control rod driving device, and the control rod operation target position included in the operation command is The first control rod setting position set based on the second control rod setting position set based on the position of the control rod at the leading position among the plurality of control rods to be gang operated, When the measured control rod position coincides with the first control rod setting position or the second control rod setting position, there is provided a power cutoff determining means for stopping the output of the input operation command. The tenth invention produces the effect obtained by the features of the fourth invention.

An eleventh aspect of the present invention to achieve the above object is characterized in that the power cutoff determining means is configured to control the first control rod based on a control rod operation target position included in the operation command input from the control rod operation command output means. Means for setting a set position, means for determining the position of the control rod at the leading position among the plurality of control rods to be gang operated, and greater than the obtained position of the control rod at the leading position. Means for setting the second control rod setting position, means for holding the second control rod setting position when the first control rod setting position coincides with the second control rod setting position, And a means for stopping the output of the input operation command when the measured control rod position matches the second control rod set position. The eleventh invention produces the function and effect obtained by the features of the fifth invention.

A feature of a twelfth invention that achieves the above object is that the first control rod setting position is such that the control rod from the control rod operation target position to a stop of power supply to the induction motor to a stop of rotation of the induction motor. The second control rod setting position is a value obtained by adding a control rod movement amount equal to or greater than the control rod movement amount to the position of the control rod at the head position. The twelfth invention produces the effect obtained by the feature of the sixth invention.

According to the first invention, the power supply to the induction motor and the electromagnetic brake is controlled on / off by using the semiconductor switching element. Therefore, when the induction motor is applied to the control rod driving device, each of the control rods is operated at the time of the gang operation. Can be reduced. For this reason, the reactor power at the position of each control rod that has been gang operated in the horizontal cross section of the core can be made substantially uniform, and the core operation management in consideration of the thermal limit value and the like can be easily performed.

According to the second aspect, even if there is a difference in the movement of the control rods by the corresponding control rod driving device that operates each control rod in the gang operation, the difference in the stop position between the control rods can be significantly reduced.

According to the third aspect, since the control rod can be prevented from stopping beyond the control rod operation target position, each control rod performing the gang operation can be accurately stopped at the control rod operation target position.

According to the fourth aspect, the same effect as that of the second aspect can be obtained.

According to the fifth aspect, when a control rod stop command is input by a manual command of the operator, the control rod can be stopped without causing an overrun from the control rod position when the control rod stop command is input. .

According to the sixth aspect, each control rod that is performing a gang operation can be accurately stopped at the control rod operation target position. Furthermore, when a control rod stop command is input as a manual command, the control rod can be stopped by significantly reducing the amount of overrun from the control rod position at the time the control rod stop command is input.

According to the seventh aspect, since the moving distance from when the electromagnetic brake is actuated to when the control rod stops is shortened, the influence of the load fluctuation of the control rod driving device is reduced, and the control rod operation target position of the control rod is reduced. The positioning accuracy for the head is further improved.

According to the eighth aspect, even if a difference occurs in the movement of the control rods by the corresponding control rod driving device that operates each control rod in the gang operation, the difference in the stop position between the control rods can be significantly reduced.

According to the ninth aspect, since the control rod can be prevented from stopping beyond the control rod operation target position, each control rod performing a gang operation can be accurately stopped at the control rod operation target position.

According to the tenth aspect, the same effects as those of the eighth aspect are obtained.

According to the eleventh aspect, when a control rod stop command is input by a manual command of an operator, the control rod can be stopped without causing an overrun from the control rod position at the time when the control rod stop instruction is input. .

According to the twelfth aspect, each control rod performing a gang operation can be accurately stopped at the control rod operation target position. Furthermore, when a control rod stop command is input as a manual command, the control rod can be stopped by significantly reducing the amount of overrun from the control rod position at the time the control rod stop command is input.

Hereinafter, a control rod control device according to an embodiment of the present invention will be described with reference to FIG. The control rod control device of the present embodiment includes a plurality of electrically driven control rod drive devices 18 using an induction motor. Each control rod driving device 18 includes an induction motor 7 and an electromagnetic brake 15 connected to a rotation shaft of the induction motor 7. Further, although not shown, the control rod driving device 18 includes a ball screw screw connected to the rotating shaft of the induction motor 7, a ball nut meshing with the ball screw screw, and a connecting rod attached to the ball nut and extending in the axial direction. Is provided.

In the ABWR reactor 5 to which the present embodiment is applied, a plurality of fuel assemblies 16 are installed while being immersed in cooling water 17. A plurality of control rods 6 are arranged between fuel assemblies 16 so as to be freely inserted and withdrawn. Each control rod 6 is connected to a connecting rod of a separate control rod drive 18 by a respective coupler (eg a gear or an electromagnetic clutch) 20. Each control rod 6 is operated by driving the induction motor 7 of the corresponding control rod driving device 18. A control rod position detector 8 for detecting the position of the control rod in the axial direction in the core is provided.

The control rod control device of the present embodiment is a control device having a device for controlling the operation of the control rod operation monitoring panel 1, the induction motor 7, and the electromagnetic brake 15 provided in the central control room, in addition to the control rod drive device 18. The control rod operation command from the rod driving auxiliary panel 3 and the control rod operation monitoring panel 1 is compared with the current control rod state, and when the control rod operation is necessary, the control rod driving auxiliary panel 3 is operated. It has a control rod position transmission auxiliary board 2 for outputting a command. The control rod position transmission auxiliary panel 2 and the control rod drive auxiliary panel 3 are provided for each control rod driving device 18.

The control rod operation monitoring panel 1 includes an input / output device (not shown) for an operator to operate and monitor, a procedure for pulling out and inserting a plurality of control rods 6, and a control rod operation procedure in which an operation amount is predetermined. It has a control rod operation procedure storage unit 11 for storing, and a control rod operation circuit 10 for outputting a pull-out / insertion command to the control rod position transmission auxiliary panel 2. The input / output devices include a display device for displaying the coordinates of control rods, a coordinate selection button, and an instruction input device for operation command buttons for control rod operation mode, insertion, and removal. The operator commands the operation of the control rod by using these devices. However, if a control rod that should not be operated is pulled out due to the operator incorrectly selecting a control rod to be operated, the thermal margin of the reactor may be deviated, and a dangerous situation may occur. In order to prevent this, the present embodiment uses the control rod operation procedure stored in the control rod operation procedure storage unit 11 to control a plurality of control rods selected by the operator without fail in controlling coordinates to be operated. It is constantly monitored whether it is a bar and whether the amount of movement does not exceed a specified value.

The control rod position transmission auxiliary panel 2 includes a control rod stop moving amount storage means 21, an excitation cutoff target position creation means 22, an excitation cutoff target position determination means 23, a control rod position determination means 24, a driving target position setting means 25, and It has an operation command cutoff means 26. The control rod position transmission auxiliary panel 2 is based on each output signal of each control rod position detector 8 and control rod operation monitoring panel 1, and the control rod position is output from the excitation cutoff target position creating means 22 withdrawing / pulling. If the insertion target value has not been reached, a control rod withdrawal / insertion command is output to the control rod drive auxiliary panel 3. On the other hand, when the position of the operated control rod matches the target value of the pull-out / insertion output from the excitation cut-off target position creating means 22, the output of the control rod pull-out / insertion command is cut off.

An AC power supply is connected to the induction motor 7 via a semiconductor switching element 13B in the control rod drive auxiliary panel 3 and the induction motor control circuit 13 by a cable 35. The electromagnetic brake 15 is connected to a cable 35 by a cable 36. The control rod drive auxiliary panel 3 changes the rotation direction of the induction motor 7 in response to a semiconductor switching element 13B for turning on / off the electric power supplied to the induction motor 7 and the electromagnetic brake 15 and a control rod withdrawal / insertion command (pulling or insertion). In response to the control rod operation direction switching circuit 13A to be set and the control rod withdrawal / insertion command, the semiconductor switching element 13B is turned on / off and a signal for setting the rotation direction of the induction motor 7 is sent to the control rod operation direction switching circuit 13A. It has an induction motor control circuit 13 for outputting. Examples of the semiconductor switching element 13B include a transistor and a thyristor.

In the ABWR, heat generated by a nuclear reaction of uranium or the like, which is a nuclear fuel, charged in the fuel assembly 16 loaded in the reactor 5 is transmitted to the cooling water 17 charged in the reactor 5. The cooling water 17 boils and becomes steam 17A. Although not shown, the turbine is rotated by the supply of the steam 17A, and rotates the generator. The control of the nuclear fission of the nuclear fuel is performed by the operation of pulling out / inserting the control rod 6. The fission of nuclear fuel is suppressed by inserting the control rod 6 into the core, and the fission of nuclear fuel is promoted by withdrawing the control rod 6 from the core.

制 御 The control rod withdrawing operation by the control rod control device of the present embodiment will be described below. The operation sequence of a plurality of control rods to be gang operated is stored in the control rod operation procedure storage unit 11. FIG. 2 shows an operation sequence of the gang operation when the control rod is pulled out of the operation sequence.

In the control rod operation, not only one control rod is operated, but also a gang operation in which a plurality of control rods are simultaneously operated as one group as shown by the control rod coordinates in FIG. This gang operation can achieve a reduction in the start-up time of the nuclear reactor plant and a saving in control rod operation. For example, there are 26 control rods whose control rod group number is indicated as 1, and the control rods in this group are first operated simultaneously. The information regarding the operation of the control rod is shown in FIG. 2 as a control rod withdrawal sequence. The operation information during the drawing sequence includes a control rod operation limit, a guide pattern, and a drawing number. The control rod operation limit is information indicating an operation target position of the control rod, the guide pattern is information indicating continuous operation and stepwise operation of the control rod, and the extraction number is information indicating the order of the extraction operation. Cases in which the control rod is operated stepwise include a step operation and a notch operation. In the notch operation, the amount of movement when the control rod is operated stepwise is larger than in the step operation.

FIG. 2 shows that all control rods of control rod group number 1 are continuously extracted up to position 18 in the order of extraction 1. The drawing order 2 is operated following the operation order 1. In the operation order 2, all the control rods of the control rod group number 1 are pulled out from the position 18 to the position 22 by the step operation. In the drawing order 3, all the control rods of the control rod group number 1 are continuously drawn from the position 22 to the position 48. The position where the control rod is completely inserted in the core is defined as position 0, and the position where the control rod is completely removed from the core is defined as position 48. From the viewpoint of minute movement of the control rod, the entire insertion position of the control rod may be set to position 0, and the entire removal position of the control rod may be set to position 200.

In the next drawing order 4, the operation of continuously drawing up to the position 18 is performed for all the control rods of the control rod group number 2. Hereinafter, the control rods are pulled out by the gang operation in the order of the drawing order according to the control rod drawing sequence of FIG. The drawing order is shown in part C of FIG.

The insertion of the control rod into the core by the gang operation is performed in the reverse order of the operation sequence of the gang operation when the control rod is withdrawn in FIG.

As described above, the operation of the plurality of control rods to be gang-operated includes the pull-out control rod coordinates (or insertion control rod coordinates) input by the operator using the input / output device and the control rod operation mode (continuous, notch, step). , And the control rod operation circuit 10 reads a control rod operation command 9 such as a pull-out command (or an insertion command). However, in the following control rod withdrawal by a gang operation, the control rod operation circuit 10 reads information (control rod operation limit, guide pattern and withdrawal number) from the control rod withdrawal sequence in the control rod operation procedure storage unit 11, and inputs This is performed by outputting a control rod operation command 9 including a pull-out command (or an insertion command) input by an operator using an output device to the excitation cutoff target position creating means 22 of the control rod position transmission auxiliary panel 2. The control rod operation command 9 includes information on a pull-out command and pull-out control rod coordinates. When the operator inputs a pull-out command from the input / output device, the control rod operation circuit 10 reads the control rod withdrawal sequence in the control rod operation procedure storage unit 11.

The control rod stop movement amount storage means 21 stores a control rod movement amount that moves from when a command to cut off power supply to the induction motor 7 is output to the semiconductor switching element 13B until the control rod 6 stops. The excitation cutoff target position creating means 22 determines the control rod movement position with respect to the pullout target position based on the pullout target position input from the control rod operation circuit 10 and the control rod movement amount read from the control rod stop movement amount storage means 21. An excitation cutoff target position (= (pull-out target position)-(control rod movement amount)) before the movement amount is created. This excitation cutoff target position finally becomes a control rod position for cutting off the power supply to the induction motor 7 and operating the electromagnetic brake 15. When the control rod reaches the power cutoff target position, the power supply to the induction motor 7 is cut off, and the control rod 6 moves by the above-described control rod movement amount after the electromagnetic brake 15 is actuated, and the control rod is pulled out. Stop at the target position. The excitation cutoff target position created by the excitation cutoff target position creation means 22 is output to the excitation cutoff target position determination means 23.

The outputs of all the control rod position detectors 8 provided for all the control rods are input to the control rod position determination means 24. The control rod position determining means 24 determines the control rod coordinates of each control rod to be subjected to the gang operation input by the excitation cutoff target position creating means 22 (for example, (02, 39) and (02, 23)). The control rod position determining means 24 inputs the measured control rod position signals from the control rod position detectors 8 corresponding to the respective control rods to be gang-operated indicated by the control rod coordinates. The control rod position determining means 24 detects the control rod position of the first control rod in the moving direction of the control rod 6 (in this case, the pulling direction) based on these control rod position signals. The driving target position setting means 25 adds the control rod position of the first control rod output from the control rod position determination means 24 and the movement addition amount read from the movement addition amount storage means 27 to control the movement during movement. Create a target position for the bar. The movement addition amount is a control rod movement amount which moves from outputting a command to cut off the power supply to the induction motor 7 to the semiconductor switching element 13B until the control rod 6 stops, or a value equal to or greater than the movement amount. . In other words, in order to add this movement addition amount to the control rod position of the current control rod and to set the target position of the moving control rod, if the control rod position of the first control rod changes due to the movement, The target position of the bar is also updated. The updating of the driving target position setting means 25 is stopped when the control rod position of the leading control rod reaches the target position of the moving control rod. The target position of the moving control rod output from the driving target position setting means 25 is input to the excitation cutoff target position determination means 23 and the holding means 28.

The excitation cutoff target position determination means 23 compares the output of the excitation cutoff target position creation means 22 with the output of the driving target position setting means 25, and holds the "target position of the moving control rod" when they match. A holding command signal for causing the holding unit 28 to hold is output to the holding unit 28. The holding unit 28 outputs the “target position of the moving control rod” output from the driving target position setting unit 25 to the target position determination unit 29 as it is until the holding command signal is input. The self-control rod position detecting means 30 detects the position of the own control rod operated.

The target position judging means 29 compares the output signal of the holding means 28 with the control rod position output from the self-control rod position detecting means 30, and when they match, sends a shut-off means open signal to the operation command shut-off means 26. Output. The operation command cutoff means 26 is opened by the input of the cutoff means open signal, and controls the induction motor control of the control rod drive auxiliary panel 3 according to the pull-out command (pull-out direction, drive ON) output from the excitation cutoff target position creation means 22. Block transmission to circuit 13. On the other hand, when the output signal of the holding means 28 does not match the control rod position from the self-control rod position detecting means 30, the target position determining means 29 outputs a shut-off means closing signal. The operation command cutoff means 26 is closed by the input of the cutoff means close signal, and transmits the extraction command output from the excitation cutoff target position creation means 22 to the induction motor control circuit 13.

When a plurality of control rods are simultaneously operated, the control rods between the respective control rods may vary depending on load conditions (for example, the degree of fitting of the control rod driving device 18 with the ball screw nut, drive history, aging, etc.). Due to a slight displacement, the control rod stops far beyond the corresponding pull-out target position, but the movement target position is set based on the control rod position of the first control rod in the movement direction. This can be prevented by moving each control rod that performs the gang operation. Further, in the present embodiment, the driving target position setting means 25 creates the “target position of the driving control rod” by adding the “control rod position of the first control rod” and the “movement addition amount”. Since a large movement target amount is not given to the current position of the control rod, even if an abnormality occurs in the control rod position determination means 24 and the movement addition amount storage means 27, it is possible to mistakenly move the control rod greatly. Can be prevented.

The induction motor control circuit 13 inputs the pull-out command output from the excitation cutoff target position creation means 22 when the operation command cutoff means 26 is closed by the cutoff means close signal. The induction motor control circuit 13 determines whether the input command corresponds to a removal command or an insertion command. If the induction motor control circuit 13 determines that the command is a pull-out command, it outputs a signal indicating the pull-out (first switching command) to the control rod operation direction switching circuit 13A and turns on the semiconductor switching element 13B. . Therefore, AC power is supplied to the induction motor 7 by the cable 35 via the semiconductor switching element 13B and the control rod operation direction switching circuit 13A. At the same time, the electric power is supplied to the electromagnetic brake 15 via the cables 35 and 36, and the braking force of the electromagnetic brake 15 that prevents the induction motor 7 from rotating is released. The induction motor 7 starts rotating in the direction in which the control rod 6 is pulled out. The control rod 6 moves in a direction in which it is withdrawn from the core.

When the target position determination unit 29 outputs the shutoff unit open signal, the input of the command (pull-out command or insertion command) from the excitation cutoff target position creation unit 22 to the induction motor control circuit 13 is stopped. The induction motor control circuit 13 turns off the semiconductor switching element 13B by stopping the input of the pull-out command. The power supply to the induction motor 7 and the electromagnetic brake 15 is stopped, the excitation of the induction motor 7 is released, and the braking force of the electromagnetic brake 15 is applied. Therefore, the control rods 6 that have performed the gang operation can be stopped at the same pullout target position.

Particularly, the response delay time of the semiconductor switching element 13B is extremely short. For this reason, by providing the semiconductor switching element 13B, the start timing of the induction motor 7 of each control rod driving device 18 and the operation timing of the electromagnetic brake 15 at the start of the gang operation do not shift, and the respective control rods being driven are not shifted. Position does not shift. Further, when the rotation of the induction motor 7 is stopped, the rotation stop position of the induction motor 7 is determined depending on the brake performance. However, since the operation timings of the electromagnetic brakes 15 of the respective control rod driving devices 18 do not shift, each control is performed. The stop position of the bar can be matched with the target pulling position. As a result, no deviation occurs in the position of each control rod that has been subjected to the gang operation, and the symmetry of the reactor power distribution is broken, so that no thermal stress is applied to the fuel rods in the fuel assembly.

In the present embodiment, since a part of the cable for supplying power to the induction motor 7 and the electromagnetic brake 15 is shared, the number of cables for about 200 control rods can be greatly reduced. If this point is not taken into consideration, power may be supplied by separate cables separated to the induction motor 7 and the electromagnetic brake 15 as in the embodiment of FIG.

When each control rod 6 for performing the gang operation is inserted into the core, the control rod operation circuit 10 performs the insertion control read out from the control rod insertion sequence of the control rod operation procedure storage unit 11 based on the insertion command input by the operator. A control rod operation command 9 including a rod coordinate, a control rod operation limit, a guide pattern, an insertion number, and an insertion command input by an operator is created, and the control rod operation command 9 is output to the excitation cutoff target position creating means 22. . Based on the extraction target position input from the control rod operation circuit 10 and the read control rod movement amount, the excitation cutoff target position creation means 22 generates an excitation cutoff target position that is before the insertion target position by this control rod movement amount. (= (Insertion target position)-(control rod movement amount)) is created. The target position judging means 29 compares the output signal of the holding means 28 with the control rod position output from the self-control rod position detecting means 30, and outputs the shut-off means open signal or the shut-off means close signal as in the case of the pull-out operation. Output. When the shutoff means close signal is output, the insertion command (insertion direction, drive ON) output from the excitation cutoff target position creating means 22 is transmitted to the induction motor control circuit 13 via the operation command cutoff means 26. The induction motor control circuit 13 outputs a signal indicating the insertion (second switching command) to the control rod operation direction switching circuit 13A, and turns on the semiconductor switching element 13B. The braking force of the electromagnetic brake 15 is released. The induction motor 7 rotates in the direction opposite to the direction in which it was pulled out, and inserts the control rod 6 into the core. The operation command cutoff means 26 is opened by the cutoff means open signal, and the input of the insertion command to the induction motor control circuit 13 is blocked. When the semiconductor switching element 13B is turned off and the braking force of the electromagnetic brake 15 acts, each control rod 6 that has performed a gang operation can stop at the same insertion target position.

(4) By installing the semiconductor switching element 13B, the same effect as that at the time of the control rod withdrawal operation is produced at the time of the control rod insertion operation.

作用 The operation of the present embodiment will be described below using specific numerical values by taking control rod pull-out as an example. For ease of understanding, it is assumed that the entire insertion position of the control rod 6 is 0 and the entire withdrawal position is 200. The target withdrawal position is set to 100, and the current position of the control rod 6 is set to 70. The control rod position of the first control rod is 71. The control rod movement amount stored in the control rod stop movement amount storage means 21 is 5 and the movement addition amount stored in the movement addition amount storage means 27 is 5 or more, but is 5 in this example. Since the operation command output from the control rod operation circuit 10 is a pull-out command, the pull-out target position is 100, and the excitation cut-off target position output from the excitation cut-off target position creating means 22 is 95. Since the control rod position of the leading control rod determined by the control rod position determining means 24 is 71, the target position of the driving control rod, which is the output of the driving target position setting means 25, is 76. The excitation cutoff target position determining means 23 compares the inputs 95 and 75 and does not output a holding command to the holding means 28 because they do not match. Accordingly, the output of the holding means 28 becomes 76, and the control rod position which is the output of the self-control rod position detecting means 30 is 70, so that the target position judging means 29 outputs the shutoff means close signal. The pull-out command (pull-out direction, drive ON) output from the creating means 22 is input to the induction motor control circuit 13.

た め For this reason, the control rod is pulled out of the core. With this pulling, the position of the control rod 6 increases, and the target position of the driving control rod, which is the output of the driving target position setting means 25, also increases. When the output of the driving target position setting means 25 becomes 95, the excitation cutoff target position determination means 23 outputs a holding command to the holding means 28 in order to match the output of the excitation cutoff target position creation means 22. The holding unit 28 holds the target position 95 of the driving control rod output from the driving target position setting unit 25. When the output of the self-control rod position detecting means 30 and the output of the holding means 28 (the value is 95) match, the target position determining means 29 outputs a shutoff means open signal to the drive command interrupting means 26. As a result, the operation command cutoff means 26 does not transmit the pull-out command (pull-out direction, drive ON) from the excitation cutoff target position creating means 22 to the induction motor control circuit 13. Accordingly, when the control rod position is at 95, the power supply to the induction motor 7 and the electromagnetic brake 15 is cut off, the excitation of the induction motor 7 is released, and the braking force of the electromagnetic brake 15 acts. Stop at Thus, the other control rods also operate, and the gang drive control rods all stop at the target position 100.

The control rod withdrawal has been described above. However, when the control rod is inserted, the driving direction is only reversed, which is the same. However, for example, when the current control rod position is driven from 100 to 70, the drive command is interrupted at 75 before the target position 70. Further, the target position of the driving control rod output from the driving target position setting means 25 has a value which is smaller by about 5 than the control rod position of the leading control rod.

FIG. 3 shows the relationship between the control rod operation command from the central control room, the operation of the induction motor 7 based thereon, and the amount of control rod movement. As shown in FIG. 3, the rotation direction of the induction motor 7 changes according to whether the control rod operation command is withdrawal / insertion. Further, when the shut-off means open signal is output, it substantially corresponds to when a control rod stop command is issued, and the induction conductor 7 is in a stopped state. Further, the control rod withdrawal amount increases when a pullout command is issued, becomes constant when the shutoff means open signal is output, and decreases when an insertion command is output.

Next, a control rod control device according to another embodiment of the present invention will be described with reference to FIG. The same components as those in the embodiment of FIG. 1 are denoted by the same reference numerals. This embodiment uses the embodiment of FIG. 1 and the control rod position transmission auxiliary panel 2A in which the driving target position setting means 25 and the movement addition amount storage means 27 are substantially deleted from the control rod position transmission auxiliary panel 2. Is different.

(4) The part of the operation of the auxiliary control rod position transmission panel 2A that is different from that of the auxiliary control rod position transmission panel 2 will be described. The excitation cutoff target position determination means 23A compares the excitation cutoff target position output from the excitation cutoff target position creation means 22 with the "control rod position of the first control rod" output from the control rod position determination means 24, When they match, the excitation cutoff target position is held by the holding means 28A. The target position determining means 29A compares the output of the holding means 28A with the output of the self-control rod position detecting means 30, and outputs a shut-off means close signal until they match, and outputs a shut-off means open signal when they match. Are output to the operation command cutoff means 26, respectively. In this embodiment, power can be supplied to the induction motor 7 and the electromagnetic brake 15 and the power supply can be stopped in the same manner as in the embodiment of FIG. 1, and the same effect as in the embodiment of FIG. 1 can be obtained. be able to.

In the case where the function of the control rod position transmission auxiliary panel 2 in the embodiment of FIG. 1 is realized by a computer system (or a microprocessor system), the operation period is increased and the driving target position setting means 25 is used for each operation period. It is necessary to obtain the target position of the moving control rod by adding the output of the movement addition amount storage means 27 and the output of the control rod position determination means 24. If the operation cycle of the computer system (or the microprocessor system) is slow, the control rod 6 may stop over the target extraction position (or the target insertion position). Computer systems (or microprocessor systems) that achieve high-speed operation cycles are large. On the other hand, in the embodiment of FIG. 4, it is not necessary to obtain the target position of the moving control rod, and the control rod position transmission auxiliary panel 2A can be realized by a small and low-cost computer system (or microprocessor system). .

A control rod control device according to another embodiment of the present invention will be described below. In the present embodiment, the control rod position transmission auxiliary panel 2 is realized by a computer system (or a microprocessor system) in the configuration of the embodiment of FIG. The control rod position transmission auxiliary panel 2 in the present embodiment executes the processing shown in FIG.

The processing contents of FIG. 5 will be described below. First, the control rod operation command 9 from the control rod operation circuit 10
(Moving direction, target position, etc.) are taken in (step 41). Based on the control rod movement amount (the information stored in the control rod stop movement amount storage means 21) that moves from the operation of the electromagnetic brake to the stop of the control rod, the induction motor Then, an excitation cutoff target position for cutting off the power supply to the motor is calculated (step 42). The control rod position information detected from all the control rod position detectors 8 is taken in, and the control rod position of the first control rod in the moving direction of the control rod is calculated (step 43). The target position of the control rod being driven is calculated by adding the movement addition amount (the information stored in the movement addition amount storage means 27) to the calculated control rod position of the first control rod (step 44). When the moving direction is the insertion, the target position of the moving control rod is calculated by subtracting the above-mentioned movement addition amount from the calculated control rod position of the leading control rod. The calculated value in step 42 and the calculated value in step 44 are compared, and it is determined whether these calculated values match (step 45). If the determination at step 45 is “mismatch”, the process at step 46 is executed. If the determination in step 45 is "match", the process of step 47 is executed. In step 46, an operation command (moving direction of the control rod, drive ON) is output to the control rod drive auxiliary panel 3. Thereby, the movement of the control rod is started, and the control rod is continuously moved until the processing of step 47 is executed. In step 47, the position of the control rod to be moved is fetched, and it is determined whether or not this position matches the "target position of the driven control rod" calculated last in step 44. If the determination in step 47 is "mismatch", a shutoff means close signal (not shown) is output to the operation command shutoff means 26, and the processing in step 47 is executed again. If the determination in step 47 is "match", the process of step 48 is executed. In step 48, a shutoff means open signal for stopping output of an operation command (control rod moving direction, drive ON) to the control rod drive auxiliary panel 3 is output to the operation command cutoff means 26. The target position of the driving control rod finally calculated in step 44 is equal to the target position for cutting off the excitation of the induction motor, which is created by the excitation cutoff target position creating means 22 in FIG. In this way, the function of the control rod position transmission auxiliary panel 2 can be realized by a computer system (or a microprocessor system).

This embodiment has the same effect as the embodiment of FIG.

A control rod control device according to another embodiment of the present invention will be described below. In the present embodiment, the control rod position transmission auxiliary panel 2A is configured by a computer system (or a microprocessor system) in the configuration of the embodiment of FIG. The control rod position transmission auxiliary panel 2A in the present embodiment executes the processing shown in FIG.

の う ち Among the processes in FIG. 6, the same processes as those in FIG. 5 are denoted by the same reference numerals. Similar to the processing of FIG. 5, the processing of steps 41, 42 and 43 is executed. Thereafter, the calculated value in step 42 is compared with the calculated value in step 33, and it is determined whether these calculated values match (step 45A). If the determination at step 45A is "mismatch", the process at step 46 is executed. If the determination in step 45A is "match", the process of step 47A is executed. In step 74A, the position of the control rod to be moved is fetched, and it is determined whether or not this position matches the "control rod position of the first control rod" calculated last in step 43. If the determination in step 47A is "mismatch", a cut-off means close signal is output to the operation command cut-off means 26 (not shown), and the process of step 47A is executed again. If the determination in step 47 is "match", the process of step 48 is executed. The control rod position of the first control rod finally calculated in step 43 is equal to the target position for interrupting the excitation of the induction motor created by the excitation cutoff target position creating means 22 in the embodiment of FIG. This embodiment can achieve the same effects as the embodiment of FIG.

制 御 A control rod control device according to another embodiment of the present invention will be described below with reference to FIG. This embodiment is different from the embodiment of FIG. 1 in that a brake power supply device 4 having a rectifier 4A and a semiconductor switching element 4B is provided.

The rectifier 4A converts the brake power supply AC into a DC power supply for operating the electromagnetic brake 15A. The semiconductor switching element 4B is connected to the rectifier 4A, and is connected to the electromagnetic brake 15A by a cable 36A. The semiconductor switching element 4 </ b> B inputs the shutoff unit close signal and the shutoff unit open signal which are outputs of the target position determination unit 29. When the shutoff means close signal is input, the semiconductor switching element 4B is turned on, and the braking force of the electromagnetic brake 15A is released. On the other hand, when the shutoff means open signal is input, the semiconductor switching element 4B is turned off, and the braking force of the electromagnetic brake 15A operates. At this time, the induction motor 7 cannot rotate.

As in the embodiment of FIG. 1, when the semiconductor switching element 13B is turned on, power is supplied to the induction motor 7, and when the semiconductor switching element 13B is turned off, the power supply to the induction motor 7 is stopped. The on / off operations of the semiconductor switching elements 4B and 13B are the same. For this reason, when the braking force of the electromagnetic brake 15A is released, electric power is supplied to the induction motor 7, the induction motor 7 rotates, and the control rod 6 moves in the set direction. This embodiment can obtain the effects produced in the embodiment of FIG.

電磁 The electromagnetic brake 15A connected to the rotating shaft of the induction motor 7 operates on DC power. The reason for using such an electromagnetic brake 15A is that the response time of the brake is shorter than that of the electromagnetic brake 15 that operates on the AC power supply. Therefore, the application of the electromagnetic brake 15A shortens the time affected by the load fluctuation as compared with the case where the electromagnetic brake operated by the AC power supply is used, so that the positioning accuracy of the control rod can be further improved. Note that the electromagnetic brake 15A may be one in which a braking force is operated by power supply. In this case, it is only necessary to excite the induction motor 7 to rotate and cut off the power supply to the electromagnetic brake 15 </ b> A so that the excitation of the induction motor 7 is cut off and supply power to the electromagnetic brake 15.

The brake power supply device 4 and the electromagnetic brake 15A can be applied to the embodiment of FIG.

It is a lineblock diagram of a control rod control device which is one suitable example of the present invention. FIG. 3 is an explanatory diagram showing a specific example of a control rod withdrawal sequence stored in a control rod operation procedure storage unit in FIG. 1. FIG. 2 is a characteristic diagram showing a relationship between an operation of the induction motor and an operation amount of a control rod in FIG. 1. FIG. 9 is a configuration diagram of a control rod control device according to another embodiment of the present invention. 9 is a flowchart of a process executed by a control rod position transmission auxiliary panel 2 of a control rod control device according to another embodiment of the present invention. 9 is a flowchart of a process executed by a control rod position transmission auxiliary panel 2 of a control rod control device according to another embodiment of the present invention. FIG. 9 is a configuration diagram of a control rod control device according to another embodiment of the present invention.

Explanation of reference numerals

DESCRIPTION OF SYMBOLS 1 ... Control rod operation monitoring panel, 2, 2A ... Control rod position transmission auxiliary panel, 3 ... Control rod drive auxiliary panel, 4 ... Electromagnetic brake power supply device, 4B, 13B ... Semiconductor switching element, 6 ... Control rod, 7 ... Induction Motor, 8: control rod position detector, 15, 15A: electromagnetic brake, 21: control rod stop moving amount storage means, 22: excitation cutoff target position creation means, 23: excitation cutoff target position determination means, 24: control rod position Judgment means, 25: driving target position setting means, 26: operation command cutoff means, 27: movement addition amount storage means, 28: holding means, 29: target position judgment means, 30: self-control rod position detection means.

Claims (3)

A plurality of control rod drive devices coupled to the control rods and driven by an induction motor;
An electromagnetic brake provided for each control rod driving device to stop rotation of the induction motor;
Control rod operation command output means for outputting operation commands to a plurality of control rods to be gang operated,
The operation command from the control rod operation command output means provided for each control rod driving device is input, and a first control rod setting position set based on a control rod operation target position included in the operation command is provided. The second control rod set position set based on the position of the control rod at the leading position among the plurality of control rods to be gang operated matches, and the measured control rod position is the first control rod. Power cutoff determining means for stopping the output of the input operation command when it matches the set position or the second control rod set position,
The power supply to the induction motor and the electromagnetic brake is turned on based on the operation command output from the power cutoff determining means, and the induction motor and the electromagnetic force are turned off by stopping the output of the operation command by the power cutoff determination means. A control rod control device comprising: a semiconductor switching element for turning off power supply to a brake; and power control means provided for each control rod drive device. 2. The device according to claim 1, wherein the power cutoff determining unit sets the first control rod setting position based on a control rod operation target position included in the operation command input from the control rod operation command output unit. Means for determining the position of the control rod at the leading position among the plurality of control rods to be gang operated, and setting the second control rod setting larger than the obtained position of the control rod at the leading position Means for setting a position, means for holding the second control rod setting position when the first control rod setting position and the second control rod setting position match, and the held second control rod setting means And a means for stopping output of the input operation command when the measured control rod position coincides with the set position. 3. The control rod according to claim 1, wherein the first control rod setting position is a movement amount of the control rod from a control rod operation target position to a stop of power supply to the induction motor to a stop of rotation of the induction motor. 4. The second control rod setting position is set to a value obtained by adding a control rod movement amount equal to or greater than the control rod movement amount to a position of the control rod at the head position. Control rod control device.

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