Control system of nuclear power steam turbine and reliability analysis method

Abstract

The invention discloses a control system of a nuclear power steam turbine and a reliability analysis method, and aims to solve the problem that reliability analysis and verification cannot be comprehensively carried out on a steam turbine main system. The control system of the nuclear power steam turbine comprises a steam turbine main system, a backboard signal damage tester and a tested board card. The steam turbine main system comprises a main frame, a redundant frame and a generator excitation regulator, the generator excitation regulator is respectively connected with communication modules of the main frame and the redundant frame, and the central controller modules are communicated through redundant optical fibers; the backboard signal damage tester comprises a backboard connector, a test circuit module and a board card connector, the test circuit module comprises a processor, a programmable logic device and a switch, one connecting end of the switch is connected to a backboard bus of a backboard of the rack through the backboard connector, the other connecting end of the switch is connected to a tested board card corresponding to the rack through the board card connector, and the tested board card is connected with the processor. The control end is connected with the programmable logic device, the programmable logic device is connected with the processor, and the processor is connected to the industrial computer.

Description

Technical Field

[0001] The present invention relates to the field of nuclear power, and in particular to a control system of a nuclear power steam turbine and a reliability analysis method. Background Art

[0002] The Turbine Control System (TCS) of a nuclear power plant, also known as the main system or control system of the turbine, is a key component of nuclear power generation. It is mainly used to regulate and control the operation of the turbine (hereinafter referred to as the turbine) to ensure that it works under safe and efficient conditions. The main task of the turbine is to convert steam energy into mechanical energy and convert it into electrical energy through the generator. Therefore, TCS needs to have high precision, high reliability and redundancy to meet the strict safety requirements of nuclear power plants. The main system TCS of the turbine consists of two rows of racks, which are redundant to each other. The two rows of racks include the required working modules. Among them, the manufacturer will conduct certain tests on the reliability of the two rows of racks, but the content and details of the test are kept confidential to the end user. Generally, only the functions of the system itself are introduced to the end user. For example, the redundant equipment will not affect the overall function of the system in the event of a single failure. Redundant equipment will quickly replace the failed equipment after other equipment fails.

[0003] However, in the production practice of nuclear power plants, there have been many cases where manufacturers claimed that there was a redundant design but actually failed to reflect the redundant function. In the subsequent troubleshooting process, the manufacturer found that its redundant design had defects. In the existing technology, fault injection is usually performed by cutting off the power to the modules in the rack, unplugging the communication cables connected to the modules, etc., so as to conduct reliability analysis on the main system of the steam turbine. However, these methods can only cover a part of the failure modes. For example, when simulating the loose wiring failure mode in the Distributed Control System (DCS), the existing technology can only simulate the situation where all contact wire cores are loose or disconnected. It can be seen that the existing technology is actually unable to comprehensively verify the reliability of the steam turbine control system. Summary of the invention

[0004] The embodiments of the present invention provide a control system of a nuclear power steam turbine and a reliability analysis method to solve the problem that the traditional solution cannot fully verify the reliability of the steam turbine control system.

[0005] A control system for a nuclear power steam turbine, the control system for the nuclear power steam turbine comprising a steam turbine main system, a backplane signal damage tester, and a tested board corresponding to a working module of a main rack or a redundant rack; The steam turbine main system includes the main frame, redundant frame, generator excitation regulator and communication IO card for controlling the steam turbine. The main frame and redundant frame respectively include power supply module, central controller module, function controller module and communication module. The generator excitation regulator is connected to the communication module of the main frame and the communication module of the redundant frame respectively. The central controller module of the main frame communicates with the central controller module of the redundant frame through redundant optical fiber. The working modules of the same column frame communicate with each other through the backplane bus of the frame backplane. The communication IO card for controlling the steam turbine is connected to the function controller modules on the main frame and the redundant frame respectively through two field buses. The backplane signal damage tester includes a backplane connector, a test circuit module, a board connector and an industrial computer communication interface. The test circuit module includes a processor, a first programmable logic device and N switches, where N is greater than 1. One connection end of the switch is connected to the backplane bus of the rack backplane via the backplane connector, and the other connection end of the switch is connected to the tested board corresponding to the working module of the main rack or redundant rack via the board connector; the control end of the switch is connected to the first programmable logic device, the first programmable logic device is connected to the processor, and the processor is connected to the industrial computer via the industrial computer communication interface; The first programmable logic device is used to respond to the control of the processor and perform an independent simulated damage test on each signal of the field bus to obtain a test result of each signal channel; The independent simulated damage test is performed on each signal of the field bus to obtain the test result of each signal channel, including: simulating the on and off, connection time, disconnection time and number of on and off times of each signal switch to obtain the test result of each signal coming from the backplane bus.

[0006] In one implementation, the control system of the nuclear power steam turbine further includes an RS485 fault damage tester; The RS485 fault damage tester includes two RS485 interfaces, two RS485 transceivers and a second programmable logic device; wherein the RS485 interface includes a first interface and a second interface, one end of the first interface is connected to the function controller module of the main rack of the field bus, and one end of the second interface is connected to the function controller module of the redundant rack of the field bus; the RS485 transceiver includes a first transceiver and a second transceiver, one end of the first transceiver is connected to the first interface, and one end of the second transceiver is connected to the second interface; one end of the second programmable logic device is connected to the other end of the first transceiver, and the other end of the second programmable logic device is connected to the other end of the second transceiver.

[0007] In one implementation, the control system further includes a controllable light attenuator; The controllable optical attenuator is serially connected to the redundant optical fiber between the central processing unit module of the main rack and the central processing unit module of the redundant rack; The controllable optical attenuator is used to simulate the fault condition of the redundant optical fiber, and the fault condition of the redundant optical fiber includes abnormal optical signal attenuation caused by poor contact or bending fault of the redundant optical fiber.

[0008] A reliability analysis method for a nuclear power steam turbine control system, wherein the nuclear power steam turbine control system is the control system mentioned above, and the analysis method comprises: Through the backplane signal damage tester, each signal in the main rack or redundant rack is subjected to an independent simulated damage test to obtain the test result of each signal channel, wherein, through the control of the first programmable logic device in response to the processor, each signal of the field bus is subjected to an independent simulated damage test to obtain the test result of each signal channel; the independent simulated damage test of each signal of the field bus is subjected to the test result of each signal channel, including: simulating the on-off, connection time, disconnection time and number of on-off times of each signal switch to obtain the test result of each signal coming from the backplane bus; By means of the RS485 fault damage tester, fault injection is respectively performed on the communication link of the field bus to which each of the RS485 fault damage testers is serially connected, so as to obtain the test result of each communication link; The test results of each signal channel and the test results of each communication circuit are analyzed to obtain an analysis conclusion on the reliability of the steam turbine main system.

[0009] In one implementation, the RS485 fault damage tester is used to perform fault injection on each communication link of the field bus connected in series with the RS485 fault damage tester to obtain a test result of each communication link, including: The second programmable logic device of the RS485 fault damage tester is used to control the RS485 transceiver of the RS485 fault damage tester to achieve fault injection into the communication link of the field bus and obtain the test result of the communication link of the field bus; the fault injection method is used to simulate the fault of the communication link of the field bus.

[0010] In one implementation, the programmable logic device of the RS485 fault damage tester is used to control the RS485 transceiver of the RS485 fault damage tester to achieve fault injection into the communication link of the field bus, including: Using the programmable logic device, the RS485 transceiver is controlled to achieve fault injection into the physical layer of the communication link; The programmable logic device is used to control the RS485 transceiver to implement fault injection into the protocol layer of the communication link.

[0011] In one implementation, the physical layer fault injection or the protocol layer fault injection respectively includes a steady-state injection mode, an intermittent injection mode, a step injection mode and a queue injection mode; The steady-state injection mode indicates that fault injection is continuously performed with set parameters; The intermittent injection mode represents intermittent fault injection at a set time regularity; The step injection mode indicates that the fault injection parameters are dynamically adjusted according to the set step rule; The queue injection mode represents dynamically adjusting fault injection parameters according to a set parameter list.

[0012] In one implementation, the physical layer fault injection includes open circuit, line short circuit, short circuit to ground, bridge fault, serial impedance and parallel impedance simulation injection; wherein the second programmable logic device is used to dynamically adjust the size of the parallel impedance.

[0013] In one implementation, the fault injection of the protocol layer includes protocol message replacement, protocol message loss and bit error generation on the communication link.

[0014] In the above-mentioned scheme, through one or more different testers, the coverage of different fault modes of the nuclear power steam turbine control system fault injection method can be effectively improved. After using the system to simulate the aforementioned fault modes, the effectiveness of the system's redundant fault-tolerant design can be effectively verified, and false redundancy events caused by inadequate design considerations can be avoided, thereby achieving comprehensive and complete reliability verification of the steam turbine control system. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for use in the description of the embodiments of the present invention will be briefly introduced below. Obviously, the accompanying drawings in the following description are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative labor.

[0016] Figure 1 is a schematic diagram of a control system of a nuclear power steam turbine in one embodiment of the present invention; Figure 2 It is a partial schematic diagram of a control system of a nuclear power steam turbine in one embodiment of the present invention; Figure 3It is a partial schematic diagram of a control system of a nuclear power steam turbine in one embodiment of the present invention; Figure 4 It is a schematic diagram of a backplane signal damage tester of a control system of a nuclear power steam turbine in one embodiment of the present invention; Figure 5 It is a partial schematic diagram of a control system of a nuclear power steam turbine in one embodiment of the present invention; Figure 6 It is a partial schematic diagram of a control system of a nuclear power steam turbine in one embodiment of the present invention; Figure 7 It is a schematic diagram of an RS485 fault damage tester for a control system of a nuclear power steam turbine in one embodiment of the present invention; Figure 8 It is another schematic diagram of a control system of a nuclear power steam turbine in one embodiment of the present invention. DETAILED DESCRIPTION

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

[0018] In order to ensure the safe operation of nuclear power plants, a large number of redundant designs are used in nuclear power plants. The main system TCS of the steam turbine contains a main rack and a redundant rack, which are redundant to each other. Each column of racks contains the same modules, and modules in different columns communicate through redundant optical fibers. When a single fault occurs in a module of the main rack, since the faulty equipment can be switched to the redundant module of the redundant rack in time, it will not cause functional impact on the entire system. Therefore, the working modules of the main rack and the redundant rack in the main system TCS of the steam turbine are crucial to nuclear power safety, and reliability testing of the working modules of the main rack and the redundant rack in the main system TCS of the steam turbine is a very important part of verifying the safety of nuclear power. In the prior art, reliability testing of the working modules of the main rack and the redundant rack in the main system TCS of the steam turbine is usually carried out by powering off the modules on the rack or unplugging the communication cables connected to the modules, thereby realizing reliability verification. However, the above-mentioned fault analysis method can only cover some fault situations, and cannot cover more fault situations, which is very limited. For example, in the case of loose wiring failure, the existing technology can only simulate the situation where all contact wire cores are loose or disconnected, but cannot simulate the situation where only 1-2 wire cores are loose. This results in incomplete and comprehensive reliability testing of the main rack or redundant rack.

[0019] Based on the above problems, a control system of a nuclear power steam turbine is provided in one embodiment of the present invention, wherein the control system of the nuclear power steam turbine comprises a steam turbine main system TCS, a backplane signal damage tester, and a tested board corresponding to a working module of a main rack or a redundant rack; wherein the steam turbine main system TCS is as follows: Figure 1 As shown, the steam turbine main system TCS includes two columns of redundant racks, and the racks include a main rack and a redundant rack, which are redundant. The steam turbine main system includes the main rack, the redundant rack, a generator excitation regulator (GRE) and a communication IO card (such as RAddFem IO card) for controlling the steam turbine. The main rack and the redundant rack respectively include a power module (such as PS405), a central controller module (such as CPU414), a function controller module (FM458 controller) and a communication module (such as CP443-1). The generator excitation regulator is connected to the communication module of the main rack and the communication module of the redundant rack respectively. The central controller module of the main rack communicates with the central controller module of the redundant rack through redundant optical fibers. The working modules of the same column of racks communicate with each other through the backplane bus of the rack backplane. The communication IO card for controlling the steam turbine is connected to the function controller modules on the main rack and the redundant rack respectively through two field buses. In one embodiment, the present application adds at least one of a backplane signal damage tester, an RS485 fault damage tester (RS485 is a standard industrial communication protocol of the physical communication layer), and a controllable optical attenuator to the control system of a nuclear power turbine.

[0020] Among them, backplane signal damage tester, such as Figure 8 As shown in the figure, the redundant rack and the main rack respectively include a backplane bus, a power module, a communication module (such as Ethernet communication, electrical network, optical network, etc.), a function controller module, a central processing unit module, and a field bus (such as Profibus). The redundant rack and the main rack can communicate with the communication IO card through the DPA profibus and the DPB profibus respectively, and specifically through the front-end module (such as Figure 2 The front-end modules 1~6 in the redundant rack are connected to the communication IO card) and so on. Among them, the backplane signal damage tester is located between the backplane bus and the board under test, that is, the backplane signal damage tester is connected in series in the link of the redundant rack's backplane bus. The board under test includes but is not limited to the corresponding board of the working module of the main rack or redundant rack (such as the power module board, central controller module board, function controller module board and communication module board, etc.).

[0021] The IO communication board that controls the steam turbine communicates with the main rack A or redundant rack B through the redundant DP A and DP B Profibus buses (fieldbuses). Among them, IO refers to input / output, and DP refers to Decentralized Periphery, the full name is Profibus DP. Profibus DP has high speed and low cost, and is used for communication between device-level control systems and decentralized IO. DPA corresponds to the fieldbus on the main rack A side, and DPB corresponds to the fieldbus on the main rack B side. The front-end module refers to FEM, also known as the RF front-end module, the full name is Front End Module. The working module of the main rack A or redundant rack B is connected to the RF front-end module through the fieldbus, and the RF front-end module is used to connect to the communication IO card. The backplane signal damage tester is located between the board under test and the backplane bus, and the backplane signal damage tester is controlled by an industrial computer.

[0022] like Figure 3 and 4 As shown, in one embodiment, the backplane signal damage tester includes a backplane connector, a test circuit module, a board connector and an industrial computer communication interface, the test circuit module includes a processor, a first programmable logic device and N switches, N is greater than 1, one connection end of the switch is connected to the backplane bus of the rack backplane through the backplane connector, and the other connection end of the switch is connected to the tested board corresponding to the working module of the main rack or redundant rack through the board connector; the control end of the switch is connected to the first programmable logic device, the first programmable logic device is connected to the processor, and the processor is connected to the industrial computer through the industrial computer communication interface; the first programmable logic device is used to respond to the control of the processor and perform an independent simulated damage test on each signal of the field bus to obtain the test result of each signal channel; the independent simulated damage test on each signal of the field bus to obtain the test result of each signal channel includes: simulating the on-off, connection time, disconnection time and number of on-off times of the switch of each signal to obtain the test result of each signal coming from the backplane bus.

[0023] In this embodiment, a backplane signal damage tester is involved, which is connected in series between the backplane connector and the board under test and is controlled by an industrial computer. The backplane connector is a connector used in large-scale communication equipment, ultra-high performance servers and supercomputers, industrial computers, and high-end storage devices. In actual test scenarios, it is often necessary to test the signal by simulating a variety of different fault types. Therefore, in this embodiment, different fault injection types can be customized through the first programmable logic device, and then the test of different signals can be completed through a variety of interfaces. Signals include but are not limited to high-speed / low-speed signals, digital / analog signals, etc.

[0024] In addition, different types of signals correspond to different switch modules. For example, low-speed signals can use electronic switches, while Ethernet or PCI buses use special chips. There is no specific limitation.

[0025] It should be noted that, since each signal in the backplane signal damage tester corresponds to a switch, and the switch is connected to the first programmable logic device and controlled by an industrial computer, the backplane signal damage tester can actually accurately control the fault simulation of each signal through a computer. Compared with the problem that the prior art cannot simulate the fault of a line core alone, this embodiment can realize comprehensive and complete reliability verification of the steam turbine control system.

[0026] In addition, based on the above-mentioned backplane signal damage tester, it can be seen that in the embodiment of the present application, when analyzing and testing, the connectivity of the signal does not affect the normal operation of the steam turbine main system TCS; each signal except the power / ground signal on the tested board can be subjected to independent damage simulation test at the same time, making the test process more flexible and practical, and the connection time, disconnection time and number of on-off times of each signal can also be set independently, which can cover more actual fault scenarios, and needs to support various test boards. The tested signals include normal low-speed signals, medium-low-speed signals and high-speed signals, covering simulation tests of multiple signals; in addition, a graphical operation interface can be provided through an industrial computer, making the simulation debugging and testing of the backplane signal damage tester more convenient and intuitive, and various operation controls can be realized by connecting to a PC through the management network port.

[0027] In one embodiment, the backplane signal damage tester may also include an automated test interface based on a preset programming language (such as) Python, which is used to input set automated test cases to implement the above simulation test, which is more intelligent.

[0028] In one embodiment, if Figure 4As shown, the waveform of the measured signal (such as signal 1-signal n) can be imported into the oscilloscope to measure the waveform of the measured signal when the on-off fault is injected, and the signal details of the fault are further analyzed using the oscilloscope, so that the reliability analysis is more detailed. In this embodiment, by connecting the oscilloscope to the backplane connector obtained in this case, when the backplane signal damage tester is used to perform simulated damage testing, the waveform of the measured signal during the on-off fault can be continuously measured, and combined with the backplane signal damage tester provided in the embodiment of the present application for analysis, the analysis results can be more comprehensive and detailed.

[0029] It should be noted that by controlling the signals of the backplane bus in the redundant racks one by one, the fault simulation of different line cores was realized, and finally the verification of a large number of signal fault conditions was completed, realizing a comprehensive and complete reliability verification of the steam turbine control system.

[0030] In one embodiment, the function controller module of the main rack communicates with the function controller module of the redundant rack through a field bus, and the control system of the nuclear power steam turbine also includes an RS485 fault damage tester; the RS485 fault damage tester includes two RS485 interfaces, two RS485 transceivers and a second programmable logic device; wherein the RS485 interface includes a first interface and a second interface, one end of the first interface is connected to the function controller module of the main rack of the field bus, and one end of the second interface is connected to the function controller module of the redundant rack of the field bus; the RS485 transceiver includes a first transceiver and a second transceiver, one end of the first transceiver is connected to the first interface, and one end of the second transceiver is connected to the second interface; one end of the second programmable logic device is connected to the other end of the first transceiver, and the other end of the second programmable logic device is connected to the other end of the second transceiver.

[0031] It should be understood that fieldbuses include Profibus and other bus forms. Taking Profibus as an example, this is a bus technology solution based on the RS485 physical layer protocol. The physical structure of Profibus can be described as follows: Figure 5 As shown, the host system generally refers to a device with a master function, which is used to manage and control the entire bus system. This embodiment designs an RS485 fault damage tester, which is connected to the communication link (Profibus bus) between the main rack and the redundant rack. Figure 5 ) is connected in series with the RS485 fault damage tester, and the following is obtained: Figure 6In the circuit shown, the RS-485 device on the Profibus refers to the device connected to the communication link of the field bus (Profibus bus), including the function controller module or communication IO card of the main rack or redundant rack.

[0032] It should be noted that since each RS485 interface is respectively connected to the function controller module of the main rack and the function controller module of the slave rack in any field bus, and then the RS485 transceiver injects faults into the bus connected to the current RS485 interface, the tester can access the wire cores one by one, so that each wire core can simulate the fault required for the test, effectively preventing the problem in the prior art that a wire core fault cannot be simulated separately, thereby achieving comprehensive and complete reliability verification of the steam turbine control system.

[0033] In one embodiment, the control system also includes: the controllable optical attenuator is serially connected to the redundant optical fiber between the central processing unit module of the main rack and the central processing unit module of the redundant rack; the controllable optical attenuator is used to simulate the failure condition of the redundant optical fiber, and the failure condition of the redundant optical fiber includes abnormal optical signal attenuation caused by poor contact or bending failure of the redundant optical fiber.

[0034] In this embodiment, Figure 2 As shown, a controllable optical attenuator is connected in series between the central processor module of the redundant rack and the central processor module of the main rack. The central processor includes but is not limited to CPU414, etc. The controllable optical attenuator can simulate the abnormal attenuation of optical signals caused by faults such as poor optical fiber contact and optical fiber bending. Redundant optical fibers include but are not limited to optical links, electrical links, etc.

[0035] It should be noted that placing the controllable optical attenuator in the redundant optical fiber between CPU414 can accurately test the reliability of each redundant optical fiber. Compared with the problem that the prior art cannot simulate the failure of a single core line, this embodiment can accurately simulate the failure of each optical fiber, thereby achieving comprehensive and complete reliability verification of the steam turbine control system.

[0036] In one embodiment, based on the above control system, a method for analyzing the reliability of a nuclear power turbine control system is provided, which specifically includes the following steps: S10: Perform an independent simulated damage test on each signal in the main rack or redundant rack through a backplane signal damage tester to obtain a test result for each signal channel, wherein, through the control of the first programmable logic device in response to the processor, perform an independent simulated damage test on each signal of the field bus to obtain a test result for each signal channel; the independent simulated damage test on each signal of the field bus to obtain a test result for each signal channel includes: simulating the on and off, connection time, disconnection time and number of on and off times of each signal switch to obtain a test result for each signal coming from the backplane bus.

[0037] S20: Using the RS485 fault damage tester, respectively perform fault injection on each line to obtain a test result of each line.

[0038] S30: Analyze the test results of each signal channel and each line to obtain an analysis conclusion on the reliability of the control system.

[0039] It should be noted that, since each backplane signal in the backplane signal damage tester corresponds to a switch module, step S10 can actually simulate all signal faults in the redundant racks one by one, ensuring a comprehensive and complete reliability verification of the steam turbine main system. In addition, since each RS485 interface of the RS485 fault damage tester is respectively connected to the function controller module of the main rack of any field bus and the function controller module of the redundant rack, and then the RS485 transceiver injects faults into the communication link of the field bus connected to the current interface, the RS485 fault damage tester can access the communication link one by one, so that each wire core can simulate the fault required for the test, therefore, step S20 can actually simulate the faults of all lines in the redundant rack or the main rack one by one, further ensuring a comprehensive and complete reliability verification of the steam turbine control system.

[0040] It should also be noted that the backplane signal damage tester designed in this embodiment does not affect the normal operation of the steam turbine main system, and will not affect the operation of the control system even when the signal of the backplane bus is connected. The backplane signal damage tester can independently simulate damage to each signal, and can set the connection time, disconnection time and number of on-off times of each signal separately. When testing Ethernet signals, the accuracy of the backplane signal damage tester is in nanoseconds, and the accuracy of testing other signals is in microseconds. In this embodiment, the on-off voltage level is preferably not less than 50VDC (direct current voltage, full name Voltage Direct Current).

[0041] It should be noted that this embodiment is essentially a simulation method for different types of signal faults, and the switch module can be controlled to make the connection time, disconnection time, and number of on-off times of each signal different. This allows each signal to pass all types of fault tests, effectively improving the reliability of the steam turbine main system.

[0042] In one embodiment, if Figure 4 As shown, the analysis method also includes the following steps: S111: The signal is introduced into an oscilloscope to obtain the signal waveform when the on-off fault occurs.

[0043] In this embodiment, the backplane signal damage tester imports the measured signal into the oscilloscope to measure the waveform when the on-off fault is injected.

[0044] It should be noted that, in this embodiment, the signal is introduced into the oscilloscope mainly to facilitate the measurement of the waveform of the on-off fault, so as to collect the test results more accurately and vividly, thereby summarizing the reliability verification report of the steam turbine control system more comprehensively.

[0045] In one embodiment, the analysis method further comprises the following steps: S114: Connecting the management network port of the backplane bus to the industrial computer to implement various operation controls on the backplane signal tester through the management network port.

[0046] S115: Generate a Web management page (graphical operation interface) to graphically manage various operations of the backplane signal damage tester, thereby making the operation of the backplane signal damage tester simpler and more intuitive.

[0047] S116: Complete the serial connection test of the backplane signal tester by debugging the serial port of the backplane bus.

[0048] The management network port refers to the network interface used for server management, also known as an out-of-band network card or out-of-band interface. The serial interface is referred to as a serial port, also known as a serial communication interface or a serial communication interface (usually referring to a COM interface), which is an expansion interface using serial communication.

[0049] In this embodiment, by automating the test interface and connecting the network port to the industrial computer, the overall process of the backplane signal test is made faster and more efficient. Then a graphical operation interface is generated to complete various operations of the backplane signal, further making the test process more concise and easy to understand. Finally, through serial port debugging, the serial connection test is completed to ensure that the backplane signal tester is accurately connected to the signal channel, preventing unexpected problems caused by instrument serial connection errors during the test process.

[0050] In one embodiment, based on the RS485 fault damage tester in the above control system, such as Figure 6 As shown, the RS485 fault damage tester is used to inject faults into each line respectively to obtain the test results of each line, including the following steps: S21: Using the second programmable logic device to control the RS485 transceiver to implement fault injection into the physical layer of the communication link.

[0051] S22: Using the second programmable logic device to control the RS485 transceiver to implement fault injection into the protocol layer of the communication link.

[0052] Among them, fieldbus refers to Profibus. Figure 5 In the example, the Profibus bus connects multiple serial communication devices (such as serial communication devices between the function controller module of the main rack and the function controller module of the redundant rack), R is an ohmic resistor, and the fault damage tester is connected in series to different lines, such as Figure 6 As shown, the test results of different lines are obtained.

[0053] In this embodiment, by controlling the RS485 transceiver and its injection mode, the simulation of each field bus line is more accurate and efficient, and the final line test result will be more accurate. In this way, the reliability analysis result of the steam turbine control system will be more accurate.

[0054] In one embodiment, if Figure 7 As shown, the fault injection of the physical layer or the fault injection of the protocol layer includes a steady-state injection mode, an intermittent injection mode, a step injection mode and a queue injection mode respectively; the steady-state injection mode indicates that the fault injection is continuously performed with the set parameters; the intermittent injection mode indicates that the fault injection is intermittent with the set time rule; the step injection mode indicates that the fault injection parameters are dynamically adjusted according to the set step rule; the queue injection mode indicates that the fault injection parameters are dynamically adjusted according to the set parameter list. Furthermore, the fault injection of the physical layer includes open circuit, line short circuit, short circuit to ground, bridge fault, serial impedance and parallel impedance simulation injection; wherein the programmable logic device is used to dynamically adjust the size of the parallel impedance.

[0055] In this embodiment, various fault injection modes are supported, including four modes, namely steady-state injection, intermittent injection, stepping injection and queue injection. Among them, steady-state injection performs fault injection by continuously performing set parameters, and intermittent injection sets regular time intervals to intermittently inject faults. Stepping injection dynamically adjusts the parameters of fault injection according to the preset stepping rules. These parameters include but are not limited to resistance value, bit error rate, etc. Queue injection dynamically adjusts the parameters of fault injection by setting a list.

[0056] In this embodiment, the RS485 fault damage tester is essentially controlled to perform physical layer fault injection and protocol layer fault injection. In this embodiment, the resistance range of the serial impedance is preferably 0Ω~1MΩ, which can be continuous or selected in points, and the final total number of selected points is preferably ≥5 points; in addition, the resistance range of the parallel impedance is also preferably 0Ω~1MΩ, and its resistance range is dynamically adjustable, which can be continuous or selected in points, and the final total number of selected points is preferably ≥5 points.

[0057] It should be noted that this embodiment decomposes the process of controlling the RS485 transceiver to inject faults in more detail, including various types of faults, which effectively improves the diversity and comprehensiveness of reliability analysis and prevents inaccurate reliability verification results due to a single fault type.

[0058] In one embodiment, the fault injection of the protocol layer includes protocol message replacement, protocol message loss and bit error generation on the communication link. Among them: injecting data fault, that is, specifying the message location and content of Profibus DP. Injecting packet loss fault, that is, matching message loss. Injecting bit error fault, that is, generating bit errors in proportion.

[0059] It should be noted that this embodiment further enriches the types of injected faults. In addition, it also describes in detail the implementation method of each fault. These different injected faults further effectively improve the diversity and comprehensiveness of reliability analysis and prevent inaccurate reliability verification results due to a single fault type.

[0060] It should be noted that this embodiment substantially completes various types of line fault simulations through different execution methods and sequences. The various fault types further effectively improve the diversity and comprehensiveness of reliability analysis, and prevent inaccurate reliability verification results due to a single fault type.

[0061] The present invention realizes fault injection simulation of various buses of nuclear power turbine control system by integrating three devices: backplane signal damage tester, RS485 fault damage tester and controllable optical attenuator, so that the control system can simulate various fault modes such as disconnection, looseness, impedance mismatch, attenuation, signal crosstalk, etc. of any signal line. The present invention can simulate and verify each signal channel and each fault mode one by one, effectively solving the problem that the existing technology cannot simulate a single core fault, thereby achieving the purpose of verifying the integrity of the redundant rack.

[0062] Since the present invention covers all signals and lines, it effectively improves the comprehensive coverage of different failure modes in the control system. For example, the looseness of contacts, accidental short circuits between connecting wires, signal interference, etc., which were previously difficult to simulate, are all completely covered by the present invention. Therefore, the present invention effectively verifies the effectiveness of redundant fault-tolerant design in the control system and avoids false redundancy events caused by redundant design errors.

[0063] In one embodiment, in order to improve the comprehensiveness of reliability analysis, the method further provides the following solutions: Using simulation software to obtain simulation data in a target simulation scenario, the simulation data is calculated by a sensor simulation module of a steam turbine main system TCS in the simulation software based on corresponding simulation function logic and data detected by a sensor model of the steam turbine main system, and the sensor model of the steam turbine main system is set based on the arrangement parameters of sensors in the actual steam turbine main system; The simulation data is transmitted to the actual steam turbine main system through the communication board of the test cabinet, so that the actual steam turbine main system performs function control simulation according to the simulation data.

[0064] As an exemplary illustration, the sensors in the main system of the steam turbine may include the following sensors: The speed sensor (Tachometer Sensor) is used to monitor the turbine speed and ensure that the speed is stable at the rated value. It participates in the speed control system (Speed ​​Control), adjusts the main steam flow, triggers overspeed protection, and performs an emergency shutdown when the speed exceeds the rated value. Exemplary, including but not limited to: magnetic pickup sensor (MPU) photoelectric speed sensor (Optical Encoder) eddy current sensor (Eddy Current Sensor), as an example of functional application: directly installed on the turbine shaft end or gear, used to measure speed and monitor overspeed. The parameters of the speed sensor model in the simulation software are calibrated according to the actual sensor of the turbine main system TCS.

[0065] Vibration Sensor: used to detect the vibration of the turbine rotor to prevent mechanical damage. Participate in the turbine protection system (TPS, Turbine Protection System), trigger an alarm or trip the machine when the set value is exceeded. Exemplary sensors include but are not limited to: piezoelectric accelerometer, eddy current displacement sensor, velocity sensor, etc. As an example of functional application, it can be used to monitor bearing vibration, casing vibration, and detect rotor imbalance or bearing damage.

[0066] The Thrust Position Sensor is used to monitor the axial displacement of the turbine thrust bearing to ensure that the rotor axis remains within the normal range. Abnormal axial displacement may mean bearing damage, steam imbalance, poor lubrication and other problems. Exemplary ones include but are not limited to: Eddy Current Proximity Sensor and Linear Variable Differential Transformer (LVDT). As an example of functional application, it can be used to monitor bearing vibration, casing vibration, detect rotor imbalance or bearing damage, and can be installed near the thrust bearing to monitor axial displacement in real time and prevent the rotor from hitting the bearing.

[0067] Temperature Sensor is used to monitor the temperature of key parts such as bearings, lubricating oil, steam, exhaust, cooling water, etc. in the main system TCS of the steam turbine to ensure the normal operation of the lubricating oil system (Lube Oil System), cooling system, and main steam system. Exemplary sensors include but are not limited to: thermocouples (TC) and platinum resistance thermometers (RTD). As an example of functional application: Detect the main steam temperature (Main Steam Temperature) to ensure that the steam temperature entering the steam turbine meets the design parameters. Detect the bearing temperature (Bearing Temperature) to prevent overheating and bearing damage. Detect the lubricating oil temperature (Lube Oil Temperature) to ensure that the oil temperature is appropriate to avoid lubrication failure.

[0068] Pressure sensor is used to monitor the main steam, lubricating oil, cooling water, exhaust pressure and other parameters of the steam turbine to ensure the stable operation of the main system TCS of the steam turbine. Exemplary include but not limited to: capacitive pressure sensor, strain gauge pressure sensor, piezoresistive pressure sensor. As an example of functional application, detect the main steam pressure: ensure the stability of steam parameters to prevent pipe burst or power drop. Detect the main lubricating oil pressure to maintain normal oil film thickness and prevent bearing wear. Detect the main exhaust pressure to ensure the normal operation of the condenser and prevent excessive back pressure from affecting the efficiency of the steam turbine.

[0069] Flow Sensor, used to monitor the flow of main steam, condensate, lubricating oil, etc. to ensure stable supply. Participate in turbine load regulation and adjust output power according to steam flow. Exemplary, including but not limited to: Vortex Flow Meter, used for steam flow measurement. Electromagnetic Flow Meter, used for condensate or lubricating oil measurement. Differential pressure flow meter (Orifice Plate / Venturi Tube), used for main steam flow monitoring. As an example of functional application, it is used to detect the main steam flow (Main Steam Flow) to ensure that the turbine load matches the power output of the nuclear reactor. Detect the condensate flow (Condensate Flow) to monitor whether the cooling system is operating normally.

[0070] It should be understood that the parameters of the sensor model in the simulation software are calibrated according to the actual parameters of the sensors of the actual steam turbine main system TCS.

[0071] It can be seen that in the simulation process of the ultrasonic sensor, the embodiment of the present application does not need to rely on complex tooling. Instead, it uses simulation software to build a simulation scene and injects simulation data into the intelligent driving domain controller of the real vehicle through a communication board to perform functional control simulation. There is no need to design tooling and it does not rely on tooling accuracy, which is beneficial to improving or controlling the simulation accuracy and cost of the ultrasonic sensor.

[0072] It is also worth noting that the sensor simulation module of the steam turbine main system TCS built in the simulation software is calculated based on the corresponding simulation function logic and the data detected by the sensor model of the steam turbine main system. For example, the sensor simulation module is determined based on the corresponding simulation function logic based on the functional application example of the actual sensor in the steam turbine main system TCS, that is, based on the functional application of the actual sensor in the steam turbine main system TCS, the functional logic of the corresponding sensor simulation module is set to obtain the sensor data required in the simulation scenario. Accordingly, sensor simulation modules corresponding to the above-mentioned various sensors can be built, such as speed sensor simulation modules, etc.

[0073] As an explanatory note only, the simulation software may use Simulink simulation software, which is not specifically limited. The sensor model of the steam turbine main system and the corresponding parameter calibration are built in the Simulink simulation software, and the sensor simulation module is built in the Simulink simulation software. It should be noted that the above-mentioned simulation software refers to a model-based system design and simulation tool, which can be used for dynamic system modeling and simulation. The specific type of simulation software is not limited in this embodiment.

[0074] In this embodiment, it is also necessary to configure the communication board (such as a CAN board) in the test cabinet. It should be noted that the interface output dimension needs to be consistent with the data output dimension.

[0075] Taking the simulation software using Simulink simulation software as an explanatory description as an example, the CAN board can be configured in the test tool Configuration desk. Configuration Desk is a configuration and code generation tool that can be used for Simulink real-time simulation, and is only an explanatory description in the embodiment of this application. After configuring the communication board, connect the communication board with the actual control device of the steam turbine main system. After obtaining the simulation data, the simulation data will be transmitted to the actual control device of the steam turbine main system through the communication board of the test cabinet, so that the control device of the steam turbine main system performs functional control simulation according to the corresponding simulation data of the sensor model. For example, the corresponding functional control in the functional application of the various sensors mentioned above.

[0076] It can be seen that in the simulation process of the sensor in the steam turbine main system TCS, the embodiment of the present application uses the simulation software to build a simulation scene, and injects the simulation data into the control module of the actual steam turbine main system TCS through the communication board to perform functional control simulation, without relying on actual tooling, which is conducive to improving or controlling the simulation accuracy and cost of the ultrasonic sensor. Moreover, the simulation results are integrated with the analysis data of the above three testers in the embodiment of the present application as reference data for reliability analysis to analyze the working conditions of the entire actual steam turbine main system TCS.

[0077] It should be understood that the order of execution of the steps in the above embodiment does not necessarily mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiment of the present invention.

[0078] Those of ordinary skill in the art can understand that all or part of the processes in the above-mentioned embodiment methods can be implemented by instructing the relevant hardware through a computer program, and the computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the embodiments of the above-mentioned methods. Among them, any reference to memory, storage, database or other media used in the embodiments provided in this application may include non-volatile and / or volatile memory. Non-volatile memory may include read-only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM) or flash memory. Volatile memory may include random access memory (RAM) or external cache memory. By way of illustration and not limitation, RAM is available in many forms, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), double data rate SDRAM (DDRSDRAM), enhanced SDRAM (ESDRAM), synchronous link (Synchlink) DRAM (SLDRAM), memory bus (Rambus) direct RAM (RDRAM), direct memory bus dynamic RAM (DRDRAM), and memory bus dynamic RAM (RDRAM), etc.

[0079] Those skilled in the art can clearly understand that for the convenience and simplicity of description, only the division of the above-mentioned functional units and modules is used as an example. In actual applications, the above-mentioned functions can be distributed and completed by different functional units and modules as needed, that is, the internal structure of the device can be divided into different functional units or modules to complete all or part of the functions described above.

[0080] The embodiments described above are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. Such modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention, and should all be included in the protection scope of the present invention.

Claims

1. A control system for a nuclear power steam turbine, characterized in that: The control system of the nuclear power steam turbine includes a steam turbine main system, a backplane signal damage tester, and a board card under test corresponding to a working module of a main rack or a redundant rack; The steam turbine main system includes the main frame, redundant frame, generator excitation regulator and communication IO card for controlling the steam turbine. The main frame and redundant frame respectively include power supply module, central controller module, function controller module and communication module. The generator excitation regulator is connected to the communication module of the main frame and the communication module of the redundant frame respectively. The central controller module of the main frame communicates with the central controller module of the redundant frame through redundant optical fiber. The working modules of the same column frame communicate with each other through the backplane bus of the frame backplane. The communication IO card is connected to the function controller modules on the main frame and the redundant frame respectively through two field buses. The backplane signal damage tester includes a backplane connector, a test circuit module, a board connector and an industrial computer communication interface. The test circuit module includes a processor, a first programmable logic device and N switches, where N is greater than 1. One connection end of the switch is connected to the backplane bus of the rack backplane via the backplane connector, and the other connection end of the switch is connected to the tested board corresponding to the working module of the main rack or redundant rack via the board connector; the control end of the switch is connected to the first programmable logic device, the first programmable logic device is connected to the processor, and the processor is connected to the industrial computer via the industrial computer communication interface; The first programmable logic device is used to respond to the control of the processor and perform an independent simulated damage test on each signal of the field bus to obtain a test result of each signal channel; The independent simulated damage test is performed on each signal of the field bus to obtain the test result of each signal channel, including: simulating the on and off, connection time, disconnection time and number of on and off times of each signal switch to obtain the test result of each signal coming from the backplane bus.

2. The control system according to claim 1, characterized in that: The control system of the nuclear power steam turbine also includes an RS485 fault damage tester; The RS485 fault damage tester includes two RS485 interfaces, two RS485 transceivers and a second programmable logic device; wherein the RS485 interface includes a first interface and a second interface, one end of the first interface is connected to the function controller module of the main rack of the field bus, and one end of the second interface is connected to the function controller module of the redundant rack of the field bus; the RS485 transceiver includes a first transceiver and a second transceiver, one end of the first transceiver is connected to the first interface, and one end of the second transceiver is connected to the second interface; one end of the second programmable logic device is connected to the other end of the first transceiver, and the other end of the second programmable logic device is connected to the other end of the second transceiver.

3. The control system according to claim 2, characterized in that: The control system also includes a controllable light attenuator; The controllable optical attenuator is serially connected to the redundant optical fiber between the central processing unit module of the main rack and the central processing unit module of the redundant rack; The controllable optical attenuator is used to simulate the fault condition of the redundant optical fiber, and the fault condition of the redundant optical fiber includes abnormal optical signal attenuation caused by poor contact or bending fault of the redundant optical fiber.

4. A reliability analysis method based on a nuclear power turbine control system, wherein the nuclear power turbine control system is the control system as claimed in claim 3, characterized in that: The analysis method comprises: Through the backplane signal damage tester, each signal in the main rack or redundant rack is subjected to an independent simulated damage test to obtain the test result of each signal channel, wherein, through the control of the first programmable logic device in response to the processor, each signal of the field bus is subjected to an independent simulated damage test to obtain the test result of each signal channel; the independent simulated damage test of each signal of the field bus is subjected to the test result of each signal channel, including: simulating the on-off, connection time, disconnection time and number of on-off times of each signal switch to obtain the test result of each signal coming from the backplane bus; By means of the RS485 fault damage tester, fault injection is respectively performed on the communication link of the field bus to which each of the RS485 fault damage testers is serially connected, so as to obtain the test result of each communication link; The test results of each signal channel and the test results of each communication circuit are analyzed to obtain an analysis conclusion on the reliability of the steam turbine main system.

5. The analysis method according to claim 4, characterized in that The RS485 fault damage tester is used to inject faults into the communication links of the field bus connected in series with each of the RS485 fault damage testers to obtain the test results of each communication link, including: The second programmable logic device of the RS485 fault damage tester is used to control the RS485 transceiver of the RS485 fault damage tester to achieve fault injection into the communication link of the field bus and obtain the test result of the communication link of the field bus; the fault injection method is used to simulate the fault of the communication link of the field bus.

6. The analysis method according to claim 5, characterized in that The method of using the second programmable logic device of the RS485 fault damage tester to control the RS485 transceiver of the RS485 fault damage tester to implement fault injection into the communication link of the field bus includes: Using the second programmable logic device, controlling the RS485 transceiver to implement fault injection into the physical layer of the communication link; The RS485 transceiver is controlled by the second programmable logic device to implement fault injection into the protocol layer of the communication link.

7. The analysis method according to claim 6, characterized in that The physical layer fault injection or the protocol layer fault injection respectively includes a steady-state injection mode, an intermittent injection mode, a step injection mode and a queue injection mode; The steady-state injection mode indicates that fault injection is continuously performed with set parameters; The intermittent injection mode represents intermittent fault injection at a set time regularity; The step injection mode indicates that the fault injection parameters are dynamically adjusted according to the set step rule; The queue injection mode represents dynamically adjusting fault injection parameters according to a set parameter list.

8. The analysis method according to claim 6, characterized in that The fault injection of the physical layer includes open circuit, line short circuit, short circuit to ground, bridge fault, serial impedance and parallel impedance simulation injection; wherein the second programmable logic device is used to dynamically adjust the size of the parallel impedance.

9. The analysis method according to claim 6, characterized in that The fault injection of the protocol layer includes protocol message replacement, protocol message loss and bit error generation on the communication link.

10. The analysis method according to claim 4, characterized in that The method further comprises: Using simulation software to obtain simulation data in a target simulation scenario, the simulation data is calculated by a sensor simulation module of a steam turbine main system in the simulation software based on corresponding simulation function logic and data detected by a sensor model of the steam turbine main system, and the sensor model of the steam turbine main system is set based on the arrangement parameters of sensors in an actual steam turbine main system; The simulation data is transmitted to the actual steam turbine main system through the communication board of the test cabinet, so that the actual steam turbine main system performs function control simulation according to the simulation data.

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