Real-time scheduling and adjusting method for long-distance water conveyance channel water transfer system

Abstract

The invention discloses a real-time scheduling and adjusting method for a long-distance water conveyance channel water transfer system, which is based on a rolling correction real-time water distribution scheme, preliminarily draws up a gate scheduling instruction according to a determined channel operation control mode, and simulates a hydraulic transition process in a channel in combination with a channel non-constant flow model. Real-time water volume scheduling is completed in a feedforward + simulation mode, the safe, stable, rapid and flexible water supply target is achieved, the scheduling instruction response speed of a water transfer system is increased, scheduling errors are reduced, and closed-loop control of the scheduling process is achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of real-time design of water transfer systems, and is particularly applicable to the real-time scheduling and regulation method of long-distance water conveyance channel water transfer systems. Background Art

[0002] For a long-distance water conveyance channel to meet the downstream water demand, it is necessary to formulate the gate control rules along the line before the downstream water demand occurs and execute them in advance. After the scheduling instruction is issued, it is also necessary to correct the gate control instruction in real time according to the gate scheduling status to ensure that the flow change process of each gate is consistent with the flow rate formulated by the initial control strategy. Currently, the real-time water volume scheduling model adopted for the water volume scheduling of long-distance water conveyance channels mostly uses the water volume balance method. It generates safe and feasible water volume scheduling instructions based on the ten-day water volume allocation plan, considering only a single water volume allocation factor.

[0003] In fact, the water volume scheduling of long-distance water conveyance channels is affected by many factors such as the gate flow capacity, gate operation mode, and channel constraint conditions. The water volume scheduling instruction considering only a single factor has problems such as untimely scheduling response, large scheduling error, and inability to achieve closed-loop control of the scheduling process. Today, with the increasing preciousness of water resources, it is imperative to adopt a more accurate and timely water volume scheduling method.

[0004] Therefore, the present invention proposes a real-time scheduling and regulation method for a long-distance water conveyance channel water transfer system, which can improve the response speed of the water transfer system scheduling instruction, reduce the scheduling error, and achieve the goals of safe, stable, fast, and flexible water supply. Summary of the Invention

[0005] The purpose of the present invention is to provide a real-time scheduling and regulation method for a long-distance water conveyance channel water transfer system, which is used to solve the problems of untimely response of the scheduling instruction, large scheduling error, and inability to achieve closed-loop control of the scheduling process in the current long-distance water conveyance channel water transfer system.

[0006] To achieve the above purpose, the present invention adopts the following technical solutions: The real-time scheduling and regulation method for a long-distance water conveyance channel water transfer system according to the present invention includes the following steps: S1, determining the target flow rate and the target water level in front of the gate for each gate in the channel; S2, through steady flow calculation, determining the real-time flow rate and real-time water level of each gate in the channel section by section from the downstream to the upstream of the channel; S3, estimating the current water storage volume of each section of the channel from the downstream to the upstream of the channel according to the real-time water level of each gate; S4, determining the compensated water storage volume of each section of the channel from the downstream to the upstream of the channel according to the current water storage volume, target flow rate, and real-time flow rate; S5. Determine the feedforward scheduling time for each section of the channel from the downstream to the upstream of the channel, in combination with the channel length, average flow velocity, and average wave velocity. S6. Determine the feedforward scheduling instructions for each gate from the downstream to the upstream of the channel, in combination with the target water level in front of each gate, compensation storage volume, and feedforward scheduling time. S7. Construct a one-dimensional unsteady flow model for the long-distance water conveyance channel, and simulate the hydraulic response process of the channel according to the feedforward scheduling instructions of each gate. S8. Determine whether the simulated hydraulic response process meets the channel operation constraint conditions; if it meets, output the corresponding feedforward scheduling instructions; if it does not meet, repeat steps S5 to S8 until the simulated hydraulic response process meets the channel operation constraint conditions.

[0007] Further, the channel operation constraint conditions include the real-time water level constraint of the channel.

[0008] The advantages of the present invention lie in the real-time water volume allocation scheme based on rolling correction. According to the determined channel operation control mode, the gate scheduling instructions are initially formulated, and in combination with the unsteady flow model of the channel, the hydraulic transition process in the channel is simulated. The real-time water volume scheduling is completed in the "feedforward + simulation" mode, achieving the safe, stable, fast, and flexible water supply target, improving the response speed of the scheduling instructions of the water diversion system, reducing the scheduling error, and realizing the closed-loop control of the scheduling process. Description of the Drawings

[0009] Figure 1 It is a flowchart of the real-time scheduling and regulation method for the long-distance water conveyance channel water diversion system of the present invention.

[0010] Figure 2 It is a schematic diagram of the change in the flow rate process of the upstream and downstream gates of the channel.

[0011] Figure 3 It is a schematic diagram of the principle for determining the feedforward instruction by the present invention using the storage compensation principle.

[0012] Figure 4 It is a comparison diagram of the actual flow rate process and the simulated hydraulic response process of the check gate 1 under normal scheduling conditions.

[0013] Figure 5 It is a comparison diagram of the actual flow rate process and the simulated hydraulic response process of the check gate 2 under normal scheduling conditions.

[0014] Figure 6 It is a comparison diagram of the actual flow rate process and the simulated hydraulic response process of the check gate 1 under the water filling scheduling conditions.

[0015] Figure 7 It is a comparison diagram of the actual flow rate process and the simulated hydraulic response process of the check gate 2 under the water filling scheduling conditions.

[0016] Figure 8 It is a comparison chart of the actual flow process and the simulated hydraulic response process of the check gate 1 under the water recession scheduling condition.

[0017] Figure 9 It is a comparison chart of the actual flow process and the simulated hydraulic response process of the check gate 2 under the water recession scheduling condition. Specific implementation manners

[0018] Next, the technical solutions in the embodiments of the present invention will be described clearly and completely. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0019] As Figure 1 shown, the real-time scheduling and regulation method for the long-distance water conveyance channel water transfer system according to the present invention includes the following steps: S1. Determine the target flow rate and the target water level in front of the gates in the channel.

[0020] S2. Through steady flow calculation, determine the real-time flow rate and the real-time water level of each gate in the channel section by section from the downstream to the upstream of the channel.

[0021] S3. Estimate the current water storage volume of each section of the channel from the downstream to the upstream of the channel according to the real-time water level of each gate.

[0022] S4. Determine the compensated water storage volume of each section of the channel from the downstream to the upstream of the channel according to the current water storage volume, the target flow rate, and the real-time flow rate.

[0023] The compensated water storage volume uses the storage volume compensation method as the calculation model. Assume that the water demand of the canal section changes from t e time onwards to Q s , that is, from the flow rate Q e at the current t s time to the flow rate Q s changing to t e at the corresponding Q e time. As Figure 2 shown, the water storage volume in the canal pool will change by .

[0024] ; In the formula: is the flow rate through the upstream gate of the channel ; It is the sum of the flow rate of the downstream gate of the channel and the flow rate of the water diversion inlet in this channel section .

[0025] According to this calculation model, the key to the water conveyance scheduling of the channel is to determine the flow rate through each regulating gate at any given time. When the sum of the downstream gate flow rate process of the channel section and the water diversion flow rate process of this channel section (i.e., the water supply plan) is known, according to the principle of storage compensation method, the upstream gate scheduling needs to satisfy that the change in the channel storage after the upstream and downstream gate scheduling should be , that is, the area enclosed by the upstream and downstream flow rate process lines of the channel should be equal to .

[0026] Using the step process line to represent the flow rate process at the inlet and outlet of the channel section, assuming that the change in the water demand of the channel pond at t e time is , and the corresponding change in the storage of the channel pond is also , then the initial inflow rate Q s of the channel pond needs to be adjusted in advance to compensate for the change in the channel storage, and adjusted to the target flow rate t e at Q e , as shown in Figure 3 . It can be seen from the figure that to determine the feedforward scheduling instructions for each gate, three steps are required: The first step is to determine the feedforward control time ; The second step is to calculate according to the compensated storage volume; The third step is to callback the gate flow rate to the target flow rate t e at Q e . Therefore, after determining the compensated storage volume of each channel section, it is necessary to determine the feedforward scheduling time of each channel section

[0027] S5. Combining the channel length, average flow velocity, and average wave velocity, determine the feedforward scheduling time of each channel section from the downstream to the upstream of the channel

[0028] The feedforward scheduling time for channel storage compensation is not unique. That is, for the same compensation volume, it can be completed with a larger flow rate change in a shorter time, or with a smaller flow rate change in a longer time. Therefore, it is necessary to reasonably determine the feedforward scheduling time

[0029] The calculation of the feed-forward scheduling time needs to be determined based on the accurate calculation of the channel operation lag time and considering various operation constraints comprehensively. The time lag problem in the operation of the canal pool is directly related to the movement characteristics of water waves in the channel. Since there are complex phenomena such as attenuation, reflection, and superposition during wave propagation, it is relatively difficult to accurately calculate the lag time. Among the existing formulas describing the movement of open-channel water waves, the dynamic wave formula can be used to estimate the time required for the leading edge of the wave crest to reach the downstream, and the kinematic wave formula can be used to estimate the time required for most of the waves to reach the downstream. From the perspective of the implementation process of storage compensation, the appropriate feed-forward control time should be between and , that is, equal to the time required for the main body of the wave group to reach the downstream. At this time, the storage supply is stable and sufficient. The relevant calculation formulas are as follows: ; ; ; In the formula: is the length of the canal pool; is the average flow velocity; is the average wave velocity; is the initial water depth; 0 is the initial state.

[0030] For a multi-canal pool channel, the feed-forward control time formula is expressed as: In the formula: is the length of the th canal pool; , are the average flow velocity and wave velocity of the th respectively; is a parameter, taking 0.25.

[0031] S6. Combining the target water level in front of each gate, the compensation storage volume, and the feed-forward scheduling time, determine the feed-forward scheduling instructions for each gate from the downstream to the upstream of the channel. That is, determine the flow rate adjusted in advance . .

[0032] According to the determined flow rate, the opening and closing time, opening and closing state, etc. of each gate can be determined. However, in this process, it is also necessary to combine the target water level in front of each gate, and it is necessary to ensure that the water level in front of each gate meets the requirements of the target water level in front of the gate.

[0033] S7. Build a one-dimensional unsteady flow model for the long-distance water conveyance channel, and simulate the hydraulic response process of the channel according to the feedforward scheduling instructions of each gate. The one-dimensional unsteady flow model of the long-distance water conveyance channel can simulate the hydraulic response process in the channel under various complex scheduling conditions.

[0034] S8. Judge whether the simulated hydraulic response process meets the channel operation constraint conditions; if it meets, output the corresponding feedforward scheduling instructions; if it does not meet, go back to steps S5 to S8 until the simulated hydraulic response process meets the channel operation constraint conditions. The channel operation constraint conditions mainly include the real-time water level constraint of the channel. If the simulated hydraulic response process can meet the real-time water level constraint of the channel throughout the process, the corresponding feedforward scheduling instruction is a feasible instruction. If the simulated hydraulic response process fails to meet the real-time water level constraint of the channel, the feedforward scheduling instruction needs to be adjusted again and the simulation is carried out again.

[0035] The real-time scheduling and regulation method of the long-distance water conveyance channel water diversion system described in the present invention is applied to the normal scheduling, water filling scheduling, and water discharging scheduling conditions of the water demand channel of a certain water diversion project. The actual scheduling is carried out according to the feedforward scheduling instructions finally determined by the one-dimensional unsteady flow model of the long-distance water conveyance channel of the present invention. The result of the actual scheduling is in good agreement with the simulated hydraulic response process as a whole, which proves that the real-time scheduling and regulation method of the long-distance water conveyance channel water diversion system described in the present invention can achieve the safe, stable, fast, and flexible water supply target, improve the response speed of the scheduling instructions of the water diversion system, reduce the scheduling error, and realize the closed-loop control of the scheduling process.

[0036] In the specific normal scheduling condition, after the water diversion flow rate of each water diversion gate increases by 30% of the target flow rate and then gradually decreases by 30% of the target flow rate, the process is repeated 3 times. Select the actual flow rate process of any two check gates in the channel and compare it with the simulated hydraulic response process. As Figure 4 shown, it is the comparison diagram of the actual flow rate process and the simulated hydraulic response process of check gate 1. As Figure 5 shown, it is the comparison diagram of the actual flow rate process and the simulated hydraulic response process of check gate 2.

[0037] In the water filling scheduling condition, the water diversion flow rate of each water diversion gate gradually increases from the target flow rate until it reaches stability. As Figure 6 shown, it is the comparison diagram of the actual flow rate process and the simulated hydraulic response process of check gate 1. As Figure 7 shown, it is the comparison diagram of the actual flow rate process and the simulated hydraulic response process of check gate 2.

[0038] In the water discharging scheduling condition, the water diversion flow rate of each water diversion gate gradually decreases from the target flow rate until it reaches stability. As Figure 8 shown, it is the comparison diagram of the actual flow rate process and the simulated hydraulic response process of check gate 1. As Figure 9As shown, it is a comparison chart of the actual flow process and the simulated hydraulic response process of the check gate 2.

Claims

1. A real-time scheduling and regulation method for a water transfer system in a long-distance water conveyance channel, characterized in that, It includes the following steps: S1. Determine the target flow rate of each sluice in the channel and the target water level in front of the sluice; S2. Through steady flow calculation, starting from the downstream of the channel and moving upstream section by section, determine the real-time flow rate and real-time water level of each sluice in the channel; S3. According to the real-time water level of each sluice, starting from the downstream of the channel and moving upstream, estimate the current water storage volume of each section of the channel; S4. According to the current water storage volume, target flow rate and real-time flow rate, starting from the downstream of the channel and moving upstream, determine the compensation water storage volume of each section of the channel; S5. Combining the channel length, average flow velocity, and average wave velocity, starting from the downstream of the channel and moving upstream, determine the feedforward scheduling time of each section of the channel; S6. Combining the target water level in front of each sluice, compensation water storage volume, and feedforward scheduling time, starting from the downstream of the channel and moving upstream, determine the feedforward scheduling instructions for each sluice; S7. Construct a one-dimensional unsteady flow model for the long-distance water conveyance channel, and simulate the hydraulic response process of the channel according to the feedforward scheduling instructions of each sluice; S8. Judge whether the simulated hydraulic response process meets the channel operation constraint conditions; if it meets, output the corresponding feedforward scheduling instructions; if it does not meet, repeat steps S5 to S8 until the simulated hydraulic response process meets the channel operation constraint conditions.

2. The real-time scheduling and regulation method for a long-distance water transfer channel water diversion system according to claim 1, characterized in that The channel operation constraint conditions include the real-time water level constraint of the channel.

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