An advanced control system and design method for lead-bismuth fast reactor

Abstract

The present invention belongs to the field of lead-bismuth fast reactor advanced control system design and discloses an advanced control system for a lead-bismuth fast reactor and a design method. The method comprises building a lead-bismuth fast reactor model, wherein the lead-bismuth fast reactor model includes two controlled object models: a reactor core and a direct current steam generator; based on the built lead-bismuth fast reactor model, characteristic analysis of controller output anti-disturbance and anti-noise capabilities is performed for multiple advanced control algorithms to obtain characteristic analysis results corresponding to each advanced control algorithm; based on the characteristic analysis results, a superior advanced control algorithm is screened and obtained; based on the superior advanced control algorithm, a core power self-disturbance controller, a steam pressure internal model controller, and a main steam flow internal model controller are designed, thereby designing an advanced control system for the lead-bismuth fast reactor; the advanced control system designed using the method not only has good response speed and stability, but also ensures that the lead-bismuth fast reactor can meet application requirements of complex operating environments and changeable operating conditions.

Description

Technical Field

[0001] The present invention belongs to the field of lead-bismuth fast reactor advanced control system design, and in particular relates to a lead-bismuth fast reactor advanced control system and a design method. Background Art

[0002] Lead-cooled fast reactors (LFRs) are fast neutron reactors that use liquid lead or lead-bismuth as a coolant. Small pool-type LBRs can power mobile devices and, through parallel connection, form large nuclear power plants. Potential applications include powering remote areas and islands. These complex operating environments and highly variable operating conditions pose challenges to the design of control systems for LFRs, placing higher demands on these systems.

[0003] Currently, small lead-bismuth fast reactors are still in the design verification stage, and system parameters are facing adjustments. Changes in system parameters will affect the response characteristics of the system, thereby leading to deterioration of the control system. As for the control of lead-bismuth fast reactors, traditional control methods have problems such as multi-loop feedback and the need for multiple adjustments of controller design and parameters, resulting in low controller design efficiency and inability to meet application requirements with complex operating environments and changing operating conditions.

[0004] It can be seen that the existing control methods have problems such as multi-loop feedback and the need for multiple adjustments of controller design and parameters, resulting in low controller design efficiency and failure to meet application requirements with complex operating environments and changing working conditions. Summary of the Invention

[0005] The present invention provides an advanced control system and design method for a lead-bismuth fast reactor, aiming to solve the technical problems that existing control methods for lead-bismuth fast reactors have low controller design efficiency and cannot meet the application requirements of complex operating environments and changing operating conditions due to the presence of multiple feedback loops and the need for multiple adjustments of design and parameters.

[0006] In order to achieve the above object, the present invention adopts the following technical contents:

[0007] In a first aspect, the present invention provides a design method for an advanced control system of a lead-bismuth fast reactor, comprising:

[0008] Building a lead-bismuth fast reactor model, wherein the lead-bismuth fast reactor model includes two controlled object models: a reactor core and a once-through steam generator;

[0009] Based on the established lead-bismuth fast reactor model, the characteristics of the controller output anti-disturbance and anti-noise capabilities are analyzed for various advanced control algorithms, and the corresponding characteristic analysis results of each advanced control algorithm are obtained;

[0010] Based on the characteristics analysis results, the advantageous advanced control algorithms are screened out;

[0011] Based on the superior advanced control algorithm, the core power self-disturbance controller, steam pressure internal model controller and main steam flow internal model controller are designed, thus designing the advanced control system of the lead-bismuth fast reactor.

[0012] Furthermore, the core adopts a point reactor dynamics model with 6 groups of delayed neutrons, and the specific expression is as follows:

[0013]

[0014] Where, n ( t ) represents neutron density / neutron number; ρ ( t ) represents the total reactivity in the core; C i ( t ) indicates the i The concentration of precursor nuclei of delayed neutrons / the number of precursor nuclei of delayed neutrons; λ i Indicates the i Decay constant of the group precursor nucleus / s; β i Indicates the i The delayed neutron fraction of the group; Λ represents the neutron generation time.

[0015] Furthermore, the once-through steam generator adopts a four-heat exchange zone model, which is modeled based on the movable boundary theory. The specific expression is:

[0016]

[0017]

[0018]

[0019] Where, ρ represents the fluid density; G represents mass flux; Q represents the wall linear heat flux density; A Indicates the flow area of ​​the flow channel; P express; g represents the acceleration due to gravity; H represents enthalpy value; represents the Fanning friction factor; l represents the wetted perimeter of the flow channel.

[0020] Furthermore, the specific steps of analyzing the characteristics of the controller output anti-disturbance and anti-noise capabilities for multiple advanced control algorithms include:

[0021] Based on the core and once-through steam generator in the lead-bismuth fast reactor model, a reactivity step disturbance is introduced into the corresponding reactor power system, a reactor power setpoint step disturbance is introduced into the corresponding reactor power system, and measurement noise and reactor power setpoint step disturbance are introduced into the corresponding reactor power system in sequence.

[0022] The characteristic analysis results corresponding to the proportional-integral algorithm, active disturbance rejection control algorithm, internal model control algorithm, and H∞ robust control algorithm are obtained respectively.

[0023] Furthermore, the measurement noise adopts Gaussian white noise, and the average power of the Gaussian white noise is 0.24%~0.26%.

[0024] Furthermore, the specific steps for screening the advantageous advanced control algorithms are as follows:

[0025] The characteristic analysis results include steady-state error, noise resistance, controller output disturbance and the number of parameters to be adjusted; a comprehensive comparative analysis of the steady-state error, noise resistance, controller output disturbance elimination capability and the number of parameters to be adjusted corresponding to each advanced control algorithm is performed to screen out the superior advanced control algorithm.

[0026] Furthermore, the advantageous advanced control algorithm adopts an active disturbance rejection control algorithm and an internal model control algorithm; wherein, a core power self-disturbance controller is designed based on the active disturbance rejection control algorithm; and a steam pressure internal model controller and a main steam flow internal model controller are designed based on the internal model control algorithm.

[0027] Furthermore, based on the active disturbance rejection control algorithm, a core power ADRC control system is constructed, whose input is the power set value and the measurement value deviation, and the output is the temperature deviation compensation. Based on the active disturbance rejection control algorithm, the controlled object model is organized into the following form:

[0028]

[0029] Where, u is the system input, y is the system output, a 1 and a 2 are model information, w is an external disturbance, g is the internal disturbance, b is the coefficient of the control input.

[0030] Furthermore, based on the internal model control algorithm, a main steam pressure IMC control system with feedwater flow as input and steam pressure as output is constructed, which is specifically expressed as follows:

[0031]

[0032] Where G c1(s) is the controller transfer function, λ1 is the parameter to be tuned;

[0033] Based on the internal model control algorithm, a main steam flow IMC control system is constructed with the main steam valve opening as input and the output as output power as output, which is specifically expressed as follows:

[0034]

[0035] Where G c2 (s) is the controller transfer function, and λ2 is the parameter to be tuned.

[0036] In a second aspect, the present invention provides an advanced control system for a lead-bismuth fast reactor, which is designed based on the above-mentioned design method for the advanced control system for a lead-bismuth fast reactor.

[0037] Compared with the prior art, the present invention has the following beneficial effects:

[0038] The present invention provides a design method for an advanced control system of a lead-bismuth fast reactor. The design method first constructs a lead-bismuth fast reactor model including two controlled object models, a reactor core and a direct current steam generator, to provide an accurate foundation for subsequent control system design. Then, based on the constructed model, various advanced control algorithms are subjected to in-depth characteristic analysis of the controller output anti-disturbance and anti-noise capabilities. This process ensures that the selected algorithms can adapt to the complex and changeable operating environment of the lead-bismuth fast reactor. By screening the characteristic analysis results, control algorithms with obvious advantages can be identified and selected, thereby avoiding the problems of multi-loop feedback and multiple controller parameter tuning in traditional control methods. Finally, based on the screened advantageous advanced control algorithms, a core power self-disturbance controller, a steam pressure internal model controller, and a main steam flow internal model controller are designed. The designs of these controllers not only improve the response speed and stability of the control system, but also ensure that the lead-bismuth fast reactor can maintain good control effects when facing changes in system parameters, thereby meeting the application requirements of complex operating environments and changeable operating conditions.

[0039] Preferably, in the present invention, a point reactor dynamics model with 6 groups of delayed neutrons is used to describe the core, which can more accurately simulate the neutron dynamics process of the lead-bismuth fast reactor, including reactivity changes, thereby providing a more accurate basis for the design of the control system.

[0040] Preferably, in the present invention, a four-heat exchange zone model is used to describe the direct current steam generator, and modeling is based on the movable boundary theory, which can more accurately reflect the heat exchange process, pressure changes and other characteristics of the steam generator, and help design a more accurate control system.

[0041] Preferably, in the present invention, by analyzing the characteristics of the controller output anti-disturbance and anti-noise capabilities, the performance of different control algorithms in a lead-bismuth fast reactor environment can be evaluated, thereby providing a basis for screening advantageous control algorithms. This method can ensure that the selected algorithm has good stability and anti-interference capabilities in practical applications.

[0042] Preferably, in the present invention, Gaussian white noise is used as the measurement noise, preferably 0.25% Gaussian white noise; it can more realistically simulate the noise interference in the actual environment, thereby evaluating the performance of the control system under noise interference. This setting helps to design a more robust control system.

[0043] Preferably, in the present invention, by comprehensively comparing and analyzing the steady-state error, anti-noise ability, controller output disturbance, and number of parameters to be adjusted of various advanced control algorithms, the control algorithm with the best performance can be screened out, thereby ensuring that the overall performance of the control system is optimized.

[0044] Preferably, in the present invention, the auto-disturbance rejection control algorithm and the internal model control algorithm are adopted as the dominant control algorithms, and the core power auto-disturbance controller, the steam pressure internal model controller and the main steam flow internal model controller can be designed respectively; these controllers can respectively cope with the characteristics of different controlled objects in the lead-bismuth fast reactor, thereby improving the overall performance and stability of the control system.

[0045] Preferably, in the present invention, a core power ADRC control system is constructed based on an active disturbance rejection control algorithm, which can achieve precise control of the core power and improve the anti-disturbance capability of the system; this method can ensure that the core power operates stably near the set value, thereby improving the operating safety and stability of the lead-bismuth fast reactor.

[0046] Preferably, in the present invention, the main steam pressure IMC control system and the main steam flow IMC control system are constructed based on the internal model control algorithm, which can achieve precise control of the steam pressure and main steam flow; this method can ensure the stable operation of the steam generator; by adjusting the controller transfer function and the parameters to be set, the performance of the control system can be further optimized.

[0047] The present invention also provides an advanced control system for a lead-bismuth fast reactor. This control system, designed based on the aforementioned design method, features a core power active disturbance rejection controller (ADRC), a steam pressure internal model controller (IMC), and a main steam flow IMC. The core power ADRC controller uses the temperature controller output as a disturbance and compensates for it, effectively improving core power control. The designed steam pressure and steam flow IMC controllers reduce controller tuning parameters and improve controller design efficiency. This invention provides a research foundation for the design of advanced control systems for small lead-bismuth fast reactors and offers a reference for the design of advanced control systems for other reactor types. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] Figure 1 A flow chart of a design method for an advanced control system of a lead-bismuth fast reactor provided by the present invention;

[0049] Figure 2 A flow chart of a design method for an advanced control system of a lead-bismuth fast reactor provided by an embodiment of the present invention;

[0050] Figure 3 This is a result diagram of a simulation condition of an advanced control system for a lead-bismuth fast reactor provided by an embodiment of the present invention; wherein (a) is power; (b) is the average coolant temperature; (c) is the steam pressure;

[0051] Figure 4 A result diagram of a simulation operating condition of an advanced control system for a lead-bismuth fast reactor provided in an embodiment of the present invention; wherein (a) is power; (b) is the average coolant temperature; and (c) is the steam pressure. DETAILED DESCRIPTION

[0052] In order to make the technical problems, technical solutions and beneficial effects solved by the present invention more clearly understood, the present invention is further described in detail in the following specific embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0053] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions of the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings herein can be arranged and designed in various different configurations.

[0054] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention as claimed, but rather merely represents selected embodiments of the present invention. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present invention without creative effort are intended to fall within the scope of protection of the present invention.

[0055] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, it does not need to be further defined or explained in subsequent drawings.

[0056] In the description of the embodiments of the present invention, it should be noted that if the terms "upper," "lower," "horizontal," "inner," etc. appear, the orientation or positional relationship indicated is based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship in which the inventive product is typically placed when in use. These terms are merely for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or component referred to must have a specific orientation, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limitations on the present invention. In addition, the terms "first," "second," etc. are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0057] In addition, if the term "horizontal" appears, it does not mean that the component must be absolutely horizontal, but can be slightly tilted. For example, "horizontal" only means that its direction is more horizontal than "vertical", and does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0058] In the description of the embodiments of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "disposed," "installed," "connected," and "connected" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections or electrical connections; they can refer to direct connections or indirect connections through an intermediate medium; and they can refer to internal connections between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0059] Example 1

[0060] As mentioned in the background technology, currently, small lead-bismuth fast reactors are still in the design verification stage, and system parameters are facing adjustments; changes in system parameters will affect the response characteristics of the system, thereby causing the control system to deteriorate; and for the control of lead-bismuth fast reactors, traditional control methods have low controller design efficiency due to the existence of multi-loop feedback and the need for multiple adjustments of controller design and parameters, which cannot meet the application requirements of complex operating environments and changing working conditions.

[0061] In order to solve the above problems, the present invention provides an advanced control system and design method for a lead-bismuth fast reactor. The use of this design method and the advanced control system obtained by the design can effectively improve the control effect and control efficiency of the lead-bismuth fast reactor.

[0062] The present invention is further described in detail below with reference to the accompanying drawings and embodiments:

[0063] like Figure 1 As shown, this embodiment provides a design method for an advanced control system of a lead-bismuth fast reactor, and the specific steps include:

[0064] Build a lead-bismuth fast reactor model, which includes two controlled object models: the reactor core and the once-through steam generator;

[0065] Based on the established lead-bismuth fast reactor model, the characteristics of the controller output anti-disturbance and anti-noise capabilities are analyzed for various advanced control algorithms, and the corresponding characteristic analysis results of each advanced control algorithm are obtained;

[0066] Based on the characteristics analysis results, the advantageous advanced control algorithms are screened out;

[0067] Based on the superior advanced control algorithm, the core power self-disturbance controller, steam pressure internal model controller and main steam flow internal model controller are designed, thus designing the advanced control system of the lead-bismuth fast reactor.

[0068] This design method first constructs a lead-bismuth fast reactor model that includes two controlled object models, the core and the direct current steam generator, to provide an accurate foundation for the subsequent control system design; then, based on the constructed model, various advanced control algorithms are subjected to in-depth characteristic analysis of the controller output anti-disturbance and anti-noise capabilities. This process ensures that the selected algorithm can adapt to the complex and changeable operating environment of the lead-bismuth fast reactor; by screening the characteristic analysis results, control algorithms with obvious advantages can be identified and selected, thus avoiding the problems of multi-loop feedback and multiple controller parameter tuning in traditional control methods; finally, based on the screened advantageous advanced control algorithms, a core power self-disturbance controller, a steam pressure internal model controller, and a main steam flow internal model controller are designed. The design of these controllers not only improves the response speed and stability of the control system, but also ensures that the lead-bismuth fast reactor can maintain good control effects when facing changes in system parameters, thereby meeting the application requirements of complex operating environments and changeable operating conditions.

[0069] Example 2

[0070] like Figure 2 As shown, this embodiment provides a design method for an advanced control system for a lead-bismuth fast reactor. The lead-bismuth fast reactor in this embodiment mainly refers to a small pool-type lead-bismuth fast reactor model, which can be applied to various scenarios. The specific steps of the design method are as follows:

[0071] S1. Build a small lead-bismuth fast reactor model based on Matlab / Simulink, which includes two types of controlled objects: the reactor core and the once-through steam generator;

[0072] S2. Study the characteristics of different controlled objects, the resistance of different advanced control algorithms to controller output disturbances, and the resistance of different advanced control algorithms to noise, and analyze the characteristics of different control algorithms;

[0073] S3. Based on the characteristics analysis of different advanced control algorithms, design the core power active disturbance rejection controller, steam pressure internal model controller and main steam flow internal model controller.

[0074] In this embodiment, a small lead-bismuth fast reactor model is built based on Matlab / Simulink, including:

[0075] The main controlled object models of the small lead-bismuth fast reactor model are: reactor core and once-through steam generator.

[0076] In this embodiment, the core neutron dynamics model is simplified by using a point reactor dynamics model containing 6 groups of delayed neutrons, which is specifically expressed as follows:

[0077]

[0078] Where, n ( t )—— Neutron density / Number of neutrons·cm -3 ; ρ ( t ) —— total reactivity in the core / dk·k -1 ; C i ( t )——No. i Concentration of precursor nuclei of delayed neutrons / Number of precursor nuclei of delayed neutrons·cm -3 ; λ i ——No. i Decay constant of the group precursor nucleus / s; β i ——No. i The delayed neutron fraction of the group, %; Λ —— neutron generation time / s.

[0079] In this embodiment, the once-through steam generator is modeled using a four-heat exchange zone model combined with the movable boundary theory, which is specifically expressed as follows:

[0080]

[0081]

[0082]

[0083] Where: ρ —— Fluid density / kg m -3 ; G —— Mass flux / kg s -1 m -2 ; Q —— Wall linear heat flux / J m -1 s -1 ; A —— Flow area of ​​the flow channel / m 2 ; P ——pressure / Pa; g —— Gravitational acceleration / m s -2 ; H —— Enthalpy value / J kg -1 ; ——Fanning friction factor; l——wetted perimeter of the flow channel / m.

[0084] In this embodiment, the characteristics of different controlled objects, the resistance of different advanced control algorithms to controller output disturbances, and the resistance of different advanced control algorithms to noise are studied, and the characteristics of different control algorithms are analyzed, including:

[0085] Based on an established small lead-bismuth fast reactor model, a reactivity step disturbance, a reactor power setpoint step disturbance, a Gaussian white noise with an average power of 0.24% to 0.26%, and, preferably, a measurement noise of 0.25% Gaussian white noise were introduced into the reactor power system. A comparison of the characteristics of different control methods is shown in Table 1. Specific advanced control algorithms include proportional-integral (PI), active disturbance rejection control (ADRC), and internal model control (IMC). PI, ADRC, and IMC can achieve steady-state error-free regulation for both systems with and without integral characteristics. ADRC can eliminate controller output disturbances and has significant advantages in multiple feedback loops. IMC control has excellent noise immunity and can achieve steady-state error-free regulation in a single feedback loop. Furthermore, the tuning parameter is 1 and the tuning direction is clear, facilitating controller design and optimization. Furthermore, IMC can calculate the parameters of the PID controller, providing guidance for PID parameter tuning. H∞ robustness is comparable to ADRC in noise immunity, but it lacks significant advantages in core coolant average temperature control systems because it cannot eliminate controller output disturbances. In single-feedback loop control, H∞ robustness is more difficult to tune than IMC and cannot eliminate steady-state errors, making it ineffective in feedwater flow control systems and steam flow control systems.

[0086] Table 1 shows the characteristic analysis results of various advanced control algorithms

[0087]

[0088] In this embodiment, based on the analysis of the characteristics of different advanced control algorithms, a core power active disturbance rejection controller, a steam pressure internal model controller, and a main steam flow internal model controller are designed, including:

[0089] ADRC can eliminate controller output disturbances and has obvious advantages in multiple feedback loops. In the core power and coolant average temperature control system, the control effect of key parameters can be prioritized by applying ADRC. ADRC, IMC, and H∞ all have good noise resistance. In comparison, IMC has better noise resistance, fewer parameters to be adjusted, and is more convenient for engineering applications. In addition, IMC can be converted into a PID controller, providing a new idea for PID controller parameter tuning. Therefore, in this embodiment, a core power ADRC controller is designed to optimize core power control through ADRC and reduce the overshoot of core power during load disturbances; steam pressure control and steam flow IMC controllers are designed to improve noise resistance while simplifying controller parameter tuning.

[0090] The core power ADRC control system inputs are the power setpoint and the measured value deviation, and the output is the temperature deviation compensation. According to the ADRC control method, the controlled object model is first organized into the following form:

[0091]

[0092] in, u is the system input, y is the system output, a 1 and a 2 is model information, w is an external disturbance, g The unmodeled part of the model is regarded as the internal disturbance of the model. b The first two parts are classified as internal disturbances in the control of model-free ADRC. g , the above formula is simplified to:

[0093]

[0094] For the six delayed neutron point reactor models, the six delayed neutrons are combined into one group, and the parameters are introduced to eliminate , At the same time, it can be considered N ( t ) is linear in a small range of change, and it is simplified into the organizational form of the controlled object model. Due to the influence of the temperature controller feedback, the output of the temperature controller is u 2 The system output generated y 2 is classified as external disturbance w , g is the internal disturbance. Finally, the ADRC controller is applied to the temperature feedback channel.

[0095] The input of the steam pressure IMC control system is the feedwater flow rate, and the output is the steam pressure. The control system design first reduces the order of the transfer function from the feedwater flow rate to the steam pressure, and uses the reduced order transfer function to design the IMC controller. The IMC controller can be expressed as:

[0096]

[0097] Where G c1 (s) is the controller transfer function, and λ1 is the parameter to be tuned.

[0098] The input of the main steam flow IMC control system is the main steam valve opening, and the output is the output power. The control system design reduces the order of the transfer function from the main steam valve opening to the output power, and then designs the IMC controller based on the reduced order transfer function. The IMC controller can be expressed as:

[0099]

[0100] Where G c2 (s) is the controller transfer function, and λ2 is the parameter to be tuned.

[0101] Example 3

[0102] This embodiment also provides an advanced control system for a lead-bismuth fast reactor designed based on the above design method, and performs simulation verification on it. Figure 3 As shown, specifically Figure 3 As shown in (a), (b), and (c), in this embodiment, the power level is 100% FP and operates for 100 seconds. At the simulation time of 100 seconds, the load setting value is stepped to -10% FP and operates for 2900 seconds. At the simulation time of 3000 seconds, the load setting value is stepped to +10% FP and remains unchanged.

[0103] Under the advanced control system, the output power regulation time of a small lead-bismuth fast reactor was 13 seconds, with an overshoot of 0.03%. During step changes in the load setpoint, the optimization effect of the advanced control algorithm was limited due to the superior load tracking performance of the PID control system. During a step decrease in the load setpoint, the core power regulation time was 217 seconds, with an overshoot of 4.3%, a 71.9% reduction compared to PID control. During a step increase in the load setpoint, the core power regulation time was 261 seconds, with an overshoot of 4%, a 69.9% reduction compared to PID control. During the step decrease in the load setpoint, the average coolant temperature varied from -3°C to +2.2°C. The maximum coolant temperature was comparable to that of the PID control, indicating that improved power regulation through ADRC did not exacerbate lead-bismuth corrosion and effectively reduced core power overshoot. During a linear increase or decrease in the load setpoint, the steam pressure varied from -0.25 MPa to +0.28 MPa. Compared to the PID controller, the pressure fluctuation range was narrower, with a 24.1% reduction in peak pressure.

[0104] Example 4

[0105] This embodiment also provides an advanced control system for a lead-bismuth fast reactor designed based on the above design method, and performs simulation verification on it. Figure 4 As shown, specifically Figure 4 As shown in (a), (b) and (c) in the figure, in this embodiment, the power level of 100% FP is operated for 100 seconds. At the simulation time of 100 seconds, the load setting value changes linearly from -0.1% FP / s to 90% FP. At the simulation time of 3000 seconds, the load setting value changes linearly from +0.1% FP / s to 100% FP and remains unchanged.

[0106] Under the advanced control system, the output power of a small lead-bismuth fast reactor (SBLFR) was adjusted within 5 seconds and had an overshoot of 0.07%. During linear load changes, the maximum deviation between the output power and the setpoint was 0.06 MW. Due to the superior load tracking performance of the PID control system, the optimization effect of the advanced control algorithm was limited. During a linear decrease in the setpoint, the core power regulation time was 217 seconds, with an overshoot of 7.3%, a 32.4% reduction compared to PID control. During a linear increase in the setpoint, the core power regulation time was 194 seconds, with an overshoot of 3.3%, comparable to PID control. During the linear decrease in the setpoint, the average coolant temperature varied from -1.7°C to +2.1°C. The minimum coolant temperature variation was comparable to that of the PID control. This indicates that optimizing core power control through ADRC effectively reduces core power overshoot. During the linear increase and decrease in the setpoint, the steam pressure varied from -0.22 MPa to +0.28 MPa. Compared to the PID controller, the pressure fluctuation range was narrower, with a 30% reduction in peak pressure.

[0107] In summary, the present invention provides an advanced control system and design method for a lead-bismuth fast reactor, which has the following advantages over existing control methods:

[0108] This method builds a small lead-bismuth fast reactor model based on Matlab / Simulink; studies the characteristics of different controlled objects, the resistance of different advanced control algorithms to controller output disturbances, and the resistance of different advanced control algorithms to noise, and analyzes the characteristics of different control algorithms; based on the analysis of the characteristics of different advanced control algorithms, designs a core power anti-disturbance control controller, a steam pressure internal model controller, and a main steam flow internal model controller. By implementing this invention, compared with traditional controllers, the designed core power ADRC controller treats the temperature controller output as a disturbance and compensates for it, effectively improving the control effect of the core power. The designed steam pressure and steam flow IMC controllers can reduce controller setting parameters and improve controller design efficiency. This invention provides a research foundation for the design of advanced control systems for small lead-bismuth fast reactors and provides a reference for the design of advanced control systems for other reactor types.

[0109] The above embodiment is only one of the implementation methods that can realize the technical solution of the present invention. The scope of protection claimed by the present invention is not limited only to this embodiment, but also includes changes, replacements and other implementation methods that can be easily thought of by any technician familiar with this technical field within the technical scope disclosed by the present invention.

Claims

1. A design method for an advanced control system of a lead-bismuth fast reactor, characterized in that: include: Building a lead-bismuth fast reactor model, wherein the lead-bismuth fast reactor model includes two controlled object models: a reactor core and a once-through steam generator; Based on the established lead-bismuth fast reactor model, the characteristics of the controller output anti-disturbance and anti-noise capabilities are analyzed for various advanced control algorithms, and the corresponding characteristic analysis results of each advanced control algorithm are obtained; Based on the characteristics analysis results, the advantageous advanced control algorithms are screened out; Based on the superior advanced control algorithm, the core power self-disturbance controller, steam pressure internal model controller and main steam flow internal model controller were designed, thus designing the advanced control system of the lead-bismuth fast reactor; The specific steps of analyzing the characteristics of the controller output anti-disturbance and anti-noise capabilities for various advanced control algorithms include: Based on the core and once-through steam generator in the lead-bismuth fast reactor model, a reactivity step disturbance is introduced into the corresponding reactor power system, a reactor power setpoint step disturbance is introduced into the corresponding reactor power system, and measurement noise and reactor power setpoint step disturbance are introduced into the corresponding reactor power system in sequence. The characteristic analysis results corresponding to the proportional-integral algorithm, active disturbance rejection control algorithm, internal model control algorithm, and H∞ robust control algorithm are obtained respectively; The specific steps for screening advantageous advanced control algorithms are as follows: The characteristic analysis results include steady-state error, noise immunity, controller output disturbance, and the number of parameters to be tuned; a comprehensive comparative analysis of the steady-state error, noise immunity, controller output disturbance elimination capability, and the number of parameters to be tuned corresponding to each advanced control algorithm is performed to screen out the superior advanced control algorithm; The advantageous advanced control algorithm adopts an active disturbance rejection control algorithm and an internal model control algorithm; wherein, a core power self-disturbance controller is designed based on the active disturbance rejection control algorithm; a steam pressure internal model controller and a main steam flow internal model controller are designed based on the internal model control algorithm; Based on the active disturbance rejection control algorithm, a core power ADRC control system is constructed with the power setpoint and measurement value deviation as input and the temperature deviation compensation as output. The controlled object model is organized into the following form based on the active disturbance rejection control algorithm: Where, u is the system input, y is the system output, a 1 and a 2 are model information, w is an external disturbance, g is the internal disturbance, b is the coefficient of the control input; Based on the internal model control algorithm, a main steam pressure IMC control system with feedwater flow as input and steam pressure as output is constructed. The specific expression is: Where G c1 (s) is the controller transfer function, λ1 is the parameter to be tuned; Based on the internal model control algorithm, a main steam flow IMC control system is constructed with the main steam valve opening as input and the output as output power as output. Specifically, it is expressed as follows: Where G c2 (s) is the controller transfer function, and λ2 is the parameter to be tuned.

2. The design method of the lead-bismuth fast reactor advanced control system according to claim 1, characterized in that: The core adopts a point reactor dynamics model with 6 groups of delayed neutrons, and the specific expression is as follows: Where, n ( t ) represents neutron density / neutron number; ρ ( t ) represents the total reactivity in the core; C i ( t ) indicates the i The concentration of precursor nuclei of delayed neutrons / the number of precursor nuclei of delayed neutrons; λ i Indicates the i Decay constant of the group precursor nucleus / s; β i Indicates the i The delayed neutron fraction of the group; Λ represents the neutron generation time.

3. The design method of the lead-bismuth fast reactor advanced control system according to claim 1, characterized in that: The once-through steam generator adopts a four-heat exchange zone model based on the movable boundary theory. The specific expression is: Where, ρ represents the fluid density; G represents mass flux; Q represents the wall linear heat flux density; A Indicates the flow area of ​​the flow channel; P express; g represents the acceleration due to gravity; H represents enthalpy value; represents the Fanning friction factor; l represents the wetted perimeter of the flow channel.

4. The design method of the lead-bismuth fast reactor advanced control system according to claim 1, characterized in that: The measurement noise adopts Gaussian white noise, and the average power of the Gaussian white noise is 0.24%~0.26%.

5. An advanced control system for a lead-bismuth fast reactor, characterized in that: The invention is designed based on the design method of the advanced control system of the lead-bismuth fast reactor described in any one of claims 1-4.

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