JPS61251790A - Method of controlling moving coil type control rod drive - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Minute Hand] The present invention relates to an improvement in a control method for a moving coil type control rod drive device for a nuclear reactor.

[Conventional technology]

A moving coil type control rod drive device in a nuclear reactor is usually a pressure batdry in the sub-reactor system, and FIG. 4 shows its configuration. The control rod drive device described above is a pressure tube (1
), and an electromagnetic plunger (
7), the drive shaft (2) is inserted into the pressure pipe (1), and an upward coil (4), a downward coil (5) and a differential transformer (6) are attached to the outer periphery of the pressure pipe (1). A moving coil (3) consisting of a coil is arranged, and the moving coil ■
is moved up and down in the tube axis direction by the drive device (8), thereby raising and lowering the electromagnetic 1 langeer (7) which is electromagnetically coupled to the movable coil (2) via the pressure tube (1). The magnetic plunger (driver M with fixed force (2) and control rods are moved up and down to control the reactor. In Figure 5, (9) is the circuit for the drive device, 00)
is an upward coil power supply, aυ is a downward coil power supply, and α2 is a differential transformer amplifier.

FIG. 5 is a diagram showing the control method of the control rod drive device,
In order to raise the drive shaft (2), the movable coil (3
) Drive device! 1 (8), the excitation current value of the upward coil (4) is set to A, and when lowering, the movable coil ■ is lowered, and the current value of the upward coil (4) is opposite to this diagram. If it goes up, it goes down,
When it goes down, it goes up. Alternatively, there is a method in which the above current control is applied to either the upward coil or the downward coil, and the other is kept at a constant flow f, -! In the range R shown by the dotted line, the positional deviation (hereinafter referred to as deviation) between the movable coil (3) and the electromagnetic plunger (force) is detected by the differential transformer (6), and the signal is transmitted to the power supply (II, ( Feed back to lυ to change the current value of each coil (4), (5),
This is the change width of the current that compensates for the movement of the electromagnetic plunger (7).

[Problem that the invention seeks to solve]

By the way, when operating the above control rod drive device to control a nuclear reactor, the drive shaft to which the control rods are fixed may suddenly be moved upward or downward from the stopped position, or the drive shaft that is moving may suddenly be moved in the opposite direction. That is, it may be necessary to change the direction from upward to downward or downward to upward, or to suddenly change the speed of movement in the same direction. In this case, in the conventional device, the movable coil 4) is moved up and down along the tube axis, and different currents are applied to the upward coil and the downward coil. For example, the current value is decreased from a predetermined high current value to a low current value, or vice versa, the current value is increased from a low current value to a high current value. Moving coil ■
The electromagnetic plunger (7) that is electromagnetically coupled to the moving coil ■
The movable coil (3
) will cause a transient excursion between the plunger (7) and the moving coil (3).

Furthermore, if the set speeds are different, not only this transient deviation but also a steady deviation will occur. .

Figure 6 is a diagram showing this state, and shows the transient deviation and steady deviation when the moving coil ■ changes from rising (speed element V1) to falling (speed -V2). (Sru.

In addition, (b) shows the change in deflection when the moving coil (3) that is descending suddenly changes its speed from -v3 to -v4.
There is. The differential transformer (6) is provided to compensate for this deviation, but if there is a large change in the moving speed of the moving coil (2), this differential transformer (6) alone may not be sufficient to compensate. Therefore, the control of the reactor will be insufficient. This was a drawback of conventional devices.

An object of the present invention is to provide a control method for a control rod drive device in which an electromagnetic plunger can sufficiently follow even if the moving speed of a moving coil changes rapidly.

[Means to solve the problem]

A control circuit for a moving coil type control rod drive device for a nuclear reactor is configured to be able to control the rate of change of the excitation current of the °C coil according to the °C and speed command signals. Note that the feedback circuit using the differential transformer functions in the same manner as the conventional device.

[For production]

Since the rate of change of the excitation current of the coil is changed according to the change in the speed command signal, the electromagnetic plunger electromagnetically coupled to the moving coil can smoothly follow the movement, and the deviation between the moving coil and the electromagnetic plunger, that is, the drive shaft is reduced. Minimized.

[Embodiments of the invention]

FIG. 1 is a configuration diagram showing an embodiment of the present invention.
3 indicates the same parts as the conventional device. (l: 1 is a speed detector and a drive device (8) that drives the moving coil (3)
detects the speed of the upper coil (4) and lower coil (5), and sends the signal to the upper coil power supply (al) and the lower coil power supply (51Q1) to control the flow of the upper coil (4) and the lower coil (5).

FIG. 2 is a diagram showing currents in the upward coil and downward coil when controlled by the control method according to the present invention. (ml is the coil speed command signal, and ■ is a command signal with a higher rising speed than ■. (b) shows the currents in the upward coil and downward coil that are controlled according to the speed command signal.Speed The rate of change of the valley coil airflow is controlled depending on the magnitude of the command signal.

(cl) is a method in which not only the rate of change of the flow of the coil in (b) but also the set value of the coil current is changed, and the same effect can be obtained.

Although the above embodiment is an example in which the coil driving direction changes, the same applies to the case where the speed command in the same direction changes. In either case, as shown in the figure, the changing speed of the coil current is changed depending on the speed command signal of the moving coil ■, so the deviation between the moving coil ■ and the electromagnetic plunger (7) is kept to a minimum. It will be done.

This current control of the coils according to the speed can be applied simultaneously to both the upward and downward coils, or the current control may be applied to one of the coils while the other is kept at a constant current.

Note that the bias compensation between the differential transformer (6) and the moving coil (2) functions in the same manner as the conventional device.

FIG. 6 shows another embodiment in which the speed command signal is input to the motor drive circuit, the upward coil power source, and the downward coil power source.
Coil current control is performed according to FIG. In the case of this embodiment as well, bias compensation between the movable coil and the electromagnetic plunger by the differential transformer is the same as in the conventional case. Further, it is also possible to apply this coil current control according to the speed to both the upward coil and the downward coil simultaneously, or to apply it to one while the other is kept at a constant current.

〔Effect of the invention〕

In the control circuit of a moving coil type control rod drive device for a nuclear reactor, the present invention controls the rate of change of coil current according to changes in the speed command signal of the moving coil drive device, thereby reducing the deviation between the moving coil and the electromagnetic plunger. This has made it possible to minimize the amount of damage caused by nuclear reactors, allowing for smoother control of the reactor.

[Brief explanation of drawings]

Fig. 1 is a configuration diagram of a moving coil type control rod drive device for a nuclear reactor showing an embodiment of the present invention, Fig. 2 is a diagram showing the speed command signal and the corresponding change in coil current, Fig. 6 is a block diagram showing another embodiment, FIG. 4 is a block diagram of a conventional device, FIG. 5 is a diagram showing the relationship between coil current and moving speed in the conventional device, and FIG. 6 is a diagram showing the relationship between deflection and moving speed. It is a figure showing a relationship. In the figure, (1) is the pressure pipe, (2) is the drive shaft, and (3) is the moving coil. (4) is an upward coil, (5) is a downward coil, (6) is a differential transformer, (force is an electromagnetic plunger, (8) is a drive device, (9) is a motor drive circuit, (1 [is an upper Direct coil power supply,
αB is a downward coil power supply, (121 is a differential transformer amplifier. Agent: Patent Attorney Masashi Sato Figure 1, Figure 3, Figure 4)

Claims (1)

[Claims] A control circuit for a moving coil control rod drive device for a nuclear reactor, characterized in that the rate of change of moving coil current is changed in accordance with speed control of the moving coil drive device. Method.