Hydroelectric generating set speed regulator load control method and system

Abstract

The invention discloses a hydroelectric generating set speed regulator load control method and system, and the control method comprises the steps: obtaining unit power # imgabs0 # and guide vane opening degree Y data of a hydroelectric generating set under different water heads, and inputting the data into a monitoring system database; the monitoring system database searches a target guide vane opening degree Y1 corresponding to the target load # imgabs2 # under the current water head according to the target load # imgabs1 #, and a speed regulator controller adjusts the guide vane opening degree Y to the target guide vane opening degree Y1 according to the given opening degree; after the guide vane opening degree Y is adjusted to the target guide vane opening degree Y1, the speed regulator controller controls the unit power # imgabs3 # to be adjusted to the target load # imgabs4 #; after the unit power # imgabs5 # is adjusted to the target load # imgabs6 #, a speed regulator controller is converted into an opening degree adjusting mode from a power mode; the speed regulator controller can quickly determine the target guide vane opening degree Y1 through the monitoring system database, the speed regulator controller can predict and adjust the guide vane opening degree Y in advance through the water head and the monitoring system database, and the speed regulator lag phenomenon caused by load change and water head fluctuation is effectively reduced.

Description

Technical Field

[0001] The invention belongs to the field of hydropower unit control and relates to a method and system for controlling a speed governor of a hydropower unit. Background Art

[0002] At present, when the hydroelectric generator set is running at no-load, the speed of the unit is controlled by frequency regulation to maintain at around 50Hz. After the grid-connected power generation, the load regulation is carried out by opening regulation or power regulation mode. The opening regulation mode is mainly realized by the monitoring system through the "active power regulation" function. For different load adjustment target values, the PID operation is used to adjust the pulse width to control the increase or decrease of the governor guide vane opening, so as to achieve the purpose of unit power regulation; the control feature of this control method is that the power closed loop is realized in the monitoring system, and the governor control system is only the execution link. The power regulation is mainly through the monitoring system using analog or digital signals to send the target power value to the governor control system. The governor control system collects the current active power signal, and forms a closed-loop regulation mode with the target power value as the control object with this signal; the main feature of this control method is that the power closed-loop regulation is completed independently by the governor control system, and the monitoring system does not participate in the power closed-loop regulation.

[0003] When the opening adjustment mode is used, the monitoring system operation takes a long time. The control quantity is the guide vane opening, and the change in the guide vane opening causes a lag in the power change. The time accumulation of each link will cause a long response time and oscillation around the target power. The power generation power of the hydropower unit is affected by the current generating head, and the head value of the unit at different times is not consistent. For some cross-flow units and daily regulation power stations, the head changes significantly during the day. The opening adjustment mode does not consider the impact of the head on the unit output, and the head signal is not included in the control process. Therefore, using the same control method for the unit power under different heads will result in a long adjustment time. At the same time, due to the uncertainty of the target load point, the unit's continuous increase in output may run to the restricted output area, causing non-stop accidents.

[0004] The control quantity of the power regulation mode is the unit power. Traditional negative feedback cannot solve the power reverse regulation problem due to the water hammer characteristics of the hydropower unit, resulting in frequent overshoot, oscillation and other phenomena during the regulation process. The main sampling signal for power regulation is the power signal. Under the electromagnetic interference of the power plant, the signal-to-noise ratio (SNR) of the signal will be reduced, increasing the difficulty of control system regulation. At the same time, the power transmitter is affected by transient characteristics, excitation inrush current, and electromagnetic interference, resulting in signal distortion problems. Therefore, relying on power regulation to achieve load regulation has obvious defects. Summary of the invention

[0005] In order to solve the above problems existing in the prior art, the present invention provides a method and system for controlling the load of a speed governor of a hydropower unit.

[0006] In order to achieve the above object, the present invention adopts the following technical solution: The present invention provides a method for controlling the speed governor load of a hydroelectric generator set, comprising: obtaining the power of the hydroelectric generator set under different water heads; and the guide vane opening Y data, and input them into the monitoring system database; the monitoring system database is based on the target load , find the target load under the current head The corresponding target guide vane opening Y1; the speed governor controller adjusts the guide vane opening Y to the target guide vane opening Y1 through the opening setting; after the guide vane opening Y is adjusted to the target guide vane opening Y1, the speed governor controller controls the unit power Adjust to target load ; Unit power Adjust to target load After that, the speed regulator controller switches from power mode to opening adjustment mode.

[0007] Furthermore, the unit power The expression corresponding to the guide vane opening Y is: =1.729Y-0.3588 in, is the unit power, and Y is the guide vane opening.

[0008] Furthermore, the unit power Goodness of fit with guide vane opening Y is 0.9976.

[0009] Furthermore, the water head of the hydroelectric generator set is 117m and the unit power is Goodness of fit with guide vane opening Y is 0.9976.

[0010] Furthermore, the opening range of the hydroelectric generator set is 20.858% 68.396%, unit power The expression corresponding to the guide vane opening Y is: =1.729Y-0.3588.

[0011] Furthermore, the monitoring system database is based on the target load , find the target load under the current head The corresponding target guide vane opening Y1 also includes: the automatic generation control AGC sends the active power control instruction to the monitoring system.

[0012] Furthermore, the power of the hydroelectric generator set under different water heads is obtained. and the guide vane opening Y data, including: online or offline database, design drawings, model test data, simulation calculation data to obtain the real-time water head of the governor and the unit power , guide vane opening Y.

[0013] Furthermore, the speed governor controller adjusts the guide vane opening Y to the target guide vane opening Y1 through the opening setting, including: after the speed governor controller receives the target guide vane opening Y1, it adjusts the guide vane opening Y to the target guide vane opening Y1 through the PID operation module, the comprehensive amplification module, the output module, and the feedback measurement module.

[0014] Furthermore, the speed governor controller is used to receive and store the target guide vane opening Y1; the PID operation module is used to perform PID operation according to the error between the target guide vane opening Y1 and the guide vane opening Y; the comprehensive amplification module is used to amplify the result of the PID operation; the output module is used to output the amplified control signal to the relay; the feedback measurement module is used to measure the guide vane opening Y in real time and feed it back to the speed governor controller.

[0015] The present invention also provides a hydropower unit speed governor load control system, including: an acquisition module: used to obtain the unit power of the hydropower unit under different water heads and the guide vane opening Y data, and input it into the monitoring system database; matching module: used for the monitoring system database to match the target load , find the target load under the current head The corresponding target guide vane opening Y1; the first adjustment module: used for the speed governor controller to adjust the guide vane opening Y to the target guide vane opening Y1 through the opening setting; the second adjustment module: used for the speed governor controller to control the unit power after the guide vane opening Y is adjusted to the target guide vane opening Y1 Adjust to target load ; Conversion module: used for unit power Adjust to target load After that, the speed regulator controller switches from power mode to opening adjustment mode.

[0016] Compared with the prior art, the present invention has the following beneficial technical effects: The invention discloses a method for controlling a speed governor load of a hydropower unit. With the help of a water head signal and a monitoring system database, a speed governor controller can predict and adjust the guide vane opening in advance, thereby effectively reducing the speed governor hysteresis caused by load changes and water head fluctuations.

[0017] The invention discloses a method for controlling a speed governor load of a hydropower unit. The fast search function of the monitoring system database enables the speed governor controller to quickly determine the target guide vane opening Y1, thereby reducing the time for manual search and calculation, and also reducing the response time and improving the response speed.

[0018] The present invention provides a method for controlling the speed governor load of a hydropower unit. The speed governor controller performs precise regulation according to a target guide vane opening Y1, thereby avoiding blindness and hysteresis in a traditional opening regulation mode, thereby improving regulation accuracy and efficiency.

[0019] The present invention provides a method for controlling the speed governor load of a hydropower unit. After the guide vane opening Y is adjusted to the target guide vane opening Y1, the speed governor controller continues to control the unit power to be adjusted to the target load. The closed-loop regulation method enables the speed governor controller to quickly respond to power deviations, thereby shortening the regulation time.

[0020] The present invention provides a method for controlling the speed governor load of a hydropower unit. The entire adjustment process is automated, which reduces the need for manual intervention and reduces the potential safety hazards caused by human factors. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 A flow chart of a method for controlling a speed governor load of a hydropower unit according to the present invention; Figure 2 This is a waveform recording diagram of the full-process load increase test of the hydraulic generator in the embodiment of the present invention; Figure 3 In the embodiment of the present invention, the water head of the hydroelectric generator set is 117m, and the power of the unit is Change curve of guide vane opening Y. DETAILED DESCRIPTION

[0022] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0023] Example 1 Frequency regulation: When operating in isolation or at no load / idling, the unit frequency (speed) tracks the frequency (speed) command signal: When the units are operating in parallel, the frequency (speed) affects the control of the grid frequency through the permanent difference coefficient and the dynamic characteristics of the regulation system.

[0024] Opening adjustment: When the unit is connected to the grid, the adjustment system receives the opening command signal and makes the opening track the control of the opening command signal. This control method is the most basic and necessary control method for the unit to connect to the grid and change the opening command signal by receiving the increase and decrease pulse commands from the monitoring system.

[0025] Power regulation: A regulation mode that should be used first when the unit is connected to the grid and runs with base load. The main control object of the power mode is the unit power, and the sampling value and feedback link are also the unit power.

[0026] There are three main regulation modes for hydroelectric generator sets in actual operation: frequency regulation, opening regulation, and power regulation. The frequency regulation mode is suitable for automatic no-load operation, or isolated grid operation or normal factory power operation; the opening regulation mode is a regulation mode for the unit to be connected to the large grid, and the differential feedback signal is mainly the output value after the governor PID adjustment; power regulation is theoretically the optimal regulation mode for the grid-connected operation of the generator set, and the main feedback signal comes from the power signal of the unit, but it has not been widely promoted due to the limitations of sensors and adoption.

[0027] The invention adopts the power of the hydroelectric generator set under different water heads and the guide vane opening Y, and query the target load according to the comparison table in Table 1 The corresponding target guide vane opening Y1, the speed governor controller adjusts the guide vane opening Y to the target guide vane opening Y1 through the opening setting, and the speed governor controls the guide vane opening Y to increase or decrease to the target load .

[0028] It should be noted that the guide vane opening signal used in the speed regulator load control has strong anti-interference ability in the measurement and transmission links, avoiding the load regulation fluctuation problem caused by interference with the control signal.

[0029]

[0030] Example 2 The invention discloses a method for controlling the speed governor load of a hydroelectric generator set, comprising: obtaining the power of the hydroelectric generator set under different water heads; and the guide vane opening Y data, and input them into the monitoring system database; the monitoring system database is based on the target load , find the target load under the current head The corresponding target guide vane opening Y1; the speed governor controller adjusts the guide vane opening Y to the target guide vane opening Y1 through the opening setting; after the guide vane opening Y is adjusted to the target guide vane opening Y1, the speed governor controller controls the unit power Adjust to target load ; Unit power Adjust to target load After that, the speed regulator controller switches from power mode to opening adjustment mode, such as Figure 1 shown.

[0031] Governor real-time water head, unit power , the guide vane opening Y can be obtained through online or offline databases, design drawings, model test data, and simulation technology data, such as Figure 2 shown.

[0032] like Figure 3 As shown in the figure, in this embodiment, the water head of the hydroelectric generator set is 117m, and the guide vane opening Y is 20.858% as an example, corresponding to the unit power is 20.684, the unit power The calculation of is as follows: =1.729Y-0.3588, specifically, 1.729×20.858%-0.3588 to calculate the rated unit power, then divide by 600 to calculate the unit power .

[0033] The present invention shortens the adjustment time by 30%, further reduces the response time, helps reduce the hysteresis of the speed regulator during the adjustment process, not only improves the response speed of the unit to load changes, but also enhances the stability and reliability of the entire hydropower generation system. In addition, accurate data collection and storage, efficient target guide vane opening Y1 search, accurate and fast guide vane opening and unit power adjustment, and speed regulation mode conversion provide a strong guarantee for the efficient and stable operation of hydropower generation.

[0034] The water head of the hydroelectric generator set is 117m, and the unit power Goodness of fit with guide vane opening Y The goodness of fit is an important indicator to measure the degree of fit between variables, and its value range is between 0 and 1. The closer the value is to 1, the more significant the linear relationship between the variables is, and the better the fit effect is. =0.9976, which is extremely close to 1. This means that when the water head is 117 m, based on the existing data and fitting model, the unit power There is a highly approximate linear relationship between the guide vane opening Y.

[0035] The unit power under different water heads The corresponding relationship between the guide vane opening Y and the input value monitoring system database, if the opening interval of the hydropower generator set is 20.858% 68.396%, which can be directly referred to Table 1.

[0036] Calculate target load using table lookup The corresponding guide vane opening Y1 reduces the operation time of the speed regulator controller compared to the opening mode adopted in the traditional load regulation.

[0037] Calculate target load using table lookup The corresponding guide vane opening Y1 is a more direct and efficient method. When a target load needs to be adjusted, the governor controller can directly look it up without complicated calculations. The data in the lookup table is usually obtained through experiments and has high accuracy, which helps ensure that the governor controller can accurately adjust the guide vane opening Y1 to achieve the target load.

[0038] After that, the automatic generation control AGC sends the active power control command to the monitoring system, which then Quickly find the unit power under the current head Corresponding relationship with the guide vane opening Y, find the target load under the current water head The corresponding target guide vane opening Y1, after finding the target guide vane opening Y1, the target load The speed controller adjusts the guide vane opening Y to the target guide vane opening Y1 through the opening setting. After that, the guide vane opening Y1 required to achieve the target load will be calculated according to the preset control strategy and algorithm. The guide vane opening directly affects the flow rate and pressure of the water flow, and thus affects the output power of the turbine.

[0039] In the initial stage of control, the opening setting method is adopted. Compared with the traditional load regulation using the power mode, the interference of the power reverse regulation on the power mode caused by the water hammer characteristics in the initial stage is avoided. Specifically, the guide vane opening Y1 is directly set to control the flow and speed of the turbine, thereby indirectly controlling the power output. It is more stable in the initial stage, the change is relatively gentle, and it will not immediately cause drastic fluctuations in power.

[0040] When the guide vane opening Y is adjusted to the target guide vane opening Y1, the speed governor controller will first send an opening setting signal to the actuator, which represents the guide vane opening position expected by the speed governor controller. After receiving the opening setting signal, the actuator will drive the guide vane to adjust the opening, ensuring that the guide vane opening Y gradually approaches and finally stabilizes near the target guide vane opening Y1.

[0041] It should be noted that during the adjustment of the guide vane opening Y, the actual power of the unit corresponding to the guide vane opening Y1 may be above the target load due to the influence of the water head signal on the sensor and the wave height. There is a problem of insufficient adjustment accuracy nearby.

[0042] After the guide vane opening Y is adjusted to the target guide vane opening Y1, the governor controller switches to the power regulation mode to control the current unit power generation load to the target load. This avoids the problem of power oscillation caused by adjusting the target load back and forth when using the traditional opening adjustment mode, and improves the adjustment accuracy.

[0043] Specifically, when the traditional opening adjustment mode is close to the target load, due to factors such as system inertia and water hammer effect, the load often fluctuates around the target value, that is, power oscillation. The control strategy of coarse adjustment first and then fine adjustment can significantly reduce this fluctuation and make the load reach the target value more smoothly.

[0044] After the unit load is adjusted to the target load, the speed governor control switches from the power regulation mode to the opening regulation mode, mainly to avoid power oscillation caused by power signal interference and signal delay.

[0045] Example 3 A speed governor load control system for a hydropower unit comprises an acquisition module, a matching module, a first adjustment module, a second adjustment module and a conversion module.

[0046] Acquisition module: used to obtain the power of the hydroelectric generator set under different water heads and the guide vane opening Y data, and input it into the monitoring system database; matching module: used for the monitoring system database to match the target load , find the target load under the current head The corresponding target guide vane opening Y1; the first adjustment module: used for the speed governor controller to adjust the guide vane opening Y to the target guide vane opening Y1 through the opening setting; the second adjustment module: used for the speed governor controller to control the unit power after the guide vane opening Y is adjusted to the target guide vane opening Y1 Adjust to target load ; Conversion module: used for unit power Adjust to target load After that, the speed regulator controller switches from power mode to opening adjustment mode.

[0047] The first adjustment module: according to the target guide vane opening Y1 obtained by the matching module, an opening given signal is sent to the speed regulator controller. Specifically: through the PID controller or other advanced control algorithms such as fuzzy control, neural network control, and adaptive control, the guide vane opening Y is smoothly adjusted until the target guide vane opening Y1 is reached. The PID controller includes calculating an immediate adjustment amount based on the deviation between the current guide vane opening Y and the target guide vane opening Y1. The adjustment amount is proportional to the deviation. The larger the deviation, the larger the adjustment amount; then the deviation is integrated to eliminate the accumulated error. If the deviation persists, the integral term will gradually increase, thereby pushing the control output to move in the direction of reducing the deviation; predicting the future deviation trend based on the rate of change of the deviation and making adjustments in advance will help reduce the overshoot and oscillation of the system.

[0048] Second adjustment module: After the guide vane opening Y is adjusted to the target guide vane opening Y1, the unit power is continuously monitored. If the unit power changes With target load If there is a deviation, the unit power can be adjusted by adjusting the parameters of the speed controller (such as frequency, voltage, etc.) Gradually approaching the target load .

[0049] Specifically: After the guide vane opening Y reaches the target value Y1, the unit power is immediately started. Real-time monitoring, using high-precision power sensors to measure unit power to ensure data accuracy and real-time performance. With target load The deviation between The deviation can be positive or negative. A positive deviation indicates that the unit power Above target load , a negative deviation indicates that the unit power Below target load .

[0050] Conversion module: In the unit power Adjust to target load After that, a mode switching signal is sent to the speed regulator controller to convert it from the power mode to the opening adjustment mode. After the mode switching, the relevant parameters of the speed regulator controller are reset to ensure its stable operation in the opening adjustment mode.

[0051] A hydropower unit speed governor load control system provided by the present invention can implement method steps consistent with the above-mentioned method, and therefore will not be described in detail.

[0052] Signal-to-noise ratio: It is the ratio of signal strength to noise strength. The larger the signal-to-noise ratio, the better the signal quality.

[0053] It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

Claims

1. A method for controlling the speed governor load of a hydropower unit, characterized in that: The following steps are involved: Get the power of the hydroelectric generator set under different water heads and the guide vane opening Y data, and input it into the monitoring system database; Monitoring system database according to target load , find the target load under the current head The corresponding target guide vane opening is Y1; The speed governor controller adjusts the guide vane opening Y to the target guide vane opening Y1 through the opening setting; After the guide vane opening Y is adjusted to the target guide vane opening Y1, the speed governor controller controls the unit power Adjust to target load ; Unit power Adjust to target load After that, the speed regulator controller switches from power mode to opening adjustment mode.

2. The method for controlling the speed governor load of a hydropower unit according to claim 1, characterized in that: The unit power The expression corresponding to the guide vane opening Y is: =1.729Y-0.3588 in, is the unit power, and Y is the guide vane opening.

3. The method for controlling the speed governor load of a hydroelectric generator set according to claim 2, characterized in that: The unit power Goodness of fit with guide vane opening Y is 0.9976.

4. The method for controlling the speed governor load of a hydroelectric generator set according to claim 2, characterized in that: The water head of the hydroelectric generator set is 117m, and the unit power Goodness of fit with guide vane opening Y is 0.9976.

5. The method for controlling the speed governor load of a hydroelectric generator set according to claim 4, characterized in that: The opening range of the hydroelectric generator set is 20.858% 68.396%, unit power The expression corresponding to the guide vane opening Y is: =1.729Y-0.3588.

6. The method for controlling the speed governor load of a hydropower unit according to claim 1, characterized in that: The monitoring system database is based on the target load , find the target load under the current head The corresponding target guide vane opening Y1 also includes: The automatic generation control AGC sends the active power control instructions to the monitoring system.

7. The method for controlling the speed governor load of a hydropower unit according to claim 1, characterized in that: The method of obtaining the power of the hydroelectric generator set under different water heads And the guide vane opening Y data, including: Online or offline database, design drawings, model test data, simulation calculation data to obtain the real-time water head and unit power of the governor , guide vane opening Y.

8. The method for controlling the speed governor load of a hydropower unit according to claim 1, characterized in that: The speed governor controller adjusts the guide vane opening Y to the target guide vane opening Y1 through the opening setting, including: After the speed governor controller receives the target guide vane opening Y1, it adjusts the guide vane opening Y to the target guide vane opening Y1 through the PID operation module, the comprehensive amplification module, the output module, and the feedback measurement module.

9. The method for controlling the speed governor load of a hydropower unit according to claim 8, characterized in that: The speed governor controller is used to receive and store the target guide vane opening Y1; The PID operation module is used to perform PID operation according to the error between the target guide vane opening Y1 and the guide vane opening Y; The comprehensive amplification module is used to amplify the result of PID operation; The output module is used to output the amplified control signal to the relay; The feedback measurement module is used to measure the guide vane opening Y in real time and feed it back to the speed governor controller.

10. A hydropower unit speed governor load control system, characterized in that: include: Acquisition module: used to obtain the power of the hydroelectric generator set under different water heads and the guide vane opening Y data, and input it into the monitoring system database; Matching module: used to monitor the system database according to the target load , find the target load under the current head The corresponding target guide vane opening is Y1; The first adjustment module: used for the speed governor controller to adjust the guide vane opening Y to the target guide vane opening Y1 through the opening setting; The second adjustment module is used for the speed governor controller to control the unit power after the guide vane opening Y is adjusted to the target guide vane opening Y1. Adjust to target load ; Conversion module: for unit power Adjust to target load After that, the speed regulator controller switches from power mode to opening adjustment mode.

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