Reliable power supply system of control rod driving mechanism in nuclear power station and switch monitoring method thereof

Abstract

The invention provides a reliable power supply system for a control rod driving mechanism in a nuclear power station and a switch monitoring method thereof. One power supply in the two power supplies is a three-phase alternating-current power supply, and the other power supply is a direct-current power supply. The three-phase alternating-current power supply is provided with an independent alternating-current power supply loop, and the direct-current power supply is provided with an independent direct-current power supply loop. The three-phase alternating-current power supply is used for generating time sequence current through an alternating-current power supply loop in the normal operation period and supplying power to a lifting coil, a transmission coil and a holding coil of a control rod driving mechanism in the nuclear power station. The direct-current power supply is used for generating a direct-current power supply through a direct-current power supply loop when alternating-current power supply fails and supplying power to a transmission coil and a holding coil of a control rod driving mechanism in the nuclear power station. According to the invention, redundant power supply input combining the three-phase alternating current power supply and the direct current power supply is adopted, so that the technical problem of shutdown risk caused by power supply input faults in the prior art is solved.

Description

Technical Field

[0001] The present application belongs to the field of nuclear power technology, and specifically relates to a reliable power supply system for a control rod drive mechanism in a nuclear power plant and a switch monitoring method thereof. Background Art

[0002] The power supply system of the control rod drive mechanism in a nuclear power plant provides the three sets of coils of the drive mechanism (lifting coil, transfer coil and holding coil) with timing current that meets their accuracy and response speed. Each coil of the drive mechanism generates corresponding actions according to the timing current provided, thereby completing the lifting, insertion, holding and dropping operations of the control rods.

[0003] The traditional drive mechanism power supply system is powered by a single three-phase AC power supply. A failure in the three-phase AC power input can easily lead to a power failure in the drive mechanism power supply system, causing accidental drop of control rods, which in turn leads to the risk of shutdown and affects the economic efficiency of nuclear power plant operation. Summary of the invention

[0004] In view of this, the present application is committed to providing a reliable power supply system for a control rod drive mechanism in a nuclear power plant and a switch monitoring method thereof, which adopts a redundant power supply input combining a three-phase AC power supply and a DC power supply to solve the existing technical problem of the risk of shutdown caused by power supply input failure.

[0005] The first aspect of the present application provides a reliable power supply system for a control rod drive mechanism in a nuclear power plant, wherein the reliable power supply system for the control rod drive mechanism in the nuclear power plant is powered by a dual power supply. One of the dual power supplies is a three-phase AC power supply, and the other is a DC power supply. The three-phase AC power supply is configured with an independent AC power supply circuit, and the DC power supply is configured with an independent DC power supply circuit. The three-phase AC power supply is used to generate a timing current through the AC power supply circuit during normal operation, and respectively power the lifting coil, transfer coil and holding coil of the control rod drive mechanism in the nuclear power plant. The DC power supply is used to generate a DC power supply through the DC power supply circuit when the AC power supply fails, and respectively power the transfer coil and holding coil of the control rod drive mechanism in the nuclear power plant.

[0006] In a specific embodiment of the present application, four switches are provided in the DC power supply circuit, and the four switches include a first switch T1, a second switch T2, a third switch T3 and a fourth switch T4. The first switch T1 and the second switch T2 are connected in parallel to the power supply input terminal of the drive mechanism coil, and the third switch T3 and the fourth switch T4 are connected in parallel to the power supply output terminal of the drive mechanism coil.

[0007] In a specific embodiment of the present application, the first switch T1 and the second switch T2 are located at the positive end of the DC power supply and the input end of the drive mechanism coil, and the third switch T3 and the fourth switch T4 are located at the negative end of the DC power supply and the output end of the drive mechanism coil.

[0008] In a specific implementation of the present application, four switches are used to be opened simultaneously when an AC power supply failure occurs.

[0009] In a specific embodiment of the present application, a current monitoring unit is provided in both the holding coil and the transfer coil.

[0010] In a specific embodiment of the present application, a current monitoring unit is provided in the lifting coil.

[0011] A second aspect of the present application provides a method for monitoring the switches of a DC power supply circuit in a reliable power supply system of a control rod drive mechanism in a nuclear power plant. The method for monitoring the switches of a DC power supply circuit in a reliable power supply system of a control rod drive mechanism in a nuclear power plant comprises: when a DC power supply supplies power to a transfer coil, performing online detection of switches in a DC power supply circuit for holding the coil; when a DC power supply supplies power to a holding coil, performing online detection of switches in a DC power supply circuit for holding the coil.

[0012] In a specific embodiment of the present application, when the DC power supply supplies power to the transmission coil, an online detection of the switches in the DC power supply circuit of the coil is performed, including: when the DC power supply supplies power to the transmission coil, first open the first switch T1 and the second switch T2, keep the fourth switch T4 disconnected, and then open the third switch T3 to obtain a first current state; when the DC power supply supplies power to the transmission coil, first open the first switch T1 and the second switch T2, keep the third switch T3 disconnected, and then open the fourth switch T4 to obtain a second current state; if the first current state is consistent with the second current state, it is judged that the switches T3 and T4 are normal. When the DC power supply supplies power to the transmission coil, first open the third switch T3 and the fourth switch T4, keep the second switch T2 disconnected, and then open the first switch T1 to obtain a third current state; when the DC power supply supplies power to the transmission coil, first open the third switch T3 and the fourth switch T4, keep the first switch T1 disconnected, and then open the second switch T2 to obtain a fourth current state; if the third current state is consistent with the fourth current state, it is judged that the switches of the first switch T1 and the second switch T2 are normal.

[0013] In a specific embodiment of the present application, when the DC power supply is used to power the holding coil, the switch in the DC power supply circuit of the transfer coil is detected online, including: when the DC power supply is used to power the holding coil, the first switch T1 and the second switch T2 are first opened, the fourth switch T4 is kept disconnected, and then the third switch T3 is opened to obtain the first current state; when the DC power supply is used to power the holding coil, the first switch T1 and the second switch T2 are first opened, the third switch T3 is kept disconnected, and then the fourth switch T4 is opened to obtain the second current state; if the first current state is consistent with the second current state, it is judged that the switches T3 and T4 are normal. When the DC power supply is used to power the holding coil, the third switch T3 and the fourth switch T4 are first opened, the second switch T2 is kept disconnected, and then the first switch T1 is opened to obtain the third current state; when the DC power supply is used to power the holding coil, the third switch T3 and the fourth switch T4 are first opened, the first switch T1 is kept disconnected, and then the second switch T2 is opened to obtain the fourth current state; if the third current state is consistent with the fourth current state, it is judged that the switches T1 and T2 are normal.

[0014] The beneficial effect of the technical solution of the present application is that by adopting a redundant power supply input combining a three-phase AC power supply and a DC power supply, and arranging the AC power supply circuit and the DC power supply circuit to work at different times, it is ensured that the reliable power supply system of the control rod drive mechanism in the nuclear power plant can effectively provide the required current to the drive mechanism according to the working state (i.e. during normal operation or AC power supply failure), thereby realizing reliable power supply to the drive mechanism load, effectively avoiding the loss of power to the drive mechanism coil due to a single switch failure (open circuit and short circuit), effectively eliminating the risk of rod falling caused by a single power supply failure, reducing the existing risk of shutdown caused by power supply input failure, and improving the economy and safety of nuclear power plant operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 Shown is a schematic structural diagram of a reliable power supply system for a control rod drive mechanism in a nuclear power plant provided by an embodiment of the present application.

[0016] Figure 2 Shown is a schematic diagram of a switch design for a DC power supply circuit in a reliable power supply system for a control rod drive mechanism in a nuclear power plant provided by an embodiment of the present application. DETAILED DESCRIPTION

[0017] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0018] At least one embodiment of the present application provides a reliable power supply system for a control rod drive mechanism in a nuclear power plant, referring to Figure 1 The reliable power supply system of the control rod drive mechanism in the nuclear power plant is powered by a dual power supply. One of the dual power supplies is a three-phase AC power supply (input 1), and the other is a DC power supply (input 2). The three-phase AC power supply is configured with an independent AC power supply circuit, and the DC power supply is configured with an independent DC power supply circuit. The three-phase AC power supply is used to generate a timing current through the AC power supply circuit during normal operation, and respectively supply power to the lifting coil, transfer coil and holding coil of the control rod drive mechanism in the nuclear power plant. The DC power supply is used to generate a DC power supply through the DC power supply circuit when the AC power supply fails, and respectively supply power to the transfer coil and holding coil of the control rod drive mechanism in the nuclear power plant.

[0019] According to the technical solution provided in the embodiment of the present application, by adopting a redundant power supply input combining a three-phase AC power supply and a DC power supply, and arranging the AC power supply circuit and the DC power supply circuit to work at different times, it is ensured that the reliable power supply system of the control rod drive mechanism in the nuclear power plant can effectively provide the required current to the drive mechanism according to the working state (i.e. during normal operation or AC power supply failure), thereby achieving reliable power supply to the drive mechanism load, effectively avoiding the loss of power to the drive mechanism coil due to a single switch failure (open circuit and short circuit), effectively eliminating the risk of rod falling caused by a single power supply failure, reducing the existing risk of shutdown due to power supply input failure, and improving the economy and safety of nuclear power plant operation.

[0020] In at least one embodiment of the present application, reference Figure 2 The DC power supply circuit is provided with four switches, including a first switch T1, a second switch T2, a third switch T3 and a fourth switch T4. The first switch T1 and the second switch T2 are connected in parallel to the power supply input terminal of the drive mechanism coil, and the third switch T3 and the fourth switch T4 are connected in parallel to the power supply output terminal of the drive mechanism coil.

[0021] In at least one embodiment of the present application, the first switch T1 and the second switch T2 are located at the positive end of the DC power supply and the input end of the drive mechanism coil, and the third switch T3 and the fourth switch T4 are located at the negative end of the DC power supply and the output end of the drive mechanism coil.

[0022] In at least one embodiment of the present application, four switches are used to be opened simultaneously when an AC power supply fails. In this way, when an AC power supply fails, switches T1 to T4 in the DC power supply circuit are opened simultaneously, which can avoid the DC power supply being unable to be disconnected or opened due to any switch failure (short circuit or open circuit).

[0023] In at least one embodiment of the present application, a current monitoring unit is provided in both the holding coil and the transfer coil, so that the current passing through the holding coil and the transfer coil is monitored in real time by the current monitoring unit.

[0024] In at least one embodiment of the present application, a current monitoring unit is provided in the lifting coil, so that the current passing through the lifting coil is monitored in real time by the current monitoring unit.

[0025] At least one embodiment of the present application also provides a switch monitoring method for a DC power supply circuit in a reliable power supply system of a control rod drive mechanism in a nuclear power plant. The switch monitoring method for a DC power supply circuit in a reliable power supply system of a control rod drive mechanism in a nuclear power plant includes the following steps.

[0026] S1: When the DC power supply is supplying power to the transfer coil, an online detection of the switch in the DC power supply circuit of the holding coil is performed.

[0027] S2: When the DC power supply is supplying power to the holding coil, an online detection of the switch in the DC power supply circuit of the transfer coil is performed.

[0028] It should be noted that when the switch state of the DC power supply circuit of the transfer coil (or holding coil) is detected, the DC power supply circuit of the holding coil (or transfer coil) can be put into operation.

[0029] According to the technical solution provided in the embodiment of the present application, by adopting two different types of power inputs and designing online detection of the drive mechanism power supply circuit and its switch devices, the control goal of preventing the control rod from accidentally falling due to damage to a single switch device is achieved. The new solution realizes reliable power supply to the drive mechanism load and improves the economy and safety of nuclear power plant operation.

[0030] For example, in some embodiments, S1.1 to S1.6 are a specific implementation of the above S1.

[0031] S1.1: When the DC power supply supplies power to the transfer coil, first turn on the first switch T1 and the second switch T2, keep the fourth switch T4 off, and then turn on the third switch T3 to obtain a first current state.

[0032] S1.2: When the DC power supply supplies power to the transfer coil, first turn on the first switch T1 and the second switch T2, keep the third switch T3 off, and then turn on the fourth switch T4 to obtain a second current state.

[0033] S1.3: If the first current state is consistent with the second current state, it is determined that switches T3 and T4 are normal.

[0034] S1.4: When the DC power supply supplies power to the transfer coil, first turn on the third switch T3 and the fourth switch T4, keep the second switch T2 off, and then turn on the first switch T1 to obtain a third current state.

[0035] S1.5: When the DC power supply supplies power to the transfer coil, first turn on the third switch T3 and the fourth switch T4, keep the first switch T1 off, and then turn on the second switch T2 to obtain a fourth current state.

[0036] S1.6: If the third current state is consistent with the fourth current state, it is determined that switches T1 and T2 are normal.

[0037] In some embodiments, S2.1 to S2.6 are a specific implementation of the above S2.

[0038] S2.1: When the DC power supply supplies power to the holding coil, first turn on the first switch T1 and the second switch T2, keep the fourth switch T4 off, and then turn on the third switch T3 to obtain the fifth current state.

[0039] S2.2: When the DC power supply is supplying power to the holding coil, the first switch T1 and the second switch T2 are first turned on, the third switch T3 is kept off, and then the fourth switch T4 is turned on to obtain the sixth current state.

[0040] S2.3: If the fifth current state is consistent with the sixth current state, it is determined that switches T3 and T4 are normal.

[0041] S2.4: When the DC power supply is supplying power to the holding coil, the third switch T3 and the fourth switch T4 are first turned on, the second switch T2 is kept off, and then the first switch T1 is turned on to obtain the seventh current state.

[0042] S2.5: When the DC power supply supplies power to the holding coil, first turn on the first switch T1 and the second switch T2, keep the first switch T1 off and then turn on the second switch T2 to obtain the eighth current state.

[0043] S2.6: If the seventh current state is consistent with the eighth current state, it is determined that switches T1 and T2 are normal.

[0044] In a nuclear power rod control position system prototype development project, the reliable power supply system for the control rod drive mechanism in the nuclear power plant provided by the embodiment of the present application has been tested and verified. The test results show that the reliable power supply system for the control rod drive mechanism in the nuclear power plant effectively avoids the loss of power to the drive mechanism coil due to a single switch failure (open circuit and short circuit), effectively eliminates the risk of rod falling caused by a single power supply failure, and improves the operating safety of the nuclear power plant.

[0045] It should be noted that the combination of the various technical features in the embodiments of the present application is not limited to the combination described in the embodiments of the present application or the combination described in the specific embodiments, and all technical features described in the present application can be freely combined or combined in any way unless there is a contradiction between them.

[0046] As shown in this application and claims, unless the context clearly indicates an exception, the words "a", "an" and / or "the" do not refer to the singular and may also include the plural. Generally speaking, the terms "include" and "comprise" only indicate the inclusion of the steps and elements that have been clearly identified, and these steps and elements do not constitute an exclusive list. The method or device may also include other steps or elements.

[0047] The terms "first", "second" and the like are used for descriptive purposes only and are not to be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, it is defined that "first", "second" and the like features may explicitly or implicitly include one or more of the features.

[0048] The above description is only a preferred embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent substitutions, etc. made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A reliable power supply system for a control rod drive mechanism in a nuclear power plant, characterized in that: Powered by dual power supplies, Among them, one of the two power sources is a three-phase AC power source, and the other power source is a DC power source; The three-phase AC power supply is equipped with an independent AC power supply circuit, and the DC power supply is equipped with an independent DC power supply circuit; The three-phase AC power supply is used to generate sequential current through the AC power supply circuit during normal operation to supply power to the lifting coil, transfer coil and holding coil of the control rod drive mechanism in the nuclear power plant; The DC power supply is used to generate DC power through the DC power supply circuit when the AC power supply fails, and supply power to the transfer coil and holding coil of the control rod drive mechanism in the nuclear power plant respectively.

2. A reliable power supply system for a control rod drive mechanism in a nuclear power plant according to claim 1, characterized in that: The DC power supply circuit is provided with 4 switches, including a first switch, a second switch, a third switch and a fourth switch; the first switch and the second switch are connected in parallel to the power supply input terminal of the drive mechanism coil, and the third switch and the fourth switch are connected in parallel to the power supply output terminal of the drive mechanism coil.

3. A reliable power supply system for a control rod drive mechanism in a nuclear power plant according to claim 2, characterized in that: The first switch and the second switch are located at the positive end of the DC power supply and the input end of the drive mechanism coil, and the third switch and the fourth switch are located at the negative end of the DC power supply and the output end of the drive mechanism coil.

4. A reliable power supply system for a control rod drive mechanism in a nuclear power plant according to claim 2, characterized in that: The four switches are used to be opened simultaneously when the AC power supply fails.

5. A reliable power supply system for a control rod drive mechanism in a nuclear power plant according to any one of claims 1 to 4, characterized in that: Current monitoring units are provided in both the holding coil and the transfer coil.

6. A reliable power supply system for a control rod drive mechanism in a nuclear power plant according to claim 1, characterized in that: A current monitoring unit is provided in the lifting coil.

7. A switch monitoring method for a DC power supply circuit in a reliable power supply system for a control rod drive mechanism in a nuclear power plant, characterized in that: include: When the DC power supply supplies power to the transfer coil, an online detection of the switch in the DC power supply circuit of the holding coil is performed; When the DC power supply is supplying power to the holding coil, an online detection of the switch in the DC power supply circuit of the transfer coil is performed.

8. A switch monitoring method for a DC power supply circuit in a reliable power supply system for a control rod drive mechanism in a nuclear power plant according to claim 7, characterized in that: When the DC power supply is supplying power to the transfer coil, the switch in the DC power supply circuit of the holding coil is tested online, including: When the DC power supply supplies power to the transfer coil, the first switch and the second switch are first turned on, the fourth switch is kept off, and then the third switch is turned on to obtain a first current state; When the DC power supply supplies power to the transfer coil, the first switch and the second switch are first turned on, the third switch is kept off, and then the fourth switch is turned on to obtain a second current state; If the first current state is consistent with the second current state, it is determined that the third switch and the fourth switch are normal; When the DC power supply supplies power to the transfer coil, the third switch and the fourth switch are first turned on, the second switch is kept off, and then the first switch is turned on to obtain a third current state; When the DC power supply supplies power to the transfer coil, the third switch and the fourth switch are first turned on, the first switch is kept off, and then the second switch is turned on to obtain a fourth current state; If the third current state is consistent with the fourth current state, it is determined that the first switch and the second switch are normal.

9. A switch monitoring method for a DC power supply circuit in a reliable power supply system for a control rod drive mechanism in a nuclear power plant according to claim 7, characterized in that: When the DC power supply is supplying power to the holding coil, the switch in the DC power supply circuit of the transfer coil is tested online, including: When the DC power supply supplies power to the holding coil, the first switch and the second switch are first turned on, the fourth switch is kept off, and then the third switch is turned on to obtain a first current state; When the DC power supply supplies power to the holding coil, the first switch and the second switch are first turned on, the third switch is kept off, and then the fourth switch is turned on to obtain a second current state; If the first current state is consistent with the second current state, it is determined that the third switch and the fourth switch are normal; When the DC power supply supplies power to the holding coil, the third switch and the fourth switch are first turned on, the second switch is kept off, and then the first switch is turned on to obtain a third current state; When the DC power supply supplies power to the holding coil, the third switch and the fourth switch are first turned on, the first switch is kept off, and then the second switch is turned on to obtain a fourth current state; If the third current state is consistent with the fourth current state, it is determined that the first switch and the second switch are normal.

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