Control method and device for open channel inverted siphon series open full flow system

Abstract

The present invention discloses a control method and device for an open channel inverted siphon series open full flow system, belonging to the field of water conservancy technology. The method comprises: establishing a time-domain open channel control model based on the open channel Saint-Venant equation; establishing a time-domain pressure flow control model based on the water hammer control equation of the pressure flow; constructing an open full flow system control model for the open channel inverted siphon series based on the time-domain open channel control model and the time-domain pressure flow control model; and optimizing and solving the open full flow system control model for the open channel inverted siphon series using a model predictive control (MPC) strategy to obtain optimal control parameters, which are used to control the open full flow system control model for the open channel inverted siphon series. This method can achieve accurate and effective control of the open full flow system for the open channel inverted siphon series.

Description

Technical Field

[0001] The present disclosure relates to the field of water conservancy technology, and in particular to a control method and device for an open channel full flow system connected in series with an inverted siphon. Background Art

[0002] A free-surface and pressurized flow system refers to a flow system in which the water flow may alternate or exist simultaneously in both free-surface and pressurized flow states in the same pipe or channel.

[0003] In traditional channel automation control, tunnels / inverted siphons are generally short (tunnels are open channels), resulting in a high safety margin during operation and scheduling, and the impact of internal pressure fluctuations on project safety can be ignored. However, based on the current and ongoing inter-basin water diversion and transfer projects, the proportion of inter-basin water diversion and transfer projects using tunnels / inverted siphons has increased dramatically, making the impact of tunnels and inverted siphons on water diversion and transfer projects no longer negligible. Therefore, if the automation control system is not properly scheduled, the pressure peaks generated within the inverted siphon may exceed the maximum pressure capacity of the pipeline, leading to serious accidents such as pipe bursts. Therefore, considering open and full flow in the operation and scheduling of large-scale water networks is an inevitable requirement and guarantee for safe and efficient operation.

[0004] For open-flow systems with both open and pressurized flows, such as open channels and inverted siphons in series, the open channel system exhibits slow changes and significant time lag, while the pressurized flow system (i.e., the flow system corresponding to the inverted siphon) exhibits rapid changes and time-varying characteristics. The combined effects of these two characteristics on the system, coupled with strong nonlinear coupling, present significant challenges for automated control of open-flow systems. Currently, there are no control models or methods for open-flow systems with open channels and inverted siphons in series. Traditional methods that ignore pressure pulsations within the inverted siphon's pressure pipe are no longer able to meet the requirements for high-precision and efficient control of open-flow systems over long distances in large water networks. Summary of the Invention

[0005] The present disclosure provides a method and device for controlling an open channel inverted siphon system with full flow, which can achieve accurate and effective control of the open channel inverted siphon system with full flow. The technical solution includes at least the following solutions:

[0006] In a first aspect, a method for controlling an open full flow system of an open channel inverted siphon in series is provided, comprising: establishing a time-domain open channel control model based on the open channel Saint-Venant equation, wherein the time-domain open channel control model is used to indicate the relationship between the water depth and flow rate at the input and output ends of the open channel; establishing a time-domain pressure flow control model based on the water hammer control equation of the pressure flow, wherein the time-domain pressure flow control model is used to indicate the relationship between the water depth and flow rate at the input and output ends of the inverted siphon; constructing an open full flow system control model of the open channel inverted siphon in series based on the time-domain open channel control model and the time-domain pressure flow control model; and optimizing and solving the open full flow system control model of the open channel inverted siphon in series using a model predictive control (MPC) strategy to obtain optimal control parameters, and the optimal control parameters are used to control the open full flow system control model of the open channel inverted siphon in series.

[0007] Optionally, the time-domain open channel control model is expressed using the following formula:

[0008] ,

[0009] in, is the intermediate variable of water depth; is the output variable of the water depth of the open channel; is the inlet flow rate among the input variables of the time-domain open channel control model, is the outlet flow rate among the input variables of the time-domain open channel control model; is the delay time; is the surface area of ​​water flow in the channel backwater zone, 、 is the high-frequency term in the downstream, is the horizontal projection of the length of the open channel;

[0010] The time-domain pressure flow control model is expressed by the following formula:

[0011] ,

[0012] in, is the intermediate variable of water depth, is the water depth output variable of pressure flow, is the inlet flow rate among the input variables of the time-domain pressure flow control model, is the outlet flow rate in the input variable of the time-domain pressure flow control model, is the pressure wave velocity, is the acceleration due to gravity, is the flow area of ​​the pressure pipe of the inverted siphon, is the projection of the length of the pressure pipe in the horizontal direction.

[0013] Optionally, the water hammer control equation based on the pressure flow establishes a time domain pressure flow control model, including: obtaining the water hammer control equation of the pressure flow; diagonalizing the state transfer matrix in the water hammer control equation of the pressure flow to obtain the frequency domain control model of the pressure flow; linearly transforming the frequency domain control model of the pressure flow to obtain the input-output conversion equation of the pressure flow in the frequency domain, in which the input is the upstream and downstream flow boundaries of the pressure flow, and the output is the water depth upstream and downstream of the pressure flow; after simplifying the input-output conversion equation of the pressure flow in the frequency domain, the simplified input-output conversion equation of the pressure flow in the frequency domain is converted to the time domain to obtain the time domain pressure flow control model.

[0014] Optionally, the open channel full flow system control model of the open channel inverted siphon in series is constructed based on the time-domain open channel control model and the time-domain pressure flow control model, including: constructing a mass conservation equation and an energy conservation equation, wherein the mass conservation equation and the energy conservation equation are used to describe the relationship between the flow rate and the water depth between the open channel output end and the inverted siphon input end; using linear transformation to solve the mass conservation equation and the energy conservation equation to obtain a node state transfer matrix between the open channel output end and the inverted siphon input end; based on the open channel state transfer matrix, the node state transfer matrix, and the inverted siphon state transfer matrix, A state transfer matrix of an open channel and inverted siphon connected in series is constructed, wherein the open channel state transfer matrix is ​​obtained in the process of establishing the time domain open channel control model, and the inverted siphon state transfer matrix is ​​obtained in the process of establishing the time domain inverted siphon control model; based on the state transfer matrix of the open channel and inverted siphon connected in series, a control model of the open channel and inverted siphon connected in series is constructed, wherein the control model of the open channel and inverted siphon connected in series includes a water depth control model of the open channel output end with the open channel flow as input and a water depth control model of the inverted siphon output end with the inverted siphon flow as input.

[0015] Optionally, the open channel output end water depth control model with the open channel flow as input is expressed by the following formula:

[0016] ,

[0017] in, When the open channel flow is used as input, the output end of the open channel is The water depth of the time step, When the open channel flow is used as input, the output end of the open channel is The water depth of the time step, To control the sampling interval of the model, is the surface area of ​​the return water zone in the open flow section, is the delay time of the bright flow propagation, is the delay time of pressure flow propagation, is the flow rate at the open channel input, is the flow rate at the output end of the open channel, is the high frequency term coefficient, From the time step To time step The increase in flow rate at the open channel input end, From the time step To time step The increase in flow rate at the output end of the open channel;

[0018] The water depth control model at the inverted siphon output end with the inverted siphon flow as input is expressed by the following formula:

[0019] ,

[0020] in, In the case of reverse siphon flow as input, the reverse siphon output is The water depth of the time step, In the case of reverse siphon flow as input, the reverse siphon output is The water depth of the time step, To control the sampling interval of the model, is the surface area of ​​the return water zone in the open flow section, is the flow rate at the inverted siphon input, is the flow rate at the inverted siphon output end, From the time step To time step The increase in flow rate within the inverted siphon input end, From the time step To time step The increase in flow rate at the output end of the inverted siphon, The reduction factor for the pressure fluctuation caused by the opening of the inverted siphon boundary is less than the water hammer pressure. is the acceleration due to gravity, is the flow area of ​​the inverted siphon pressure pipe, is the pressure wave velocity.

[0021] Optionally, the use of the model predictive control (MPC) strategy to optimize and solve the open full flow system control model of the open channel inverted siphon in series to obtain optimal control parameters includes: constructing a state space equation of the open full flow system of the open channel inverted siphon in series; obtaining a set of constraints, the set of constraints including controller output constraints, slew rate constraints and system output constraints; based on the state space equation and the set of constraints, using a quadratic programming method to solve the open full flow system control model of the open channel inverted siphon in series to obtain the optimal control parameters.

[0022] In the second aspect, a control device for an open channel inverted siphon in series with an open full flow system is also provided, including: a first modeling module, used to establish a time-domain open channel control model based on the open channel Saint-Venant equation, and the time-domain open channel control model is used to indicate the relationship between the water depth and flow rate at the input and output ends of the open channel; a second modeling module, used to establish a time-domain pressure flow control model based on the water hammer control equation of the pressure flow, and the time-domain pressure flow control model is used to indicate the relationship between the water depth and flow rate at the input and output ends of the inverted siphon; a third modeling module, used to construct an open full flow system control model for an open channel inverted siphon in series based on the time-domain open channel control model and the time-domain pressure flow control model; a parameter solving module, used to optimize and solve the open full flow system control model for the open channel inverted siphon in series using a model predictive control MPC strategy to obtain optimal control parameters, and the optimal control parameters are used to control the open full flow system control model for the open channel inverted siphon in series with an open channel.

[0023] Optionally, in the first modeling module, the time-domain open channel control model is expressed using the following formula:

[0024] ,

[0025] in, is the intermediate variable of water depth; is the output variable of the water depth of the open channel; is the inlet flow rate among the input variables of the time-domain open channel control model, is the outlet flow rate among the input variables of the time-domain open channel control model; is the delay time; is the surface area of ​​water flow in the channel backwater zone, 、 is the high-frequency term in the downstream, is the horizontal projection of the length of the open channel;

[0026] In the second modeling module, the time-domain pressure flow control model is expressed by the following formula:

[0027] ,

[0028] in, is the intermediate variable of water depth, is the water depth output variable of pressure flow, is the inlet flow rate among the input variables of the time-domain pressure flow control model, is the outlet flow rate in the input variable of the time-domain pressure flow control model, is the pressure wave velocity, is the acceleration due to gravity, is the flow area of ​​the pressure pipe of the inverted siphon, is the projection of the length of the pressure pipe in the horizontal direction.

[0029] Optionally, the second modeling module is also used to obtain the water hammer control equation of the pressure flow; diagonalize the state transfer matrix in the water hammer control equation of the pressure flow to obtain the frequency domain control model of the pressure flow; linearly transform the frequency domain control model of the pressure flow to obtain the input-output conversion equation of the pressure flow in the frequency domain, in which the input is the upstream and downstream flow boundaries of the pressure flow, and the output is the water depth upstream and downstream of the pressure flow; after simplifying the input-output conversion equation of the pressure flow in the frequency domain, the simplified input-output conversion equation of the pressure flow in the frequency domain is converted to the time domain to obtain the time domain pressure flow control model.

[0030] Optionally, the third modeling module is also used to construct a mass conservation equation and an energy conservation equation, which are used to describe the relationship between the flow rate and water depth between the open channel output end and the inverted siphon input end; linear transformation is used to solve the mass conservation equation and the energy conservation equation to obtain a node state transfer matrix between the open channel output end and the inverted siphon input end; based on the open channel state transfer matrix, the node state transfer matrix, and the inverted siphon state transfer matrix, a state transfer matrix of an open channel inverted siphon in series open full flow system is constructed, the open channel state transfer matrix is ​​obtained in the process of establishing the time domain open channel control model, and the inverted siphon state transfer matrix is ​​obtained in the process of establishing the time domain inverted siphon control model; based on the state transfer matrix of the open channel inverted siphon in series open full flow system, a control model of the open channel inverted siphon in series open full flow system is constructed, and the open channel inverted siphon in series open full flow system control model includes an open channel output end water depth control model with open channel flow as input and an inverted siphon output end water depth control model with inverted siphon flow as input.

[0031] Optionally, in the third modeling module, the open channel output end water depth control model with the open channel flow as input is expressed by the following formula:

[0032] ,

[0033] in, When the open channel flow is used as input, the output end of the open channel is The water depth of the time step, When the open channel flow is used as input, the output end of the open channel is The water depth of the time step, To control the sampling interval of the model, is the surface area of ​​the return water zone in the open flow section, is the delay time of the bright flow propagation, is the delay time of pressure flow propagation, is the flow rate at the open channel input, is the flow rate at the output end of the open channel, is the high frequency term coefficient, From the time step To time step The increase in flow rate at the open channel input end, From the time step To time step The increase in flow rate at the output end of the open channel;

[0034] The water depth control model at the inverted siphon output end with the inverted siphon flow as input is expressed by the following formula:

[0035] ,

[0036] in, In the case of reverse siphon flow as input, the reverse siphon output is The water depth of the time step, In the case of reverse siphon flow as input, the reverse siphon output is The water depth of the time step, To control the sampling interval of the model, is the surface area of ​​the return water zone in the open flow section, is the flow rate at the inverted siphon input, is the flow rate at the inverted siphon output end, From the time step To time step The increase in flow rate within the inverted siphon input end, From the time step To time step The increase in flow rate at the output end of the inverted siphon, The reduction factor for the pressure fluctuation caused by the opening of the inverted siphon boundary is less than the water hammer pressure. is the acceleration due to gravity, is the flow area of ​​the inverted siphon pressure pipe, is the pressure wave velocity.

[0037] Optionally, the parameter solving module is also used to construct a state space equation of an open channel inverted siphon in series open full flow system; obtain a set of constraints, the set of constraints including controller output constraints, slew rate constraints and system output constraints; based on the state space equation and the set of constraints, a quadratic programming method is used to solve the control model of the open channel inverted siphon in series open full flow system to obtain the optimal control parameters.

[0038] In a third aspect, a computer device is also provided, comprising: a memory and a processor, wherein at least one computer program is stored in the memory, and the at least one computer program is loaded and executed by the processor, thereby executing the open full flow system control method for open channel inverted siphon series connection described in the above embodiment.

[0039] In a fourth aspect, a computer-readable storage medium is also provided, in which at least one computer program is stored. The at least one computer program is loaded and executed by a processor, thereby executing the open full flow system control method for open channel inverted siphon series connection described in the above embodiment.

[0040] In a fifth aspect, a computer program product is provided, comprising a computer program / instruction, which implements the method described in the first aspect when executed by a processor.

[0041] The beneficial effects of the technical solutions provided by the embodiments of the present disclosure include at least:

[0042] In the disclosed embodiments, a time-domain open channel control model is established based on the Saint-Venant equation for open channels. The time-domain open channel control model is used to indicate the relationship between the water depth and flow rate at the input and output ends of the open channel. A time-domain pressure flow control model is established based on the water hammer control equation for pressure flow. The time-domain pressure flow control model is used to indicate the relationship between the water depth and flow rate at the input and output ends of the inverted siphon. Based on the time-domain open channel control model and the time-domain pressure flow control model, a control model for an open channel and inverted siphon in series is constructed. This control model can reflect the complex dynamic response characteristics of the open channel and inverted siphon series system and accurately predict the system's state response under different input signals. By using an MPC strategy to optimize and solve the open channel and inverted siphon series open flow system control model, the optimal control parameters are obtained. These optimal control parameters can realize automated control of the open channel and inverted siphon series open flow system control model. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] In order to more clearly illustrate the technical solutions in the embodiments of the present disclosure, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present disclosure. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0044] Figure 1 A flow chart of a method for controlling an open channel inverted siphon series open full flow system provided by an exemplary embodiment of the present disclosure is shown;

[0045] Figure 2 It is a schematic diagram of a simplified open channel inverted siphon series system;

[0046] Figure 3 Schematic diagram of the frequency domain response characteristics of an open channel full flow system with an open channel inverted siphon in series;

[0047] Figure 4 A flow chart showing a method for controlling an open channel inverted siphon series open full flow system provided by another exemplary embodiment of the present disclosure is shown;

[0048] Figure 5 This is a schematic diagram of the principle of the MPC strategy;

[0049] Figure 6 This is a schematic diagram of an actual open channel inverted siphon series open full flow system;

[0050] Figure 7 Schematic diagram comparing the control effects of the present invention and traditional composite control under the same working conditions;

[0051] Figure 8 A schematic structural diagram of an open channel full flow system control device for an open channel inverted siphon series connection is shown in an exemplary embodiment of the present disclosure;

[0052] Figure 9 It is a structural diagram of a computer device provided in an embodiment of the present disclosure. DETAILED DESCRIPTION

[0053] Unless otherwise defined, the technical or scientific terms used herein shall have the usual meanings understood by persons of ordinary skill in the field to which the present disclosure belongs. The words "first", "second", "third" and similar terms used in the present patent application do not indicate any order, quantity or importance, but are only used to distinguish different components. Similarly, words such as "one" or "a" do not indicate a quantity limitation, but rather indicate the presence of at least one. Words such as "include" or "comprising" and similar terms mean that the elements or objects appearing before "include" or "comprising" cover the elements or objects listed after "include" or "comprising" and their equivalents, and do not exclude other elements or objects. Words such as "connect" or "connected" and similar terms are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect.

[0054] In order to make the objectives, technical solutions and advantages of the present disclosure more clear, the embodiments of the present disclosure will be further described in detail below with reference to the accompanying drawings.

[0055] Figure 1 A flow chart of a method for controlling an open channel inverted siphon series open full flow system provided by an exemplary embodiment of the present disclosure is shown. The method can be executed by a computer device. Figure 1 , the method comprising:

[0056] In step 101, a time-domain open channel control model is established based on the open channel Saint-Venant equation.

[0057] The time-domain open channel control model is used to indicate the relationship between water depth and flow rate at the input and output ends of an open channel.

[0058] When establishing a time-domain open channel control model, the Saint-Venant equation is typically established first. This equation is then simplified by linearizing it near the control points. The simplified Saint-Venant equation is then diagonally separated to create variables. (Under conditions of constant nonuniform flow, diagonal separation cannot be performed directly; instead, a Laplace transform and linearization are required before diagonal separation.) This diagonal separation yields the state-transfer matrix for the open channel, which in turn yields the frequency-domain control model. This frequency-domain control model is linearly transformed to obtain the input-output conversion equations for the open channel in the frequency domain. Finally, these frequency-domain conversion equations are simplified and then converted to the time domain, yielding the time-domain open channel control model. The control points for the open channel are the flow rate and water depth at the input and output ends of the channel, respectively.

[0059] There are many methods for obtaining the time-domain open channel control model and the relevant formulas involved in the acquisition process in the related technologies, and detailed description is omitted here.

[0060] The time-domain open channel control model obtained based on the above ideas can be expressed using formula (1).

[0061] ;

[0062] In formula (1), is the intermediate variable of water depth; is the water depth output variable; is the inlet flow rate in the input variables of the time-domain open channel control model, The outlet flow rate is one of the input variables of the time-domain open channel control model; is the delay time; is the surface area of ​​water flow in the channel backwater zone, 、 is the high-frequency term downstream. is the horizontal projection of the length of the open channel.

[0063] In step 102, a time-domain pressure flow control model is established based on the water hammer control equation of the pressure flow.

[0064] The time-domain pressure-flow control model is used to indicate the relationship between water depth and flow rate at the input and output ends of the inverted siphon.

[0065] The time domain pressure flow control model can be obtained in a similar manner to the time domain open channel control model. In this case, optionally, step 102 includes the following steps ad

[0066] Step a: Obtain the water hammer control equation of the pressure flow.

[0067] Optionally, the water hammer control equations of the pressure flow are expressed using formula (2) and formula (3).

[0068] ;

[0069] ;

[0070] In formula (2) and formula (3), is the pressure head, in m; For time; is the axial coordinate of the pressure pipe; is the flow rate, in m 3 / s; is the acceleration due to gravity, in m / s 2 ; is the cross-sectional area of ​​the flow, in m 2 ; is the water hammer wave velocity, in m / s; is the friction coefficient; is the pressure pipe diameter.

[0071] By first performing Laplace transform and linearizing the pressure flow water hammer control equation, the differential equation of the linearized pressure flow water hammer equation can be easily obtained. The differential equation of the pressure flow water hammer equation is expressed by formula (4).

[0072] ;

[0073] In formula (4), is the state transfer matrix, expressed by formula (5); is the initial state matrix, expressed by formula (6); is the general solution of this differential equation.

[0074] ;

[0075] ;

[0076] In formula (5) and formula (6), is the flow rate under the initial state. The meanings of other parameters in formula (5) and formula (6) are the same as those in formula (3), and their detailed description is omitted here.

[0077] Step b: diagonalizing the state transfer matrix in the water hammer control equation of the pressure flow to obtain a frequency domain control model of the pressure flow.

[0078] Since the pressure flow water hammer equation is simpler than the open flow Saint-Venant equation, and most of the hydraulic parameters remain unchanged along the flow, the state transfer matrix in the pressure flow water hammer equation is It is relatively easy to perform diagonalization processing, and the state transfer matrix after diagonalization processing can be expressed by formula (7).

[0079] ;

[0080] In formula (7), is the state transfer matrix after diagonalization, is the cross-sectional area of ​​the flow in the initial state, and for The eigenvalues ​​of The meanings of other parameters in formula (7) are the same as those in formula (3), and their detailed description is omitted here.

[0081] Therefore, it is relatively easy to obtain the expression of the frequency domain control model of pressure flow as shown in formula (8).

[0082] ;

[0083] In formula (8), is the numerical solution of the state transfer matrix, Therefore 、 、 、 These four variables can be expressed by formula (9).

[0084] ;

[0085] The meanings of the parameters in formula (9) are the same as those in formula (3), and their detailed description is omitted here.

[0086] Since signals in real-world systems often vary over time, practical operations focus on the dynamic changes in signals and control actions along the time axis. Therefore, typical channel control systems are based on the time domain. In this case, steps c and d are also required to convert the frequency-domain pressure flow control model to the time domain, resulting in a time-domain pressure flow control model.

[0087] Step c: performing linear transformation on the frequency domain control model of the pressure flow to obtain the input-output conversion equation of the pressure flow in the frequency domain.

[0088] In the input-output conversion equation, the input is the upstream and downstream flow boundaries of the pressure flow, and the output is the water depth upstream and downstream of the pressure flow.

[0089] The input-output conversion equation of the pressure flow system can be obtained by a simple linear transformation of formula (9). The input-output conversion equation of the pressure flow system is expressed by formula (10).

[0090] ;

[0091] In formula (10), represents the relationship between upstream flow input and upstream water depth output, represents the relationship between upstream flow input and downstream water depth output, represents the relationship between downstream flow input and upstream water depth output, Represents the relationship between downstream flow input and downstream water depth output. , , , are the transfer functions in four different states. These four transfer functions can be expressed by formula (11).

[0092] ;

[0093] The meanings of the parameters in formula (11) are the same as those in formula (9) and formula (10), and their detailed description is omitted here.

[0094] Step d: After simplifying the input-output conversion equation of the pressure flow in the frequency domain, the simplified input-output conversion equation of the pressure flow in the frequency domain is converted to the time domain to obtain a time-domain pressure flow control model.

[0095] The input-output conversion equation for pressure flow in the frequency domain consists of an integral link, a delay link, and a zero-order link. Because the pressure wave velocity is much greater than the average flow velocity across the cross section, the delay time for the upstream signal to be transmitted to the downstream is the same as the delay time for the downstream signal to be transmitted to the upstream. Therefore, the model can be simplified. The simplified input-output conversion equation for pressure flow in the frequency domain can be expressed using Equation (12).

[0096] ;

[0097] In formula (12), It represents the rate of change of the pressure pipe volume when the flow rate increases, which is similar to the backwater area of ​​the open channel control model; Indicates the sudden change in pipeline pressure caused by the sudden change in upstream and downstream flow, which can be obtained by the water hammer pressure calculation formula; Indicates the delay time for upstream signals to be transmitted to downstream.

[0098] The simplified input-output conversion equation of the pressure flow in the frequency domain is converted to the time domain, and the obtained time domain pressure flow control model can be expressed by formula (13).

[0099] ;

[0100] In formula (13), is the intermediate variable of water depth; is the water depth output variable, is the inlet flow rate in the input variable of the time-domain pressure flow control model, is the outlet flow rate in the input variable of the time-domain pressure flow control model, is the pressure wave velocity, is the acceleration due to gravity, is the flow area of ​​the pressure pipe of the inverted siphon, It is the horizontal projection of the length of the pressure pipe.

[0101] In step 103, based on the time-domain open channel control model and the time-domain pressure flow control model, a control model of an open channel inverted siphon series open full flow system is constructed.

[0102] Through steps 101 and 102, the time domain control models of the open channel system and the inverted siphon pipeline system have been analyzed in detail. For the open channel inverted siphon system directly connected in series, it is also necessary to obtain the node state transfer matrix from the open channel output end to the inverted siphon input end. Then, through linear transformation, the state transfer matrix and transfer function of the open full flow system of the open channel inverted siphon in series can be obtained, and finally the control model of the open full flow system of the open channel inverted siphon in series is obtained.

[0103] Figure 2 This is a simplified schematic diagram of an open channel inverted siphon series system. Figure 2 As shown, Indicates the water depth at the input end of the open channel, Indicates the water depth at the output end of the open channel, Indicates the water depth at the inverted siphon input end. Indicates the water depth at the output end of the inverted siphon. represents the flow rate at the open channel input end, represents the flow rate at the output end of the open channel, Indicates the flow rate at the inverted siphon input end, Indicates the flow rate at the inverted siphon output end.

[0104] based on Figure 2In the open channel inverted siphon series system, step 103 can be implemented using the following steps eh.

[0105] Step e: Construct the mass conservation equation and energy conservation equation.

[0106] The mass conservation equation and energy conservation equation are used to describe the relationship between flow rate and water depth between the open channel output end and the inverted siphon input end.

[0107] Optionally, the mass conservation equation is expressed using formula (14), and the energy conservation equation is expressed using formula (15).

[0108] ;

[0109] ;

[0110] In formula (14) and formula (15), represents the flow rate at the output end of the open channel, Indicates the flow rate at the inverted siphon input end, in m 3 / s; is the flow area at the output end of the open channel, are the flow areas at the input terminals, in m 2 ; is the static pressure term at the output end of the open channel, is the static pressure term at the inverted siphon input, in m; is the local head loss coefficient.

[0111] Step f: using linear transformation to solve the mass conservation equation and the energy conservation equation to obtain the node state transfer matrix between the open channel output end and the inverted siphon input end.

[0112] By performing linear transformation on the mass conservation equation and the energy conservation equation, the node state transfer matrix between the open channel output and the inverted siphon input can be obtained as shown in formula (16).

[0113] ;

[0114] In formula (16), Indicates the water depth at the inverted siphon input end. Indicates the water depth at the output end of the open channel, represents the node state transition matrix, 、 、 、 is an intermediate parameter and is expressed in formula (17). The meanings of other parameters in formula (16) are the same as those in formula (14) and formula (15), and their detailed description is omitted here.

[0115] ;

[0116] The meanings of the parameters in formula (17) are the same as those in formula (14) and formula (15), and their detailed description is omitted here.

[0117] Step g: constructing a state transfer matrix of an open channel and inverted siphon series open full flow system based on the open channel state transfer matrix, the node state transfer matrix, and the inverted siphon state transfer matrix.

[0118] The open channel state transfer matrix is ​​obtained during the establishment of the time-domain open channel control model, and the inverted siphon state transfer matrix is ​​obtained during the establishment of the time-domain inverted siphon control model (i.e., Formula (5)). The node state transfer matrix is ​​already reflected in Formula (16).

[0119] The open channel inverted siphon series open full flow system is constructed by sequentially connecting the open channel, the node between the open channel output and the inverted siphon input, and the inverted siphon. Based on this idea, the state transition matrix of the open channel inverted siphon series open full flow system can be constructed. The state transition matrix of the open channel inverted siphon series open full flow system can be expressed using Equation (18).

[0120] ;

[0121] In formula (18), represents the state transition matrix of the inverted siphon, represents the node state transfer matrix between the open channel output and the inverted siphon input, represents the state transfer matrix of the open channel, Indicates the water depth at the input end of the open channel, Indicates the water depth at the inverted siphon output end. represents the flow rate at the open channel input end, Indicates the flow rate at the inverted siphon output end.

[0122] Step h: constructing a control model of the open channel inverted siphon open full flow system based on the state transfer matrix of the open channel inverted siphon open full flow system in series.

[0123] The open full flow system control model of the open channel inverted siphon in series includes an open channel output end water depth control model with the open channel output end flow rate as input, and an inverted siphon output end water depth control model with the inverted siphon output end flow rate as input.

[0124] Figure 3 This is a diagram showing the frequency domain response characteristics of an open channel full flow system with an inverted siphon in series. Figure 3 Part (a) is the frequency domain response characteristics of the open channel output end of the open full flow system with an open channel inverted siphon in series; Figure 3Part (b) is the frequency domain response characteristic of the inverted siphon output end in an open full flow system with an open channel inverted siphon in series. This frequency domain response characteristic can be obtained based on formula (18).

[0125] like Figure 3 As shown in the figure, the frequency domain response characteristics of the open channel output and the inverted siphon pressure pipe output are quite different. When a low-frequency signal is input, the open channel output decreases at a slope of -40dB, while the inverted siphon output decreases at a slope of -20dB. This indicates that the open channel output exhibits the characteristics of a second-order system, while the inverted siphon output corresponds to an integral link, which has a significant impact on the selection and establishment of the control model. When a high-frequency signal is input, the frequency domain response of the open channel output is different for upstream and downstream flow signal inputs. For upstream flow signal input, the frequency domain response of the open channel output is similar to that of open flow. For downstream flow signal input, the frequency domain response of the open channel output is similar to that of open flow in the mid-frequency range and that of pressure flow in the high-frequency range. This highly reflects the unique characteristics of the open channel output, which combines the dynamic characteristics of both open flow and pressure flow. The frequency domain characteristics of the output end of the inverted siphon pressure pipeline when high-frequency signals are input are more complex. It not only has the dynamic characteristics of open flow and pressure flow, but also the amplitude and phase characteristics of the upstream and downstream flow input signals in the high-frequency band are different. This means that the upstream and downstream flow input signals of the same frequency cause different pressure head responses at the output end of the pressure pipeline, and the pressure pipeline is more sensitive to the downstream flow signal.

[0126] The frequency domain response characteristics of the open channel output indicate that this control point exhibits a second-order system response when a low-frequency signal is input. However, the time domain response of the open channel inverted siphon series open full flow system exhibits strong first-order system characteristics. If the flow rate at the open channel output rather than the inverted siphon output is used as the input of the open channel inverted siphon series open full flow system, the water depth downstream of the open channel can be expressed using formula (19). Formula (19) is a linear model.

[0127] ;

[0128] In formula (19), When the open channel flow is used as input, the output end of the open channel is The water depth of the time step, When the open channel flow is used as input, the output end of the open channel is The water depth of the time step, To control the sampling interval of the model, is the surface area of ​​the return water zone in the open flow section, is the delay time of the bright flow propagation, is the delay time of pressure flow propagation, is the flow rate at the open channel input, is the flow rate at the output end of the open channel, is the high frequency term coefficient, From the time step To time step The increase in flow at the open channel input end, From the time step To time step The increase in flow rate at the output end of the open channel.

[0129] The frequency domain characteristics of the open full flow system of an open channel inverted siphon in series reflect that the system responds differently to the high-frequency signal inputs of the upstream and downstream flows. The system is more sensitive to the high-frequency signal of the downstream flow, so the system only considers the high-frequency oscillation caused by the downstream flow signal. From the perspective of the actual physical system, it is assumed that the water hammer effect of the upstream flow change of the open channel on the inverted siphon pressure pipe can be ignored. Considering the water hammer effect caused by the downstream flow change of the inverted siphon pipe, the high-frequency term is consistent with the pressure flow control model. However, it is worth noting that the above derivation process is based on theoretical derivation, which assumes that the flow boundary is constant within the control time interval. In reality, the inlet and outlet of the inverted siphon are open boundaries. The inlet and outlet flows change with the transmission of the pressure wave back and forth in the pipe. The frequency of change is much smaller than the control time interval, so a reduction coefficient needs to be added to offset its influence. Based on this, the water depth control model of the inverted siphon output end with the inverted siphon flow as input is expressed by formula (20).

[0130] ;

[0131] In formula (20), In the case of reverse siphon flow as input, the reverse siphon output is The water depth of the time step, In the case of reverse siphon flow as input, the reverse siphon output is The water depth of the time step, To control the sampling interval of the model, is the surface area of ​​the return water zone in the open flow section, is the flow rate at the inverted siphon input, is the flow rate at the inverted siphon output end, From the time step To time step The increase in the flow rate at the inverted siphon input end, From the time step To time step The increase in the flow rate at the output end of the inverted siphon, The reduction factor for the pressure fluctuation caused by the opening of the inverted siphon boundary is less than the water hammer pressure. is the acceleration due to gravity, is the flow area of ​​the inverted siphon pressure pipe, is the pressure wave velocity.

[0132] Currently, there is no control model applied to the open channel-inverted siphon series open full flow system. The simplified linear control model established through steps 101 to 104 can accurately predict the dynamic response characteristics of the system. In addition, the control model of the series system can simultaneously detect the dynamic response at the end of the open channel and in the pressure pipe, which is of great significance for the precise and efficient control of large-scale water network systems with simultaneous open full flow.

[0133] The linear control model established through steps 101 to 104 has fewer control parameters and is easy to calculate. It can be easily calculated based on the various parameters of the physical system. Moreover, its various parameters have strong physical meanings and can also quickly identify systems with complex changes in hydraulic parameters.

[0134] In step 104, the MPC strategy is used to optimize and solve the open channel inverted siphon series open full flow system control model to obtain the optimal control parameters.

[0135] The optimal control parameters are used to control the open channel inverted siphon series open full flow system control model.

[0136] The MPC (Model Predictive Control) strategy is a control strategy based on a dynamic model. The MPC strategy implements constraint management of multivariable systems by optimizing control actions within a limited future time domain in real time.

[0137] In the disclosed embodiments, a time-domain open channel control model is established based on the Saint-Venant equation for open channels. The time-domain open channel control model is used to indicate the relationship between the water depth and flow rate at the input and output ends of the open channel. A time-domain pressure flow control model is established based on the water hammer control equation for pressure flow. The time-domain pressure flow control model is used to indicate the relationship between the water depth and flow rate at the input and output ends of the inverted siphon. Based on the time-domain open channel control model and the time-domain pressure flow control model, a control model for an open channel and inverted siphon in series is constructed. This control model can reflect the complex dynamic response characteristics of the open channel and inverted siphon series system and accurately predict the system's state response under different input signals. By using an MPC strategy to optimize and solve the open channel and inverted siphon series open flow system control model, the optimal control parameters are obtained. These optimal control parameters can realize automated control of the open channel and inverted siphon series open flow system control model.

[0138] Figure 4 A flow chart showing a method for controlling an open channel inverted siphon series open full flow system provided by another exemplary embodiment of the present disclosure is shown. The method can be executed by a computer device. Figure 4 , the method comprising:

[0139] In step 401, a time-domain open channel control model is established based on the open channel Saint-Venant equation.

[0140] The time-domain open channel control model is used to indicate the relationship between water depth and flow rate at the input and output ends of an open channel.

[0141] In step 402, a time-domain pressure flow control model is established based on the water hammer control equation of the pressure flow.

[0142] The time-domain pressure-flow control model is used to indicate the relationship between water depth and flow rate at the input and output ends of the inverted siphon.

[0143] In step 403, based on the time-domain open channel control model and the time-domain pressure flow control model, a control model of an open channel inverted siphon series open full flow system is constructed.

[0144] The relevant contents of steps 401 to 403 refer to the aforementioned steps 101 to 103, and detailed description is omitted here.

[0145] In step 404, the model predictive control (MPC) strategy is used to optimize and solve the control model of the open channel inverted siphon series open full flow system to obtain the optimal control parameters.

[0146] The optimal control parameters are used to control the open channel inverted siphon series open full flow system control model.

[0147] Optionally, step 404 includes the following steps ik.

[0148] Step i, construct the state space equation of the open full flow system of open channel inverted siphon in series.

[0149] The MPC strategy solves a linear model. The open channel inverted siphon series open full flow system control model obtained in the above steps 401 to 403 is already a linear model. The subsequent solution only needs to be carried out according to the process of the MPC strategy.

[0150] MPC is based on a known control model to predict the state of the system in the next few time steps and to perform control actions on the system within a certain time step. To control the time domain, This constant determines how far in advance the control action is calculated; set For the prediction time domain, This constant determines the advance degree of the prediction system. On this basis, the state space equation of the open channel inverted siphon series open full flow system can be expressed by formula (21).

[0151] ;

[0152] In formula (21), represent The predicted value of the time step is obtained by State quantity of time step and control the amount of movement The combined impact. Represents the state vector of the system, which contains , ,…, common state variables, and the number of state variables is related to the number of energy storage components in the system. Represents the control vector of the system, which contains , ,…, common control variables, and the number of control variables is related to the number of control elements in the system. represents a known disturbance, is the system matrix, which represents the connection between the internal states of the system; is the control matrix, which represents the effect of input on the state; is the output matrix, which represents the relationship between the output and the state variables; is the disturbance matrix, which represents the impact of the disturbance on the system.

[0153] Set the control time domain according to the control requirements of the actual physical system and prediction time domain , and then the state space equation of the system in the prediction domain can be obtained as shown in formula (22).

[0154] ;

[0155] in, To predict the state space equation of the open full flow system of the open channel inverted siphon in series, is the state transition matrix, The initial state matrix, is the output matrix, is the perturbation matrix. 、 、 、 It is expressed using formulas (23) to (26).

[0156] ;

[0157] ;

[0158] ;

[0159] ;

[0160] In formulas (23) to (26), To control the time domain, The meanings of other parameters in formulas (23) to (26) are the same as those in formulas (21) to (22), and their detailed description is omitted here.

[0161] Step j: Get the constraint condition set.

[0162] The constraint set includes controller output constraints, controller limit constraints, and system output constraints.

[0163] Actual physical systems often have certain physical constraints. There are three common types of constraints: controller change rate constraints , controller limit constraints and system output constraints .

[0164] System output constraints Including the maximum value constraint of the system output and the minimum value constraint of the system output. Since the object of optimization is the controller output, the system output constraint It also needs to be converted into constraints for controller output before processing.

[0165] Step k, based on the state space equation and the set of constraints, the quadratic programming method is used to solve the open channel inverted siphon series open full flow system control model to obtain the optimal control parameters.

[0166] When solving, you need to set the current time (such as The detection value of the physical system control point or the simulation value of the simulation system is input into the controller to solve the constrained quadratic optimal problem, thereby obtaining the optimal control parameters. The optimal control parameters are Control parameters at the moment.

[0167] Figure 5 This is a schematic diagram of the principle of the MPC strategy. The prediction time domain is derived through step i. All states within a time step, so the predicted state can be made closer to the target state by minimizing the quadratic optimal function, that is, Figure 5 The green predicted moment system trajectory has the smallest variance with the red target trajectory.

[0168] In addition, when the system Figure 5 When the predicted trajectory (as shown in ) exceeds the target trajectory, the system is considered to have overshooted. This means that the control action is too large, resulting in unnecessary energy loss. Therefore, to reduce the energy consumption of the control system, MPC adds terms related to the control action to the optimal control function to avoid energy consumption caused by frequent system actions.

[0169] Taking the above requirements into consideration, the control target (i.e., target trajectory) can be described in the form of formula (27).

[0170] ;

[0171] In formula (27), To control the target, is the time step The output of the following system; is the time step The target trajectory output by the system; is the time step Control actions of the lower system; Output tracking error penalty matrix for the system; is the penalty matrix of the control action, because we do not want the control variables to change frequently, is a larger penalty matrix.

[0172] The constraint set can be converted into a standard form, and then based on the objective function, the optimal control problem can be written in the form of a quadratic programming (QP) problem as in formula (28).

[0173] ;

[0174] In formula (28), is the state quantity, is the weight coefficient matrix, is a linear matrix, are inequality constraints (obtained through the constraint set).

[0175] If a quadratic programming problem only involves equality constraints, the Lagrange multiplier method can be used to solve it. However, when inequality constraints exist, the Karush-Kuhn-Tucker (KKT) conditions are required. The KKT conditions are a generalization of the Lagrange multiplier method, extending the Lagrange multiplier method from equality-constrained optimization problems to inequality-constrained ones. They are also essential for achieving optimal solutions in nonlinear programming. Solving these KKT conditions yields the optimal solution to the quadratic programming problem under both equality and inequality constraints. This optimal solution is the optimal control parameter.

[0176] This optimal control parameter is the system control parameter for the next moment. It can be output and transmitted to control structures such as regulating gates and diversion gates, and the gate opening can be adjusted by local flow controllers to achieve real-time online control of the system.

[0177] After using the optimal control parameters for control, it is necessary to determine whether the system state has reached the control target. If so, the online control of the system can be stopped. If not, step k can be re-executed to calculate the optimal control parameters at the next moment to continue controlling the system. By repeatedly controlling the system until the control target is reached, the online control of the system can be stopped.

[0178] By using the MPC algorithm to solve the optimal control parameters, the physical constraints of the physical system's flooding limit and pressure limit can be better met, and good control performance can be demonstrated under various complex water demand conditions, which is beneficial to improving the operation and management level of large-scale water network systems and reducing safety risks.

[0179] Figure 6 This is a schematic diagram of an actual open channel inverted siphon series open full flow system. Figure 6 The effect of the method in the embodiment of the present disclosure was verified in the actual open channel inverted siphon series open full flow system.

[0180] like Figure 6 As shown in the figure, this example consists of two open channel sections, 5 km and 4 km long respectively, and an inverted siphon with a length of 2.3 km between them. The system has a reservoir upstream and water users downstream. Both the reservoir and the water users draw water through gates. In this case, the upstream head gate and the most downstream user water intake gate are both included in the control system. The open channel section has a rectangular cross-section with a width of 9 m, and the inverted siphon has a single circular cross-section with a diameter of 7.4 m. The bottom slope of the open channel section is 1 / 4000. Channel pool 1 corresponds to Figure 6 Among the 1-1 and 2-2 pipelines, channel pool 1 is an open channel inverted siphon series open full flow system; channel pool 2 corresponds to Figure 6 Among the 3-3 pipelines, channel pool 2 is a pure open channel pipeline.

[0181] To evaluate the controller performance of the open channel-inverted siphon series double-channel tank system, a special operating condition was set up. In this condition, the initial water demand was 81 (the minimum demand water intake flow rate) and suddenly increased to 135 (the planned water intake flow rate) in the sixth hour.

[0182] The traditional composite feedforward + PID feedback control is compared with the method of the present invention.

[0183] Traditional composite control uses a constant downstream water level. The difference between the downstream water level and the target water level in the channel pool is used to calculate the flow rate flowing into the channel pool through the upstream gate. The corresponding gate opening is then calculated. The calculation principle is shown in the formula. Because the upstream regulating gate of Channel Pool 2 is directly connected to the inverted siphon pipeline, the flow rate at the inlet of Channel Pool 2 is frequently affected by pressure fluctuations in the inverted siphon penstock. When using traditional composite control, gate operation causes frequent pressure fluctuations in the penstock, complicating control. After multiple parameter adjustment attempts, the optimal control parameters were obtained, as shown in Table 1.

[0184] Table 1: PID control parameters

[0185]

[0186] The optimal control parameters obtained by the method of the present invention include the control time interval, prediction time domain, control time domain and controller weight parameters. For 5 minutes, the forecast time domain and control time domain Both are 2 hours. The controller weight parameter includes the water level control weight. and control action weights , where the water level controls the weight Take 1 to control the action weight Take 0.01. Substitute these parameters into the corresponding method to Figure 6 The system in control.

[0187] Figure 7 Schematic diagram comparing the control effects of the present invention and traditional composite control under the same working conditions. Figure 7 Part (a) is the open channel output end of channel pool 1 (i.e. Figure 6 The output end of the 1-1 pipeline) pressure measuring tube head change process line, Figure 7 Part (b) is the output end of the inverted siphon (i.e. Figure 6 The output end of the 2-2 pipe) pressure measuring tube head change process line, Figure 7 Part (c) is the output end of channel 2 (i.e. Figure 6 The output end of the 3-3 pipeline) pressure measuring tube head change process line,

[0188] Figure 7 Part (a) and Figure 7Part (c) of the figure reflects the shortcomings of traditional composite feedforward + feedback control. Under more extreme initial conditions and more dramatic operating condition changes, the constraint effect of traditional control weakens. The same control parameters in traditional control cause the controlled water depth before the inverted siphon to deviate further from the control point, failing to meet the required submergence depth. However, the control method of the present invention exhibits the opposite effect of traditional control. It can accurately predict the system's dynamic response characteristics and take corresponding control actions to achieve the optimal control result. Therefore, it exhibits similar control performance under different control requirements.

[0189] The following are device embodiments of the present application. For details not described in detail in the device embodiments, reference may be made to the above method embodiments.

[0190] Figure 8 The schematic diagram of the structure of a control device for an open channel inverted siphon series open full flow system provided by an exemplary embodiment of the present disclosure is shown. Figure 8 The open channel inverted siphon series open full flow system control device 800 includes: a first modeling module 801, a second modeling module 802, a third modeling module 803 and a parameter solving module 804.

[0191] The first modeling module 801 is used to establish a time-domain open channel control model based on the open channel Saint-Venant equation, where the time-domain open channel control model is used to indicate the relationship between the water depth and flow rate at the input and output ends of the open channel;

[0192] The second modeling module 802 is used to establish a time-domain pressure flow control model based on the water hammer control equation of the pressure flow, and the time-domain pressure flow control model is used to indicate the relationship between the water depth and flow rate at the input end and the output end of the inverted siphon;

[0193] The third modeling module 803 is used to construct an open channel full flow system control model of an open channel inverted siphon in series based on the time domain open channel control model and the time domain pressure flow control model;

[0194] The parameter solving module 804 is used to optimize and solve the open channel inverted siphon series open full flow system control model using the model predictive control MPC strategy to obtain the optimal control parameters. The optimal control parameters are used to control the open channel inverted siphon series open full flow system control model.

[0195] Optionally, in the first modeling module 801, the time-domain open channel control model is expressed using the following formula:

[0196] ;

[0197] in, is the intermediate variable of water depth; is the output variable of the water depth of the open channel; is the inlet flow rate in the input variables of the time-domain open channel control model, The outlet flow rate is one of the input variables of the time-domain open channel control model; is the delay time; is the surface area of ​​water flow in the channel backwater zone, 、 is the high-frequency term in the downstream, is the horizontal projection of the length of the open channel;

[0198] In the second modeling module 802, the time-domain pressure flow control model is expressed using the following formula:

[0199] ;

[0200] in, is the intermediate variable of water depth, is the water depth output variable of pressure flow, is the inlet flow rate in the input variable of the time-domain pressure flow control model, is the outlet flow rate in the input variable of the time-domain pressure flow control model, is the pressure wave velocity, is the acceleration due to gravity, is the flow area of ​​the pressure pipe of the inverted siphon, It is the horizontal projection of the length of the pressure pipe.

[0201] Optionally, the second modeling module 802 is also used to obtain the water hammer control equation of the pressure flow; diagonalize the state transfer matrix in the water hammer control equation of the pressure flow to obtain the frequency domain control model of the pressure flow; perform linear transformation on the frequency domain control model of the pressure flow to obtain the input-output conversion equation of the pressure flow in the frequency domain, in which the input is the upstream and downstream flow boundaries of the pressure flow, and the output is the water depth upstream and downstream of the pressure flow; after simplifying the input-output conversion equation of the pressure flow in the frequency domain, the simplified input-output conversion equation of the pressure flow in the frequency domain is converted to the time domain to obtain the time domain pressure flow control model.

[0202] Optionally, the third modeling module 803 is also used to construct a mass conservation equation and an energy conservation equation, which are used to describe the relationship between the flow rate and water depth between the open channel output end and the inverted siphon input end; linear transformation is used to solve the mass conservation equation and the energy conservation equation to obtain a node state transfer matrix between the open channel output end and the inverted siphon input end; based on the open channel state transfer matrix, the node state transfer matrix, and the inverted siphon state transfer matrix, a state transfer matrix of an open channel inverted siphon in series open full flow system is constructed, the open channel state transfer matrix is ​​obtained in the process of establishing a time-domain open channel control model, and the inverted siphon state transfer matrix is ​​obtained in the process of establishing a time-domain inverted siphon control model; based on the state transfer matrix of the open channel inverted siphon in series open full flow system, a control model of the open channel inverted siphon in series open full flow system is constructed, and the open channel inverted siphon in series open full flow system control model includes an open channel output end water depth control model with open channel flow as input and an inverted siphon output end water depth control model with inverted siphon flow as input.

[0203] Optionally, in the third modeling module 803, the water depth control model at the output end of the open channel with the open channel flow as input is expressed by the following formula:

[0204] ;

[0205] in, When the open channel flow is used as input, the output end of the open channel is The water depth of the time step, When the open channel flow is used as input, the output end of the open channel is The water depth of the time step, To control the sampling interval of the model, is the surface area of ​​the return water zone in the open flow section, is the delay time of the bright flow propagation, is the delay time of pressure flow propagation, is the flow rate at the open channel input, is the flow rate at the output end of the open channel, is the high frequency term coefficient, From the time step To time step The increase in flow at the open channel input end, From the time step To time step The increase in flow at the output end of the open channel;

[0206] The water depth control model at the inverted siphon output end with the inverted siphon flow as input is expressed by the following formula:

[0207] ;

[0208] in, In the case of reverse siphon flow as input, the reverse siphon output is The water depth of the time step, In the case of reverse siphon flow as input, the reverse siphon output is The water depth of the time step, To control the sampling interval of the model, is the surface area of ​​the return water zone in the open flow section, is the flow rate at the inverted siphon input, is the flow rate at the inverted siphon output end, From the time step To time step The increase in the flow rate at the inverted siphon input end, From the time step To time step The increase in the flow rate at the output end of the inverted siphon, The reduction factor for the pressure fluctuation caused by the opening of the inverted siphon boundary is less than the water hammer pressure. is the acceleration due to gravity, is the flow area of ​​the inverted siphon pressure pipe, is the pressure wave velocity.

[0209] Optionally, the parameter solving module 804 is also used to construct the state space equation of the open full flow system of the open channel inverted siphon in series; obtain a set of constraints, the constraint condition set including controller output constraints, slew rate constraints and system output constraints; based on the state space equation and the constraint condition set, use the quadratic programming method to solve the control model of the open full flow system of the open channel inverted siphon in series to obtain the optimal control parameters.

[0210] It should be noted that the above-mentioned embodiments provide an example of the division of the functional modules described above when performing system control in the open channel inverted siphon series open flow system control device. In actual applications, the above-mentioned functions can be assigned to different functional modules as needed, that is, the internal structure of the device can be divided into different functional modules to complete all or part of the functions described above. In addition, the above-mentioned embodiments provide an open channel inverted siphon series open flow system control device and the open channel inverted siphon series open flow system control method embodiment. The specific implementation process is detailed in the method embodiment and will not be repeated here.

[0211] The division of modules in the embodiments of the present disclosure is illustrative and represents only a logical functional division. In actual implementation, other division methods may be used. Furthermore, the functional modules in the various embodiments of the present disclosure may be integrated into a single processor, exist physically as separate modules, or be integrated into a single module. The integrated modules may be implemented in either hardware or software functional modules.

[0212] If the integrated module is implemented in the form of a software functional module and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present disclosure, or the part that contributes to the prior art, or all or part of the technical solution can be embodied in the form of a software product. The computer software product is stored in a storage medium and includes several instructions for enabling a terminal device (which can be a personal computer, mobile phone, or communication device, etc.) or a processor to execute all or part of the steps of the method of each embodiment of the present disclosure. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM), random access memory (RAM), disk or optical disk, and other media that can store program code.

[0213] Figure 9 Schematic diagram of the structure of the computer device provided by the embodiment of the present disclosure. Figure 9 As shown, the computer device 900 includes a processor 901 and a memory 902 .

[0214] Processor 901 may include one or more processing cores, such as a quad-core processor or an octa-core processor. Processor 901 may be implemented in hardware using at least one of the following: a DSP (Digital Signal Processing), an FPGA (Field-Programmable Gate Array), or a PLA (Programmable Logic Array). Processor 901 may also include a main processor and a coprocessor. The main processor is used to process data in the awake state, also known as a CPU (Central Processing Unit); the coprocessor is a low-power processor used to process data in the standby state. In some embodiments, processor 901 may be integrated with a GPU (Graphics Processing Unit), which is responsible for rendering and drawing content displayed on the display screen. In some embodiments, processor 901 may also include an AI (Artificial Intelligence) processor, which is used to handle computational operations related to machine learning.

[0215] Memory 902 may include one or more computer-readable storage media, which may be non-transitory. Memory 902 may also include high-speed random access memory and non-volatile memory, such as one or more disk storage devices or flash memory storage devices. In some embodiments, the non-transitory computer-readable storage medium in memory 902 is used to store at least one instruction, which is executed by processor 901 to implement the open channel inverted siphon series open full flow system control method provided in the embodiments of the present disclosure.

[0216] Those skilled in the art will understand that Figure 9 The structure shown in the figure does not constitute a limitation on the computer device 900, and the computer device 900 may include more or fewer components than shown in the figure, or combine some components, or adopt a different component arrangement.

[0217] The embodiment of the present disclosure also provides a non-temporary computer-readable storage medium. When the instructions in the storage medium are executed by the processor of a computer device, the computer device is able to execute the open full flow system control method for open channel inverted siphon series provided in the embodiment of the present disclosure.

[0218] The embodiments of the present disclosure also provide a computer program product, including a computer program / instruction, which, when executed by a processor, implements the open full flow system control method for open channel inverted siphon series provided in the embodiments of the present disclosure.

[0219] The above description is merely an optional embodiment of the present disclosure and is not intended to limit the present disclosure. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present disclosure shall be included in the scope of protection of the present disclosure.

Claims

1. A control method for an open channel inverted siphon series open full flow system, characterized in that: The method comprises: Based on the open channel Saint-Venant equation, a time-domain open channel control model is established, wherein the time-domain open channel control model is used to indicate the relationship between the water depth and flow at the input and output ends of the open channel; Based on the water hammer control equation of the pressure flow, a time-domain pressure flow control model is established, wherein the time-domain pressure flow control model is used to indicate the relationship between the water depth and flow rate at the input end and the output end of the inverted siphon; Based on the time-domain open channel control model and the time-domain pressure flow control model, a control model of an open channel inverted siphon series open full flow system is constructed; The model predictive control (MPC) strategy is used to optimize and solve the open channel inverted siphon series open full flow system control model to obtain optimal control parameters, which are used to control the open channel inverted siphon series open full flow system control model.

2. The method according to claim 1, characterized in that The time domain open channel control model is expressed by the following formula: ， in, is the intermediate variable of water depth; is the output variable of the water depth of the open channel; is the inlet flow rate among the input variables of the time-domain open channel control model, is the outlet flow rate among the input variables of the time-domain open channel control model; is the delay time; is the surface area of ​​water flow in the channel backwater zone, 、 is the high-frequency term in the downstream, is the horizontal projection of the length of the open channel; The time-domain pressure flow control model is expressed by the following formula: ， in, is the intermediate variable of water depth, is the water depth output variable of pressure flow, is the inlet flow rate among the input variables of the time-domain pressure flow control model, is the outlet flow rate in the input variable of the time-domain pressure flow control model, is the pressure wave velocity, is the acceleration due to gravity, is the flow area of ​​the pressure pipe of the inverted siphon, is the projection of the length of the pressure pipe in the horizontal direction.

3. The method according to claim 1, characterized in that The water hammer control equation based on the pressure flow is used to establish a time domain pressure flow control model, including: Obtaining the water hammer control equation of the pressure flow; Diagonalizing the state transfer matrix in the water hammer control equation of the pressure flow to obtain a frequency domain control model of the pressure flow; Performing a linear transformation on the frequency domain control model of the pressure flow to obtain an input-output conversion equation of the pressure flow in the frequency domain, wherein the input of the input-output conversion equation is the upstream and downstream flow boundaries of the pressure flow, and the output is the upstream and downstream water depths of the pressure flow; After simplifying the input-output conversion equation of the pressure flow in the frequency domain, the simplified input-output conversion equation of the pressure flow in the frequency domain is converted to the time domain to obtain the time domain pressure flow control model.

4. The method according to any one of claims 1 to 3, characterized in that The open channel full flow system control model of the open channel inverted siphon in series is constructed based on the time domain open channel control model and the time domain pressure flow control model, including: Constructing a mass conservation equation and an energy conservation equation, wherein the mass conservation equation and the energy conservation equation are used to describe the relationship between the flow rate and the water depth between the open channel output end and the inverted siphon input end; Solving the mass conservation equation and the energy conservation equation using linear transformation to obtain a node state transfer matrix between the open channel output end and the inverted siphon input end; Based on the open channel state transfer matrix, the node state transfer matrix, and the inverted siphon state transfer matrix, a state transfer matrix of an open full flow system in which an open channel and an inverted siphon are connected in series is constructed, wherein the open channel state transfer matrix is ​​obtained during the process of establishing the time-domain open channel control model, and the inverted siphon state transfer matrix is ​​obtained during the process of establishing the time-domain inverted siphon control model; Based on the state transfer matrix of the open channel inverted siphon series open full flow system, a control model of the open channel inverted siphon series open full flow system is constructed. The control model of the open channel inverted siphon series open full flow system includes an open channel output end water depth control model with open channel flow as input and an inverted siphon output end water depth control model with inverted siphon flow as input.

5. The method according to claim 4, characterized in that The water depth control model at the output end of the open channel with the open channel flow as input is expressed by the following formula: ， in, When the open channel flow is used as input, the output end of the open channel is The water depth of the time step, When the open channel flow is used as input, the output end of the open channel is The water depth of the time step, To control the sampling interval of the model, is the surface area of ​​the return water zone in the open flow section, is the delay time of the bright flow propagation, is the delay time of pressure flow propagation, is the flow rate at the open channel input, is the flow rate at the output end of the open channel, is the high frequency term coefficient, From the time step To time step The increase in flow rate at the open channel input end, From the time step To time step The increase in flow rate at the output end of the open channel; The water depth control model at the inverted siphon output end with the inverted siphon flow as input is expressed by the following formula: ， in, In the case of reverse siphon flow as input, the reverse siphon output is The water depth of the time step, In the case of reverse siphon flow as input, the reverse siphon output is The water depth of the time step, To control the sampling interval of the model, is the surface area of ​​the return water zone in the open flow section, is the flow rate at the inverted siphon input, is the flow rate at the inverted siphon output end, From the time step To time step The increase in flow rate within the inverted siphon input end, From the time step To time step The increase in flow rate at the output end of the inverted siphon, The reduction factor for the pressure fluctuation caused by the opening of the inverted siphon boundary is less than the water hammer pressure. is the acceleration due to gravity, is the flow area of ​​the inverted siphon pressure pipe, is the pressure wave velocity.

6. The method according to any one of claims 1 to 3, characterized in that The model predictive control (MPC) strategy is used to optimize and solve the open channel inverted siphon series open full flow system control model to obtain the optimal control parameters, including: Construct the state space equation of the open full flow system of open channel and inverted siphon in series; Obtaining a set of constraint conditions, wherein the set of constraint conditions includes a controller output constraint, a slew rate constraint, and a system output constraint; Based on the state space equation and the set of constraints, a quadratic programming method is used to solve the open full flow system control model of the open channel inverted siphon in series to obtain the optimal control parameters.

7. A control device for an open channel inverted siphon series open full flow system, characterized in that: The device comprises: A first modeling module is used to establish a time-domain open channel control model based on the open channel Saint-Venant equation, wherein the time-domain open channel control model is used to indicate the relationship between the water depth and flow rate at the input end and the output end of the open channel; A second modeling module is used to establish a time-domain pressure flow control model based on a water hammer control equation of the pressure flow, wherein the time-domain pressure flow control model is used to indicate the relationship between the water depth and flow rate at the input end and the output end of the inverted siphon; A third modeling module is configured to construct an open channel full flow system control model of an open channel inverted siphon in series based on the time-domain open channel control model and the time-domain pressure flow control model; The parameter solving module is used to optimize and solve the open channel inverted siphon series open full flow system control model using the model predictive control MPC strategy to obtain the optimal control parameters, and the optimal control parameters are used to control the open channel inverted siphon series open full flow system control model.

8. A computer device, characterized in that: The computer device includes: a memory and a processor, wherein at least one computer program is stored in the memory, and the at least one computer program is loaded and executed by the processor to implement the method according to any one of claims 1 to 6.

9. A computer-readable storage medium, characterized in that At least one computer program is stored in the computer-readable storage medium, and the at least one computer program is loaded and executed by the processor to implement the method according to any one of claims 1 to 6.

10. A computer program product comprising a computer program / instructions, characterized in that When the computer program / instructions are executed by a processor, the method according to any one of claims 1 to 6 is implemented.

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