A method and system for calculating water head of a hydropower station

Abstract

The present invention relates to a method and system for calculating water head in a hydropower station, the method comprising collecting data, judging sensor failure, calculating the reliability of collected values ​​and water head calculation. By performing reliability calculation, a stable and reliable water head monitoring value is obtained, which can improve the accuracy of water level measurement.

Description

Technical Field

[0001] The invention relates to the field of water level measurement systems, and in particular to a method and system for calculating water head in a hydropower station. Background Art

[0002] At present, the water level measurement system of hydropower stations is mostly a sensor that directly sends water level measurement and display through 4-20mA to PLC. The head calculation is calculated by a single water level difference. However, due to wind power and water flow caused by unit power generation, the water level fluctuates greatly. The single sensor direct measurement method is not accurate and reliable. The water level display and the actual water level have a large deviation. The system has weak pressure overload resistance and is prone to inaccurate measurement, which leads to large errors in head calculation. The head calculation method is also easily affected and has weak anti-interference performance, resulting in the monitoring briefing screen being refreshed, affecting the power plant operators' judgment of the actual water level and head. Therefore, it is necessary to improve the existing water level measurement system. Summary of the invention

[0003] In order to solve the above problems, the present invention proposes a method and system for calculating the water head of a hydropower station, which can obtain a stable and reliable water head monitoring value by performing reliability calculation, thereby improving the accuracy of water level measurement.

[0004] The technical solution of the present invention is as follows:

[0005] A method for calculating the hydraulic head of a hydropower station is as follows:

[0006] The data collected are collected from two radar water level sensors and one input water level sensor for reservoir water level and tailwater level respectively;

[0007] Determine sensor failure and calculate the reliability of collected values;

[0008] Head calculation:

[0009] The gross head of the power station is calculated by subtracting the tail water level from the reservoir water level. The head value is then sampled every several seconds, and the sampled values ​​of several cycles are subjected to sliding average filtering. The first cycle is taken as the reference value. If the average value of each several sampling cycles differs from the value of the previous cycle by less than a distance, the sampling value is selected, and the head is updated to the current value and sent to the monitoring system. If the difference with the value of the previous cycle is greater than the distance, the head input is locked, the program maintains the head value of the previous cycle, and an alarm message is issued.

[0010] Furthermore, the water head value is sampled and collected every 10 seconds, with a cycle of 10 cycles and a distance of 1 meter; or, the interval time, cycle and distance are set according to the actual needs of each power station.

[0011] Furthermore, whether the water head is reasonable is determined based on the alarm information, and an artificial water head is manually set.

[0012] Furthermore, the sensor failure is judged as follows: the input 4-20mA signal is converted into a digital value 0-10000, and the water level value of each measuring point is calculated according to the range value s and zero value f of each measuring point sensor and the normal value of the sensor input, and then the actual installation altitude position n of each measuring point is added to obtain the water level altitude value m of each measuring point reservoir; the calculation is performed according to the following formula:

[0013] Where X is the input value;

[0014] If the reservoir water level elevation value is greater than 10100 or less than -500, or the data change exceeds 1 / 10 of the sensor range every 2 seconds, it is judged as a sensor failure and the sensor input value is invalid.

[0015] Furthermore, the reliability of the calculated collected values ​​is specifically as follows: the reservoir water levels at the three measuring points are comprehensively processed to obtain the comprehensive reservoir water level: the reservoir water level is screened by pairwise comparison and then the average value is taken. When the numerical deviation between the reservoir water level immersion water level sensor and the new reservoir water level radar does not exceed 30, two average values ​​A are taken. When the deviation between the reservoir water level immersion water level sensor and the new reservoir water level radar exceeds 30, the larger value is taken as A; when the deviation between the reservoir water level immersion water level sensor and the original reservoir water level radar does not exceed 30, two average values ​​B are taken. When the deviation between the reservoir water level immersion water level sensor and the original reservoir water level radar exceeds 30, the larger value is taken as B; then compare the A and B values. When the deviation does not exceed 30, the average value of A and B is taken as the reservoir water level. When the deviation between A and B exceeds 30, the larger value is taken as the reservoir water level. The comprehensive reservoir water level is obtained after comprehensive processing; the reservoir water level and tail water level values ​​obtained by the on-site measured scale water level are consistent with the calculated values.

[0016] The present invention also relates to a water level measurement system for a hydropower station, comprising a reservoir water level measurement device, a tailwater level measurement device, a collector and a processor; the reservoir water level measurement device and the tailwater level measurement device are both composed of two radar water level sensors and one input water level sensor; the collector includes an analog signal lightning protection and isolation module to collect the above sensor data;

[0017] The processor determines the sensor failure, calculates the reliability of the collected value, and performs the water head calculation, and processes according to the above method; the processor uploads the processing result to the monitoring system.

[0018] Furthermore, the system also includes an alarm and a display. The alarm sends out an alarm message according to the judgment result of the processor; the display displays the processing result and receives the artificial water head input and parameter setting.

[0019] The present invention also relates to an electronic device, comprising a memory, a processor, and a computer program on the memory and executable on the processor, wherein the processor implements the steps of the above method when executing the computer program.

[0020] The present invention also relates to a non-transitory computer-readable storage medium having a computer program stored thereon, which implements the steps of the above method when executed by a processor.

[0021] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0022] The present invention can avoid the situation where the reservoir water level of a hydropower station is fluctuating due to other factors such as wind power and power generation, resulting in inaccurate or impossible reservoir water level measurement, thereby reducing reservoir water level monitoring errors and reducing real-time monitoring fluctuations.

[0023] The traditional data collection method is that a single sensor directly uploads the collected data. However, due to the complex environment of the reservoir, if there is strong wind or large fluctuations in the water surface, the error will reach 2-3 meters. The difference will be even greater when the sensor fails. After using the algorithm of the present invention, the uploaded value is basically consistent with the actual value. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 is a flow chart of the method of the present invention;

[0025] Figure 2 It is a system block diagram of the present invention. DETAILED DESCRIPTION

[0026] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0027] Unless otherwise defined, the technical terms or scientific terms used in the embodiments of the present application should be understood by people with ordinary skills in the field. The words "first", "second" and similar words used in this embodiment do not indicate any order, quantity or importance, but are only used to distinguish different components. "Include" or "comprise" and similar words mean that the elements or objects appearing before the word include the elements or objects listed after the word and their equivalents, without excluding other elements or objects. "Install", "connect", "connect" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be directly connected, or indirectly connected through an intermediate medium, or it can be the internal connection of two elements. "Up", "down", "left", "right", "horizontal" and "vertical" are only used relative to the orientation of the components in the drawings. These directional terms are relative concepts. They are used for description and clarification relative to the components, and they can change accordingly according to the change of the orientation of the components in the drawings.

[0028] like Figure 1 As shown, the water level measurement system of the hydropower station in this embodiment includes a reservoir water level measurement device, a tail water level measurement device, a collector, a processor, an alarm and a display; the reservoir water level measurement device and the tail water level measurement device are both composed of 2 radar water level sensors and 1 input water level sensor; the collector includes an analog signal lightning protection and isolation module to collect the above sensor data.

[0029] The processor determines sensor failure, calculates the reliability of the collected values, performs water head calculations, and uploads the processing results to the monitoring system.

[0030] The alarm sends out an alarm message according to the judgment result of the processor; the display shows the processing result and receives the artificial water head input and parameter setting.

[0031] The measuring elements of this embodiment are configured with two sets. One set of on-site measuring elements is used for reservoir water level measurement, and the other set is used for tailwater level measurement. Each set of measuring elements consists of two radar water level sensors and one input water level sensor. After collecting the water level, the 4-20mA signal is connected to the PLC analog input channel of the water inlet water level measurement product, and an analog signal lightning protection and isolation module is installed at the front end of each signal access to protect the sensor and reduce signal interference. After calculation by the PLC, it is sent to the monitoring system for display.

[0032] It should be noted that it should be understood that the division of the various modules of the above device is only a division of logical functions. In actual implementation, they can be fully or partially integrated into one physical entity, or physically separated. Moreover, these modules can be all implemented in the form of software calling through processing elements; they can also be all implemented in the form of hardware; some modules can also be implemented in the form of software calling through processing elements, and some modules can be implemented in the form of hardware.

[0033] The processing element described here can be an integrated circuit with signal processing capability. In the implementation process, each step of the above method or each module can be completed by an integrated logic circuit of hardware in the processor element or an instruction in software form.

[0034] For example, the above modules can be one or more integrated circuits configured to implement the above methods, such as: one or more application specific integrated circuits (ASIC), or one or more microprocessors (DSP), or one or more field programmable gate arrays (FPGA). For another example, when a certain module above is implemented in the form of a processing element scheduling program code, the processing element can be a general-purpose processor, such as a central processing unit (CPU) or other processor that can call program code. For another example, these modules can be integrated together and implemented in the form of a system-on-a-chip (SOC).

[0035] In the above embodiments, it can be implemented in whole or in part by software, hardware, firmware or any combination thereof. When implemented using software, it can be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, the process or function described in the embodiment of the present application is generated in whole or in part. The computer may be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions may be stored in a readable storage medium, or transmitted from one readable storage medium to another readable storage medium, for example, the computer instructions may be transmitted from a website site, computer, server or data center by wired (e.g., coaxial cable, optical fiber, digital subscriber line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) mode to another website site, computer, server or data center. The readable storage medium may be any available medium that a computer can access or a data storage device such as a server or data center that includes one or more available media integrated. The available medium may be a magnetic medium, (e.g., a floppy disk, a hard disk, a tape), an optical medium (e.g., a DVD), or a semiconductor medium (e.g., a solid state disk (SSD)), etc.

[0036] The above-mentioned processor can be a general-purpose processor, including a central processing unit (CPU), a network processor (NP), etc.; it can also be a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components.

[0037] The method for calculating the water head of a hydropower station in this embodiment includes the following steps:

[0038] Data collection;

[0039] Determine sensor failure:

[0040] The input 4-20mA signal is converted into a digital value of 0-10000. The water level value of each measuring point is calculated based on the range value s and zero value f of each measuring point sensor and the normal value of the sensor input. Adding the actual installation altitude position n of each measuring point, the water level altitude value m of each measuring point reservoir is obtained; calculate according to the following formula:

[0041]

[0042] Where X is the input value; 10000 represents the maximum conversion value of the 4-20mA input to the PLC channel.

[0043] If the reservoir water level elevation value is greater than 10100 or less than -500, or the data change exceeds 1 / 10 of the sensor range every 2 seconds, it is judged as a sensor failure and the sensor input value is invalid.

[0044] Reliability calculation of water level acquisition value:

[0045] The reservoir water levels at the three measuring points are then processed comprehensively to obtain the comprehensive reservoir water level: the reservoir water level is screened by pairwise comparison and then the average value is taken. When the deviation between the reservoir water level immersion water level sensor and the new reservoir water level radar does not exceed 30, two average values ​​A are taken. When the deviation between the reservoir water level immersion water level sensor and the new reservoir water level radar exceeds 30, the larger value is taken as A; when the deviation between the reservoir water level immersion water level sensor and the original reservoir water level radar does not exceed 30, two average values ​​B are taken. When the deviation between the reservoir water level immersion water level sensor and the original reservoir water level radar exceeds 30, the larger value is taken as B; then compare the A and B values. When the deviation does not exceed 30, the average value of A and B is taken as the reservoir water level. When the deviation between A and B exceeds 30, the larger value is taken as the reservoir water level. The comprehensive reservoir water level is obtained after comprehensive processing. The reservoir water level and tail water level values ​​obtained by the on-site measured scale water level are consistent with the PLC comprehensive calculation.

[0046] The water head is calculated as follows:

[0047] The water level of the water inlet reservoir and the tailwater level are sent to the PLC in the water level measurement screen of the underground central control room through Ethernet and optical fiber communication respectively. The PLC in the water level measurement screen of the underground central control room then performs logical judgment and processing to obtain the head value: the main station of the water level measurement system judges the quality and effectiveness of the received reservoir water level and tailwater level, and then calculates the gross head of the power station by subtracting the tailwater level from the reservoir water level. The head value is then sampled every 10 seconds, and the sampled values ​​of 10 cycles are subjected to sliding average filtering. The first cycle is taken as the reference value. If the average value of every 10 sampling cycles differs from the value of the previous cycle by less than 1m, the sampling value is selected, and the head is updated to the current value and sent to the monitoring system; if the difference from the value of the previous cycle is greater than 1 meter, the head input is locked, the program maintains the head value of the previous cycle, and issues an alarm message; at this time, the operating personnel can judge whether the head is reasonable based on the signal, and can manually set the artificial head on the touch screen.

[0048] Specific examples:

[0049] Nuozhadu water level measurement system on a certain day:

[0050] The following values ​​are the values ​​detected when the sensor is normal and the measurement environment is good. They are the initial values ​​after sensor failure judgment and deviation comparison basic calculation.

[0051] The initial values ​​calculated after the three tailwater level sensors collect the original data are as follows:

[0052] Tailwater level 1 immersion type (immersion type water level sensor detection) 603.6m;

[0053] Tailwater level 2 new radar (radar water level sensor detection) 603.08m;

[0054] Tailwater level 3 radar type (radar water level sensor detection) 603.19m;

[0055] The initial value of the reservoir water level calculated after collecting the original data from the three sensors is as follows:

[0056] Reservoir water level 1 immersion (immersion water level sensor detection) 811.16m;

[0057] Reservoir water level 2 new radar (radar water level sensor detection) 811.13m;

[0058] Reservoir water level 3 radar type (radar water level sensor detection) 811.13m;

[0059] The final results of the reservoir water level, tailwater level, and gross head after processing according to the embodiment method are as follows:

[0060] The comprehensive water level of the reservoir is 811.13m;

[0061] The comprehensive tailwater level is 603.10m;

[0062] Power station gross head 208.04; (finally calculated head)

[0063] It can be seen that the reservoir water level and tail water level calculated by the method of the present invention are consistent with the scale water level (the actual physical scale measured water level).

[0064] The reservoir water level of 811.30m calculated by other head calculation methods (direct collection and uploading by a single water level sensor) has a large error with the scale water level of 811.20m, and the tail water level of 602.24m is quite different from the scale water level of 602.65m.

[0065] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for calculating the water head of a hydropower station, characterized in that: Proceed as follows: The data collected are collected from two radar water level sensors and one input water level sensor for reservoir water level and tailwater level respectively; Determine sensor failure and calculate the reliability of collected values; Head calculation: The gross water head of the power station is calculated by subtracting the tail water level from the reservoir water level. Then the water head value is sampled every several seconds, and the sampled values ​​of several cycles are subjected to sliding average filtering. The first cycle is taken as the reference value. If the average value of each several sampling cycles differs from the value of the previous cycle by less than a distance, the sampling value is selected, and the water head is updated to the current value and sent to the monitoring system; if the difference with the value of the previous cycle is greater than the distance, the water head input is locked, the program maintains the water head value of the previous cycle, and issues an alarm message; The reliability of the calculated collected values ​​is specifically as follows: the reservoir water levels at the three measuring points are comprehensively processed to obtain the comprehensive reservoir water level: the reservoir water level is screened by pairwise comparison and then the average value is taken. When the numerical deviation between the reservoir water level immersion water level sensor and the new reservoir water level radar does not exceed 30, the average value of the two is taken as A. When the numerical deviation between the reservoir water level immersion water level sensor and the new reservoir water level radar exceeds 30, the larger value is taken as A. When the numerical deviation between the reservoir water level immersion water level sensor and the original reservoir water level radar does not exceed 30, the average value of the two is taken as B. When the numerical deviation between the reservoir water level immersion water level sensor and the original reservoir water level radar exceeds 30, the larger value is taken as B. Then compare the A and B values. When the deviation between A and B does not exceed 30, the average value of A and B is taken as the reservoir water level. When the deviation between A and B exceeds 30, the larger value is taken as the reservoir water level. After comprehensive processing, the comprehensive reservoir water level is obtained. The on-site measured scale water level is consistent with the reservoir water level and tail water level values ​​obtained by comprehensive calculation.

2. The method according to claim 1, characterized in that: The water head value is sampled and collected every 10 seconds, with a cycle of 10 cycles and a distance of 1 meter; or, the interval time, cycle and distance are set according to the actual needs of each power station.

3. The method according to claim 1, characterized in that: Determine whether the water head is reasonable based on the alarm information and manually set the artificial water head.

4. The method according to claim 1, characterized in that: The specific method of judging sensor failure is as follows: the input 4-20mA signal is converted into a digital value 0-10000, and the water level value of each measuring point is calculated based on the range value s and zero value f of each measuring point sensor and the normal value of the sensor input, and then the actual installation altitude position n of each measuring point is added to obtain the water level altitude value m of each measuring point reservoir; Calculate as follows: ; Where X is the input value; If the reservoir water level elevation value is greater than 10100 or less than -500, or the data change exceeds 1 / 10 of the sensor range every 2 seconds, it is judged as a sensor failure and the sensor input value is invalid.

5. A water level measurement system for a hydropower station, characterized in that: It includes a reservoir water level measuring device, a tailwater level measuring device, a collector and a processor; the reservoir water level measuring device and the tailwater level measuring device are both composed of two radar water level sensors and one input water level sensor; the collector includes an analog signal lightning protection and isolation module to collect the above sensor data; The processor determines the sensor failure, calculates the reliability of the collected value, and performs the water head calculation, and processes according to the method described in any one of claims 1-4; the processor uploads the processing result to the monitoring system.

6. The system according to claim 5, characterized in that: The system also includes an alarm and a display. The alarm sends out an alarm message according to the judgment result of the processor; the display displays the processing result and receives the artificial water head input and parameter setting.

7. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein: When the processor executes the computer program, the steps of the method described in any one of claims 1 to 4 are implemented.

8. A non-transitory computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 4 are implemented.

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