Advanced control system and design method for lead-bismuth fast reactor

Abstract

The invention belongs to the field of lead-bismuth fast reactor advanced control system design, and discloses a lead-bismuth fast reactor advanced control system and a design method.The method comprises the steps that a lead-bismuth fast reactor model is built, and the lead-bismuth fast reactor model comprises two controlled object models of a reactor core and a once-through steam generator; on the basis of the built lead-bismuth fast reactor model, characteristic analysis of controller output anti-disturbance and anti-noise capability is carried out for various advanced control algorithms, and characteristic analysis results corresponding to the advanced control algorithms are obtained; based on a characteristic analysis result, screening to obtain an advantage advanced control algorithm; based on an advanced advantage control algorithm, a reactor core power self-disturbance controller, a steam pressure internal model controller and a main steam flow internal model controller are designed, so that the advanced control system of the lead-bismuth fast reactor is designed. The advanced control system designed by the method has good response speed and stability; and the lead-bismuth fast reactor can meet the application requirements of complex operating environment and variable working 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 refer to fast neutron reactors that use liquid lead or lead-bismuth as coolant. Small pool-type lead-bismuth fast reactors can provide power for mobile devices and can be connected in parallel to form large nuclear power plants; their potential application scenarios include remote areas and island power supply. The complex operating environment and changing working conditions of these scenarios have brought challenges to the design of small lead-bismuth fast reactor control systems, and higher requirements have been placed on the control system.

[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, which in turn will lead 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 failure to meet application requirements with complex operating environments and changing operating conditions.

[0004] It can be seen that the existing 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, and cannot meet the application requirements of complex operating environments and changeable working conditions. Summary of the invention

[0005] The present invention provides an advanced control system and design method for a lead-bismuth fast reactor, so as to solve the technical problems that the existing control method for lead-bismuth fast reactor has multiple loop feedbacks and the design and parameters need to be adjusted multiple times, resulting in low controller design efficiency and failure to meet the application requirements of complex operating environments and changeable working conditions.

[0006] In order to achieve the above object, the present invention adopts the following technical contents: In a first aspect, the present invention provides a design method for an advanced control system of a lead-bismuth fast reactor, comprising: 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 a variety of advanced control algorithms, and the corresponding characteristic analysis results of each advanced control algorithm are obtained; Based on the characteristics analysis results, the superior advanced control algorithm is 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 are designed, thus the advanced control system of the lead-bismuth fast reactor is designed.

[0007] Furthermore, the core adopts a point reactor dynamics model with 6 groups of delayed neutrons, and the specific expression is as follows:

[0008] In the formula, 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 i Decay constant of the group precursor nucleus / s; β i Indicates i The delayed neutron fraction of the group; Λ represents the neutron generation time.

[0009] 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:

[0010]

[0011]

[0012] In the formula, ρ represents the density of the fluid; 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; represents the Fanning friction factor; l represents the wetted perimeter of the flow channel.

[0013] Furthermore, the specific steps of analyzing the characteristics of the controller output anti-disturbance and anti-noise capabilities for a variety of advanced control algorithms include: Based on the core and the once-through steam generator in the lead-bismuth fast reactor model, the reactivity step disturbance is introduced into the corresponding reactor power system, the reactor power setting value step disturbance is introduced into the corresponding reactor power system, and the measurement noise and the reactor power setting value 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.

[0014] Furthermore, the measurement noise adopts Gaussian white noise, and the average power of the Gaussian white noise is 0.24%~0.26%. Furthermore, the specific steps for screening the superior advanced control algorithm are as follows: The characteristic analysis results include steady-state error, anti-noise capability, controller output disturbance and the number of parameters to be adjusted; a comprehensive comparative analysis is performed on the steady-state error, anti-noise capability, controller output disturbance elimination capability and the number of parameters to be adjusted corresponding to each advanced control algorithm to screen out an advantageous advanced control algorithm.

[0015] Furthermore, the advantageous advanced control algorithm adopts an auto-disturbance rejection control algorithm and an internal model control algorithm; wherein, a core power auto-disturbance controller is designed based on the auto-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.

[0016] 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 measured value deviation and whose output is the temperature deviation compensation. Based on the active disturbance rejection control algorithm, the controlled object model is organized into the following form:

[0017] In the formula, u For system input, y is the system output, a 1 and a 2 are model information, w is the external disturbance, g is the internal disturbance, b is the coefficient of the control input.

[0018] 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:

[0019] In the formula, G c1 (s) is the controller transfer function, λ1 is the parameter to be tuned; Based on the internal model control algorithm, the main steam flow IMC control system with the input as the main steam valve opening and the output as the output power is constructed. The specific expression is:

[0020] In the formula, G c2 (s) is the controller transfer function, and λ2 is the parameter to be tuned.

[0021] In a second aspect, the present invention provides an advanced control system for a lead-bismuth fast reactor, which is designed based on the design method of the advanced control system for a lead-bismuth fast reactor.

[0022] Compared with the prior art, the present invention has the following beneficial effects: The present invention provides a design method for an advanced control system of a lead-bismuth fast reactor. The design method firstly builds a lead-bismuth fast reactor model including two controlled object models, a core and a direct current steam generator, so as to provide an accurate basis for subsequent control system design. Then, based on the built model, various advanced control algorithms are subjected to in-depth characteristic analysis of 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, thereby avoiding the problems of multi-loop feedback and multiple controller parameter setting 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 a good control effect when facing changes in system parameters, thereby meeting the application requirements of complex operating environment and changeable working conditions.

[0023] Preferably, in the present invention, a point reactor kinetic model with 6 groups of delayed neutrons is used to describe the core, which can more accurately simulate the neutron kinetic process of the lead-bismuth fast reactor, including reactivity changes, etc., thereby providing a more accurate basis for the design of the control system.

[0024] Preferably, in the present invention, a four-heat exchange zone model is used to describe the direct current steam generator, and modeling is performed based on the movable boundary theory, which can more accurately reflect the heat exchange process, pressure change and other characteristics of the steam generator, and help design a more accurate control system.

[0025] 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.

[0026] 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, so as to evaluate the performance of the control system under noise interference. This setting helps to design a more robust control system.

[0027] Preferably, in the present invention, by comprehensively comparing and analyzing indicators such as steady-state error, noise resistance, controller output disturbance, and the 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 optimal.

[0028] Preferably, in the present invention, the self-disturbance rejection control algorithm and the internal model control algorithm are adopted as the dominant control algorithms, and the core power self-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.

[0029] 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.

[0030] Preferably, in the present invention, a main steam pressure IMC control system and a main steam flow IMC control system are constructed based on an internal model control algorithm, which can achieve precise control of the steam pressure and the main steam flow; this method can ensure the stable operation of the steam generator; and the performance of the control system can be further optimized by adjusting the controller transfer function and the parameters to be set.

[0031] The present invention also provides an advanced control system for a lead-bismuth fast reactor, which is designed based on the design method of the lead-bismuth fast reactor advanced control system. The lead-bismuth fast reactor advanced control system is equipped with a core power anti-disturbance controller, a steam pressure internal model controller and a main steam flow internal model controller; wherein the core power ADRC controller uses the temperature controller output as a disturbance and compensates it, effectively improving the control effect of the core power, and the designed steam pressure and steam flow IMC controllers can reduce the controller setting parameters and improve the controller design efficiency. The present invention provides a research basis 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. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] 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; 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; Figure 3 A result diagram of a simulation condition of a lead-bismuth fast reactor advanced control system provided by an embodiment of the present invention; wherein (a) is power; (b) is the average coolant temperature; (c) is the steam pressure; Figure 4 A result diagram of a simulation condition of a lead-bismuth fast reactor advanced control system provided in an embodiment of the present invention; wherein (a) is power; (b) is average coolant temperature; and (c) is steam pressure. DETAILED DESCRIPTION

[0033] 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 used to limit the present invention.

[0034] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings 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. Generally, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

[0035] 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 claimed for protection, but merely represents selected embodiments of the present invention. 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.

[0036] 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, further definition and explanation thereof is not required in subsequent drawings.

[0037] In the description of the embodiments of the present invention, it should be noted that if the terms "upper", "lower", "horizontal", "inner", etc. indicate an orientation or positional relationship based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship in which the product of the invention is usually placed when in use, it is only for the convenience of describing the present invention and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention. In addition, the terms "first", "second", etc. are only used to distinguish the description, and cannot be understood as indicating or implying relative importance.

[0038] 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", which does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0039] In the description of the embodiments of the present invention, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "set", "install", "connect", and "connect" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal connection of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0040] Example 1 As mentioned in the background technology, currently, small-scale 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. 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 failure to meet application requirements with complex operating environments and changing operating conditions.

[0041] In order to solve the above problems, the present invention provides an advanced control system and a design method for a lead-bismuth fast reactor. The use of the design method and the designed advanced control system can effectively improve the control effect and control efficiency of the lead-bismuth fast reactor.

[0042] The present invention is further described in detail below with reference to the accompanying drawings and embodiments: 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: Build a lead-bismuth fast reactor model, which includes two controlled object models: the core and the direct current 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 a variety of advanced control algorithms, and the corresponding characteristic analysis results of each advanced control algorithm are obtained; Based on the characteristics analysis results, the superior advanced control algorithm is 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 are designed, thus the advanced control system of the lead-bismuth fast reactor is designed.

[0043] This design method first provides an accurate foundation for the subsequent control system design by building a lead-bismuth fast reactor model that includes two controlled object models, the core and the direct current steam generator; then, based on the built model, an in-depth characteristic analysis of the controller output anti-disturbance and anti-noise capabilities of various advanced control algorithms is carried out. This process ensures that the selected algorithm can adapt to the complex and changeable operating environment of the lead-bismuth fast reactor; through the screening of the characteristic analysis results, the control algorithm with obvious advantages can be identified and selected, thereby avoiding the problems of multi-loop feedback and multiple controller parameter settings in traditional control methods; finally, based on the screened advantageous advanced control algorithms, the core power self-disturbance controller, steam pressure internal model controller and 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.

[0044] Example 2 like Figure 2 As shown, this embodiment provides a design method for an advanced control system of 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 a variety of scenarios. The specific steps of the design method are as follows: S1. Build a small lead-bismuth fast reactor model based on Matlab / Simulink, which includes two types of controlled objects: the core and the direct current steam generator; 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; S3. According to the characteristics analysis of different advanced control algorithms, the core power anti-disturbance controller, steam pressure internal model controller and main steam flow internal model controller are designed.

[0045] In this embodiment, a small lead-bismuth fast reactor model is built based on Matlab / Simulink, including: The main controlled object models of the small lead-bismuth fast reactor model are: core and direct-flow steam generator.

[0046] In this embodiment, the core adopts a point reactor dynamics model containing 6 groups of delayed neutrons to simplify the core neutron dynamics model, which is specifically expressed as follows:

[0047] In the formula, 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.

[0048] In this embodiment, the once-through steam generator is modeled using a four-heat exchange zone model combined with a movable boundary theory, which is specifically expressed as follows:

[0049]

[0050]

[0051] Where: ρ —— Fluid density / kg m -3 ; G —— Mass flux / kg s -1 m -2 ; Q —— Wall linear heat flux density / J m -1 s -1 ; A —— Flow area of ​​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 flow channel / m.

[0052] 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: Based on the established small lead-bismuth fast reactor model, the reactor power system is introduced with a reactivity step disturbance; a reactor power setting value step disturbance is introduced; a Gaussian white noise with an average power of 0.24%~0.26% is introduced; and after the measurement noise of 0.25% Gaussian white noise is preferably introduced, a reactor power setting value step disturbance is introduced. The characteristics of different control methods are compared as shown in Table 1. Specific advanced control algorithms include: proportional integral (PI), active disturbance rejection control (ADRC), and internal model control (IMC); proportional integral (PI), active disturbance rejection control (ADRC), and internal model control (IMC) can achieve steady-state error-free regulation for objects with or without integral characteristics. Among them, ADRC can eliminate controller output disturbances and has obvious advantages in multiple feedback loops; IMC control has good anti-noise ability, can achieve steady-state error-free regulation in a single feedback loop, and the parameter to be tuned is 1 and the tuning direction is clear, which brings convenience to the design and optimization of the controller. In addition, the parameters of the PID controller can be calculated by IMC, which can provide guidance for the parameter tuning of the PID controller. The anti-noise capability of H∞ robustness is comparable to that of ADRC. Since it cannot eliminate the disturbance of the controller output, it has no obvious advantage in the core coolant average temperature control system. In single feedback loop control, the tuning difficulty of H∞ robustness is greater than that of IMC, and it cannot eliminate the steady-state error. It has no obvious advantage in the feedwater flow control system and the steam flow control system.

[0053] Table 1 shows the characteristic analysis results of various advanced control algorithms

[0054] In this embodiment, according to the characteristics analysis of different advanced control algorithms, a core power anti-disturbance controller, a steam pressure internal model controller and a main steam flow internal model controller are designed, including: 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 through the application of ADRC. ADRC, IMC, and H∞ all have good noise resistance. In comparison, IMC has better anti-noise effect, 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, a core power ADRC controller is designed in this embodiment, and the core power control is optimized by ADRC to reduce the overshoot of the core power during load disturbances; the steam pressure control and steam flow IMC controllers are designed to improve noise resistance while simplifying the controller parameter setting.

[0055] The core power ADRC control system input is the power setting value 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:

[0056] in, u For system input, y is the system output, a 1 and a 2 is the model information, w is the external disturbance, g The unmodeled part of the model is regarded as the internal disturbance of the model. b is the coefficient of the control input. In the control of model-free ADRC, the first two parts are classified as internal disturbances. g , the above formula is simplified to:

[0057] For the six-group delayed neutron point reactor model, the six groups of delayed neutrons are combined into one group, and the various parameters are introduced to eliminate , At the same time, it can be considered N ( t ) changes linearly within a small range, and is simplified into a controlled object model organization form. Due to the influence of the temperature controller feedback, the output of the temperature controller is u 2 The resulting system output y 2 Classified as external disturbance w , g is the internal disturbance. Finally, the ADRC controller is applied to the temperature feedback channel.

[0058] 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 transfer function from the feedwater flow rate to the steam pressure, and uses the reduced transfer function to design the IMC controller. The IMC controller can be expressed as:

[0059] In the formula, G c1 (s) is the controller transfer function, and λ1 is the parameter to be tuned.

[0060] 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:

[0061] In the formula, G c2 (s) is the controller transfer function, and λ2 is the parameter to be tuned.

[0062] Example 3 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 the figure, in this embodiment, the 100% FP power level runs for 100 seconds. At the simulation time of 100 seconds, the load setting value changes stepwise by -10% FP and runs for 2900 seconds. At the simulation time of 3000 seconds, the load setting value changes stepwise by +10% FP and remains unchanged.

[0063] Under the action of the advanced control system, the output power adjustment time of the small lead-bismuth fast reactor is 13s, and the overshoot is 0.03%. When the load setting value changes stepwise, the optimization effect of the advanced control algorithm is limited due to the good load tracking effect of the PID control system; when the load setting value decreases stepwise, the power adjustment time of the core power is 217s, and the overshoot is 4.3%, which is 71.9% less than the overshoot of PID control. When the load setting value increases stepwise, the power adjustment time of the core power is 261s, and the overshoot is 4%, which is 69.9% less than the overshoot of PID control. During the step decrease of the load setting value, the average coolant temperature changes from -3℃ to + 2.2℃. The maximum coolant temperature is equivalent to PID, indicating that the improvement of power regulation by ADRC does not aggravate the lead-bismuth corrosion phenomenon, and can effectively reduce the overshoot of the core power. During the linear increase and decrease of the load setting value, the steam pressure changes from -0.25MPa to +0.28MPa. Compared with the PID controller, the pressure fluctuation range is smaller, and the pressure peak decreases by 24.1%.

[0064] Example 4 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 this embodiment, the 100% FP power level operates for 100 s. At the simulation time of 100 s, the load setting value changes linearly from -0.1% FP / s to 90% FP. At the simulation time of 3000 s, the load setting value changes linearly from +0.1% FP / s to 100% FP and remains unchanged.

[0065] Under the action of the advanced control system, the output power adjustment time of the small lead-bismuth fast reactor is 5s, and the overshoot is 0.07%. When the load changes linearly, the maximum deviation between the output power and the load setting value is 0.06MW. Due to the good load tracking effect of the PID control system, the optimization effect of the advanced control algorithm is limited. When the load setting value decreases linearly, the power adjustment time of the core power is 217s, and the overshoot is 7.3%, which is 32.4% less than the overshoot of PID control. When the load setting value increases linearly, the power adjustment time of the core power is 194s, and the overshoot is 3.3%, which is equivalent to PID. During the linear decrease of the load setting value, the average coolant temperature changes from -1.7℃ to + 2.1℃. The minimum temperature change of the coolant is equivalent to that of PID. It can be seen that optimizing the core power control through ADRC can effectively reduce the overshoot of the core power. During the linear increase and decrease of the load setting value, the steam pressure changes from -0.22 MPa to +0.28 MPa. Compared with the PID controller, the pressure fluctuation range is smaller and the pressure peak decreases by 30%.

[0066] 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: 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; designs a core power self-anti-disturbance controller, a steam pressure internal model controller and a main steam flow internal model controller according to the characteristics analysis of different advanced control algorithms. By implementing the present invention, compared with the traditional controller, the designed core power ADRC controller uses the temperature controller output as a disturbance and compensates, which effectively improves the control effect of the core power. The designed steam pressure and steam flow IMC controllers can reduce the controller setting parameters and improve the controller design efficiency; the present invention provides a research basis 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.

[0067] 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 the 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 a variety of advanced control algorithms, and the corresponding characteristic analysis results of each advanced control algorithm are obtained; Based on the characteristics analysis results, the superior advanced control algorithm is 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 are designed, thus the advanced control system of the lead-bismuth fast reactor is designed.

2. The design method of the lead-bismuth fast reactor advanced control system according to claim 1 is characterized in that: The core adopts a point reactor dynamics model with 6 groups of delayed neutrons, and the specific expression is as follows: In the formula, 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 i Decay constant of the group precursor nucleus / s; β i Indicates 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 is characterized in that: 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: In the formula, ρ represents the density of the fluid; 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; 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 is characterized in that: 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 the once-through steam generator in the lead-bismuth fast reactor model, the reactivity step disturbance is introduced into the corresponding reactor power system, the reactor power setting value step disturbance is introduced into the corresponding reactor power system, and the measurement noise and the reactor power setting value 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.

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

6. The design method of the lead-bismuth fast reactor advanced control system according to claim 4 is characterized in that: The specific steps for screening the superior advanced control algorithms are as follows: The characteristic analysis results include steady-state error, anti-noise capability, controller output disturbance and the number of parameters to be adjusted; a comprehensive comparative analysis is performed on the steady-state error, anti-noise capability, controller output disturbance elimination capability and the number of parameters to be adjusted corresponding to each advanced control algorithm to screen out an advantageous advanced control algorithm.

7. The design method of the lead-bismuth fast reactor advanced control system according to claim 6 is characterized in that: The advantageous advanced control algorithm adopts an auto-disturbance rejection control algorithm and an internal model control algorithm; wherein, a core power auto-disturbance controller is designed based on the auto-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.

8. The design method of the lead-bismuth fast reactor advanced control system according to claim 7 is characterized in that: Based on the active disturbance rejection control algorithm, a core power ADRC control system with power setpoint and measurement value deviation as input and temperature deviation compensation as output is constructed. Based on the active disturbance rejection control algorithm, the controlled object model is organized into the following form: In the formula, u For system input, y is the system output, a 1 and a 2 are model information, w is the external disturbance, g is the internal disturbance, b is the coefficient of the control input.

9. The design method of the lead-bismuth fast reactor advanced control system according to claim 7, characterized in that: 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: In the formula, G c1 (s) is the controller transfer function, λ1 is the parameter to be tuned; Based on the internal model control algorithm, the main steam flow IMC control system with the input as the main steam valve opening and the output as the output power is constructed. The specific expression is: In the formula, G c2 (s) is the controller transfer function, and λ2 is the parameter to be tuned.

10. An advanced control system for a lead-bismuth fast reactor, characterized in that: The design is obtained based on the design method of the advanced control system of the lead-bismuth fast reactor described in any one of claims 1-9.

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