A pumped storage unit pumping-to-pumping phase modulation control method and system

Abstract

A pumped storage unit pumping-to-pumping phase modulation control method and system relate to the field of hydroelectric power generation and energy storage. The method solves the problems of existing control methods, such as large water flow impact, abnormal noise, poor short-term stability index of the unit, etc. The method comprises: the unit control system receives the pumping-to-pumping phase modulation switching instruction, triggers and starts the preset working condition conversion program; the water pump guide vane is controlled to be closed from the current working opening to the first preset opening; the water pump guide vane is maintained at the first preset opening to achieve smooth transition of the unit water flow working condition and input power; during or after the guide vane hovering, the ball valve starts to be closed, the closing action of the ball valve starts immediately after the guide vane hovering starts, or is delayed to start 0.2 seconds before the hovering ends, and the water hammer pressure generation is inhibited by optimizing the opening and closing time sequence; after the ball valve is completely closed, the water pump guide vane is controlled to be closed from the first preset opening to full closing, and the gas compression operation is performed to establish the pumping phase modulation working condition.

Description

Technical Field

[0001] This invention relates to the field of hydropower generation and energy storage technology, specifically to a method and system for controlling the pumping phase transition of a pumped storage unit. Background Technology

[0002] Pumped storage units play a crucial role in power grid operation, including peak shaving, valley filling, frequency regulation, phase regulation, and emergency backup. To respond to the real-time demands of the power grid, the units need to flexibly switch between various operating conditions, among which switching from pumping mode to pumping phase regulation mode is a common operation.

[0003] Traditional methods for controlling the pumping-to-pumping phase regulation process typically employ a coordinated closure of guide vanes and ball valves. However, in practical applications, numerous problems have been exposed: The water hammer pressure is high during the guide vane closing process, and the pressure and water velocity are high in the bladeless area when the guide vane is at a small opening. Improper coordination between the guide vane and the ball valve closing sequence can easily generate large water hammer pressure during the guide vane closing process. Large pressure and high water velocity are easily generated in the small opening area of ​​the guide vane, causing instability in the movement trend of the guide vane, which in turn impacts the structural components and produces abnormal noise. When the energy accumulates to a certain level, a loud noise may occur, which may damage the equipment and affect the long-term stable operation of the unit.

[0004] Poor stability during phase adjustment: When the unit enters the phase adjustment process, its stability is poor, and there may be increased vibration or excessive speed fluctuations. This not only affects the performance of the unit itself, but may also have an adverse impact on the stability of the power grid.

[0005] Issues with timing of air compression in the turbine runner: Inaccurate timing of air compression in the turbine runner may cause compressed air to enter the water flow channel, reducing the compression effect, or may prevent the establishment of a stable phase adjustment condition due to untimely air compression.

[0006] Therefore, developing a control method that can optimize the conversion process, effectively reduce water hammer pressure, and significantly improve the smoothness and safety of operating condition transitions is of great practical significance. Summary of the Invention

[0007] This invention addresses the shortcomings of existing technologies where traditional pumping units often employ a coordinated closing control method involving guide vanes and ball valves for switching between pumping and phase adjustment modes. This method has significant drawbacks in actual operation. Due to improper timing matching between the guide vanes and ball valves, the guide vane closing process easily generates substantial water hammer pressure. Furthermore, when the guide vanes are at a small opening, the pressure in the bladeless zone is high, and the water flow velocity is high, easily causing instability in the guide vane's operating state, inducing structural impacts and abnormal noises, and even equipment damage. Additionally, there are issues with inaccurate timing of air compression in the turbine runner and poor air compression phase establishment, making it difficult to quickly establish a stable phase adjustment condition. This results in significant vibration and speed fluctuations during the phase adjustment process, not only reducing the unit's operational stability but also adversely affecting the safety of the power grid.

[0008] To address this issue, the present invention proposes a method and system for controlling the pumping-to-pumping phase adjustment of a pumped storage unit. The present invention achieves this through the following technical solution: Option 1: This invention proposes a method for controlling the pumping-to-pumping phase transition of a pumped storage unit, the method comprising the following steps: Step 1: The unit control system receives the pumping to pumping phase switching command, triggers and starts the preset operating condition switching program; Step 2: Control the water pump guide vanes to close from the current operating opening to the first preset opening. The guide vanes are closed at a uniform speed or in stages with deceleration. The closing rate is adaptively adjusted according to the real-time head and flow parameters of the unit. Step 3: Control the water pump guide vanes to remain suspended at the first preset opening to achieve a smooth transition between the unit's water flow conditions and input power; Step 4: During or after the guide vane is hovering, start closing the ball valve. The ball valve closing action is initiated immediately after the guide vane begins to hover, or delayed until 0.2 seconds before the end of the hovering. This optimizes the opening and closing sequence to suppress the generation of water hammer pressure. Step 5: After the ball valve is fully closed, control the water pump guide vanes to close from the first preset opening to full closure; Step 6: After confirming that the pump guide vanes are completely closed, execute the air compression subroutine to introduce compressed air into the impeller chamber, monitor the water level in the impeller chamber in real time, and stop air compression when the water level drops to the preset threshold. Maintain the air pressure in the impeller chamber within the range required for the phase adjustment condition, and complete the establishment of the pumping phase adjustment condition.

[0009] Furthermore, a preferred embodiment is provided in which the first preset opening degree in step 2 is 5% of the maximum opening degree of the guide vane.

[0010] Furthermore, in a preferred embodiment, the duration for which the water pump guide vane is kept hovering at the first preset opening in step 3 is 1 second.

[0011] Furthermore, in a preferred embodiment, the ball valve described in step 5 is fully closed and then activated after the guide vane reaches the first preset opening and begins to hover.

[0012] Furthermore, in a preferred embodiment, the closing rate of the guide vane from the first preset opening to full closure in step 5 is less than the closing rate of the guide vane from the normal opening to the first preset opening in step 2.

[0013] Furthermore, a preferred embodiment is provided in which the compressed air in step 6 includes the steps of injecting compressed air into the impeller chamber and monitoring the water level or air pressure to meet the requirements for phase adjustment operation.

[0014] Furthermore, a preferred embodiment is provided, wherein the method further includes the step of synchronously collecting parameters such as guide vane opening, ball valve position, impeller chamber water level and unit head flow rate, and real-time linkage correction of the action sequence and operating rate of each device to achieve fully automatic and non-interventional operation mode switching.

[0015] Option 2: A pumped storage unit pumping-to-pumping phase adjustment control system, the system comprising: The instruction receiving and starting module is used by the unit control system to receive the pumping to pumping phase switching instruction, trigger and start the preset operating condition switching program. The first-stage guide vane adjustment module is used to control the water pump guide vane to close from the current working opening to the first preset opening. The guide vane adopts a uniform speed closing or segmented deceleration closing method, and the closing rate is adaptively matched and adjusted according to the real-time head and flow parameters of the unit. The guide vane hovering and stabilization module is used to control the water pump guide vanes to remain hovering at the first preset opening, so as to achieve a smooth transition between the unit's water flow conditions and input power. The ball valve timing control module is used to start closing the ball valve during or after the guide vane is hovering. The ball valve closing action is initiated immediately after the guide vane begins to hover, or delayed until 0.2 seconds before the end of the hovering. The optimization of the opening and closing sequence suppresses the generation of water hammer pressure. In the second stage, after the ball valve is fully closed, the guide vane of the water pump is controlled to close from the first preset opening to full closure. The impeller chamber air compression control module is used to execute the air compression subroutine after confirming that the water pump guide vanes are completely closed, to introduce compressed air into the impeller chamber, monitor the water level in the impeller chamber in real time, and stop air compression when the water level drops to a preset threshold, so as to maintain the air pressure in the impeller chamber within the range required for the phase adjustment condition and complete the establishment of the pumping phase adjustment condition.

[0016] Option 3: A computer-readable storage medium storing a computer program that, when executed by a processor, implements the steps of the method described in Option 1.

[0017] Option 4: A computer device, including a memory and a processor, wherein the memory stores a computer program, and when the processor runs the computer program stored in the memory, the processor executes the method described in Option 1.

[0018] The advantages of this invention are: The pumped storage unit pumping-to-pumping phase adjustment control method and system described in this invention optimizes the collaborative control logic of the entire pumping-to-pumping phase adjustment process, and rationally matches the timing of guide vane segmental closure, small-opening hovering, and ball valve opening and closing. This effectively suppresses water hammer pressure during the operating condition transition, improves the problem of high pressure and turbulent water flow velocity in the bladeless zone under small guide vane opening conditions, and avoids phenomena such as guide vane instability, structural impact noise, and equipment damage. At the same time, it accurately controls the timing of air compression in the turbine runner, effectively improving the efficiency of air compression phase establishment and the reliability of operating condition establishment, significantly reducing unit vibration and speed fluctuations during phase adjustment, and greatly improving the smoothness and stability of unit operating condition transition, thereby ensuring the safety and stability of the overall power grid operation.

[0019] This invention optimizes the closing sequence and coordination between the guide vane and the ball valve, thereby preventing excessive water hammer pressure, excessive pressure difference between the volute and the bladeless area when the guide vane is at a small opening, and excessive water flow velocity during the closing process. This prevents instability in the guide vane's movement trend, eliminates abnormal noise from the guide vane and severe vibration of the unit, and improves the stability of operating condition transitions, thus enhancing equipment safety.

[0020] This invention is also applicable to the control process of smoothly and safely switching from pumping operation to pumping phase adjustment operation. Attached Figure Description

[0021] Figure 1 This is a flowchart illustrating the pumped storage unit pumping-to-pumping phase control method described in Implementation Method 1. Detailed Implementation

[0022] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them.

[0023] Implementation Method 1, see Figure 1 This embodiment describes a method for controlling the transition from pumping to pumping phase regulation in a pumped storage unit. By optimizing the closing timing and coordination of the guide vanes and ball valves, a smooth and safe transition between pumping and pumping phase regulation conditions is achieved. The method specifically includes the following steps: Step 1: After receiving the pumping to pumping phase adjustment command, the operating condition switching procedure is initiated. This step serves as the starting point for the entire operating condition switching process. The unit control system receives the switching command from the dispatch center or automatic program, and then initiates the internal operating condition switching procedure to prepare for subsequent operations.

[0024] Step 2: Control the water pump guide vanes to close from the current opening (e.g., 80%) until they close to 5% of the maximum opening. In this step, the guide vanes can close at a constant speed or in stages with reduced speed. The specific closing rate is adaptively adjusted based on the unit's current head and flow rate. This allows for flexible adjustment of the guide vane closing speed according to different operating conditions, ensuring relatively stable water flow changes and reducing the impact on the unit.

[0025] Step 3: Hold the pump guide vanes at 5% of their maximum opening for 1 second. Holding the guide vanes at this opening provides a brief period of stability for the unit, reducing and stabilizing the residual flow through the guide vanes. This significantly reduces the unit's input power, creating favorable conditions for subsequent water flow cutoff.

[0026] Step 4: During the guide vane hovering period (e.g., 0.5 seconds after the start of hovering) or after the end of hovering, begin closing the ball valve. Specifically, the ball valve closing action should begin immediately after the guide vane begins hovering, or be delayed until 0.2 seconds before the end of hovering. This ensures that the ball valve has entered the closing process while the guide vane is kept at a small opening, optimizing the closing sequence and reducing the generation of water hammer pressure.

[0027] Step 5: Monitor the ball valve position. After the ball valve is fully closed, control the water pump guide vane to close from 5% of its maximum opening to the fully closed position. The closing rate of the guide vane from 5% of its maximum opening to full closure is slower than the closing rate in Step 2. This is to further reduce sudden changes in water flow and reduce the impact on the unit.

[0028] Step 6: After confirming that the guide vanes are fully closed, execute the air compression subroutine to inject compressed air into the turbine runner chamber, thus establishing the pumping phase adjustment mode. The air compression subroutine includes monitoring the water level in the turbine runner chamber, opening the air compression solenoid valve, injecting compressed air into the turbine runner chamber, and compressing the water level below the runner, so that the unit operates in a rotating but non-pumping state, i.e., entering the pumping phase adjustment mode. During the air compression process, the air pressure and water level in the turbine runner chamber are monitored, and the air compression valve is closed after the set values ​​are reached.

[0029] Implementation Method 2: This implementation method proposes a pumped storage unit pumping-to-pumping phase adjustment control system. The system is based on the control method described in Implementation Method 1 and includes: The instruction receiving and starting module is used by the unit control system to receive the pumping to pumping phase switching instruction, trigger and start the preset operating condition switching program. The first-stage guide vane adjustment module is used to control the water pump guide vane to close from the current working opening to the first preset opening. The guide vane adopts a uniform speed closing or segmented deceleration closing method, and the closing rate is adaptively matched and adjusted according to the real-time head and flow parameters of the unit. The guide vane hovering and stabilization module is used to control the water pump guide vanes to remain hovering at the first preset opening, so as to achieve a smooth transition between the unit's water flow conditions and input power. The ball valve timing control module is used to start closing the ball valve during or after the guide vane is hovering. The ball valve closing action is initiated immediately after the guide vane begins to hover, or delayed until 0.2 seconds before the end of the hovering. The optimization of the opening and closing sequence suppresses the generation of water hammer pressure. In the second stage, after the ball valve is fully closed, the guide vane of the water pump is controlled to close from the first preset opening to full closure. The impeller chamber air compression control module is used to execute the air compression subroutine after confirming that the water pump guide vanes are completely closed, to introduce compressed air into the impeller chamber, monitor the water level in the impeller chamber in real time, and stop air compression when the water level drops to a preset threshold, so as to maintain the air pressure in the impeller chamber within the range required for the phase adjustment condition and complete the establishment of the pumping phase adjustment condition.

[0030] In summary, this implementation uses a timing logic of "first closing the guide vane to a small opening and hovering, then closing the ball valve, and finally fully closing the guide vane." The 1-second hovering at 5% guide vane opening is an optimal parameter verified through extensive simulations and experiments, achieving the best balance between stability and switching speed.

[0031] Those skilled in the art will understand that the above description is merely a preferred embodiment of the present invention, and the features described in the various embodiments and / or claims of this disclosure can be combined or combined in various ways, even if such combinations or combinations are not explicitly described in this disclosure. This is not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

[0032] Although preferred embodiments of the invention have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including both the preferred embodiments and all changes and modifications falling within the scope of the invention. Clearly, those skilled in the art can make various alterations and modifications to the invention without departing from its spirit and scope. Thus, if these modifications and modifications of the invention fall within the scope of the claims and their equivalents, the invention is also intended to include these modifications and modifications.

Claims

1. A method for controlling the pumping-to-pumping phase adjustment of a pumped storage unit, characterized in that, The method includes the following steps: Step 1: The unit control system receives the pumping to pumping phase switching command, triggers and starts the preset operating condition switching program; Step 2: Control the water pump guide vanes to close from the current operating opening to the first preset opening. The guide vanes are closed at a uniform speed or in stages with deceleration. The closing rate is adaptively adjusted according to the real-time head and flow parameters of the unit. Step 3: Control the water pump guide vanes to remain suspended at the first preset opening to achieve a smooth transition between the unit's water flow conditions and input power; Step 4: During or after the guide vane is hovering, start closing the ball valve. The ball valve closing action is initiated immediately after the guide vane begins to hover, or delayed until 0.2 seconds before the end of the hovering. This optimizes the opening and closing sequence to suppress the generation of water hammer pressure. Step 5: After the ball valve is fully closed, control the water pump guide vanes to close from the first preset opening to full closure; Step 6: After confirming that the pump guide vanes are completely closed, execute the air compression subroutine to introduce compressed air into the impeller chamber, monitor the water level in the impeller chamber in real time, and stop air compression when the water level drops to the preset threshold. Maintain the air pressure in the impeller chamber within the range required for the phase adjustment condition, and complete the establishment of the pumping phase adjustment condition.

2. The method for controlling the pumping-to-pumping phase adjustment of a pumped storage unit according to claim 1, characterized in that, The first preset opening in step 2 is 5% of the maximum opening of the guide vane.

3. The method for controlling the pumping-to-pumping phase adjustment of a pumped storage unit according to claim 1, characterized in that, In step 3, the water pump guide vane is kept hovering at the first preset opening for 1 second.

4. The method for controlling the pumping-to-pumping phase adjustment of a pumped storage unit according to claim 1, characterized in that, The ball valve described in step 5 is fully closed and then activated after the guide vane reaches the first preset opening and begins to hover.

5. The method for controlling the pumping-to-pumping phase adjustment of a pumped storage unit according to claim 1, characterized in that, In step 5, the closing rate of the guide vane from the first preset opening to full closure is less than the closing rate of the guide vane from the normal opening to the first preset opening in step 2.

6. The method for controlling the pumping-to-pumping phase adjustment of a pumped storage unit according to claim 1, characterized in that, The compressed air mentioned in step 6 includes injecting compressed air into the impeller chamber and monitoring the water level or air pressure to meet the requirements for phase adjustment operation.

7. The method for controlling the pumping-to-pumping phase adjustment of a pumped storage unit according to claim 1, characterized in that, The method also includes the steps of synchronously collecting parameters such as guide vane opening, ball valve position, impeller chamber water level, and unit head and flow rate, and real-time linkage correction of the action sequence and operating rate of each device to achieve fully automatic and non-interventional operation condition switching.

8. A pumped storage unit pumping-to-pumping phase adjustment control system, characterized in that, The system includes: The instruction receiving and starting module is used by the unit control system to receive the pumping to pumping phase switching instruction, trigger and start the preset operating condition switching program. The first-stage guide vane adjustment module is used to control the water pump guide vane to close from the current working opening to the first preset opening. The guide vane adopts a uniform speed closing or segmented deceleration closing method, and the closing rate is adaptively matched and adjusted according to the real-time head and flow parameters of the unit. The guide vane hovering and stabilization module is used to control the water pump guide vanes to remain hovering at the first preset opening, so as to achieve a smooth transition between the unit's water flow conditions and input power. The ball valve timing control module is used to start closing the ball valve during or after the guide vane is hovering. The ball valve closing action is initiated immediately after the guide vane begins to hover, or delayed until 0.2 seconds before the end of the hovering. The optimization of the opening and closing sequence suppresses the generation of water hammer pressure. In the second stage, after the ball valve is fully closed, the guide vane of the water pump is controlled to close from the first preset opening to full closure. The impeller chamber air compression control module is used to execute the air compression subroutine after confirming that the water pump guide vanes are completely closed, to introduce compressed air into the impeller chamber, monitor the water level in the impeller chamber in real time, and stop air compression when the water level drops to a preset threshold, so as to maintain the air pressure in the impeller chamber within the range required for the phase adjustment condition and complete the establishment of the pumping phase adjustment condition.

9. A computer storage medium storing a computer program, characterized in that, When the computer program is executed by a processor, it implements the method described in any one of claims 1-7.

10. A computer device, characterized in that, include: A memory, a processor, and a computer program stored in the memory and executable on the processor, the processor executing the program to implement the method of any one of claims 1-7.

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