Cascade power plant low valley starting control method, device and system based on reservoir water level

Abstract

This invention provides a method, apparatus, and system for controlling the off-peak operation of cascade power plants based on reservoir water levels. The method includes: obtaining a first target power plant and a second target power plant based on the current reservoir water level of each cascade power plant; obtaining the expected reservoir water level of the second target power plant based on the grid load in the current grid load command, the power generation flow of the first target power plant, and the current reservoir water level of the second target power plant; and determining the first target power plant as an off-peak operation power plant if the expected reservoir water level of the second target power plant is within a preset range. This invention solves the problems of low control accuracy and poor versatility in existing cascade power plant off-peak operation control methods. It not only lowers the water level of the first target power plant but also prevents the water level of downstream power plants from exceeding the corresponding warning water level, thereby achieving precise control of the off-peak operation of power plants in a cascade basin and preventing the risk of flood discharge due to excessively high reservoir water levels.

Description

Technical Field

[0001] This invention relates to the field of power generation control technology for river basin power plants, specifically to a method, device, and system for controlling the start-up of cascade power plants during off-peak hours based on reservoir water levels. Background Technology

[0002] The cascade power plants in the basin consist of three levels (or possibly multiple levels). Power Plant A is located upstream, with a multi-year regulating reservoir. The generator units are mixed-flow type, with a single unit capacity of 460MW. These generator units have a wide vibration range (145MW-300MW). After generating electricity, the units are connected to the 500kV grid via a switching station. Power Plant B is located in the middle reaches, with an annual regulating reservoir. The generator units are mixed-flow type, with a single unit capacity of 300MW. These generator units have a wide vibration range (75MW-180MW). After generating electricity, the units are connected to the 220kV and 500kV grids via a switching station. Power Plant C is located downstream, with a daily regulating reservoir. The generator units are axial-flow propeller type, with a single unit capacity of 86MW. These generator units have a prohibited operating range (0MW-30MW). After generating electricity, the units are connected to the 220kV grid via a switching station. Similarly, there can be multiple levels of power plants, and the reservoirs of the cascade power plants in the river basin can be of different forms, and they can be connected to power grids of different voltage levels or to power grids of different dispatch levels.

[0003] The off-peak operating period is from 10 p.m. to 6 a.m. daily. The water level of the reservoirs of each power plant is an important factor affecting off-peak operation. Therefore, when carrying out centralized control of cascade power plants, it is necessary to prevent the water level of the reservoirs of cascade power plants from being too high and causing flood discharge. At present, the off-peak operation control of cascade power plants is usually carried out by staff based on experience, which has the problems of low control accuracy and poor versatility, and cannot meet the control needs of power plants. Summary of the Invention

[0004] To address the shortcomings of existing technologies, the present invention provides a method, device, and system for controlling the off-peak operation of cascade power plants based on reservoir water levels, which solves the problems of low control accuracy and poor versatility in existing cascade power plant off-peak operation control methods.

[0005] In a first aspect, the present invention provides a method for controlling the operation of cascade power plants during off-peak hours based on reservoir water levels. The method includes: acquiring the current grid load command and the current reservoir water level of each cascade power plant during off-peak hours; acquiring a first target power plant and a second target power plant based on the current reservoir water level of each cascade power plant, wherein the first target power plant is a power plant whose current reservoir water level exceeds a corresponding warning level, and the second target power plant is a downstream power plant of the first target power plant; obtaining the expected reservoir water level of the second target power plant based on the grid load in the current grid load command, the power generation flow of the first target power plant, and the current reservoir water level of the second target power plant; and determining the first target power plant as an off-peak operation power plant if the expected reservoir water level of the second target power plant is within a preset range.

[0006] Optionally, if the expected reservoir water level of the second target power plant is not within a preset range, the method further includes: dividing the grid load in the grid load command into a first load and a second load; obtaining a first expected water level of the first target power plant based on the first load, the power generation flow of the first target power plant, and the current reservoir water level of the first target power plant; obtaining a second expected water level of the second target power plant based on the second load, the power generation flow of the second target power plant, and the current reservoir water level of the second target power plant; and determining that both the first target power plant and the second target power plant are off-peak operating power plants when both the first expected water level and the second expected water level are within their corresponding preset ranges.

[0007] Optionally, obtaining the expected reservoir water level of the second target power plant based on the grid load in the grid load instruction, the power generation flow of the first target power plant, and the current reservoir water level of the second target power plant includes: obtaining the power generation water consumption based on the grid load in the grid load instruction and the power generation flow of the first target power plant; obtaining the reservoir water change of the second target power plant based on the power generation water consumption and the reservoir capacity of the second target power plant; and obtaining the expected reservoir water level of the second target power plant based on the current reservoir water level and the reservoir water change.

[0008] Optionally, the method further includes: obtaining the expected rainfall over a preset time period; obtaining the expected water level change of each cascade power plant based on the expected rainfall and the reservoir capacity of each cascade power plant; and obtaining the current reservoir water level of each cascade power plant during the preset time period based on the expected water level change of each cascade power plant and the corresponding initial reservoir water level.

[0009] Optionally, after determining that the first target power plant is a power plant that operates during off-peak hours, the method further includes: obtaining the off-peak operating time of the first target power plant based on the transmission time in the current grid load instruction; obtaining the target control water level of the first target power plant in each preset interval based on the difference between the current reservoir water level and the warning water level of the first target power plant, and the off-peak operating time; and controlling the operation of the corresponding generator unit based on the target control water level of each preset interval.

[0010] Optionally, the method further includes: obtaining the control deviation of the current preset interval based on the target control water level and the actual operating water level of the current preset interval; and then using the control deviation of the current preset interval and the target control water level of the next preset interval as the target control water level of the next preset interval.

[0011] Optionally, when the first target power plant is the lowest-level power plant, the method further includes: determining that the first target power plant is a power plant that operates during off-peak hours.

[0012] Secondly, the present invention provides a cascade power plant off-peak start-up control device based on reservoir water level. The device includes: a data acquisition module for acquiring the current grid load command and the current reservoir water level of each cascade power plant during off-peak hours; a target power plant acquisition module for acquiring a first target power plant and a second target power plant based on the current reservoir water level of each cascade power plant, wherein the first target power plant is a power plant whose current reservoir water level exceeds the corresponding warning water level, and the second target power plant is a downstream power plant of the first target power plant; a calculation module for obtaining the expected reservoir water level of the second target power plant based on the grid load in the current grid load command, the power generation flow of the first target power plant, and the current reservoir water level of the second target power plant; and a determination module for determining the first target power plant as an off-peak start-up power plant if the expected reservoir water level of the second target power plant is within a preset range.

[0013] Thirdly, the present invention provides a cascade power plant off-peak start-up control system based on reservoir water level, the system including a cascade power plant off-peak start-up control device based on reservoir water level.

[0014] Optionally, the control system further includes: a grid load command receiving device, connected to the reservoir level-based cascade power plant off-peak start-up control device, for receiving grid load commands and transmitting the grid load commands to the reservoir level-based cascade power plant off-peak start-up control device; a basin-wide cascade power plant real-time load monitoring device, connected to the reservoir level-based cascade power plant off-peak start-up control device, for monitoring the real-time load of the generating units of the basin-wide cascade power plants; and a database, connected to the reservoir level-based cascade power plant off-peak start-up control device. A cascade power plant off-peak start-up control device is connected to the reservoir level-based cascade power plant off-peak start-up control device to store grid load commands and real-time loads of the generating units of the cascade power plants in the basin; a start-up / shutdown decision device is connected to the reservoir level-based cascade power plant off-peak start-up control device to control the start-up and shutdown of the cascade power plants in the basin; a load distribution adjustment device is connected to the reservoir level-based cascade power plant off-peak start-up control device to adjust the load of the cascade power plants in the basin according to the distribution scheme output by the reservoir level-based cascade power plant off-peak start-up control device.

[0015] Compared with the prior art, the present invention has the following beneficial effects:

[0016] This embodiment obtains the information of the first target power plant whose reservoir water level exceeds the warning level, as well as the downstream power plants of the first target power plant. Then, based on the grid load in the current grid load command, it obtains the impact of the first target power plant's power generation on the water level of the downstream power plants. If the impact of the first target power plant's power generation on the water level of the downstream power plants will not cause the water level of the downstream power plants to exceed the corresponding warning level, then the first target power plant is determined as the current off-peak power plant. This not only reduces the water level of the first target power plant but also prevents the water level of its downstream power plants from exceeding the corresponding warning level, thereby achieving the purpose of precise control over the off-peak operation of power plants in the cascade basin and preventing the risk of flood discharge due to excessively high reservoir water levels. Attached Figure Description

[0017] Figure 1 The diagram shown is a flowchart illustrating a method for controlling the low-peak operation of a cascade power plant based on reservoir water level, according to an embodiment of the present invention.

[0018] Figure 2 The diagram shown is a flowchart illustrating another method for controlling the low-peak operation of a cascade power plant based on reservoir water level, provided by an embodiment of the present invention.

[0019] Figure 3 The diagram shown is a structural schematic of a cascade power plant off-peak start-up control system based on reservoir water level, provided by an embodiment of the present invention. Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0021] In a first aspect, the present invention provides a method for controlling the low-valley start-up of a cascade power plant based on reservoir water levels, specifically including the following embodiments:

[0022] Figure 1 The diagram shown is a flowchart illustrating a method for controlling the low-peak operation of a cascade power plant based on reservoir water level, according to an embodiment of the present invention. Figure 1 As shown, the control method specifically includes the following steps:

[0023] Step S101: Obtain the current grid load command and the current reservoir water level of each cascade power plant during the off-peak period.

[0024] It should be noted that the current grid load instruction includes the grid load and transmission duration. The grid load is the power demand of the grid, and the transmission duration is the time required to complete the transmission. For example, if the grid load is 1000W and the transmission duration is 2 hours, then the cascade power plants need to output 1000W to the State Grid within 2 hours. Each cascade power plant has a corresponding reservoir, and the reservoir capacity of each cascade power plant can be the same or different.

[0025] Step S102: Based on the current reservoir water level of each cascade power plant, obtain the first target power plant and the second target power plant.

[0026] In this embodiment, the first target power plant is the power plant whose current reservoir water level exceeds the corresponding warning water level, and the second target power plant is the downstream power plant of the first target power plant; wherein, the warning water level is a higher warning water level, that is, among all the current reservoir water levels, there is a power plant whose water level exceeds the warning water level as the first target power plant; according to the upstream and downstream settings of the cascade power plants in the basin, the power plant located downstream of the first target power plant is the second target power plant.

[0027] It should be noted that when the water levels of some cascade power plants are high, timely water level control is necessary to avoid flood discharge due to excessively high water levels. Regardless of whether it is the flood season or the off-season, or the off-peak or peak period, priority should be given to controlling the water levels of cascade power plant reservoirs to prevent flood discharge. Therefore, when the water level is high and a certain distance from the limit water level, it is necessary to start controlling the reservoir water level through power generation. When the water level of some cascade power plant reservoirs is high, when controlling the water level through power generation, attention must be paid to the power generation situation of upstream and downstream power plants. For adjacent power plants, if the upstream plant is generating electricity during off-peak hours, it can cause the water level of the downstream plant to rise continuously, easily leading to exceeding the limit water level or flood discharge. Therefore, when formulating off-peak start-up and shutdown strategies for cascade power plants, the impact of upstream and downstream power generation on the water level of the cascade power plant reservoirs must be considered.

[0028] Therefore, when the first target power plant is the lowest-level power plant, there is no second target power plant, and the first target power plant is directly determined to be a power plant that operates during off-peak hours; when the first target power plant is not the lowest-level power plant, after the first target power plant starts operating during off-peak hours, the water in the reservoir of the first target power plant will flow to its downstream power plant, thereby causing the water level in the reservoir of the second target power plant to rise.

[0029] Step S103: Obtain the expected reservoir water level of the second target power plant based on the grid load in the current grid load instruction, the power generation flow of the first target power plant, and the current reservoir water level of the second target power plant.

[0030] In this embodiment, obtaining the expected reservoir water level of the second target power plant based on the grid load in the grid load command, the power generation flow of the first target power plant, and the current reservoir water level of the second target power plant includes: obtaining the power generation water consumption based on the grid load in the grid load command and the power generation flow of the first target power plant; obtaining the reservoir water change of the second target power plant based on the power generation water consumption and the reservoir capacity of the second target power plant; and obtaining the expected reservoir water level of the second target power plant based on the current reservoir water level and the reservoir water change.

[0031] It should be noted that the power generation water consumption of the first target power plant is obtained by multiplying the grid load by the power generation flow rate. The power generation water consumption is divided by the reservoir capacity of the second target power plant to obtain the reservoir change of the second target power plant. The current reservoir water level of the second target power plant is added to the reservoir change to obtain the expected reservoir water level of the second target power plant. The power generation flow rate refers to the amount of water used to generate electricity per unit load.

[0032] Step S104: If the expected reservoir water level of the second target power plant is within a preset range, determine that the first target power plant is a power plant that operates during off-peak hours.

[0033] It should be noted that the preset range is below the warning water level corresponding to the second target power plant. In this embodiment, if the expected reservoir water level of the second target power plant is within the preset range, that is, when the grid load in the grid load command is provided by the first target power plant, not only can the water level of the first target power plant drop, but the water level of its downstream power plants will also not exceed the corresponding warning water level. This achieves the purpose of precise control over the low-peak start-up of power plants in the cascade basin, and also prevents the risk of flood discharge due to excessively high reservoir water levels.

[0034] Compared with the prior art, this embodiment has the following beneficial effects:

[0035] This embodiment obtains the information of the first target power plant whose reservoir water level exceeds the warning level, as well as the downstream power plants of the first target power plant. Then, based on the grid load in the current grid load command, it obtains the impact of the first target power plant's power generation on the water level of the downstream power plants. If the impact of the first target power plant's power generation on the water level of the downstream power plants will not cause the water level of the downstream power plants to exceed the corresponding warning level, then the first target power plant is determined as the current off-peak power plant. This not only reduces the water level of the first target power plant but also prevents the water level of its downstream power plants from exceeding the corresponding warning level, thereby achieving the purpose of precise control over the off-peak operation of power plants in the cascade basin and preventing the risk of flood discharge due to excessively high reservoir water levels.

[0036] Figure 2 The diagram shown is a flowchart illustrating another method for controlling the low-peak operation of a cascade power plant based on reservoir water level, according to an embodiment of the present invention. Figure 2 As shown, if the expected reservoir water level of the second target power plant is not within the preset range, the control method further includes the following steps:

[0037] Step S201: Divide the grid load in the grid load command into a first load and a second load;

[0038] Step S202: Based on the first load, the power generation flow of the first target power plant, and the current reservoir water level of the first target power plant, obtain the first expected water level of the first target power plant;

[0039] Step S203: Based on the second load, the power generation flow of the second target power plant, and the current reservoir water level of the second target power plant, obtain the second expected water level of the second target power plant;

[0040] Step S204: When the first predicted water level and the second predicted water level are both within the corresponding preset range, determine that the first target power plant and the second target power plant are both off-peak power plants.

[0041] It should be noted that if the projected reservoir water level of the second target power plant is not within the preset range, that is, if the grid load in the current grid load command is entirely generated by the first target power plant, causing the water level of the downstream power plant to exceed the warning level, then both the first and second target power plants need to be started simultaneously to lower the second projected water level. The ratio of grid load carried by the first and second target power plants can be adjusted to regulate the projected water level; therefore, the first load can be equal to, less than, or greater than the second load.

[0042] In another embodiment of the present invention, the method further includes: obtaining the expected rainfall over a preset time period; obtaining the expected water level change of each cascade power plant based on the expected rainfall and the reservoir capacity of each cascade power plant; and obtaining the current reservoir water level of each cascade power plant during the preset time period based on the expected water level change of each cascade power plant and the corresponding initial reservoir water level.

[0043] It should be noted that when heavy rainfall occurs at night, it significantly impacts the off-peak power generation and shutdown strategy. In such cases, it is necessary to increase the operating load of cascade power plants to rapidly reduce the rapid rise in reservoir water levels caused by the rainfall, ensuring that the reservoir water levels remain below the normal operating levels. In this situation, all cascade power plants will operate at high loads, which is outside the scope of the off-peak power generation and shutdown strategy. During off-peak periods, heavy rainfall in the basin, coupled with high reservoir water levels at cascade power plants, makes flood discharge more likely. In this case, it is necessary to increase the power generation (operating load) of cascade power plants to rapidly reduce the reservoir water levels.

[0044] Therefore, the low-valley start-up control during heavy rainfall includes: (1) Calculating the expected rainfall: Based on the rain gauges installed within the control area of ​​the cascade power plants in the basin, rainfall monitoring is carried out in each area; when calculating the rainfall inflow to each cascade power plant, the rainfall of the power plant is calculated based on the rainfall of the rain gauges within the range of the cascade power plant and the proportion of the area occupied by the rain gauges to the control area of ​​the cascade power plant; after calculating the rainfall, the subsequent rainfall inflow and the amount of water generated by the rainfall can be calculated accordingly. (2) Calculating the rise in the power plant reservoir water level caused by rainfall: After calculating the amount of water generated by the current rainfall, the rise in the reservoir water level caused by the rainfall can be calculated based on the reservoir capacity under the current water level of the power plant. (3) Calculate the rise in water level of downstream reservoirs after power generation by each power plant: Based on the recent or previous day's off-peak power generation situation, mainly the operating load situation, calculate the rise in water level of each cascade power plant. The calculation is mainly performed when the power plant does not generate electricity, but its upstream power plant does, and calculate the water level change of the power plant. Calculate the water level change of each cascade power plant under this situation. (4) Calculate the water level change caused by rainfall plus the water level change caused by power generation: Based on the water level change caused by off-peak power generation calculated above and the water level change caused by rainfall, perform the superposition calculation to calculate the water level change of each cascade power plant after rainfall plus off-peak power generation. (5) Calculate the impact of the total water level change on the power generation benefits of cascade power plants operating during off-peak hours: After calculating the water level change under various conditions, when the water level of the reservoirs of each cascade power plant is below the safe operating level, it is possible to consider prioritizing the reduction of the water level of the power plant with the higher water level, or to determine the off-peak operation situation according to economic benefits. (6) Determine the off-peak start-up and shutdown operation mode of cascade power plants: Determine the off-peak start-up strategy of cascade power plants, including the start-up power plants and their start-up and shutdown operation modes.

[0045] In another embodiment of the present invention, after determining that the first target power plant is a power plant operating during off-peak hours, the method further includes: obtaining the off-peak operating time of the first target power plant based on the transmission time in the current grid load instruction; obtaining the target control water level of the first target power plant in each preset interval based on the difference between the current reservoir water level and the warning water level of the first target power plant and the off-peak operating time; and controlling the operation of the corresponding generator unit based on the target control water level of each preset interval.

[0046] Optionally, the method further includes: obtaining the control deviation of the current preset interval based on the target control water level and the actual operating water level of the current preset interval; and then using the control deviation of the current preset interval and the target control water level of the next preset interval as the target control water level of the next preset interval.

[0047] It should be noted that during the actual operation of cascade power plants, water level control targets need to be determined based on factors such as actual operating conditions, rainfall, grid power generation demand, maintenance status, and weather conditions. Because actual power generation is quite complex, the water level control targets also change accordingly. The water level control targets of cascade power plants are subject to rolling revisions. In practice, there is no fixed time for revision; generally, the water level control targets of the cascade power plant reservoirs are revised when necessary. For example, if there is heavy rainfall today, the control targets need to be revised; if there is a sustained high temperature today, the control targets need to be revised; if water storage begins today, the control targets need to be revised. Therefore, the water level control targets of cascade power plant reservoirs are subject to rolling revision and optimization.

[0048] In this embodiment, the calculation of the reservoir water level control target is based on factors such as subsequent rainfall, safe operating water level, and water level balance among the cascade power plant reservoirs. The calculation methods differ, and the constraints also differ. The common goal is to ensure that the water level in the cascade power plant reservoirs remains below the safe level, i.e., it cannot exceed the maximum safe operating water level.

[0049] In the absence of rainfall, cascade power plants maintain a horizontal balance in their reservoirs, meaning that the water level in the reservoirs of all cascade power plants except the one at the highest level remains constant. When there is no rainfall, only the power generation of the cascade power plants affects the reservoir water level. To ensure that the water level in a particular power plant's reservoir remains constant, the inflow (average flow) and outflow (average flow) must be equal. In other words, the amount of water entering the reservoir of that power plant equals the amount of water flowing out. The inflow of that power plant is the power generation flow of the next higher-level power plant, and the outflow of that power plant is the power generation flow of the current power plant.

[0050] The power generation F of cascade power plants i (i is the number of the cascade power plant), the power generation flow (average flow) Q corresponding to the power generation of the cascade power plant. i (i represents the cascade power plant number), the inflow (average flow) Q of the cascade power plant. i+1 (i+1 is the number of the power plant above this cascade power plant), in order to control the water level balance of the reservoirs of the cascade power plants, it is necessary to make Q i =Q i+1 .

[0051] Due to factors such as water head and generator unit type, the water consumption for power generation varies among different cascade power plants. This means that for the same 100MW output, the power generation flow rate differs across plants. To ensure that the power generation flow rate of a particular power plant matches the inflow flow (the power generation flow rate of the preceding power plant), a coefficient β is applied between the power output of that power plant and the power output of the preceding power plant. i (i is the number of the cascade power plant, β) i (This represents the coefficient between power plant i and its upstream power plant). To control the water level balance in the reservoirs of the cascade power plants, F needs to be...i+1 =F i β i .

[0052] Generally, it's difficult for the actual operating water level to reach the water level control target 100%. The closer the actual operating water level is to the control target, the better the control effect. The actual operating water level may exceed or not exceed the control target. Exceeding the water level control target is considered a positive deviation, and falling below the target is considered a negative deviation. Positive and negative deviations are merely the numerical relationship of the water level deviation and do not represent the quality of control. The smaller the deviation rate of water level control, the better the water level control. For example, if the water level control target is 195 meters, and after optimized scheduling by staff, the actual operating water level is 194.8 meters, then the water level deviation is negative. Alternatively, after optimized scheduling, the actual operating water level is 195.3 meters, then the water level deviation is positive. Both of these actual operating water levels are below the safe operating water level. Based on the deviation rate, 194.8 meters indicates better control. The formula for calculating the water level control deviation rate is:

[0053]

[0054] Among them, H k H represents the water level control target. i Indicates the actual operating water level, (H) i -H k The deviation rate () represents the water level control error. The water level control target is calculated on a rolling basis, and the water level control deviation rate is also calculated on a rolling basis. The deviation rate indicates the effectiveness of water level control; whether positive or negative, a smaller deviation rate indicates higher accuracy in water level control. In the case of a positive deviation, the safe operating water level for the power plant needs to be considered. If the positive deviation is large, and the water level in the power plant's reservoir is high, the water level needs to be lowered promptly to ensure safe operation.

[0055] Secondly, the present invention provides a cascade power plant off-peak start-up control device based on reservoir water level, the device comprising:

[0056] The data acquisition module is used to acquire the current grid load command and the current reservoir water level of each cascade power plant during off-peak hours;

[0057] The target power plant acquisition module is used to acquire the first target power plant and the second target power plant based on the current reservoir water level of each cascade power plant. The first target power plant is the power plant whose current reservoir water level exceeds the corresponding warning water level, and the second target power plant is the power plant at the lower level of the first target power plant.

[0058] The calculation module is used to obtain the expected reservoir water level of the second target power plant based on the grid load in the current grid load instruction, the power generation flow of the first target power plant, and the current reservoir water level of the second target power plant;

[0059] The determination module is used to determine that the first target power plant is a power plant that operates during off-peak hours if the expected reservoir water level of the second target power plant is within a preset range.

[0060] Thirdly, this invention provides a cascade power plant off-peak start-up control system based on reservoir water levels, such as... Figure 3 As shown, the system includes the cascade power plant off-peak start-up control device based on reservoir water level as described in the above embodiment;

[0061] A power grid load command receiving device is connected to the cascade power plant off-peak start-up control device based on reservoir water level, and is used to receive power grid load commands and transmit the power grid load commands to the cascade power plant off-peak start-up control device based on reservoir water level.

[0062] The real-time load monitoring device for the cascade power plants in the basin is connected to the off-peak start-up control device for the cascade power plants based on the reservoir water level, and is used to monitor the real-time load of the generating units of the cascade power plants in the basin.

[0063] The database is connected to the cascade power plant off-peak start-up control device based on reservoir water level and is used to store grid load commands and real-time loads of the power generation units of the cascade power plants in the basin.

[0064] The start-up and shutdown decision-making device is connected to the cascade power plant low-valley start-up control device based on reservoir water level, and is used to control the start-up and shutdown of the cascade power plants in the basin.

[0065] The load distribution adjustment device is connected to the cascade power plant off-peak start-up control device based on reservoir water level, and is used to adjust the load of the cascade power plants in the basin according to the distribution scheme output by the cascade power plant off-peak start-up control device based on reservoir water level.

[0066] Those skilled in the art will understand that all or part of the processes in the above embodiments can be implemented by a computer program instructing related hardware. The program can be stored in a non-volatile computer-readable storage medium, and when executed, it can include the processes of the embodiments described above. Any references to memory, storage, databases, or other media used in the embodiments provided in this application can include non-volatile and / or volatile memory. Non-volatile memory can include read-only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM), or flash memory. Volatile memory can include random access memory (RAM) or external cache memory. By way of illustration and not limitation, RAM is available in various forms, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), dual data rate SDRAM (DDRSDRAM), enhanced SDRAM (ESDRAM), synchronous link DRAM (SLDRAM), RAMbus direct RAM (RDRAM), direct memory bus dynamic RAM (DRDRAM), and RAMbus dynamic RAM (RDRAM), etc.

[0067] It should be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

Claims

1. A method for controlling the start-up of cascade power plants during off-peak hours based on reservoir water levels, characterized in that, The method includes: Obtain the current grid load command and the current reservoir water level of each cascade power plant during off-peak hours; Based on the current reservoir water level of each cascade power plant, the first target power plant and the second target power plant are obtained, wherein the first target power plant is the power plant whose current reservoir water level exceeds the corresponding warning water level, and the second target power plant is the power plant below the first target power plant. The expected reservoir water level of the second target power plant is obtained based on the grid load in the current grid load command, the power generation flow of the first target power plant, and the current reservoir water level of the second target power plant; If the expected reservoir water level of the second target power plant is within the preset range, the first target power plant is determined to be a power plant that operates during off-peak hours. After determining that the first target power plant is a power plant operating during off-peak hours, the method further includes: Based on the transmission duration in the current power grid load instruction, the off-peak start-up duration of the first target power plant is obtained; Based on the difference between the current reservoir water level and the warning water level of the first target power plant, and the off-peak start-up time, the target control water level of the first target power plant in each preset interval is obtained. The operation of the corresponding generator set is controlled according to the target control water level of each preset interval.

2. The method for controlling the start-up of cascade power plants during off-peak hours based on reservoir water levels as described in claim 1, characterized in that, If the expected reservoir water level of the second target power plant is not within the preset range, the method further includes: The power grid load in the power grid load command is divided into a first load and a second load; Based on the first load, the power generation flow of the first target power plant, and the current reservoir water level of the first target power plant, the first expected water level of the first target power plant is obtained; Based on the second load, the power generation flow of the second target power plant, and the current reservoir water level of the second target power plant, the second expected water level of the second target power plant is obtained; When the first predicted water level and the second predicted water level are both within their respective preset ranges, it is determined that both the first target power plant and the second target power plant are power plants that operate during off-peak hours.

3. The method for controlling the start-up of cascade power plants during off-peak hours based on reservoir water levels as described in claim 1, characterized in that, The predicted reservoir water level of the second target power plant is obtained based on the grid load in the grid load command, the power generation flow of the first target power plant, and the current reservoir water level of the second target power plant, including: Based on the grid load in the grid load command and the power generation flow of the first target power plant, obtain the power generation water consumption; Based on the power generation water consumption and the reservoir capacity of the second target power plant, the change in the reservoir capacity of the second target power plant is obtained. Based on the current reservoir water level and the change in water level of the second target power plant, the expected reservoir water level of the second target power plant is obtained.

4. The method for controlling the start-up of cascade power plants during off-peak hours based on reservoir water levels as described in claim 1, characterized in that, The method further includes: Obtain the estimated rainfall for a preset time period; Based on the predicted rainfall and the reservoir capacity of each cascade power plant, the predicted water level change for each cascade power plant is obtained. Based on the expected water level change of each cascade power plant and the corresponding initial reservoir water level, the current reservoir water level of each cascade power plant within a preset time period is obtained.

5. The method for controlling the start-up of cascade power plants during off-peak hours based on reservoir water levels as described in claim 1, characterized in that, The method further includes: The control deviation of the current preset interval is obtained based on the target control water level and the actual operating water level of the current preset interval. The control deviation of the current preset interval is fused with the target control water level of the next preset interval, and then used as the target control water level of the next preset interval.

6. The method for controlling the start-up of cascade power plants during off-peak hours based on reservoir water levels as described in claim 1, characterized in that, When the first target power plant is the lowest level power plant, the method further includes: determining that the first target power plant is a power plant that operates during off-peak hours.

7. A cascade power plant off-peak start-up control device based on reservoir water level, characterized in that, The device includes: The data acquisition module is used to acquire the current grid load command and the current reservoir water level of each cascade power plant during off-peak hours; The target power plant acquisition module is used to acquire the first target power plant and the second target power plant based on the current reservoir water level of each cascade power plant. The first target power plant is the power plant whose current reservoir water level exceeds the corresponding warning water level, and the second target power plant is the power plant at the lower level of the first target power plant. The calculation module is used to obtain the expected reservoir water level of the second target power plant based on the grid load in the current grid load instruction, the power generation flow of the first target power plant, and the current reservoir water level of the second target power plant; The determination module is used to determine that the first target power plant is a power plant that operates during off-peak hours if the expected reservoir water level of the second target power plant is within a preset range.

8. A cascade power plant off-peak start-up control system based on reservoir water level, characterized in that, The system includes the off-peak start-up control device for cascade power plants based on reservoir water level as described in claim 7.

9. The cascade power plant off-peak start-up control system based on reservoir water level as described in claim 8, characterized in that, The control system further includes: A power grid load command receiving device is connected to the cascade power plant off-peak start-up control device based on reservoir water level, and is used to receive power grid load commands and transmit the power grid load commands to the cascade power plant off-peak start-up control device based on reservoir water level. The real-time load monitoring device for the cascade power plants in the basin is connected to the off-peak start-up control device for the cascade power plants based on the reservoir water level, and is used to monitor the real-time load of the generating units of the cascade power plants in the basin. The database is connected to the cascade power plant off-peak start-up control device based on reservoir water level and is used to store grid load commands and real-time loads of the power generation units of the cascade power plants in the basin. The start-up and shutdown decision-making device is connected to the cascade power plant low-valley start-up control device based on reservoir water level, and is used to control the start-up and shutdown of the cascade power plants in the basin. The load distribution adjustment device is connected to the cascade power plant off-peak start-up control device based on reservoir water level, and is used to adjust the load of the cascade power plants in the basin according to the distribution scheme output by the cascade power plant off-peak start-up control device based on reservoir water level.

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