Hydropower station governor water head optimization system and optimization method thereof

Abstract

The invention relates to the technical field of water conservancy and hydropower engineering unit control, and particularly discloses a hydropower station governor water head optimization system and method. The system comprises a public LCU, a water head monitoring device, a unit LCU and a speed regulator, the public LCU collects upstream and downstream water level signals, the water head monitoring device processes the water level signals and then outputs standard analog quantity, and the unit LCU mutually takes the water level signals through a monitoring system network, obtains real-time water head signals through operation and issues the real-time water head signals to the speed regulator; the speed regulator carries out fault judgment, data validity screening and undisturbed switching control on the real-time water head signals, and the processed water head signals are applied to open limit adjustment and paddle joint control under the starting-up no-load and grid-connected working conditions of a unit. Through software acquisition and fault-tolerant design, accurate acquisition and stable control of water head signals are realized, and the operation reliability and safety of a unit are improved.

Description

Technical Field

[0001] This invention belongs to the field of hydropower station unit control technology in water conservancy and hydropower engineering, and particularly relates to a hydropower station governor head optimization system and method, which is applicable to the optimization and improvement of the hydropower station governor head signal acquisition method and control logic. Background Technology

[0002] During the operation of hydropower station units, the governor is one of the core control devices. It receives head signals and adjusts the unit's start-up limits, no-load limits, grid connection limits, and blade coordination control, directly affecting the unit's start-up stability, no-load operation quality, load control safety after grid connection, and the unit's stability and efficiency. Currently, most hydropower station governors rely on differential pressure transmitters for head signal acquisition. This equipment calculates the head value by collecting the difference between the tailrace outlet pressure and the pressure after the intake gate.

[0003] Taking the Yakou Hydropower Station as an example, its original governor head signal acquisition system used the aforementioned differential pressure transmitter scheme. However, in actual operation, due to the presence of silt in the hydropower station's water, silt easily accumulates in the measuring pipeline of the differential pressure transmitter after long-term operation, leading to inaccurate pressure signal acquisition. At the same time, the traditional acquisition method lacks an effective fault-tolerance mechanism, which easily leads to problems such as head data loss, display dead values, signal disconnection, and large fluctuations. These problems directly cause the governor to be unable to obtain accurate head signals, resulting in deviations between the start-up limit and the no-load limit adjustment, and an increased risk of unit overload under grid-connected conditions, seriously affecting the safe and stable operation of the hydropower station units.

[0004] Therefore, there is an urgent need for a governor head optimization scheme that can avoid the impact of siltation, has fault tolerance, and has high data acquisition accuracy, in order to overcome the shortcomings of existing technologies. Summary of the Invention

[0005] The purpose of this invention is to overcome the problems in the prior art where the differential pressure transmitter used in the governor of a hydropower station is prone to inaccurate head signal acquisition due to siltation, and also suffers from data loss, dead values, disconnection, and large signal fluctuations. This invention provides a head optimization system and method for the governor of a hydropower station, which enables accurate and stable acquisition and reliable application of head signals, ensuring the control accuracy and operational safety of the unit.

[0006] To achieve the above objectives, the present invention provides a hydropower station governor head optimization system, including a common LCU, a head monitoring device, a unit LCU, and a governor; The public LCU is used to collect upstream and downstream water level signals of the hydropower station; The head monitoring device is communicatively connected to the public LCU and is used to receive the upstream water level signal and the downstream water level signal. It performs A / D conversion and CPU processing calculation on the upstream water level signal and the downstream water level signal in sequence to obtain the upstream water level value, the downstream water level value and the head value, and outputs three standard analog quantities. The three standard analog quantities correspond one-to-one with the upstream water level value, the downstream water level value and the head value, respectively. The standard analog quantity corresponding to the head value is transmitted to the speed controller after signal isolation and distribution. The unit LCU uses the network interoperability function of the monitoring system to call the upstream and downstream water level signals of the public LCU, or to call the upstream and downstream water level signals of the hydrological system, and performs head calculation on the called upstream and downstream water level signals to obtain the real-time head signal, and then sends the real-time head signal to the speed governor through communication. The speed controller is used to receive the real-time head signal, process the real-time head signal, and realize unit operation control based on the processed head signal.

[0007] Furthermore, the speed controller's processing of the real-time head signal includes head signal fault judgment: when the head value corresponding to the real-time head signal exceeds 2-9m, the speed controller automatically sets the head signal fault flag.

[0008] Furthermore, the speed governor's processing of the real-time head signal also includes data validity judgment: within a 2-minute period, if the calculated value of the real-time head signal changes by less than 0.1m or more than 0.2m, the calculated data is deemed invalid; within a 10-minute period, 5 valid calculated data are selected, and the average of these 5 valid calculated data is calculated to obtain the valid automatic head. If dead values ​​are not eliminated, the speed governor will adjust the opening limit based on a fixed head value. For example, if the water level has risen but the head value remains unchanged, it will lead to a lower opening limit on the grid, preventing the unit from operating at full capacity; or if the water level has fallen but the head value remains unchanged, it will lead to a higher opening limit, causing overload. If fluctuation signals are not filtered, the speed governor will frequently adjust the opening limit, causing unit speed / load oscillations and affecting operational quality. Through automated screening and averaging, there is no need for manual judgment of data reliability, reducing operation and maintenance costs and avoiding control risks caused by human error.

[0009] Furthermore, the speed controller is also equipped with a manual head signal; when the speed controller is in automatic head mode and the head signal fault flag is not set, the manual head signal automatically follows the effective automatic head, so as to achieve seamless switching between automatic head and manual head signals when the head signal fails.

[0010] Furthermore, the speed governor realizes unit operation control based on the processed head signal, specifically including: during the unit start-up no-load process, automatically adjusting the start-up limit and no-load limit according to the processed head signal.

[0011] Furthermore, the speed governor realizes unit operation control based on the processed head signal, specifically including: under the unit grid-connected operation condition, automatically adjusting the grid connection limit according to the processed head signal to prevent unit overload; under the unit grid-connected operation condition, automatically adjusting the blade coordination control opening according to the processed head signal to ensure the unit operates at optimal efficiency.

[0012] Furthermore, when the unit LCU calls the water level signal through the network interoperability function, it prioritizes calling the upstream and downstream water level signals of the public LCU; when the upstream or downstream water level signal of the public LCU is abnormal, it switches to calling the upstream and downstream water level signals of the hydrological system.

[0013] On the other hand, the present invention also provides a method for optimizing the head of a hydropower station governor, comprising the following steps: S1. Water level signal acquisition: The upstream and downstream water level signals of the hydropower station are acquired through the public LCU; or the upstream and downstream water level signals of the public LCU are accessed through the network interoperability function of the monitoring system via the unit LCU, or the upstream and downstream water level signals of the hydrological system are accessed. S2. Head Value Processing and Distribution: The upstream and downstream water level signals from the public LCU are received by the head monitoring device. After A / D conversion, the CPU processes and calculates the upstream water level, downstream water level, and head value, and outputs the corresponding standard analog quantity. The standard analog quantity corresponding to the head value is then transmitted to the speed governor after signal isolation and distribution. At the same time, the unit LCU performs head calculation on the requested water level signal to obtain the real-time head signal, and transmits the real-time head signal to the speed governor via communication. S3. Speed ​​Regulator Signal Processing: The speed regulator receives the real-time head signal and sequentially performs fault judgment and data validity judgment on the real-time head signal; and when the speed regulator is in automatic head mode and there is no fault, the manual head signal follows the automatic head. S4. Application of head signal: During the no-load start-up process of the unit, the start-up limit and no-load limit are automatically adjusted according to the processed head signal; under grid-connected operation, the grid connection limit is automatically adjusted according to the processed head signal to prevent the unit from overloading.

[0014] Furthermore, the specific process of fault judgment in step S3 is as follows: when the head value corresponding to the real-time head signal exceeds 2-9m, the speed controller automatically sets the head signal fault flag.

[0015] Furthermore, the specific process for determining the validity of data in step S3 is as follows: within a 2-minute timeframe, if the change in the calculated value of the real-time head signal is less than 0.1m or greater than 0.2m, the calculated data is determined to be invalid; within a 10-minute timeframe, 5 sets of calculated data that are determined to be valid are selected, and the 5 sets of valid calculated data are averaged to obtain the valid automatic head.

[0016] Beneficial effects of this invention: Solving the problem of siltation: Abandoning the traditional method of acquiring pressure signals using differential pressure transmitters, a software-based solution is adopted to calculate the head based on upstream and downstream water level signals, fundamentally avoiding signal inaccuracies caused by siltation and improving the long-term reliability of head acquisition; It has fault tolerance capabilities: By redundantly calling the public LCU and the water level signal of the hydrological system through the unit LCU, the problems of data loss and disconnection are solved; by judging the validity of data on the governor side, dead values ​​and abnormal fluctuation data are eliminated, which solves the problem of large signal fluctuations. Achieve seamless switching: The manual head signal updates synchronously with the automatic head signal, and can seamlessly switch to manual control in case of failure, avoiding unit control interruption and improving operational stability; Improved control precision: The head signal is accurately applied to the opening limit adjustment under no-load and grid-connected conditions, effectively preventing unit start-up fluctuations and grid overload, reducing equipment losses, and ensuring the safe and efficient operation of the hydropower station. Detailed Implementation

[0017] The technical solutions of the present invention will be clearly and completely described in conjunction with specific embodiments thereof. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0018] This embodiment first provides a hydropower station governor head optimization system. The system includes a common LCU (Local Control Unit), a head monitoring device, a unit LCU, and a governor. These components work together to acquire, process, transmit, and apply head signals. The specific structure and functions are as follows: Public LCU: Used to collect upstream and downstream water level signals of hydropower stations in real time, serving as the basic data source for head calculation; the collected water level signals can be directly transmitted to the head monitoring device and used as the priority data source for unit LCU.

[0019] The head monitoring device communicates with the public LCU (Liquid Cooling Unit) and receives upstream and downstream water level signals output by the public LCU. The device integrates an A / D conversion module and a CPU (Central Processing Unit). First, the A / D conversion module converts the analog water level signal into a digital signal. Then, the CPU processes the digital signal to obtain the upstream water level value, the downstream water level value, and the difference between the two, i.e., the head value. Subsequently, the head monitoring device outputs three standard analog signals, each corresponding one-to-one with the upstream water level value, the downstream water level value, and the head value. The standard analog signal corresponding to the head value is processed by a signal isolation distributor and then synchronously transmitted to the governors of the six generating units of the hydropower station, ensuring the safety and stability of signal transmission.

[0020] Unit LCU: Relying on the network interoperability function of the hydropower station monitoring system, it realizes redundant access to water level signals, giving priority to accessing upstream and downstream water level signals collected by the public LCU; if the water level signal of the public LCU is abnormal, such as disconnection or dead value, it automatically switches to accessing the upstream and downstream water level signals of the hydrological system; the unit LCU performs head calculation on the accessed water level signals to obtain the real-time head signal, and sends the real-time head signal to the corresponding governor through the industrial communication bus.

[0021] Speed ​​controller: As the application terminal for head signals, its core functions include: Water head signal fault judgment: Real-time monitoring of the received water head signal. If the water head value corresponding to the signal exceeds the normal range of 2~9m, the water head signal fault flag will be automatically set. Data validity judgment: Within a 2-minute time window, if the calculated value of the real-time head signal changes by less than 0.1m, it is judged as a dead value; if it changes by more than 0.2m, it is judged as an abnormal signal fluctuation, and the calculated data is marked as invalid. Within a 10-minute time window, 5 valid calculated data are selected and their arithmetic average is calculated to obtain the valid automatic head. Disturbance-free switching control: A manual head signal is configured as a backup; when the governor is in automatic head mode and the head signal fault flag is not set, the manual head signal will automatically follow the effective automatic head and update synchronously; if a head signal fault occurs later, the governor can directly switch to manual head signal control to avoid unit control interruption or fluctuation. Unit operation control: Effective automatic head control is applied to different operating stages of the unit: During start-up and no-load operation, the start-up limit and no-load limit are automatically adjusted according to the head value. For example, the start-up limit is appropriately lowered when the head increases to avoid excessive start-up speed. Under grid-connected operation, the grid-connected limit is automatically adjusted according to the head value. For example, the grid-connected limit is raised when the head increases and lowered when the head decreases to prevent the unit from operating under overload. Under grid-connected operation, the blade coordination control opening is automatically adjusted according to the processed head signal to ensure that the unit operates at optimal efficiency.

[0022] This invention also provides a method for optimizing the head of a hydropower station governor, comprising the following steps: Step S1: Water level signal acquisition Method 1: Directly acquire water level signals output from upstream and downstream water level sensors at the hydropower station via a public LCU; Method 2: Use the network access function of the monitoring system through the unit's LCU to call the water level signal. Prioritize calling the water level signal collected by the public LCU. If the public LCU signal is abnormal, switch to calling the water level signal of the hydrological system.

[0023] Step S2: Head value processing and distribution The head monitoring device receives the water level signal from the public LCU, and obtains the upstream water level value, downstream water level value and head value through A / D conversion and CPU calculation. It outputs three standard analog quantities, among which the head analog quantity is sent to the speed controller after isolation distribution. The unit's LCU performs head calculations on the requested water level signals to obtain real-time head signals, which are then transmitted to the speed governor via communication.

[0024] Step S3: Speed ​​Controller Signal Processing The speed controller receives real-time head signals and first performs fault diagnosis; if the head exceeds 2-9m, a fault flag is set. Then perform a data validity check, judge the change within 2 minutes, and obtain the valid automatic head by averaging 5 valid data within 10 minutes; When the automatic head is in operation and there is no fault, the manual head signal will follow the effective automatic head update.

[0025] Step S4: Application of Head Signal No-load start-up phase: Adjust the start-up limit and no-load limit according to the effective automatic head to ensure smooth unit startup; During grid connection: The grid connection limit is adjusted according to the effective automatic head to prevent unit overload and ensure safe grid connection operation; the blade coordination control opening is automatically adjusted according to the effective automatic head to ensure that the unit operates at its optimal efficiency.

[0026] Finally, the method described in this application is merely a preferred embodiment and is not intended to limit the scope of protection of this invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this invention should be included within the scope of protection of this invention.

Claims

1. A hydroelectric power plant governor head optimization system, characterized by, The utility LCU, the water head monitoring device, the unit LCU and the governor are included. The utility LCU is used for collecting the upstream water level signal and the downstream water level signal of the hydropower station. The water head monitoring device is in communication connection with the utility LCU, and is used for receiving the upstream water level signal and the downstream water level signal, sequentially performing A / D conversion and CPU processing calculation on the upstream water level signal and the downstream water level signal, obtaining the upstream water level value, the downstream water level value and the water head value, and outputting three standard analog signals, wherein the three standard analog signals correspond to the upstream water level value, the downstream water level value and the water head value one by one, and the standard analog signal corresponding to the water head value is transmitted to the governor after signal isolation distribution. The unit LCU calls the upstream water level signal and the downstream water level signal of the utility LCU or the upstream water level signal and the downstream water level signal of the water regime system through the network interchanging function of the monitoring system, performs water head operation on the called upstream water level signal and downstream water level signal, obtains the real-time water head signal, and then transmits the real-time water head signal to the governor through communication. The governor is used for receiving the real-time water head signal, processing the real-time water head signal, and realizing unit operation control based on the processed water head signal.

2. The hydroelectric governor head optimization system of claim 1, wherein, The processing of the real-time water head signal by the governor includes water head signal fault judgment: when the water head value corresponding to the real-time water head signal exceeds 2-9m, the governor automatically sets the water head signal fault flag.

3. The hydroelectric governor head optimization system of claim 2, wherein, The processing of the real-time water head signal by the governor also includes data validity judgment: within 2min, if the change amount of the calculated value of the real-time water head signal is less than 0.1m or greater than 0.2m, it is determined that this calculation data is invalid; within 10min, 5 calculation data determined to be valid are selected, and the 5 valid calculation data are averaged to obtain the effective automatic water head.

4. The hydroelectric governor head optimization system of claim 3, wherein, The governor is also provided with a manual water head signal; when the governor is in the automatic water head working condition and the water head signal fault flag is not set, the manual water head signal automatically follows the effective automatic water head to realize the disturbance-free switching of the automatic water head and the manual water head signal in the case of water head signal fault.

5. The hydroelectric governor head optimization system of claim 1, wherein, The governor realizes unit operation control based on the processed water head signal, specifically including: during the unit start-up no-load process, automatically adjusting the start-up opening limit and the no-load opening limit according to the processed water head signal.

6. The hydroelectric governor head optimization system of claim 5, wherein, The governor realizes unit operation control based on the processed water head signal, specifically also including: under the unit grid-connected working condition, automatically adjusting the grid-connected opening limit according to the processed water head signal to prevent the unit from overloading; under the unit grid-connected working condition, automatically adjusting the blade coordinated control opening according to the processed water head signal to ensure that the unit is in the optimal efficiency working condition.

7. The hydroelectric governor head optimization system of claim 1, wherein, When the unit LCU calls the water level signal through the network interchanging function, the upstream water level signal and the downstream water level signal of the utility LCU are preferentially called; when the upstream water level signal or the downstream water level signal of the utility LCU is abnormal, the upstream water level signal and the downstream water level signal of the water regime system are switched to be called.

8. A method for optimizing the water head of a hydroelectric power station governor, characterized in that, The method comprises the following steps: S1, water level signal collection: collecting upstream water level signal and downstream water level signal of the hydropower station through a public LCU; or calling the upstream water level signal and downstream water level signal of the public LCU or calling the upstream water level signal and downstream water level signal of a water regime system through a unit LCU using the network interchanging function of a monitoring system; S2, water head value processing and issuing: receiving the upstream water level signal and downstream water level signal of the public LCU through a water head monitoring device, and obtaining upstream water level value, downstream water level value and water head value through CPU processing and calculation after A / D conversion, and outputting corresponding standard analog quantity, wherein the standard analog quantity corresponding to the water head value is transmitted to a speed regulator after signal isolation distribution; at the same time, the unit LCU obtains real-time water head signal through water head operation on the called water level signal, and issues the real-time water head signal to the speed regulator through communication; S3, speed regulator signal processing: the speed regulator receives the real-time water head signal, and sequentially performs fault judgment and data validity judgment on the real-time water head signal; and when the speed regulator is in automatic water head working condition and has no fault, the manual water head signal follows the automatic water head; S4, water head signal application: in the process of unit start-up and no-load, automatically adjusting start-up and no-load limits according to the processed water head signal; in the unit grid-connected working condition, automatically adjusting the grid-connected upper limit according to the processed water head signal to prevent the unit from overloading; in the unit grid-connected working condition, automatically adjusting the blade coordinated control opening according to the processed water head signal to ensure that the unit is in the optimal efficiency working condition.

9. The hydroelectric governor head optimization method of claim 8, wherein, The specific process of the fault judgment in step S3 is that when the water head value corresponding to the real-time water head signal exceeds 2-9m, the speed regulator automatically sets the water head signal fault flag.

10. The hydroelectric governor head optimization method of claim 9, wherein, The specific process of the data validity judgment in step S3 is that within 2min, if the calculation value change of the real-time water head signal is less than 0.1m or greater than 0.2m, it is determined that the calculation data is invalid; within 10min, 5 times of calculation data determined to be valid are selected, and the 5 times of valid calculation data are averaged to obtain effective automatic water head.