A guide vane opening detection method and system for an axial flow Kaplan turbine generator set

Abstract

The present invention discloses a guide vane opening detection method and system for an axial flow Kaplan turbine generator set, belonging to the technical field of hydrogenerator detection. First, the first guide vane opening value and the second guide vane opening value are respectively detected and compared with a preset difference threshold value. When the comparison result has a large error, the third guide vane opening value is detected for verification. The present invention ensures the detection accuracy of the guide vane opening, effectively solves the technical problem of large measurement error existing in the prior art, and ensures the safe and stable operation of the hydrogenerator set. At the same time, the system is simply constructed, has a high degree of automation, and can avoid the influence of the detection result caused by the damage or failure of individual electronic displacement sensors.

Description

Technical Field

[0001] The present invention belongs to the technical field of hydrogenerator detection, and particularly relates to a guide vane opening detection method and system for a Kaplan hydrogenerator unit. Background Art

[0002] Axial flow hydrogenerator units are suitable for medium and low head power stations, with the head generally ranging from 3m to 30m. The runner blade structure is divided into two types: fixed blade and adjustable blade. Among them, adjustable blades are mostly used in power stations with large and medium capacities and significant changes in head and load.

[0003] The control and regulation of the hydroturbine speed and output are related to the size of the guide vane opening. In the speed regulation system of the hydroturbine, the core of its regulation is the control of the guide vane opening size. Currently, the measurement of the guide vane opening size is carried out using the servomotor stroke, and the guide vane opening is obtained based on the relationship between the servomotor stroke and the guide vane opening. It mainly has the problem of large measurement errors, and even leads to the distortion of the guide vane opening measurement, affecting the normal operation of the entire unit. Summary of the Invention

[0004] In order to solve the defects existing in the above-mentioned prior art, the purpose of the present invention is to provide a guide vane opening detection method and system for a Kaplan hydrogenerator unit, which can improve the measurement accuracy of the guide vane opening and ensure the safe and stable operation of the hydrogenerator unit.

[0005] The present invention is realized through the following technical solutions:

[0006] A guide vane opening detection method for a Kaplan hydrogenerator unit includes:

[0007] S1: Collect the first guide vane opening value and the second guide vane opening value of the Kaplan hydrogenerator unit;

[0008] S2: Calculate the difference between the first guide vane opening value and the second guide vane opening value, and compare it with a preset difference threshold. If the difference is not greater than the preset difference threshold, then output the average value of the first guide vane opening value and the second guide vane opening value as the detected value of the guide vane opening; if the difference is greater than the preset difference threshold, then go to S3;

[0009] S3: Collect the third guide vane opening value of the Kaplan hydrogenerator unit, and calculate the difference between the third guide vane opening value and the first guide vane opening value and the difference between the third guide vane opening value and the second guide vane opening value respectively;

[0010] S4: Compare the difference between the third guide vane opening value and the first guide vane opening value with a preset difference threshold, and compare the difference between the third guide vane opening value and the second guide vane opening value with the preset difference threshold; if there is a set of guide vane opening values whose difference is not greater than the preset difference threshold, then output the average value of this set of guide vane opening values as the detected value of the guide vane opening value; if the differences of both sets of guide vane opening values are greater than the preset difference threshold, then output detection abnormal information.

[0011] Preferably, in S1, the first guide vane opening value, the second guide vane opening value, and the third guide vane opening value are respectively measured by different guide vane opening detection devices.

[0012] More preferably, the guide vane opening detection device is an electronic displacement sensor.

[0013] Preferably, the preset difference threshold is obtained according to the technical parameters of the guide vane opening detection device.

[0014] Preferably, it further includes S5: Retrieve the guide vane opening control output of the hydrogenerator governor, and compare it with the detected value of the output guide vane opening value. If the detected value of the output guide vane opening value is within the error range, then the detection result is normal; if the detected value of the output guide vane opening value is greater than the error range, then output detection abnormal information.

[0015] More preferably, the error range is the detection accuracy of the guide vane opening detection device.

[0016] A guide vane opening detection system for a Kaplan hydrogenerator unit disclosed by the present invention includes:

[0017] A first electronic displacement sensor for detecting the first guide vane opening value;

[0018] A second electronic displacement sensor for detecting the second guide vane opening value;

[0019] A third electronic displacement sensor for detecting the third guide vane opening value;

[0020] A first master slave computer for collecting the first guide vane opening value detected by the first electronic displacement sensor and transmitting it to the upper computer;

[0021] A second master slave computer for collecting the second guide vane opening value detected by the second electronic displacement sensor and transmitting it to the upper computer;

[0022] A spare slave computer for collecting the third guide vane opening value detected by the third electronic displacement sensor and transmitting it to the upper computer;

[0023] The host computer stores a preset difference threshold value; calculates the difference between the first guide vane opening value and the second guide vane opening value, and compares it with the preset difference threshold value; calculates the differences between the third guide vane opening value and the first guide vane opening value and between the third guide vane opening value and the second guide vane opening value respectively; compares the difference between the third guide vane opening value and the first guide vane opening value with the preset difference threshold value, and compares the difference between the third guide vane opening value and the second guide vane opening value with the preset difference threshold value; outputs the detected value of the guide vane opening value; outputs detection abnormal information.

[0024] Preferably, the host computer includes a central processing unit, a host computer communication module connected to the central processing unit, a comparison module for comparing the detected guide vane opening value with the preset difference threshold value, a switching control module for switching between the main slave computer and the standby slave computer, and a calling module for retrieving the guide vane opening control output of the water turbine generator governor.

[0025] Preferably, the slave computer includes a single-chip microcomputer, a power conversion module connected to the single-chip microcomputer, an A / D conversion module, a slave computer communication module, an analog quantity output module, and a signal isolation module connected to the A / D conversion module. The electronic displacement sensor is connected to the signal isolation module.

[0026] Compared with the prior art, the present invention has the following beneficial technical effects:

[0027] The guide vane opening detection method for an axial flow Kaplan turbine generator set disclosed by the present invention first detects two guide vane opening values, namely the first guide vane opening value and the second guide vane opening value, and compares them with the preset difference threshold value. When the comparison result has a large error, the third guide vane opening value is detected for verification, ensuring the detection accuracy of the guide vane opening, effectively solving the technical problem of large measurement error existing in the prior art, and ensuring the safe and stable operation of the water turbine generator set.

[0028] Furthermore, the guide vane opening control output of the water turbine generator governor is retrieved to further verify the detected value of the guide vane opening value, thereby judging whether the detection is abnormal, and further improving the reliability of the detection result.

[0029] The guide vane opening detection system for an axial flow Kaplan turbine generator set disclosed by the present invention has a simple structure and high automation. Three groups of slave computers are used as detection execution mechanisms, two of which are main slave computers and the other is a standby slave computer. Combined with the comparative analysis of the host computer, on the one hand, the comparison and verification of the detection results of the two main slave computers are realized. On the other hand, when the detection results of the two main slave computers do not match, the detection is switched to the standby slave computer for re-verification, thereby ensuring the detection accuracy of the guide vane opening, effectively solving the technical problem of large measurement error existing in the prior art; in addition, the design of two main and one standby can avoid the influence of the damage or failure of individual electronic displacement sensors on the detection results. Description of the Drawings

[0030] Figure 1 is a schematic flow chart of the method of the present invention;

[0031] Figure 2 is a schematic structural diagram of the system of the present invention;

[0032] Figure 3 is a principle block diagram of the host computer of the present invention;

[0033] Figure 4 is a principle block diagram of the slave computer of the present invention. Specific Embodiments

[0034] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. The following is an explanation rather than a limitation of the present invention.

[0035] As Figures 2 to 4 shown, this embodiment provides a guide vane opening detection device for an axial flow Kaplan turbine generator set. The detection device measures the guide vane opening through an electronic displacement sensor, and on this basis, adopts the design concept of two main units and one standby unit to improve the accuracy and reliability of the detection results. Specifically, the guide vane opening detection device for the axial flow Kaplan turbine generator set includes: a host computer for receiving and processing the feedback data from the slave computer, a slave computer for performing the detection of the guide vane opening, and an electronic displacement sensor used in cooperation with the slave computer. Among them, there are three slave computers: two main slave computers and one standby slave computer. Under normal conditions, the two main slave computers work and continuously feedback the detection data to the host computer for detection and verification. In the case of failed verification, the standby slave computer is switched to for detection, and then the detection data of the standby slave computer and the detection data of the two main slave computers are compared and analyzed, and finally the detected value of the guide vane opening or the detection abnormal information is output.

[0036] In this embodiment, the host computer adopts a computer terminal, and its functional modules include a central processing unit, a host computer communication module connected to the central processing unit, a comparison module for comparing the detection data of the slave computer, a switching control module for switching between the main slave computer and the standby slave computer, and a calling module for retrieving the guide vane opening control output of the water turbine generator governor. Among them, the guide vane opening control output of the water turbine generator governor can be directly retrieved from the speed regulation system of the water turbine generator set. The host computer communication module is used to realize the communication between the host computer and the slave computer. When verifying the detection results, the comparison module can also be used for the comparative analysis of the detected value of the guide vane opening and the guide vane opening control output of the water turbine generator governor.

[0037] The lower computers with two main units and one standby unit both adopt the same structure. Specifically, the lower computer includes a single-chip microcomputer, a power conversion module, an A / D conversion module, a lower computer communication module, an analog quantity output module connected to the single-chip microcomputer, and a signal isolation module connected to the A / D conversion module. The electronic displacement sensor is connected to the signal isolation module. Among them, the single-chip microcomputer adopts the MCS-51 series single-chip microcomputer, and the basic structure of this series of single-chip microcomputers is as follows: 8-bit CPU, on-chip oscillator, 4K bytes of ROM, 128 bytes of RAM, 21 special function registers, 32 I / O lines, addressable 64K bytes of external data, program storage space, 2 16-bit timers, counter interrupt structure: having two priorities, five interrupt sources, a full-duplex serial port, bit addressing (that is, the content of a certain bit can be found) function, and is suitable for a bit processor for logical operations by bit. Except for 128 bytes of RAM, 4K bytes of ROM, and interrupt, serial port, and timer modules, there are also 4 groups of I / O ports P0 to P3, and the rest is all the components of the CPU. The signal collected by the electronic displacement sensor is sent to the single-chip microcomputer for calculation after A / D conversion to obtain the guide vane opening value. On the basis of the above structure, the lower computer can also include a display module for displaying the current guide vane opening detection information of the lower computer on-site. The lower computer is connected to the commercial power through the power conversion module.

[0038] The electronic displacement sensors corresponding to the lower computers with two main units and one standby unit generally adopt electronic displacement sensors of the same manufacturer and the same model to ensure the consistency of information collection of the electronic displacement sensors under the same working environment.

[0039] Such as Figure 1 , for the guide vane opening detection method of a Kaplan turbine generator set, includes the following steps:

[0040] Step 1: Under the normal working state, the standby lower computer does not work, and the two main lower computers collect the guide vane opening values through the electronic displacement sensors: the first guide vane opening value and the second guide vane opening value.

[0041] Step 2: The two standby lower computers transmit the first guide vane opening value and the second guide vane opening value to the upper computer.

[0042] Step 3: The upper computer compares the first guide vane opening value and the second guide vane opening value through the comparison module to judge whether they match. If so, it outputs the average value of the two as the guide vane opening value detection value; if not, it executes Step 4. Among them, judging whether they match means whether the absolute value of the difference between the first guide vane opening value and the second guide vane opening value is greater than the error threshold. If so, they do not match; if not, they match. The error threshold is the maximum detection error value set by those skilled in the art according to the relevant specification information of the electronic displacement sensor and the information provided by the manufacturer.

[0043] Step 4: The host computer switches to the standby slave computer through the switching control module, and the standby slave computer starts to work. The host computer issues a control instruction through the switching control module. The main slave computer stops working, and the standby slave computer starts to work and begins to collect the guide vane opening degree.

[0044] Step 5: The standby slave computer collects the guide vane opening degree value through the electronic displacement sensor: the third guide vane opening degree value.

[0045] Step 6: The standby slave computer transmits the third guide vane opening degree value to the host computer.

[0046] Step 7: After receiving the third guide vane opening degree value from the standby slave computer, the host computer compares the collected values of the two main slave computers with the collected value of the standby slave computer. Specifically, the host computer compares the first guide vane opening degree value with the third guide vane opening degree value and the second guide vane opening degree value with the third guide vane opening degree value through the comparison module respectively, so as to verify the detection information of the two main slave computers. The host computer judges whether the two sets of data match, and outputs the average value of the set of data judged to be matched as the detection value of the guide vane opening degree value. For example, if the first guide vane opening degree value and the third guide vane opening degree value match, the average value of the first guide vane opening degree value and the third guide vane opening degree value is output as the detection value of the guide vane opening degree value; if neither matches, a detection exception information is output. After outputting the detection exception information, the staff should perform shutdown detection and maintenance. Among them, judging whether they match means whether the absolute value of the difference between the first guide vane opening degree value and the third guide vane opening degree value and the absolute value of the difference between the second guide vane opening degree value and the third guide vane opening degree value are greater than the error threshold. If so, they do not match; if not, they match. The error threshold is the maximum detection error value set by those skilled in the art according to the relevant specification information of the electronic displacement sensor and the information provided by the manufacturer.

[0047] To further improve the reliability of the guide vane opening degree detection, this embodiment further includes Step 8. This step mainly compares the detected value of the guide vane opening degree value output with the guide vane opening degree control output of the hydrogenerator governor to judge whether the detected value of the guide vane opening degree value is within the detection error range. If so, it is considered that the detection is normal; if not, a detection exception information is output. The detection error range is determined according to the accuracy of the used electronic displacement sensor, generally provided by the manufacturer. After outputting the detection exception information, the staff should perform shutdown detection and maintenance.

[0048] It should be noted that the above is only a part of the embodiments of the present invention. Equivalent changes made according to the system described in the present invention are all included in the protection scope of the present invention. Those skilled in the art of the present invention can make similar substitutions for the specific examples described as long as they do not deviate from the structure of the present invention or exceed the scope defined by this claim book, and all belong to the protection scope of the present invention.

Claims

1. An adjustable blade axial flow hydro-generator guide vane opening detection method, characterized in that Including: S1: Collect the first guide vane opening value and the second guide vane opening value of the Kaplan turbine generator unit; S2: Calculate the difference between the first guide vane opening value and the second guide vane opening value, and compare it with a preset difference threshold. If the difference is not greater than the preset difference threshold, then output the average value of the first guide vane opening value and the second guide vane opening value as the detected value of the guide vane opening value; if the difference is greater than the preset difference threshold, then go to S3; S3: Collect the third guide vane opening value of the Kaplan turbine generator unit, and calculate the difference between the third guide vane opening value and the first guide vane opening value and the difference between the third guide vane opening value and the second guide vane opening value respectively; S4: Compare the difference between the third guide vane opening value and the first guide vane opening value with the preset difference threshold, and compare the difference between the third guide vane opening value and the second guide vane opening value with the preset difference threshold; If there is a set of guide vane opening values whose difference is not greater than the preset difference threshold, then output the average value of this set of guide vane opening values as the detected value of the guide vane opening value; if the differences of both sets of guide vane opening values are greater than the preset difference threshold, then output detection abnormal information; S5: Retrieve the guide vane opening control output quantity of the hydrogenerator governor, and compare it with the output detected value of the guide vane opening value. If the output detected value of the guide vane opening value is within the error range, then the detection result is normal; if the output detected value of the guide vane opening value is greater than the error range, then output detection abnormal information; the error range is the detection accuracy of the guide vane opening detection device.

2. The guide vane opening detection method for the Kaplan turbine generator unit according to claim 1, characterized in that The first guide vane opening value, the second guide vane opening value, and the third guide vane opening value are measured by different guide vane opening detection devices respectively.

3. The guide vane opening detection method for the Kaplan turbine generator unit according to claim 2, characterized in that The guide vane opening detection device is an electronic displacement sensor.

4. The guide vane opening detection method for an axial flow Kaplan turbine generator set according to claim 1, characterized in that, The preset difference threshold is obtained according to the technical parameters of the guide vane opening detection device.

5. A guide vane opening detection system for an axial flow Kaplan turbine generator set, characterized in that, Used to implement the guide vane opening detection method for the Kaplan turbine generator unit as described in any one of claims 1 to 4, including: The first electronic displacement sensor, detecting the first guide vane opening value; The second electronic displacement sensor, detecting the second guide vane opening value; The third electronic displacement sensor, detecting the third guide vane opening value; The first master slave computer, collecting the first guide vane opening value detected by the first electronic displacement sensor and transmitting it to the upper computer; The second master slave computer, collecting the second guide vane opening value detected by the second electronic displacement sensor and transmitting it to the upper computer; The standby slave computer, collecting the third guide vane opening value detected by the third electronic displacement sensor and transmitting it to the upper computer; The upper computer, storing the preset difference threshold; calculating the difference between the first guide vane opening value and the second guide vane opening value, and comparing it with the preset difference threshold; calculating the difference between the third guide vane opening value and the first guide vane opening value and the difference between the third guide vane opening value and the second guide vane opening value respectively; comparing the difference between the third guide vane opening value and the first guide vane opening value with the preset difference threshold, and comparing the difference between the third guide vane opening value and the second guide vane opening value with the preset difference threshold; outputting the detected value of the guide vane opening value; outputting detection abnormal information.

6. The guide vane opening detection system for an axial flow Kaplan turbine generator set according to claim 5, characterized in that, The host computer includes a central processing unit, a host computer communication module connected to the central processing unit, a comparison module for comparing the detected guide vane opening value with a preset difference threshold value, a switching control module for switching between the main slave computer and the standby slave computer, and a call module for retrieving the guide vane opening control output of the water turbine generator governor.

7. The guide vane opening detection system for an axial flow Kaplan turbine generator set according to claim 5, wherein The slave computer includes a single-chip microcomputer, a power conversion module connected to the single-chip microcomputer, an A / D conversion module, a slave computer communication module, an analog quantity output module, and a signal isolation module connected to the A / D conversion module. The electronic displacement sensor is connected to the signal isolation module.

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