Accurate measurement method and system for speed regulator guide vane opening limitation

Abstract

The invention relates to the technical field of hydroelectric generating sets, in particular to a speed regulator guide vane opening limit accurate measurement method and system, and the method comprises the steps: initializing a hydroelectric generating set speed regulator control system, and selecting a plurality of point positions in a set range to set characteristic water heads; the hydroelectric generating set speed regulator control system executes an automatic water head mode, collects upstream and downstream water head signals of a hydroelectric generating set, and solves a current water purification head value based on the upstream and downstream water head signals of the hydroelectric generating set; judging whether the current water purification head is equal to a certain characteristic water head or not, and if yes, outputting a guide vane opening limit value corresponding to the characteristic water head; if not, determining two characteristic water heads closest to the current water purification head, and calculating and outputting a guide vane opening limit value corresponding to the current water purification head through linear interpolation; and related parameters of the hydroelectric generating set speed regulator control system are updated based on the output guide vane opening limit value, and stable operation of the hydroelectric generating set speed regulator is completed.

Description

Technical Field

[0001] The present invention relates to the technical field of hydro-generator units, and in particular, to a precise measurement method and system for the opening limit of a governor guide vane. Background Art

[0002] The governor control system of a hydro-generator unit is a key device to ensure the safe, stable and efficient operation of a hydro-turbine generator set. With the continuous improvement of the operation requirements of hydropower stations, the governor control system faces greater challenges. Especially in power stations with large head variations, how to adjust the control parameters in a timely manner according to the real-time head change to achieve the optimal operation of the unit has become a technical problem that needs to be solved urgently. At present, the traditional governor control system of a hydro-generator unit usually adopts fixed parameter settings or simple segmented control methods. On the one hand, it is difficult to adapt when the head changes greatly, which easily leads to mismatched control parameters and affects the operation efficiency and stability of the unit. On the other hand, the traditional method has a slow response speed to head changes and cannot adjust the control strategy in a timely manner, which easily causes uneconomical operation of the unit or exceeding the safe operation range. Based on this, in view of the above problems, we have designed a precise measurement method and system for the opening limit of a governor guide vane. Summary of the Invention

[0003] The purpose of the present invention is to provide a precise measurement method and system for the opening limit of a governor guide vane, which realizes the precise dynamic adjustment of the opening limit value of the guide vane through the setting of characteristic heads and linear interpolation calculations, improves the adaptability and response speed of the system to head changes, optimizes the operation efficiency of the unit, and enhances the operation safety and stability.

[0004] The embodiments of the present invention are realized through the following technical solutions:

[0005] A precise measurement method for the opening limit of a governor guide vane, the steps of the method include:

[0006] Initialize the governor control system of the hydro-generator unit, and select multiple points within a set range to set characteristic heads;

[0007] The governor control system of the hydro-generator unit executes the automatic head mode, collects the upstream and downstream head signals of the hydro-generator unit, and solves the current net head value based on the upstream and downstream head signals of the hydro-generator unit;

[0008] Determine whether the current net head is equal to a certain characteristic head. If so, output the opening limit value of the guide vane corresponding to this characteristic head; if not, determine the two characteristic heads closest to the current net head, and calculate and output the opening limit value of the guide vane corresponding to the current net head through linear interpolation;

[0009] Update the relevant parameters of the governor control system of the hydro-generator unit based on the output opening limit value to complete the stable operation of the governor of the hydro-generator unit.

[0010] Optionally, the characteristic water heads include: the maximum water head, the minimum water head, the rated water head, and a plurality of set water heads, and the plurality of set water heads are arranged at equal intervals between the maximum water head and the minimum water head.

[0011] Optionally, for collecting the upstream and downstream water head signals of the hydropower unit, specifically:

[0012] Measure the upstream water head of the hydropower unit based on the pressure transmitter at the inlet of the spiral case;

[0013] Measure the downstream water head of the hydropower unit based on the pressure transmitter at the outlet of the draft tube;

[0014] Convert the measurement data of the upstream and downstream water heads into current signals, isolate them through an analog signal isolator, and output the upstream and downstream water head signals of the hydropower unit.

[0015] Optionally, for solving the current net water head value based on the upstream and downstream water head signals of the hydropower unit, specifically:

[0016] Receive the upstream and downstream water head signals of the hydropower unit based on the PLC module;

[0017] Perform per-unit calculation on the upstream and downstream water head signals of the hydropower unit, and convert the actual values of the upstream and downstream water head signals into the standard unit system;

[0018] Perform disconnection detection on the upstream and downstream water head signals of the hydropower unit to ensure the continuity of the upstream and downstream water head signals;

[0019] Perform over-limit judgment on the upstream and downstream water head signals of the hydropower unit to ensure that the upstream and downstream water head signals are within the effective range;

[0020] Solve the difference between the upstream and downstream water head signals, and obtain the current net water head value by subtracting the head loss of the water inlet system of the preset hydropower unit from the difference between the upstream and downstream water head signals.

[0021] Optionally, for calculating and outputting the guide vane opening limit value corresponding to the current net water head through linear interpolation, specifically:

[0022] Determine the two characteristic water heads closest to the current net water head, including: the maximum characteristic water head and the minimum characteristic water head, and obtain the guide vane opening limit values corresponding to the maximum characteristic water head and the minimum characteristic water head;

[0023] Calculate the difference between the current net water head and the maximum characteristic water head;

[0024] Calculate the difference between the maximum characteristic water head and the minimum characteristic water head;

[0025] Calculate the difference between the guide vane opening corresponding to the minimum characteristic water head and the guide vane opening corresponding to the maximum characteristic water head;

[0026] Apply the linear interpolation formula to calculate the guide vane opening limit value corresponding to the current net water head.

[0027] Optionally, the guide vane opening limit value corresponding to the current net water head is calculated and output by linear interpolation, and its calculation formula is:

[0028]

[0029] where α net is the guide vane opening limit value corresponding to the current net water head, H net is the current net water head value, H 1 is the lower limit characteristic water head, i.e., the maximum characteristic water head, H 2 is the upper limit characteristic water head, i.e., the minimum characteristic water head, α 1 is the guide vane opening limit value corresponding to the lower limit characteristic water head, α 2 is the guide vane opening limit value corresponding to the upper limit characteristic water head.

[0030] A precise measurement system for the guide vane opening limit of a governor, comprising:

[0031] A system initialization module that initializes the governor control system of the hydropower unit and sets characteristic water heads at multiple points within a set range;

[0032] An acquisition module, where the governor control system of the hydropower unit executes the automatic water head mode, acquires the upstream and downstream water head signals of the hydropower unit, and solves the current net water head value based on the upstream and downstream water head signals of the hydropower unit;

[0033] A calculation module that determines whether the current net water head is equal to a certain characteristic water head. If so, it outputs the guide vane opening limit value corresponding to this characteristic water head; if not, it determines the two characteristic water heads closest to the current net water head, and calculates and outputs the guide vane opening limit value corresponding to the current net water head by linear interpolation;

[0034] An execution module that updates the relevant parameters of the governor control system of the hydropower unit based on the output guide vane opening limit value to complete the stable operation of the governor of the hydropower unit.

[0035] Optionally, the acquisition module includes: a spiral case inlet pressure transmitter and a tail water outlet pressure transmitter.

[0036] The technical solution of the embodiment of the present invention has at least the following advantages and beneficial effects:

[0037] In the embodiments of the present invention, through the setting of characteristic water heads and linear interpolation calculations, the accurate dynamic adjustment of the guide vane opening limit value is achieved, the adaptability and response speed of the system to water head changes are improved, the operating efficiency of the unit is optimized, and the operating safety and stability are enhanced. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 FIG. is a schematic flowchart of a method for accurately measuring the guide vane opening limit of a speed governor provided by an embodiment of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0039] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. Generally, the components of the embodiments of the present invention described and illustrated herein can be arranged and designed in various different configurations.

[0040] As Figure 1 shown, the present invention provides one of the embodiments: a method for accurately measuring the guide vane opening limit of a speed governor, and the steps of the method include:

[0041] Initialize the speed governor control system of the hydropower unit, and set multiple characteristic water heads at multiple points within a set range;

[0042] The speed governor control system of the hydropower unit executes the automatic water head mode, collects the upstream and downstream water head signals of the hydropower unit, and solves the current net water head value based on the upstream and downstream water head signals of the hydropower unit;

[0043] Determine whether the current net water head is equal to a certain characteristic water head. If so, output the guide vane opening limit value corresponding to this characteristic water head; if not, determine the two characteristic water heads closest to the current net water head, and calculate and output the guide vane opening limit value corresponding to the current net water head through linear interpolation;

[0044] Update the relevant parameters of the speed governor control system of the hydropower unit based on the output guide vane opening limit value to complete the stable operation of the speed governor of the hydropower unit.

[0045] In this embodiment, this embodiment is set based on the speed governor control system of a certain hydropower station. When in the automatic water head mode, it uses the measured values of the spiral case inlet pressure transmitter and the tail water outlet pressure transmitter as the upstream and downstream water head signals, and calculates the net water head value. The water head measurement signal is a 4-20 mA signal, which is isolated by an analog signal isolator and then sent to the PLC module for processing. The processing includes per-unit calculation, disconnection, and over-limit judgment.

[0046] Specifically, the characteristic water heads include: the maximum water head, the minimum water head, the rated water head, and multiple set water heads, and the multiple set water heads are arranged at equal intervals between the maximum water head and the minimum water head.

[0047] In implementation, when the governor is in the automatic water head mode, a total of 7 characteristic water heads are set between the water heads of 153m and 240m. These include the maximum water head, the minimum water head, and the rated water head. The other four water head values are at equal intervals, generally taking integer values with a deviation within 1m, and are set between the maximum water head and the minimum water head.

[0048] In the above implementation, the collection of the upstream and downstream water head signals of the hydroelectric generating unit is specifically as follows:

[0049] Based on the pressure transmitter at the inlet of the spiral case to measure the upstream water head of the hydroelectric generating unit;

[0050] Based on the pressure transmitter at the outlet of the draft tube to measure the downstream water head of the hydroelectric generating unit;

[0051] Convert the measurement data of the upstream and downstream water heads into current signals, and isolate them through an analog signal isolator to output the upstream and downstream water head signals of the hydroelectric generating unit.

[0052] More specifically, the solution of the current net water head value based on the upstream and downstream water head signals of the hydroelectric generating unit is specifically as follows:

[0053] Based on the PLC module to receive the upstream and downstream water head signals of the hydroelectric generating unit;

[0054] Perform per-unit calculation on the upstream and downstream water head signals of the hydroelectric generating unit to convert the actual values of the upstream and downstream water head signals into the standard unit system;

[0055] Perform disconnection detection on the upstream and downstream water head signals of the hydroelectric generating unit to ensure the continuity of the upstream and downstream water head signals;

[0056] Perform over-limit judgment on the upstream and downstream water head signals of the hydroelectric generating unit to ensure that the upstream and downstream water head signals are within the effective range;

[0057] Solve the difference between the upstream and downstream water head signals, and subtract the head loss of the inlet system of the preset hydroelectric generating unit from the difference between the upstream and downstream water head signals to obtain the current net water head value.

[0058] In the specific implementation of this embodiment, optionally, the calculation and output of the guide vane opening limit value corresponding to the current net water head through linear interpolation are specifically as follows:

[0059] Determine the two characteristic water heads closest to the current net water head, including: the maximum characteristic water head and the minimum characteristic water head, and obtain the guide vane opening limit values corresponding to the maximum characteristic water head and the minimum characteristic water head;

[0060] Calculate the difference between the current net head and the maximum characteristic head;

[0061] Calculate the difference between the maximum characteristic head and the minimum characteristic head;

[0062] Calculate the difference between the guide vane opening of the minimum characteristic head and the guide vane opening of the maximum characteristic head;

[0063] Apply the linear interpolation formula to calculate the guide vane opening limit value corresponding to the current net head.

[0064] The guide vane opening limit value corresponding to the current net head is calculated and output by linear interpolation, and its calculation formula is:

[0065]

[0066] where α net is the guide vane opening limit value corresponding to the current net head, H net is the current net head value, H 1 is the lower limit characteristic head, i.e., the maximum characteristic head, H 2 is the upper limit characteristic head, i.e., the minimum characteristic head, α 1 is the guide vane opening limit value corresponding to the lower limit characteristic head, α 2 is the guide vane opening limit value corresponding to the upper limit characteristic head.

[0067] In actual operation, when the governor net head meets one of the corresponding characteristic heads, set the active power of the unit at this time to the initial value, and continuously compare it with the subsequent changes in the unit's active power until the rated output of the unit is reached, and record and save the guide vane opening at this time, that is, the maximum guide vane opening value under the governor's rated output. Set the other 6 characteristic head values of the governor in turn, and record the maximum guide vane opening values under the governor's rated output for the other 6 characteristic head values. Considering the situation where the guide vane changes during the primary frequency regulation of the unit, increase the opening by 6% on the basis of the maximum value of the guide vane sampling as the guide vane opening limit at this head, as shown in Table 1 for details.

[0068] Table 1 Theoretical values and calculated values of the governor control system at each characteristic head

[0069]

[0070] In this embodiment, at 7 characteristic water heads for the governor control system's association, by recording the guide vane opening values at the maximum output of the unit for each characteristic water head, and then considering the guide vane change values during the primary frequency regulation operation process of the governor at this water head, the sum of the two is the guide vane opening limit value actually operating in the governor control system at the characteristic water head. The guide vane opening limit values corresponding to other water heads can be calculated by the interpolation association method with the characteristic water heads. Therefore, it can ensure that the calculation of the guide vane opening limit value in the governor control system is more accurate, and the function of restricting the guide vane opening is more precise.

[0071] The present invention also provides another embodiment: A precise measurement system for the guide vane opening limit of a governor, comprising:

[0072] A system initialization module, which initializes the governor control system of the hydropower unit and selects multiple points within a set range to set characteristic water heads;

[0073] An acquisition module, where the governor control system of the hydropower unit executes the automatic water head mode, acquires the upstream and downstream water head signals of the hydropower unit, and solves the current net water head value based on the upstream and downstream water head signals of the hydropower unit;

[0074] A calculation module, which determines whether the current net water head is equal to a certain characteristic water head. If so, it outputs the guide vane opening limit value corresponding to this characteristic water head; if not, it determines the two characteristic water heads closest to the current net water head, and calculates and outputs the guide vane opening limit value corresponding to the current net water head through linear interpolation;

[0075] An execution module, which updates the relevant parameters of the governor control system of the hydropower unit based on the output guide vane opening limit value to complete the stable operation of the governor of the hydropower unit.

[0076] Specifically, the acquisition module includes: a spiral case inlet pressure transmitter and a tail water outlet pressure transmitter.

[0077] The above are only the preferred embodiments of the present invention and are not used to limit the present invention. For those skilled in the art, the present invention can have various changes and modifications. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A method for accurately measuring the opening limit of a speed governor guide vane, characterized in that: The steps of the method include: Initialize the speed governor control system of the hydropower unit and select multiple points within the set range to set the characteristic water head; The speed governor control system of the hydropower unit executes the automatic water head mode, collects the upstream and downstream water head signals of the hydropower unit, and solves the current net water head value based on the upstream and downstream water head signals of the hydropower unit; Determine whether the current net water head is equal to a certain characteristic water head. If so, output the guide vane opening limit value corresponding to this characteristic water head; if not, determine the two characteristic water heads closest to the current net water head, calculate and output the guide vane opening limit value corresponding to the current net water head through linear interpolation; Based on the output guide vane opening limit value, the relevant parameters of the hydropower unit speed governor control system are updated to achieve stable operation of the hydropower unit speed governor.

2. The method for accurately measuring the governor guide vane opening limit according to claim 1, characterized in that: The characteristic water head includes: a maximum water head, a minimum water head, a rated water head and a plurality of set water heads, and the plurality of set water heads are arranged at equal intervals between the maximum water head and the minimum water head.

3. The method for accurately measuring the governor guide vane opening limit according to claim 2, characterized in that: The upstream and downstream water head signals of the hydroelectric generator units are collected as follows: Measuring the upstream water head of the hydropower unit based on the volute inlet pressure transmitter; Measuring the downstream head of the hydropower unit based on the tailwater outlet pressure transmitter; The measurement data of the upstream and downstream water heads are converted into current signals, isolated by analog signal isolators, and the upstream and downstream water head signals of the hydropower unit are output.

4. The method for accurately measuring the governor guide vane opening limit according to claim 3 is characterized in that: The current net water head value is solved based on the upstream and downstream water head signals of the hydropower unit, which is specifically: Receive upstream and downstream water head signals of hydropower units based on PLC module; Perform per-unit calculation on the upstream and downstream water head signals of the hydropower unit, and convert the actual values ​​of the upstream and downstream water head signals into standard units; Conduct disconnection detection on the upstream and downstream water head signals of the hydropower unit to ensure the continuity of the upstream and downstream water head signals; Conduct over-limit judgment on the upstream and downstream water head signals of the hydropower unit to ensure that the upstream and downstream water head signals are within the effective range; The difference between the upstream and downstream head signals is solved, and the current net head value is obtained by subtracting the head loss of the water inlet system of the preset hydropower unit from the difference between the upstream and downstream head signals.

5. The method for accurately measuring the governor guide vane opening limit according to claim 4, characterized in that: The guide vane opening limit value corresponding to the current net water head is calculated and outputted by linear interpolation, which is specifically: Determine two characteristic water heads closest to the current net water head, including: a maximum characteristic water head and a minimum characteristic water head, and obtain the guide vane opening limit values ​​corresponding to the maximum characteristic water head and the minimum characteristic water head; Calculate the difference between the current net head and the maximum characteristic head; Calculate the difference between the maximum characteristic head and the minimum characteristic head; Calculate the difference between the guide vane opening at the minimum characteristic water head and the guide vane opening at the maximum characteristic water head; The linear interpolation formula is used to calculate the guide vane opening limit value corresponding to the current net water head.

6. The method for accurately measuring the governor guide vane opening limit according to claim 5, characterized in that: The guide vane opening limit value corresponding to the current net water head is calculated and output by linear interpolation, and its calculation formula is: Among them, αnet is the guide vane opening limit value corresponding to the current net water head, H net is the current net water head value, H1 is the lower limit characteristic water head, i.e. the maximum characteristic water head, H2 is the upper limit characteristic water head, i.e. the minimum characteristic water head, α1 is the guide vane opening limit value corresponding to the lower limit characteristic water head, and α2 is the guide vane opening limit value corresponding to the upper limit characteristic water head.

7. A governor guide vane opening limit accurate measurement system, characterized in that: include: The system initialization module initializes the speed governor control system of the hydropower unit and selects multiple points within the set range to set the characteristic water head; The acquisition module, the speed governor control system of the hydropower unit executes the automatic water head mode, and collects the upstream and downstream water head signals of the hydropower unit, and solves the current net water head value based on the upstream and downstream water head signals of the hydropower unit; The calculation module determines whether the current net water head is equal to a certain characteristic water head. If so, the guide vane opening limit value corresponding to the characteristic water head is output; if not, the two characteristic water heads closest to the current net water head are determined, and the guide vane opening limit value corresponding to the current net water head is calculated and output through linear interpolation; The execution module updates the relevant parameters of the hydropower unit speed governor control system based on the output guide vane opening limit value, and completes the stable operation of the hydropower unit speed governor.

8. The method for accurately measuring the governor guide vane opening limit according to claim 7, characterized in that: The acquisition module includes: a volute inlet pressure transmitter and a tailwater outlet pressure transmitter.

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