Pumped storage power station water pump working condition closed valve pressure generation system and method

Abstract

The invention provides a pumped storage power station water pump working condition valve closing pressure making system and method. The system comprises an upstream water diversion module, a body module and a control module. The body module comprises a main water inlet valve, a pump turbine and a generator motor; the generator motor is in transmission connection with the pump turbine; the main water inlet valve is used for cutting off or connecting water flow; the control module is configured to receive a pressure making instruction, start a static frequency converter in a generator motor and control the rotating speed of a pump turbine runner to increase at a preset rotating speed; acquiring a pressure-making pressure value; determining a target pressure value; calculating a pressure deviation value based on the pressure making pressure value and the target pressure value; based on the pressure deviation value, the rotating speed of a rotating wheel of the pump turbine is adjusted through the water pump similarity law, the pressure deviation value is made to be within the preset pressure range, and the problems that the existing water pump working condition starting process seriously depends on bypass valve flat pressing, the pressure making process is passive and uncontrollable, hydraulic impact is likely to be generated, and starting response lags are solved.

Description

Technical Field

[0001] This application relates to the field of pumped storage control technology, and in particular to a pumped storage power station pump operating condition valve closing pressure generation system and method. Background Technology

[0002] In the construction of new power systems, pumped storage power stations play an indispensable role as key energy storage and regulation power sources. With their flexible energy conversion and storage capabilities, they effectively balance the supply and demand of the power grid, improve grid stability and reliability, and meet the grid's urgent need for rapid and precise power regulation. As the requirements for the response speed and operational stability of pumped storage units in new power systems continue to increase, optimizing the startup process of pumped storage power station units from a static state to pump operation (pumping mode) has become a crucial aspect of improving their performance.

[0003] Currently, in existing pumped storage power stations, the traditional starting method for switching the unit from a static state to pump operation is usually air-start. The core pressurization and grid connection process of this method is as follows: When the unit is shut down, compressed air is injected into the tailrace pipe and impeller chamber using a compressed air device, causing the impeller to detach from the water surface and idle to reduce starting resistance torque; then, the static frequency converter (SFC) drives the motor rotor to rotate and accelerate, reaching the rated speed and completing grid synchronization. After that, the SFC is disengaged, and the motor enters grid-driven mode; subsequently, the control system issues an exhaust and water filling command, expelling the compressed air from the impeller chamber, causing the tailrace pipe water level to rise and submerge the impeller. The impeller performs work on the water at its rated speed to establish high pressure; finally, after establishing a pressure difference on both sides of the main inlet valve, the bypass valve system of the main inlet valve opens a small bypass valve to balance the pressure on both sides. After the pressure difference drops to the allowable range, the main valve is opened, and the guide vanes open according to a predetermined pattern, and the unit officially enters the pumping operation state.

[0004] However, the aforementioned pressurization process is passive and uncontrollable. The pressure shock at the "closed-off point" is significant, and the "closed-off point head" at rated speed is much higher than the static head of the upper reservoir. After the main valve opens, excessively high pressure is instantly built up in the pressure pipeline, which puts a large mechanical stress burden on the equipment, easily causing hydraulic shock and pressure pulsation, and exacerbating the water hammer effect. Moreover, the reliance on the bypass valve system increases the system complexity and failure rate, not only increasing hardware costs and maintenance workload, but also because the bypass valve is a vulnerable component, it suffers severe erosion and wear under high pressure differential, and failure will lead to unit start-up failure. Furthermore, at high speed, the water filling and pressurization process causes violent collisions between the impeller blades and the water flow, inducing dynamic and static interference in the bladeless region. The operating point of high-head units is prone to fall into the unstable region, resulting in power oscillation or abnormal noise, affecting the unit's lifespan. Summary of the Invention

[0005] This application provides a closed-valve pressure-building system and method for pumped storage power station pump operation to solve the technical problems of existing pump operation start-up process heavily relying on bypass valve pressure equalization, passive and uncontrollable pressure-building process, easy generation of hydraulic shock, and delayed start-up response.

[0006] The first aspect of this application provides a pumped storage power station pump operation valve shut-off pressure generation system, comprising: Upstream water diversion module, main body module, control module; The upstream water diversion module is configured as follows: Water from the upstream reservoir is diverted to the main body module through a water diversion steel pipe; The body module includes: The system includes a main inlet valve, a water pump turbine, and a generator motor; the generator motor is driven and connected to the water pump turbine; the main inlet valve is used to cut off or connect the water flow. The control module is configured as follows: Upon receiving a pressure-generating command, the static frequency converter inside the generator motor is activated to control the speed of the water pump turbine runner to increase to a preset speed. Obtain the pressure value; Determine the target pressure value; Based on the pressure initiation value and the target pressure value, a pressure deviation value is calculated; the pressure deviation value is: ΔP = P2 - P1; In the formula, P2 is the pressure value generated; P1 is the target pressure value; Based on the pressure deviation value, the turbine speed of the water pump is adjusted using the similarity law of water pumps so that the pressure deviation value is within a preset pressure range.

[0007] In some embodiments, the system further includes: A first pressure sensor is located upstream of the main inlet valve, and the first pressure sensor is configured to: Collect the static head pressure value of the upstream reservoir; A second pressure sensor is located downstream of the main inlet valve, and the second pressure sensor is configured to: The pressure generated during the operation of the water pump and turbine is collected.

[0008] In some embodiments, the control module is further configured to: Determine the required pressure margin; Based on the static head pressure value and the reserved pressure margin, the target pressure value is determined; the target pressure value is: P1 = P0 + δ; In the formula, P0 is the static head pressure value; δ is the reserved pressure margin.

[0009] In some embodiments, the control module is further configured to: Upon receiving a pressure-generating command, determine whether the main inlet valve is fully closed and whether the guide vanes of the water pump turbine are fully closed; If so, then proceed with the step of activating the static inverter within the generator motor.

[0010] In some embodiments, the control module is further configured to: When the pressure deviation value is less than 0, the static frequency converter is controlled to increase the output power and increase the runner speed of the water pump turbine.

[0011] In some embodiments, the control module is further configured to: When the pressure deviation value is equal to 0, the static frequency converter is controlled to operate at the current output power, so that the water pump turbine operates at the current runner speed.

[0012] In some embodiments, the control module is further configured to: When the pressure deviation value is greater than 0, the static frequency converter is controlled to reduce the output power and reduce the runner speed of the water pump turbine.

[0013] In some embodiments, the control module is further configured to: When the pressure deviation value is within the preset pressure range and the duration is greater than the preset time, the main water inlet valve is opened and the generator motor is connected to the power grid. After the generator motor is connected to the power grid, it controls the water pump turbine to run at the target speed of the water pump turbine corresponding to the power grid frequency; Once the water pump turbine reaches the target speed, the static frequency converter is turned off, and the generator motor operates using the power grid and opens the guide vane opening of the water pump turbine to the preset pumping opening.

[0014] In some embodiments, the control module is further configured to: Obtain the speed characteristic curve of the water pump turbine; Based on the aforementioned speed characteristic curve, the unstable speed is determined; Control the water pump turbine to prevent it from operating at the unstable speed; Specifically, when the rotational speed of the water pump turbine exceeds a preset upper limit, the water pump turbine is shut down.

[0015] The second aspect of this application provides a method for pressurizing a pumped storage power station under pump operation conditions by closing the valve, applicable to a pumped storage power station pump operation condition valve-closing pressurization system as described in any one of the first aspects above, comprising: Upon receiving the pressure-generating command, the static frequency converter inside the generator motor is activated to control the speed of the water pump turbine runner to increase to a preset speed; Obtain the pressure value; Determine the target pressure value; Based on the pressure initiation value and the target pressure value, a pressure deviation value is calculated; the pressure deviation value is: ΔP = P2 - P1; In the formula, P2 is the pressure value generated; P1 is the target pressure value; Based on the pressure deviation value, the turbine speed of the water pump is adjusted using the similarity law of water pumps so that the pressure deviation value is within a preset pressure range.

[0016] This application provides a closed-valve pressure-generating system and method for pumped storage power station pump operation. The system includes: an upstream water intake module, a main body module, and a control module. The upstream water intake module is configured to: divert water from an upstream reservoir to the main body module through a water intake steel pipe. The main body module includes: a main inlet valve, a pump turbine, and a generator motor. The generator motor is drivenly connected to the pump turbine. The main inlet valve is used to cut off or connect the water flow. The control module is configured to: receive a pressure-generating command, activate the static frequency converter in the generator motor, control the speed of the pump turbine impeller to increase by a preset speed; obtain the pressure-generating value; determine the target pressure value; and... The pressure deviation value is calculated based on the pressure generated and the target pressure value. The pressure deviation value is: ΔP = P2 - P1; where P2 is the pressure generated and P1 is the target pressure value. Based on the pressure deviation value, the turbine runner speed is adjusted using the pump similarity law to ensure that the pressure deviation value is within a preset pressure range. This allows for precise control of the unit speed using a static frequency converter while the main inlet valve is closed. Based on the pump similarity law, a pressure environment matching the upstream side of the main inlet valve is actively constructed downstream of the main inlet valve, thereby eliminating or simplifying the bypass valve pressure equalization system. This eliminates the need for a complex air charging process and enables a smooth, rapid, and low-impact start-up of the unit. Attached Figure Description

[0017] To more clearly illustrate the technical solution of this application, the drawings used in the embodiments will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1This is a schematic diagram of the valve-closing pressure generation system for the pumped storage power station in this application.

[0019] Explanation of reference numerals in the attached figures: 1-Upstream water diversion module; 11-Upstream reservoir; 12-Water diversion steel pipe; 2-Main body module; 21-Main inlet valve; 22-Water pump turbine; 23-Generator motor; 3-Control module; 4-First pressure sensor; 5-Second pressure sensor. Detailed Implementation

[0020] To enable those skilled in the art to better understand the technical solutions in this application, the technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of this application.

[0021] In some technologies, the pump startup process heavily relies on bypass valves for pressure equalization, the pressurization process is passive and uncontrollable, prone to hydraulic shock, and suffers from delayed startup response. To address these issues, this application provides a closed-valve pressurization system and method for pump operation in a pumped storage power station. The following describes the closed-valve pressurization system and method for pump operation in a pumped storage power station: For example, as new power systems place increasingly higher demands on the response speed and operational stability of pumped-storage units, their inherent limitations are gradually becoming apparent, mainly in the following four aspects: 1. The pressure-building process is passive and uncontrollable (large pressure shock at the "closed-off point"). Currently, the turbine runner contacts the water and builds pressure at its rated speed. According to the full characteristic curve of the pump-turbine, the "closed-off point head" at rated speed is usually much higher than the static head of the upper reservoir (potentially 1.2 times or even higher than the rated head). This means that after the main valve opens, extremely high pressure will instantly build up in the pressure pipeline. This excessively high pressure not only places a huge mechanical stress burden on the volute, main valve seals, and flow channel walls, but also easily triggers violent hydraulic shocks and pressure pulsations at the moment the main valve opens, exacerbating the water hammer effect in the pressure pipeline.

[0022] Second: The heavy reliance on bypass valve systems increases system complexity and failure rate. Currently, the pressure generation scheme cannot directly control pressure through the main unit; it must rely on bypass valves for pressure equalization before and after the main valve. This not only adds a set of high-pressure pipelines, valves, and corresponding control loops, increasing hardware costs and maintenance workload, but also, as a vulnerable component, the bypass valve suffers severe erosion and wear under high pressure differentials. If the bypass valve malfunctions (such as jamming or leakage), it will directly prevent the main valve from meeting opening conditions, causing unit startup failure.

[0023] Third: The startup process is time-consuming, resulting in a delay in responding to grid demands. The current startup control logic is as follows: venting and filling with water, establishing high pressure at the shut-off point, opening the bypass valve to balance pressure, determining the pressure difference, and opening the main valve. In particular, the pressure balancing process of the bypass valve is often lengthy for large-capacity units due to the small diameter of the bypass pipe, which severely restricts the rapid response capability of pumped storage power stations as "plug-and-play" regulating power sources for the grid.

[0024] Fourth: It can easily cause hydraulic instability. During high-speed pressurization, the violent impact between the turbine blades and the water flow can easily induce strong dynamic and static interference in the bladeless region. Especially in high-head units, if pressurization is performed at high speed, the operating point is very likely to fall into the unstable region of the pump-turbine, causing power oscillations or abnormal noise at the moment of grid connection or main valve opening, affecting the unit's lifespan.

[0025] like Figure 1 The diagram shown is a structural schematic of the pump-operated valve-closing pressure-generating system of the pump in this application.

[0026] The first aspect of this application provides a pumped storage power station pump operation valve shut-off pressure generation system, comprising: Upstream water diversion module 1, main body module 2, control module 3.

[0027] For example, the control module 3 is further configured to: Upon receiving a pressure-generating command, determine whether the main inlet valve 21 is fully closed and whether the guide vanes of the water pump turbine 22 are fully closed; if so, execute the step of activating the static frequency converter inside the generator motor 23.

[0028] Specifically, before the system starts, a self-check and initialization operation is required to confirm that the pumped storage unit (main module 2) is in a shutdown state or a transitional initial state from power generation to pumping. It is also confirmed that the main inlet valve 21 is fully closed and the guide vanes are fully closed or in a preset small-opening start-up position.

[0029] The upstream water diversion module 1 is configured as follows: Water from the upstream reservoir 11 is diverted to the main body module 2 via a water diversion steel pipe 12.

[0030] The body module 2 includes: The system includes a main inlet valve 21, a water pump turbine 22, and a generator motor 23; the generator motor 23 is connected to the water pump turbine 22; the main inlet valve 21 is used to cut off or connect the water flow.

[0031] The control module 3 is configured as follows: Upon receiving a pressure-generating command, the static frequency converter (SFC) within the generator motor 23 is activated, controlling the rotational speed of the water pump turbine 22 to increase by a preset speed; the SFC starts and the speed climbs. The SFC or a back-to-back starting device is activated, driving the rotor of the generator motor 23 to rotate. The control module 3 controls the unit speed to gradually increase according to a preset "speed-time" slope curve. During this process, the turbine rotates in a water-filled environment, using the centrifugal force generated by the blade rotation to pressurize the water in the flow channel.

[0032] Obtain the pressure value at which pressure is generated; determine the target pressure value.

[0033] For example, the system further includes: A first pressure sensor 4 is disposed upstream of the main inlet valve 21, and the first pressure sensor 4 is configured as follows: The static head pressure value of the upstream reservoir 11 is collected; the static head pressure value is the pressure value on the upstream side of the main inlet valve 21. When the pressure values ​​on the downstream side and the upstream side of the main inlet valve 21 are equal, the pressure fluctuation at the moment the main valve opens is minimal, essentially achieving pressure difference-free opening.

[0034] For example, the control module 3 is further configured as follows: Determine the reserved pressure margin; based on the static head pressure value and the reserved pressure margin, determine the target pressure value; the target pressure value is: P1 = P0 + δ; In the formula, P0 is the static head pressure value; δ is the reserved pressure margin. The reserved pressure margin is a set small positive pressure difference, that is, the allowable fluctuation value of the target pressure value.

[0035] The second pressure sensor 5 is located downstream of the main inlet valve 21, and is configured as follows: The pressure generated during the operation of the water pump turbine 22 is collected. The pressure generated by the rotation of the impeller of the water pump turbine 22 after the water pump turbine 22 is turned on is the pressure value on the downstream side of the main inlet valve 21.

[0036] To prevent single points of failure, both the inner and outer pressure sensors employ a dual-channel or triple-channel redundant configuration. Control module 3 uses voting logic (such as two out of three) to ensure data reliability. The dual-channel or triple-channel redundant configuration means that data is not acquired solely by a single pressure sensor, but rather by two or three independent pressure sensor channels simultaneously. Each channel can independently collect pressure information from both the inner and outer sides. These channels are independent at both the hardware and software levels, so even if one channel fails—for example, due to sensor damage, a short circuit, or electromagnetic interference—the remaining normally functioning channels can still continuously and accurately provide pressure data. This ensures that the system does not lose its pressure monitoring capability due to the failure of a single sensor.

[0037] In the data processing stage, a three-out-of-two voting logic is used as an example. Control module 3 simultaneously receives data from three pressure sensor channels. This data is then comprehensively analyzed and compared. When the data from at least two channels are consistent within a reasonable error range, control module 3 uses this consistent data as valid pressure data for subsequent processing and control. This ensures that the entire system can make correct decisions and actions based on accurate and reliable pressure data, effectively avoiding system malfunctions or failures caused by data errors, and further improving the system's stability and safety.

[0038] For example, the system further includes a speed acquisition module, which is used to acquire the rotor speed of the water pump turbine 22 in real time.

[0039] Based on the pressure initiation value and the target pressure value, a pressure deviation value is calculated; the pressure deviation value is: ΔP = P2 - P1; In the formula, P2 is the pressure value generated; P1 is the target pressure value.

[0040] Specifically, with the main inlet valve 21 closed, the control module 3 monitors the real-time pressure value P2 (pressure build-up pressure value) on the inner side of the main inlet valve 21 near the volute. The control module 3 introduces a pressure feedback closed-loop control algorithm, based on the pump similarity law (pressure is proportional to the square of the rotational speed), to dynamically calculate the required rotational speed command. Specifically, the control module 3 compares the pressure build-up pressure value P2 with the target pressure value P1, calculating the pressure deviation ΔP = P2 - P1.

[0041] Based on the pressure deviation value, the speed of the turbine runner of the water pump 22 is adjusted using the similarity law of water pumps so that the pressure deviation value is within the preset pressure range.

[0042] In this embodiment, the control module 3 is further configured as follows: When the pressure deviation value is less than 0, the static frequency converter is controlled to increase the output power and increase the runner speed of the water pump turbine 22.

[0043] When the pressure deviation value is equal to 0, the static frequency converter is controlled to operate at the current output power, so that the water pump turbine 22 operates at the current runner speed.

[0044] When the pressure deviation value is greater than 0, the static frequency converter is controlled to reduce the output power and reduce the runner speed of the water pump turbine 22.

[0045] Specifically, when ΔP<0, the static inverter is controlled to increase the output frequency, thereby increasing the unit speed and thus increasing the water pressure inside the volute, which in turn increases the pressure value.

[0046] When ΔP=0 (i.e., the pressure balance condition is reached), the control system locks the current speed, maintains the stable rotation of the impeller, and keeps the pressure balanced.

[0047] When ΔP>0, the unit speed is maintained or reduced to control the water pressure inside the volute and reduce the pressure value.

[0048] The control module 3 internally stores a full characteristic curve data model of the pump-turbine 22. The control module 3 receives pressure and speed signals and calculates the frequency command of the static inverter in real time using a PID algorithm or fuzzy control algorithm. The control module 3 has a pressure rheology feedforward compensation function, which can adjust the speed in advance according to fluctuations in external pressure (such as water hammer caused by load shedding from nearby units) to maintain a constant pressure difference (the pressure generated P2 is equal to the target pressure P1). The speed of the pump-turbine 22 is precisely controlled by adjusting the output voltage and frequency of the generator motor 23.

[0049] In this embodiment, the control module 3 is further configured as follows: When the pressure deviation value is within the preset pressure range and the duration is greater than the preset time, the main inlet valve 21 is opened and the generator motor 23 is connected to the power grid; after the generator motor 23 is connected to the power grid, the pump turbine 22 is controlled to run at the target speed of the pump turbine 22 corresponding to the power grid frequency; after the speed of the pump turbine 22 reaches the target speed, the static frequency converter is turned off, the generator motor 23 runs using the power grid and opens the guide vane opening of the pump turbine 22 to the preset pumping opening.

[0050] Specifically, when control module 3 detects that the pressure difference ΔP across the main inlet valve 21 remains within the preset pumping opening and the duration exceeds the set time, the system determines that pressure balancing is complete. At this time, control module 3 sends an opening command to the hydraulic actuator of the main inlet valve 21. Since the pressure on both sides has been balanced through speed regulation, the main inlet valve 21 opens smoothly under a slight pressure difference, avoiding the wear of the sealing surface and water hammer impact caused by the current high pressure difference opening. After the main inlet valve 21 is fully open, the static frequency converter continues to control the speed of the water pump turbine 22 to match the grid frequency and complete synchronous grid connection. Subsequently, the static frequency converter disengages, the generator motor 23 switches to grid drive, and the guide vanes open to the preset pumping opening, completing the entire startup process.

[0051] In this embodiment, the control module 3 is further configured as follows: The rotational speed characteristic curve of the water pump turbine 22 is obtained; based on the rotational speed characteristic curve, the unstable rotational speed is determined; the water pump turbine 22 is controlled to avoid operating at the unstable rotational speed; the target speed for pressurization set by the system must avoid the unstable region in the rotational speed characteristic curve of the water pump turbine 22 to ensure that the water pump turbine 22 does not experience severe pressure pulsations during the pressurization process. The rotational speed characteristic curve is used to reflect the intrinsic relationship between the rotational speed of the water pump turbine 22 and parameters such as input power and flow rate.

[0052] Specifically, when setting the target speed for pressurization, it is crucial to strictly avoid the unstable region in the speed characteristic curve of the pump-turbine 22. If the pump-turbine 22 operates at an unstable speed during pressurization, it will trigger severe pressure pulsations. These severe pressure pulsations will not only cause fatigue damage to the components of the pump-turbine 22 itself, shortening its service life, but may also be transmitted to other parts of the system through pipelines, affecting the stability and safety of the entire system. Therefore, by ensuring that the pump-turbine 22 does not operate at the aforementioned unstable speed during pressurization, severe pressure pulsations are prevented, thus ensuring the reliable operation of the system.

[0053] Specifically, when the rotational speed of the water pump turbine 22 exceeds a preset upper limit, the water pump turbine 22 is shut down. This system features adaptive feedforward functionality; the control module 3 stores a speed-head characteristic curve, allowing for rapid matching of the pressurization speed regardless of changes in the upper reservoir water level. Furthermore, the system includes an overpressure protection mechanism. If, during pressurization, the static inverter malfunctions, causing the rotational speed to increase excessively (i.e., the pressurization pressure P2 exceeds the preset upper limit), a shutdown protection mechanism is immediately triggered.

[0054] This application provides a valve-closing pressurization system for pump operation in a pumped storage power station, which has the following advantages: 1. System Simplification and Cost Reduction (Bypass Elimination): This application utilizes the main turbine runner as a "variable pressure booster pump" to directly establish the required balancing pressure inside the main inlet valve 21. This allows the pumped storage power station to eliminate the main valve bypass valve (pressure balancing valve), air filling pipeline and its associated high-pressure pipeline, maintenance valve, and control cable. This not only directly reduces the power station's infrastructure investment and equipment procurement costs but also completely eliminates the risk of start-up failure caused by bypass valve leakage or jamming, reducing maintenance workload during operation.

[0055] Second: Significantly improved stability and safety during startup (reducing water hammer). Current pressure generation methods use a "constant speed, variable pressure" approach, where the speed is reached in one step, and pressure is passively generated, often accompanied by significant pressure overshoot and impact. This application utilizes a "variable speed, controlled pressure" approach, achieving linear and flexible pressure increase through stepless speed adjustment via a static frequency converter. The main inlet valve 21 opens in a true "zero pressure differential" environment, greatly extending the service life of the main valve seals and effectively preventing hydraulic impact on the water intake system during opening, thus ensuring the safety of the pressure pipeline.

[0056] Third: Improve grid response speed. Currently, bypass valve pressure leveling is limited by the small pipe diameter, and pressure leveling for large-capacity units takes a long time. This application utilizes a turbine pressurization system, which has strong pressurization capacity and rapid response (second-level response), and can significantly shorten the conversion time of the unit from shutdown to full-load pumping, thereby better meeting the stringent requirements of modern power systems for energy storage regulation speed.

[0057] Fourth: Strong adaptability. For power stations with large fluctuations in upper reservoir water level and wide ranges in head, current processes may require manual intervention for adjustment. This application is based on real-time differential pressure feedback control, which allows the system to automatically find the most suitable rotational speed for pressure equalization regardless of changes in upper reservoir water level, demonstrating extremely strong adaptability to operating conditions.

[0058] The second aspect of this application provides a method for pressurizing a pumped storage power station under pump operation condition with valve closure, applied to a pumped storage power station pump operation condition with valve closure pressurization system described in any of the above embodiments, comprising: Upon receiving the pressure-generating command, the static frequency converter inside the generator motor is activated to control the speed of the water pump turbine runner to increase to a preset speed; Obtain the pressure value; Determine the target pressure value; Based on the pressure initiation value and the target pressure value, a pressure deviation value is calculated; the pressure deviation value is: ΔP = P2 - P1; In the formula, P2 is the pressure value generated; P1 is the target pressure value; Based on the pressure deviation value, the turbine speed of the water pump is adjusted using the similarity law of water pumps so that the pressure deviation value is within a preset pressure range.

[0059] It is worth noting that the effects of the above method embodiments can be found in the effects of the above system embodiments, and will not be repeated here.

[0060] The above detailed embodiments further illustrate the purpose, technical solution, and beneficial effects of the embodiments of this application. It should be understood that the above are merely specific embodiments of the embodiments of this application and are not intended to limit the protection scope of the embodiments of this application. Any modifications, equivalent substitutions, improvements, etc., made on the basis of the technical solutions of the embodiments of this application should be included within the protection scope of the embodiments of this application.

Claims

1. A valve-closing pressure generation system for pump operation in a pumped storage power station, characterized in that, include: Upstream water diversion module (1), main body module (2), control module (3); The upstream water diversion module (1) is configured as follows: Water from the upstream reservoir (11) is diverted to the main body module (2) through a water diversion steel pipe (12); The body module (2) includes: The main inlet valve (21), the water pump turbine (22), and the generator motor (23) are connected to the water pump turbine (22). The main inlet valve (21) is used to cut off or connect the water flow. The control module (3) is configured as follows: Upon receiving the pressure-generating command, the static frequency converter inside the generator motor (23) is turned on, and the rotational speed of the water pump turbine (22) is increased to a preset speed. Obtain the pressure value; Determine the target pressure value; Based on the pressure initiation value and the target pressure value, a pressure deviation value is calculated; the pressure deviation value is: ΔP = P2 - P1; In the formula, P2 is the pressure value generated; P1 is the target pressure value; Based on the pressure deviation value, the speed of the turbine (22) of the water pump is adjusted using the similarity law of water pumps so that the pressure deviation value is within the preset pressure range.

2. The pump-storage power station pump operation valve shut-off pressurization system according to claim 1, characterized in that, The system also includes: A first pressure sensor (4) is located upstream of the main inlet valve (21), and the first pressure sensor (4) is configured as follows: Collect the static head pressure value of the upstream reservoir (11); The second pressure sensor (5) is located downstream of the main inlet valve (21) and is configured as follows: The pressure generated during the operation of the water pump turbine (22) is collected.

3. The pump-storage power station pump operation valve shut-off pressurization system according to claim 2, characterized in that, The control module (3) is further configured as follows: Determine the required pressure margin; Based on the static head pressure value and the reserved pressure margin, the target pressure value is determined; the target pressure value is: P1 = P0 + δ; In the formula, P0 is the static head pressure value; δ is the reserved pressure margin.

4. The pump-storage power station pump operation valve shut-off pressurization system according to claim 1, characterized in that, The control module (3) is also configured to: Receive the pressure-generating command and determine whether the main inlet valve (21) is in a fully closed state and whether the guide vanes of the water pump turbine (22) are in a fully closed state; If so, then proceed with the step of activating the static inverter inside the generator motor (23).

5. A pumped storage power station pump operating condition valve shut-off pressure generation system according to claim 1, characterized in that, The control module (3) is further configured as follows: When the pressure deviation value is less than 0, the static frequency converter is controlled to increase the output power and increase the runner speed of the water pump turbine (22).

6. The pump-storage power station pump operation valve shut-off pressurization system according to claim 1, characterized in that, The control module (3) is further configured as follows: When the pressure deviation value is equal to 0, the static frequency converter is controlled to operate at the current output power, so that the water pump turbine (22) operates at the current runner speed.

7. A pumped storage power station pump operating condition valve shut-off pressurization system according to claim 1, characterized in that, The control module (3) is further configured as follows: When the pressure deviation value is greater than 0, the static frequency converter is controlled to reduce the output power and reduce the runner speed of the water pump turbine (22).

8. A pumped storage power station pump operating condition valve shut-off pressure generation system according to claim 1, characterized in that, The control module (3) is also configured to: When the pressure deviation value is within the preset pressure range and the duration is greater than the preset time, the main water inlet valve (21) is opened and the generator motor (23) is connected to the power grid; After the generator motor (23) is connected to the power grid, it controls the water pump turbine (22) to run at the target speed of the water pump turbine (22) corresponding to the frequency of the power grid. Once the water pump turbine (22) reaches the target speed, the static frequency converter is turned off, and the generator motor (23) operates using the power grid and opens the guide vane opening of the water pump turbine (22) to the preset pumping opening.

9. A pumped storage power station pump operating condition valve shut-off pressurization system according to claim 1, characterized in that, The control module (3) is also configured to: Obtain the speed characteristic curve of the water pump turbine (22); Based on the aforementioned speed characteristic curve, the unstable speed is determined; Control the water pump turbine (22) to prevent it from operating at the unstable speed; When the rotational speed of the water pump turbine (22) is greater than the preset upper limit of rotational speed, the water pump turbine (22) is shut down.

10. A method for pressurizing a pumped-storage power station under pump operating condition with valve closure, applied to a pumped-storage power station pump operating condition valve closure pressurization system as described in any one of claims 1 to 9, characterized in that, include: Upon receiving the pressure-generating command, the static frequency converter inside the generator motor is activated to control the speed of the water pump turbine runner to increase to a preset speed; Obtain the pressure value; Determine the target pressure value; Based on the pressure initiation value and the target pressure value, a pressure deviation value is calculated; the pressure deviation value is: ΔP = P2 - P1; In the formula, P2 is the pressure value generated; P1 is the target pressure value; Based on the pressure deviation value, the turbine speed of the water pump is adjusted using the similarity law of water pumps so that the pressure deviation value is within a preset pressure range.

Images