阅读说明：本技术 用于快堆的控制棒驱动机构的驱动方法 (Driving method of control rod driving mechanism for fast reactor ) 是由 刘桂娟 段天英 张媛媛 刘勇 刘国发 靳峰雷 冯伟伟 于 2020-03-30 设计创作，主要内容包括：本发明的实施例提供一种用于快堆的控制棒驱动机构的驱动方法,所述控制棒驱动机构由电机驱动,所述驱动方法包括：获取关于所述控制棒驱动机构下一时刻运动状态的指令信号；根据所述指令信号确定电机的通电相并通电,使所述电机旋转,由所述电机带动所述控制棒驱动机构运动；当所述控制棒驱动机构运动至目标位置并保持不动,控制所述电机的当前通电相输出直流电；其中,所述电机的当前通电相为相邻两相。本发明实施例的驱动方法,能够实现控制棒驱动机构的灵活调控,降低其运行故障导致反应堆及核电厂的非计划降功率甚至停堆的概率,从而提高快堆核电厂运行可靠性。(An embodiment of the present invention provides a driving method of a control rod drive mechanism for a fast reactor, the control rod drive mechanism being driven by a motor, the driving method including: acquiring a command signal related to the motion state of the control rod drive mechanism at the next moment; determining the power-on phase of a motor according to the command signal and powering on, so that the motor rotates, and the motor drives the control rod driving mechanism to move; when the control rod driving mechanism moves to a target position and keeps still, controlling the current power-on phase of the motor to output direct current; wherein the current power-on phase of the motor is two adjacent phases. The driving method provided by the embodiment of the invention can realize flexible regulation and control of the control rod driving mechanism, and reduce the probability of unplanned power reduction and even shutdown of the reactor and the nuclear power plant caused by operation faults, thereby improving the operation reliability of the fast reactor nuclear power plant.)

1. A method of driving a control rod drive mechanism for a fast reactor, the control rod drive mechanism being driven by a motor, the method comprising:

acquiring a command signal related to the motion state of the control rod drive mechanism at the next moment;

determining the power-on phase of the motor according to the command signal and powering on, so that the motor rotates, and the control rod driving mechanism is driven by the motor to move;

when the control rod driving mechanism moves to a target position and keeps still, controlling the current electrified phase of the motor to output direct current, and enabling the motor to enter an electric static state;

wherein the current power-on phase of the motor is two adjacent phases.

2. The driving method according to claim 1,

when the motor is in an electric static state and one of the two adjacent phases which are electrified currently has a driving fault, the other phase outputs direct current and the power supply of the fault phase is disconnected.

3. The driving method according to claim 1 or 2, wherein,

the number of phases of the motor is four;

when the motor rotates, the power-on phases of the motor at the same time are controlled to be two phases.

4. The driving method according to claim 1 or 2, wherein,

the number of phases of the motor is three;

when the motor rotates, the power-on phases of the motor at the same time are controlled to be two phases.

5. The driving method according to claim 3 or 4,

and when the current electrified phase of the motor is controlled to output direct current, the output direct current is lower than the current amplitude output when the motor rotates.

Technical Field

The invention relates to the technical field of nuclear power control rod driving mechanisms, in particular to a driving method of a control rod driving mechanism for a fast reactor.

Background

The control rod driving mechanism is a key device of the nuclear reactor, and can lift, descend, hold or quickly insert a control rod according to the instruction of a reactor control and protection system so as to complete the functions of starting the reactor, adjusting the reactor power, maintaining the reactor power, stopping the reactor with the reactor descending power, quickly stopping the reactor (also called as accident rod drop) under the accident condition and the like.

The common pressurized water reactor control rod driving mechanism is of a magnetic lifting type and comprises a driving rod assembly, a claw assembly, a coil assembly and the like, and the working principle is that the claw is operated to drive a driving rod and a control rod connected with the lower part of the driving rod to perform lifting, inserting, holding and rod dropping motions through the change of a magnetic field generated when three working coils of a lifting coil, a transmission coil and a holding coil are powered on/off.

For a fast reactor, the structure and the working principle of a control rod driving mechanism are different from those of a pressurized water reactor; the transmission chain of the control rod driving mechanism of the fast reactor comprises the following components: the rotation of the motor is transmitted to the chain wheel mechanism and the chain wheel mechanism through the gear reduction mechanism and then transmitted to the linear motion of the control rod, so that the control rod driving mechanism can be lifted, descended or maintained by controlling the motor to rotate according to the required direction and speed.

The motor driving device is used for driving the motor, and for example, the motor driving device comprises a driving device and a stepping motor, and the driving device is used for receiving control signals sent by the reactor rod control and rod position indication system and supplying current corresponding to the control signals to the stepping motor so as to control the stepping motor to rotate.

Based on the operating characteristics of the control rod drive mechanism of fast reactor, improve the operation security and the reliability of its nuclear power plant for the solution.

Disclosure of Invention

An embodiment of the present invention provides a driving method of a control rod drive mechanism for a fast reactor, the control rod drive mechanism being driven by a motor, the driving method including: acquiring a command signal related to the motion state of the control rod drive mechanism at the next moment; determining the power-on phase of the motor according to the command signal and powering on, so that the motor rotates, and the control rod driving mechanism is driven by the motor to move; when the control rod driving mechanism moves to a target position and keeps still, controlling the current electrified phase of the motor to output direct current, and enabling the motor to enter an electric static state; wherein the current power-on phase of the motor is two adjacent phases.

In some embodiments, when the motor is in an electric static state and one of the two adjacent phases which are currently electrified has a driving fault, the other phase is enabled to output direct current, and the power supply of the fault phase is disconnected.

In some of these embodiments, the number of phases of the motor is four; when the motor rotates, the power-on phases of the motor at the same time are controlled to be two phases.

In some of these embodiments, the number of phases of the motor is three; when the motor rotates, the power-on phases of the motor at the same time are controlled to be two phases.

In some embodiments, when the currently energized phase of the motor outputs direct current, the output direct current is controlled to be lower than the current amplitude output when the motor rotates.

According to the driving method of the control rod driving mechanism for the fast reactor, which is disclosed by the embodiment of the invention, the corresponding phases of the motors are controlled to be electrified, so that the motors are in different working states, the control rod driving mechanism is driven to move or the position of the control rod driving mechanism is kept unchanged, the flexible regulation and control of the control rod driving mechanism are realized, the probability of unplanned power reduction and even shutdown of the reactor and a nuclear power plant caused by the operation fault of the control rod driving mechanism is reduced, and the operation reliability of the fast reactor nuclear power plant is improved.

Drawings

Other objects and advantages of the present invention will become apparent from the following description of the invention which refers to the accompanying drawings, and may assist in a comprehensive understanding of the invention.

FIG. 1 is a schematic diagram of a motor structure according to one embodiment of the present invention;

FIG. 2 is a schematic wiring diagram of the motor and the driving device shown in FIG. 1;

fig. 3 is a schematic diagram of the output current of the motor in different operation states according to an embodiment of the present invention.

It is noted that the drawings are not necessarily to scale and are merely illustrative in nature and not intended to obscure the reader.

Detailed Description

According to the driving method of the control rod driving mechanism for the fast reactor, the control rod driving mechanism is driven by the motor, and the driving method comprises the following steps: acquiring a command signal related to the motion state of the control rod drive mechanism at the next moment; determining the electrifying phase of the motor according to the command signal and electrifying to rotate the motor, and driving the rod driving mechanism to move by the motor; when the control rod driving mechanism moves to a target position and keeps still, the current power-on phase of the control motor outputs direct current, and the motor enters an electric static state; wherein, the current power-on phase of the motor is two adjacent phases.

Specifically, in the normal operation process of the reactor, the actions related to the control rod drive mechanism include lifting, descending and holding (i.e. hovering at the current position) to realize introducing reactivity change, so as to realize reactor starting, reactor power regulation, reactor power maintenance and the like; the control rod driving mechanism comprises a transmission assembly, the transmission assembly is connected with the control rod assembly, and the transmission assembly provides driving force through a power source to realize control rod position adjustment.

The reactor rod control and rod position indication system (for example, comprising control modules for realizing the functions of signal acquisition, logic linkage, calculation, network communication and the like) outputs instructions to the motor driving device according to the operation requirements of the reactor, and the motor driving device controls the motor to operate according to the instructions so as to drive the control rod driving mechanism to execute the relevant rod position adjustment. When the reactor needs to be opened or power is regulated, the reactor rod control and rod position indicating system outputs action signals to the motor driving device, wherein the action signals comprise lifting signals or descending signals which respectively correspond to the lifting or descending actions of the control rod driving mechanism at the next moment; when the reactor needs to be maintained at a certain power level, the reactor rod control and rod position indicating system outputs a holding signal to the motor drive device, which indicates that the motor is in an electric static state (at this time, the motor is electrified but not rotated; referred to as a holding state of the motor in this application), so that the motor controls the control rod drive mechanism to be kept in a current position and not to move.

Further, the motor driving device controls the motor to operate based on the rotation direction of the motor, the rotation speed of the motor and the like according to the received command signal, for example, the motor driving device enables each phase of wheel current of the motor to be electrified according to a certain electrifying sequence and controls the motor to rotate forwards or backwards, so that the motor drives the control rod driving mechanism to lift or descend; when the control rod driving mechanism needs to stay at the current position, the motor driving device controls the current electrified phase of the motor to output direct current, and provides proper holding torque for the motor, so that the motor stops rotating.

The motor is a stepping motor, and the number of phases of the motor is, for example, three, four, or more than four. When the motor is electrified in a certain sequence, the motor rotates, and in the process, the number of electrified phases of the motor at the same time is one phase or two phases; when the motor needs to enter a holding state from a rotating state, adjusting the current electrified phase number of the motor into two phases and providing direct current for the two phases; therefore, when the motor is in a holding state, the motor adopts a mode of conducting direct current to two adjacent phases, and compared with the mode that the motor adopts a mode of conducting and holding single phase, the control rod driving mechanism can be prevented from influencing normal operation of the reactor due to direct power failure of the motor caused by single phase fault (namely, the phase can not normally output current) when the motor is electrified, and further caused by abnormal driving of the control rod driving mechanism (for example, accidents such as control rod dropping and reactor shutdown forced by rod dropping of the control rod); meanwhile, compared with a single-phase power-on maintaining mode, the double-phase power-on maintaining mode can output larger maintaining torque, reduces the current amplitude of the winding, is beneficial to reducing the current capacity of components and prolongs the service life of the motor.

In some embodiments, when the motor is in an electric static state and one of the two adjacent phases which are electrified currently has a driving fault, the other phase is enabled to output direct current, and the power supply of the fault phase is disconnected.

In order to further improve the regulation flexibility of the control rod driving mechanism and improve the operation reliability of the reactor, when the motor is in a holding state, the motor has the capability of keeping single-phase direct current, namely when one of the two electrified phases has a fault (the fault refers to the fault of the motor driving device for controlling the phase, so that the phase cannot normally output current), the power supply of the fault phase is disconnected, and the other phase is kept to continuously output direct current (the single-phase direct current can provide enough holding torque for the motor), at the moment, the motor can still be in the holding state, so that the control rod driving mechanism is kept hovering at the current position.

From this, when the motor is in the hold condition, the motor has two looks logical direct current concurrently and keeps and the ability that single-phase logical direct current keeps, and it provides the advantage for drive arrangement carries out online maintenance, if one of them looks trouble appears when two looks logical direct current promptly, at this moment, can make the motor carry out single-phase logical direct current and keep, and needn't make the motor cut off the power supply completely, in order to reduce the influence of trouble to the reactor operation, can carry out online maintenance to the drive arrangement of trouble simultaneously, thereby improve maintenance efficiency.

In some of these embodiments, the number of phases of the motor is four; when the motor rotates, the power-on phases of the motor at the same time are controlled to be two phases.

Referring to fig. 1, the motor is, for example, a four-phase 8/6-pole switched reluctance motor (i.e., the motor has a stator pole number of 8 and a rotor pole number of 6), and includes a stator 10 and a rotor 11, the stator 10 includes stator salient poles on which motor coils (i.e., windings) A, B, C, D are wound, and the rotor 11 includes rotor salient poles a, a ', b ', c ', wherein two coils diametrically opposite to each other on the stator salient poles are connected together to form one phase, and thus the motor has A, B, C, D four phases. The working principle of the switched reluctance motor is as follows: the rotor salient poles of the motor tend to correspond to the minimum magnetic resistance of the excitation magnetic field, namely the rotor salient poles are opposite to the corresponding stator salient poles.

Referring to fig. 1, the working principle of the motor is (taking the motor working in a single-four-beat manner as an example): switch S_APower on, while S_B、S_C、S_DWhen the rotor salient pole a is disconnected, the rotor salient pole a approaches to the direction of the stator salient pole corresponding to the A-phase winding until the rotor salient pole a is opposite to the stator salient pole corresponding to the A-phase winding (at the moment, the rotor salient pole b is staggered with the stator salient pole corresponding to the B, C-phase winding, and the rotor salient pole c is staggered with the stator salient pole corresponding to the C, D-phase winding); at this time, S is turned off_AIs connected to S_BThe rotor salient pole B approaches to the stator salient pole corresponding to the phase B winding until the rotor salient pole B is opposite to the stator salient pole corresponding to the phase B winding; by analogy, the A, B, C, D four-phase windings are electrified in turn to realize clockwise rotation of the motor rotor, namely, the motor rotates forwards; similarly, when the windings of the phases are sequentially energized in opposite directions, the motor can be reversed.

In the driving process of the control rod driving mechanism, in order to improve the flexibility of the operation state switching of the control rod driving mechanism, when the four-phase motor is used for driving the control rod driving mechanism, when the control rod driving mechanism needs to perform lifting or descending movement, the motor is controlled by the motor driving device to rotate, the motor works in a double four-beat mode, for example, when the motor is electrified according to the electrifying sequence of AB-BC-CD-DA, the motor rotates forwards, and when the motor is electrified according to the electrifying sequence of AB-DA-CD-BC, the motor rotates backwards, so that the control rod driving mechanism is driven to move.

When the motor is in a rotating state, the phase number electrified at the same time is controlled to be two phases, therefore, when the motor needs to be switched from the rotating state to a holding state, the phase number electrified by the motor is already two phases according to the electrifying sequence of the current phase sequence, at the moment, only direct current needs to be provided for the two phases, and the motor can be stopped rotating to enter the holding state by adjusting the current magnitude, so that favorable conditions are provided for switching the running state of the motor.

However, in other embodiments, the motor operates in a single-double eight-beat manner, for example, when the motor is energized in the sequence of a-AB-B-BC-C-CD-D-DA, the motor rotates forward, that is, when the motor is in the rotating state, the number of phases energized at the same time is one or two, so that when the motor needs to be switched from the rotating state to the holding state, if the current number of phases energized by the motor is one, the phases can be switched to the two-phase direct current in the energizing sequence, so as to better maintain the motor in the holding state, and even when a phase fault occurs in the two phases, the requirement is still met by using the other one-phase direct current.

In the above description, the holding state of the motor means that the rotor of the motor is locked and the motor does not perform a rotational motion. For the working mode of the motor, "single", "double" and "beat" mean: "single" means that only one phase winding is energized before and after each switching, "double" means that two phase windings are energized at a time, and "beat" means that one phase winding is switched from one energization state to another energization state and is called a beat.

In some of these embodiments, the number of phases of the motor is three; when the motor rotates, the power-on phases of the motor at the same time are controlled to be two phases.

Specifically, the motor has A, B, C three phases, when the motor works in double three-beat mode, for example, when the motor is electrified according to the electrifying sequence of AB-BC-CA, the motor rotates forwards, and when the motor is electrified according to the electrifying sequence of AB-CA-BC, the motor rotates backwards, thereby driving the control rod driving mechanism to move.

When the motor is in a rotating state, the phase number electrified at the same time is controlled to be two phases, therefore, when the motor needs to be switched from the rotating state to a holding state, according to the electrifying sequence of the current phase sequence, the phase number electrified by the motor is already two phases, at the moment, only direct current needs to be provided for the two phases, and the motor can stop rotating to enter the holding state by adjusting the current magnitude, so that favorable conditions are provided for switching the running state of the motor.

In some embodiments, when the current power-on phase of the motor outputs direct current, the output direct current is controlled to be lower than the current amplitude output when the motor rotates.

In the process of driving the motor, a control module of the driving device converts an operation instruction into a time sequence pulse signal such as a triangular wave, and then the driving device converts the pulse signal into the angular displacement of the stepping motor, so that the forward rotation or the reverse rotation of the motor is realized. The pulse signal waveform is, for example, a triangular wave, when the motor rotates and operates, each phase outputs current (with current amplitude) according to the electrifying sequence, further, when the direct current is provided for the electrified phase, the motor is switched to a holding state, in order to reduce the heat productivity of the motor coil, on the premise that the direct current can provide enough holding torque, the size of the direct current can be adjusted to be lower than the current amplitude, for example, the direct current with half of the current amplitude is provided for the electrified phase, so that the motor is in the holding state, therefore, when the motor needs to be held for a long time, the heat productivity of the motor can be reduced, and the service life of the motor can be prolonged.

Referring to fig. 1 to 3, the present invention provides a preferred embodiment of a driving method of a control rod driving mechanism for a fast reactor, wherein a driving power source is a four-phase 8/6-pole switched reluctance motor as an example, the motor has A, B, C, D four phases, and a winding coil of the four-phase winding of the motor is connected to a motor driving device through a power cable, as shown in fig. 2, an electrical signal output by the motor driving device 20 is transmitted to a stator winding 21 of the motor through the power cable to generate an electromagnetic torque to drive a rotor of the motor to rotate, so that the motor converts the electromagnetic energy into mechanical energy to drive the control rod driving mechanism; the driving method comprises the following steps:

the reactor rod control and rod position indicating system outputs an action signal '1' to the motor driving device and indicates lifting operation, the motor driving device enables the motor to be electrified according to the electrifying sequence of AB-BC-CD-DA according to corresponding pulse signals, at the moment, the motor rotates forwards, and the motor drives the control rod driving mechanism to carry out lifting motion;

the reactor rod control and rod position indicating system outputs an action signal '1' to the motor driving device and indicates descending operation, the motor driving device enables the motor to be electrified according to the electrifying sequence of AB-DA-CD-BC according to a corresponding pulse signal, and at the moment, the motor rotates reversely and drives the control rod driving mechanism to descend;

when the control rod driving mechanism moves to a target position and needs to stay at the position, the reactor rod control and rod position indicating system outputs a holding signal '0' to the motor driving device, the motor driving device provides direct current to the current adjacent two phases (AB/BC/CD/DA) according to the electrifying sequence, and the power supplies of the other two phases are disconnected, at the moment, the motor rotor is not moved, the motor enters a holding state, and the control rod driving mechanism is also in the holding state;

when one of the two adjacent phases has a drive fault, the power supply of the fault phase is cut off, and the other phase is continuously electrified with direct current, and at the moment, the motor is still in a holding state.

Therefore, according to the driving method provided by the embodiment of the invention, the holding state of the motor is realized by adopting a mode of enabling two adjacent motors to be communicated with direct current, and compared with a holding mode of single-phase direct current, the holding method can output larger holding torque, so that the holding (hovering) capacity of the control rod driving mechanism is improved;

furthermore, the mode that adopts double-phase current-carrying direct current to make the motor be in the hold state provides the precondition for realizing the online maintenance of motor drive arrangement, compares in adopting single-phase hold mode, can avoid causing control rod drive mechanism to drop because of the current interruption that the motor looks switch arouses when drive arrangement trouble, influences nuclear power plant's normal operating.

Referring to fig. 3, a schematic diagram of the output current of the motor in different operating states is shown. When the motor rotates forwards or backwards, the motor driving device provides a triangular wave pulse signal to the motor, and the current amplitude is 10A; when the motor enters a holding state, according to the electrifying sequence, if the motor is electrified by two BC phases, the driving device provides direct current, so that B, C phases output 4A direct current; therefore, the current capacity of the components is reduced while sufficient holding torque is provided, the heat productivity of the motor is reduced, and the service life of the motor is prolonged.

It should also be noted that, in the case of the embodiments of the present invention, features of the embodiments and examples may be combined with each other to obtain a new embodiment without conflict.

The above description is only an embodiment of the present invention, but the scope of the present invention is not limited thereto, and the scope of the present invention is subject to the scope of the claims.