Integrated wind power hydraulic variable pitch device

Abstract

The invention discloses an integrated wind power hydraulic variable-pitch device, which is mounted in a blade hub and comprises an energy accumulator group 1, a hydraulic pump 3, a pressure oil tank 2, a variable-pitch cylinder group 12 and a valve group which are connected through a plurality of pressure-bearing hydraulic oil pipelines, the variable pitch cylinder group 12 comprises a plurality of groups of variable pitch cylinders, and each variable pitch cylinder comprises a rodless cavity 12.1 and a rod cavity 12.2; a piston rod of the rod cavity 12.2 is connected with a paddle; the energy accumulator set 1 supplies high-pressure hydraulic oil to the variable-pitch cylinder set 12, and the hydraulic oil drives a piston rod of the variable-pitch cylinder set 12 to drive a wind power paddle to change the windward angle of the paddle. The wind power paddle has two working states of feathering and opening, and the pressure oil tank 2 is connected with a pressure-bearing hydraulic oil pipeline through the hydraulic pump 3. The whole hydraulic variable pitch device is installed in the wind power hub and arranged around the axis of the wind power hub. The hydraulic variable-pitch device rotates along with the hub, the size is small, functions are complete, and leakage points of a hydraulic system are reduced; and the working environment of the hydraulic system is greatly improved.

Description

Technical Field

[0001] The present invention relates to the technical field of wind turbines, and in particular to an integrated wind power hydraulic pitch device. Background Art

[0002] For wind turbines, wind energy efficiency, output power quality, turbine lifespan, and grid compatibility are all key indicators for the healthy development of the industry. Pitch control technology plays an indispensable role in this regard. As a core component of large wind turbine control systems, the pitch system plays a crucial role in ensuring safe, stable, and efficient operation. Stable pitch control has become a hot topic in large wind turbine control technology. Simply put, pitch control technology involves adjusting the pitch angle of the blades to change the angle of attack of the airflow on the blades, thereby controlling the aerodynamic torque and aerodynamic power captured by the rotor. Wind turbines equipped with pitch control systems offer the advantage of high power density. In the past, electric pitch systems were more widely used in wind turbines. However, as wind turbines have become larger, so have pitch systems. Hydraulic pitch systems, with their advantages in high torque output and fast response, are gradually gaining market share. The wind turbine's pitch control system uses a hydraulic system. Simply put, a hydraulic oil tank on the turbine provides the hydraulic oil required to drive the blades. This hydraulic oil-powered blade-changing method changes the airflow's angle of attack on the blades, thereby controlling the aerodynamic torque and power captured by the rotor.

[0003] Hydraulic pitch systems are typically powered by a traditional hydraulic station located within the engine room. However, the accumulators are large and numerous, and the hydraulic station's placement within the engine room results in long hydraulic lines, numerous joints, and a complex structure. This results in low transmission efficiency and makes maintenance difficult. Placing the hydraulic oil tank within the wheel hub offers numerous advantages, including shorter hydraulic lines, fewer joints, and a simpler structure. If the hydraulic station and accumulator could be located within the wheel hub, the hydraulic pitch system could be significantly reduced in size and oil circuit length, improving pitch operation efficiency. Summary of the Invention

[0004] A first aspect of the present invention provides an integrated wind turbine hydraulic pitch device, which is completely installed inside a wind turbine blade hub and includes: an accumulator group, a hydraulic pump, a pressure oil tank, a pitch cylinder group, and a valve group connected via multiple pressurized hydraulic oil pipelines; The pitch cylinder group includes multiple groups of pitch cylinders, each of which includes a rodless cavity and a rod cavity; the piston rod in the rod cavity is connected to a wind turbine blade; The accumulator group includes a plurality of high-pressure oil storage chambers for storing hydraulic oil; the accumulator group provides high-pressure hydraulic oil to the pitch cylinder group, and the hydraulic oil drives the movement of the piston rod of the pitch cylinder group. The movement of the piston rod drives the wind turbine blades to rotate to change the windward angle of the wind turbine blades; The hydraulic oil port of the pressure oil tank is connected to the pressure-bearing hydraulic oil pipeline through the hydraulic pump; The valve group includes: a safety relief valve, a first normally open electromagnetic reversing valve, a second normally open electromagnetic reversing valve, a first throttle valve, a first normally closed electromagnetic reversing valve, a second normally closed electromagnetic reversing valve, a proportional reversing valve, a first one-way valve, a second one-way valve, a second relief valve and a second throttle valve.

[0005] As described in the first aspect of the present invention, the integrated wind power hydraulic pitch device further includes a control device, which controls the opening or closing of each valve of the valve group; The proportional reversing valve includes four ports: a low-pressure port, a high-pressure port, a first output port, and a second output port; The first normally open electromagnetic reversing valve, the second normally open electromagnetic reversing valve, the first normally closed electromagnetic reversing valve, the second normally closed electromagnetic reversing valve, the first throttle valve, the second throttle valve, the first check valve and the second check valve each include an input port and an output port.

[0006] As in the hydraulic pitch device according to the first aspect of the present invention, the outlet of the accumulator group is connected to the high-pressure port of the hydraulic pump, the output port of the safety relief valve and the high-pressure port of the proportional reversing valve through a pressurized hydraulic oil pipeline; The first output port of the proportional reversing valve is connected to the rodless chamber of the pitch cylinder group through a pressurized hydraulic oil pipeline; The second output port of the proportional reversing valve is connected to the input port of the second normally open electromagnetic reversing valve and the rod chamber of the pitch cylinder group through a pressurized hydraulic oil pipeline; The output port of the second normally open electromagnetic reversing valve is connected to the input port of the second relief valve through a pressurized hydraulic oil pipeline and a second throttle valve; the input port of the second relief valve is also connected to the hydraulic oil port of the pressure oil tank.

[0007] As described in the hydraulic pitch device of the first aspect of the present invention, the first output port of the proportional reversing valve is connected to the input port of the second normally closed electromagnetic reversing valve through a pressurized hydraulic oil pipeline, and the output port of the second normally closed electromagnetic reversing valve is connected to the rodless chamber of the pitch cylinder group through a pressurized hydraulic oil pipeline; The outlet of the accumulator group is connected to the input port of the first normally closed electromagnetic reversing valve through a pressurized hydraulic oil pipeline, and the output port of the first normally closed electromagnetic reversing valve is connected to the output port of the second one-way valve of the pressurized hydraulic oil pipeline and the high-pressure port of the proportional reversing valve; the input port of the second one-way valve is connected to the rod chamber of the pitch cylinder group through a pressurized hydraulic oil pipeline.

[0008] As described in the first aspect of the present invention, the outlet of the accumulator group is connected to the input port of the first normally open electromagnetic reversing valve through a pressurized hydraulic oil pipeline, the output port of the first normally open electromagnetic reversing valve is connected to the input port of the first one-way valve through a pressurized hydraulic oil pipeline, and the input port of the first one-way valve is connected to the output port of the first throttle valve; the input port of the first throttle valve is connected to the rodless chamber of the pitch cylinder group and the input port of the safety overflow valve through a pressurized hydraulic oil pipeline.

[0009] As in the hydraulic pitch device according to the first aspect of the present invention, the pressure oil tank is a fully enclosed structure; The hydraulic oil port of the pressure oil tank is connected to the oil extraction port of the hydraulic pump; An elastic device is used inside the pressure oil tank to keep the hydraulic oil port of the pressure oil tank always in a full oil state.

[0010] A second aspect of the present invention provides a method for operating a hydraulic pitch device as described in any one of the above items, the method comprising the following steps: Step 1: The control device of the integrated wind power hydraulic pitch device obtains surrounding wind force and wind direction data through sensors, and controls the angle change of the blades according to the obtained wind force and wind direction data; Step 2: The control device obtains hydraulic oil pressure data inside the accumulator group through a sensor. When the hydraulic oil pressure is lower than a predetermined oil pressure threshold, the control device starts the hydraulic pump to replenish hydraulic oil from the pressure oil tank to the accumulator group, so that the hydraulic oil pressure inside the accumulator group reaches or exceeds the predetermined oil pressure threshold. Step 3: When the wind force data exceeds a predetermined wind force threshold, the control device controls the wind turbine blades to feather and stop generating electricity.

[0011] As described in the second aspect of the present invention, step 1 includes sub-steps: Step 1.1: Feathering action. The control device energizes the first normally closed electromagnetic reversing valve, the second normally closed electromagnetic reversing valve, and the proportional reversing valve. This causes the hydraulic oil in the accumulator group to flow through the first normally closed electromagnetic reversing valve and the proportional reversing valve into the rodless chamber of the pitch cylinder group, pushing the piston rod to extend. The piston rod then drives the wind turbine blades to feather. Step 1.2, the propeller opening action, the control device energizes the first normally closed electromagnetic reversing valve, the second normally closed electromagnetic reversing valve and the proportional reversing valve, so that the hydraulic oil inside the accumulator group is injected into the rod chamber of the pitch cylinder group through the first normally closed electromagnetic reversing valve and the proportional reversing valve, driving the piston rod to retract, and the piston rod drives the wind turbine blades to open.

[0012] According to the method of the second aspect of the present invention, step 1.1 further includes the sub-steps of: Step 1.11: The control device adjusts the opening size of the proportional reversing valve to control the flow of hydraulic oil and adjust the movement speed of the piston rod; Step 1.12: The control device controls the second one-way valve to adjust the flow ratio of the hydraulic oil in the rod chamber of the pitch cylinder group flowing through the second one-way valve to the high-pressure port of the proportional reversing valve, thereby increasing the speed at which the piston rod extends.

[0013] According to the method of the second aspect of the present invention, step 3 includes an emergency feathering step: In step 3.1, the control device de-energizes the first normally open electromagnetic reversing valve and the second normally open electromagnetic reversing valve, allowing the hydraulic oil in the accumulator group to flow into the rodless chamber of the pitch cylinder group through the first normally open electromagnetic reversing valve, the first check valve, and the first throttle valve, pushing the piston rod to extend and drive the blades to feather. Step 3.2: During emergency feathering, the hydraulic oil in the rod chamber of the pitch cylinder group flows back to the pressure oil tank through the second normally open electromagnetic reversing valve and the second throttle valve.

[0014] The method of the present invention has the following advantages: the hydraulic pitch device of the present invention is completely installed in the wind turbine hub, the hydraulic pitch device rotates with the hub, has a small size and full functions, reduces hydraulic system leakage points, and greatly improves the working environment of the hydraulic system.

[0015] The above description is only an overview of the technical solution of the present invention. In order to more clearly understand the technical means of the present invention, which can be implemented in accordance with the contents of the specification, and to make the above and other purposes, features and advantages of the present invention more obvious and easy to understand, the following specifically cites preferred embodiments and describes them in detail with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 Internal structure diagram of the integrated wind power hydraulic pitch device of the present invention; Figure 2 Schematic diagram of the pipeline connection of the integrated wind power hydraulic pitch device of the present invention; Figure 3 A structural diagram of a hydraulic pitch device of the present invention; Figure 4 Schematic diagram of the overall structure of multiple hydraulic pitch devices of the present invention; Figure 5 Schematic diagram of the arrangement of multiple sets of hydraulic pitch devices in the hub of the present invention.

[0017] Among them, 1-accumulator group; 2-pressure oil tank; 3-hydraulic pump; 4-safety relief valve; 5.1-first normally open solenoid reversing valve; 5.2-second normally open solenoid reversing valve; 6-first throttle valve; 7.1-first normally closed solenoid reversing valve; 7.1-second normally closed solenoid reversing valve; 8-proportional reversing valve; 9.1-first one-way valve; 9.2-second one-way valve; 10-second relief valve; 11-second throttle valve; 12-pitch cylinder group; 12.1-rodless chamber; 12.2-rod chamber; 13-servo motor; 14-pressure hydraulic oil pipeline; A-proportional reversing valve first output port; B-proportional reversing valve second output port; P-high pressure port; T-low pressure port. DETAILED DESCRIPTION

[0018] The invention relates to a hydraulic pitch-changing device for a wind turbine generator which adopts airtight sealing and pressure-bearing properties.

[0019] Wind turbines use ordinary oil storage devices. Due to the volatilization and consumption of hydraulic oil, the hydraulic oil often comes into contact with the air, causing the hydraulic oil to oxidize and impurities to enter the system, affecting the stability of the system operation. This invention proposes a hydraulic pitch control device installed within a wind turbine hub and rotating with the hub. The device's accumulator assembly uses a hermetically sealed pressure seal. This keeps the hydraulic oil free of bubbles at all times, ensuring stable and reliable oil suction by the hydraulic pump and minimizing pump cavitation.

[0020] The hydraulic pitch devices of the present invention are all installed on the wind turbine hub. The entire hydraulic pitch system includes three hydraulic pitch devices. The three hydraulic pitch devices are installed in a herringbone shape on the base, and the base is configured on the central rotating axis of the wind turbine hub, so that the hydraulic pitch system rotates with the wind turbine hub. The pitch cylinder group of each hydraulic pitch device is connected to a wind turbine blade to drive the wind turbine blade to pitch or open.

[0021] The technical solutions of the present invention will be clearly and completely described below in conjunction with specific embodiments. However, it should be understood by those skilled in the art that the embodiments described below are only used to illustrate the present invention and should not be regarded as limiting the scope of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative work are within the scope of protection of the present invention.

[0022] The internal structure diagram of the integrated wind power hydraulic pitch device of the present invention is shown in the attached figure. Figure 1 As shown; The schematic diagram of the pipeline connection of the integrated wind power hydraulic pitch device of the present invention is shown in the attached figure. Figure 2 shown.

[0023] A first aspect of the present invention provides an integrated wind turbine hydraulic pitch device, which is completely installed inside a wind turbine blade hub. The integrated wind turbine hydraulic pitch device includes: an accumulator group 1, a hydraulic pump 3, a pressure oil tank 2, a pitch cylinder group 12, and a valve group connected via multiple pressurized hydraulic oil pipelines; The pitch cylinder group 12 includes multiple pitch cylinders, each of which includes a rodless cavity 12.1 and a rod cavity 12.2; the piston rod in the rod cavity 12.2 is connected to a wind turbine blade; The accumulator group 1 includes a plurality of high-pressure oil storage chambers for storing hydraulic oil; the accumulator group 1 provides high-pressure hydraulic oil to the pitch cylinder group 12, and the hydraulic oil drives the movement of the piston rod of the pitch cylinder group 12, and the movement of the piston rod drives the wind turbine blades to rotate to change the windward angle of the wind turbine blades; The hydraulic oil port of the pressure oil tank 2 is connected to the pressure hydraulic oil pipeline through the hydraulic pump 3; The valve group includes: a safety relief valve 4, a first normally open electromagnetic reversing valve 5.1, a second normally open electromagnetic reversing valve 5.2, a first throttle valve 6, a first normally closed electromagnetic reversing valve 7.1, a second normally closed electromagnetic reversing valve 7.2, a proportional reversing valve 8, a first one-way valve 9.1, a second one-way valve 9.2, a second relief valve 10, and a second throttle valve 11. Example 1

[0024] The hydraulic pitch device of the present invention, the integrated wind power hydraulic pitch device also includes a control device, which controls the opening or closing of each valve by energizing each control valve; The valve group includes: a safety relief valve 4, a first normally open electromagnetic reversing valve 5.1, a second normally open electromagnetic reversing valve 5.2, a first throttle valve 6, a first normally closed electromagnetic reversing valve 7.1, a second normally closed electromagnetic reversing valve 7.2, a proportional reversing valve 8, a first non-return valve 9.1, a second non-return valve 9.2, a second relief valve 10 and a second throttle valve 11. These valves and the interconnected pressurized hydraulic oil pipelines are integrated in a housing to form a power unit. The servo motor 13 that drives the hydraulic oil pump, the pressure oil tank 2 and the accumulator group 1 are arranged outside the power unit and are connected to the pressurized hydraulic oil pipeline in the power unit through the pressurized hydraulic oil pipeline. Its overall appearance can be seen in the attached figure. Figure 3 . The proportional reversing valve 8 includes four ports: a low-pressure port T, a high-pressure port P, a first output port A, and a second output port B.

[0025] The first normally open electromagnetic reversing valve 5.1, the second normally open electromagnetic reversing valve 5.2, the first normally closed electromagnetic reversing valve 7.1, the second normally closed electromagnetic reversing valve 7.2, the first throttle valve 6, the second throttle valve 11, the first one-way valve 9.1 and the second one-way valve 9.2 each include an input port and an output port.

[0026] The hydraulic oil outlet of the accumulator group 1 is connected to the high-pressure port of the hydraulic pump 3, the output port of the safety relief valve 4 and the high-pressure port P of the proportional reversing valve 8 through a pressure-bearing hydraulic oil pipeline; The integrated wind power hydraulic pitch device further comprises a control device, which controls the opening or closing of each valve of the valve group.

[0027] The first output port A of the proportional reversing valve 8 is connected to the rodless chamber 12.1 of the pitch cylinder group 12 through a pressurized hydraulic oil pipeline; this hydraulic oil pipeline controls the extension and contraction of the piston rod to adjust the angle of the wind turbine blades. The second output port B of the proportional reversing valve 8 is connected to the input port of the second normally open electromagnetic reversing valve 5.2 and the rod chamber 12.2 of the pitch cylinder group 12 through a pressurized hydraulic oil pipeline; the hydraulic oil circuit is used to control the propeller and emergency propeller operations.

[0028] The output port of the second normally open solenoid reversing valve 5.2 is connected to the input port of the second relief valve 10 via a pressurized hydraulic oil pipeline and a second throttle valve 11. The input port of the second relief valve 10 is also connected to the hydraulic oil port of the pressure oil tank 2. This path provides an oil return path during feathering.

[0029] The first output port of the proportional reversing valve 8 is connected to the input port of the second normally closed electromagnetic reversing valve 7.2 through a pressurized hydraulic oil pipeline, and the output port of the second normally closed electromagnetic reversing valve 7.2 is connected to the rodless chamber 12.1 of the pitch cylinder group 12 through a pressurized hydraulic oil pipeline; The outlet of accumulator group 1 is connected to the input port of first normally closed solenoid reversing valve 7.1 via a pressurized hydraulic oil pipeline. The output port of first normally closed solenoid reversing valve 7.1 is connected to the output port of second one-way valve 9.2 of the pressurized hydraulic oil pipeline and the high-pressure port of proportional reversing valve 8. The input port of second one-way valve 9.2 is connected to rod chamber 12.2 of pitch cylinder group 12 via a pressurized hydraulic oil pipeline. This pressure-dividing oil circuit is used to control the proportion of oil in rod chamber 12.2 of pitch cylinder group 12 flowing through second one-way valve 9.2 to the high-pressure port of proportional reversing valve 8, thereby conserving hydraulic oil flow.

[0030] The outlet of accumulator group 1 is connected to the input port of the first normally open solenoid reversing valve 5.1 via a pressurized hydraulic oil pipeline. The output port of the first normally open solenoid reversing valve 5.1 is connected to the input port of the first check valve 9.1 via a pressurized hydraulic oil pipeline. The input port of the first check valve 9.1 is connected to the output port of the first throttle valve 6. The input port of the first throttle valve 6 is connected to the rodless chamber 12.1 of the pitch cylinder group 12 and the input port of the safety relief valve 4 via a pressurized hydraulic oil pipeline. Accumulator group 1 is the main power source of the system, providing pressurized oil for feathering, opening, and emergency feathering operations.

[0031] The hydraulic pump 3 is mainly used to replenish the pressurized oil for the accumulator group 1. When the pressure is less than the predetermined threshold, the hydraulic pump 3 starts and the oil replenishment begins; when the pressure reaches or exceeds the set threshold, the hydraulic pump 3 stops and the oil replenishment ends.

[0032] As described in the first aspect of the hydraulic pitch device of the present invention, the hydraulic oil port of the pressure oil tank 2 is connected to the oil extraction port of the hydraulic pump 3; an elastic device is used inside the pressure oil tank 2 to keep the hydraulic oil port of the pressure oil tank 2 always full of oil.

[0033] Attachment Figure 3 and attached Figure 4 The arrangement of the accumulator group 1, the pressure oil tank 2, the pitch cylinder group 12 and the valve group in the wind turbine blade hub is clearly described. The valves and pipelines of the valve group are integrated in a shell. The servo motor 13, the pressure oil tank 2 and the accumulator group 1 that drive the hydraulic oil pump are arranged outside the power unit and are connected to the pressurized hydraulic oil pipeline in the power unit through the pressurized hydraulic oil pipeline.

[0034] The power unit integrates the servo motor 13, hydraulic pump 3, and control valve into a single unit, facilitating installation and reducing intermediate piping and leak points. The power unit features an accumulator port for connection to the accumulator assembly; the hydraulic oil port connects to the pressure oil tank; both ports utilize SAE flanges. The pressure oil tank 2 utilizes compressed air or a spring to provide a constant pressure of hydraulic oil to the hydraulic pump. The hydraulic oil in the tank has no external connection, preventing leakage, ensuring that the entire hydraulic pitch system rotates with the wheel hub without leaks.

[0035] Attachment Figure 5 A schematic diagram of the arrangement of multiple sets of hydraulic pitch devices in the hub of the present invention is provided. The present invention provides a wind turbine generator configuration with three blades. Of course, a multi-blade wind turbine generator configuration with more than two wind turbine blades is also applicable to the structure of the present invention.

[0036] The hydraulic pitch devices of the present invention are all installed in the wind turbine hub. The entire hydraulic pitch system includes three hydraulic pitch devices. The pitch cylinder group of each hydraulic pitch device is connected to a wind turbine blade to drive the wind turbine blade to feather or open. In order to control the opening and feathering of the three wind turbine blades, the three hydraulic pitch devices are installed in a triangular shape on the base, and the base is configured on the central rotating shaft of the wind turbine hub, so that the hydraulic pitch system composed of the three hydraulic pitch devices rotates with the wind turbine hub. The hydraulic pitch system rotates with the hub as a whole and is sealed in the hub, with a small size and short pipelines. The three hydraulic pitch devices surround the side of the central rotating shaft of the wind turbine hub and are close to the central rotating shaft, so that its centrifugal force is small. The above measures greatly reduce the failure rate of wind turbines.

[0037] Feathering means the blades are perpendicular to the wind direction, and the blades no longer rotate with the wind. Opening means the blades are at a predetermined angle to the wind direction, and the wind forces the blades to rotate, driving the generator to generate electricity. In this state, the control device adjusts the angle between the blades and the wind direction to achieve optimal power generation efficiency.

[0038] A second aspect of the present invention provides a method for operating a hydraulic pitch device as described in any one of the preceding claims, the method comprising the following steps: Step 1: The control device of the integrated wind power hydraulic pitch device obtains the wind force and wind direction data, and controls the angle change of the blade according to the obtained wind force and wind direction data; Step 2: The control device obtains hydraulic oil pressure data inside the accumulator group 1 through a sensor. When the hydraulic oil pressure is lower than a predetermined oil pressure threshold, the control device starts the hydraulic pump 3 to replenish the hydraulic oil for the accumulator group 1. Step 3: When the wind speed data exceeds a predetermined wind speed threshold, the control device controls the blades to feather and stops power generation.

[0039] As described in the method of the second aspect of the present invention, step 1 includes sub-steps: Step 1.1: Feathering. The control device energizes first normally closed solenoid reversing valve 7.1, second normally closed solenoid reversing valve 7.2, and proportional reversing valve 8. This causes the hydraulic oil in accumulator assembly 1 to flow through first normally closed solenoid reversing valve 7.1, first normally closed solenoid reversing valve 7.2, and proportional reversing valve 8 and into rodless chamber 12.1 of pitch cylinder assembly 12, pushing the piston rod out. Step 1.2, start the propeller. The control device energizes the first normally closed electromagnetic reversing valve 7.1, the second normally closed electromagnetic reversing valve 7.2 and the proportional reversing valve 8, so that the hydraulic oil inside the accumulator group 1 is injected into the rod chamber 12.2 of the pitch cylinder group 12 through the first normally closed electromagnetic reversing valve 7.1 and the proportional reversing valve 8, driving the piston rod to retract.

[0040] According to the method of the second aspect of the present invention, step 1.1 further includes the sub-steps of: Step 1.11: The control device adjusts the opening size of the proportional valve by adjusting the proportional reversing valve 8, thereby controlling the flow of hydraulic oil to adjust the blade angle; In step 1.12, the control device controls the one-way valve 9 to adjust the flow ratio of the hydraulic oil flowing through the one-way valve 9 and the flow through the high-pressure port of the proportional reversing valve 8, thereby realizing differential pitch control of the blades.

[0041] According to the method of the second aspect of the present invention, step 3 includes an emergency feathering step: Step 3.1: The control device energizes the first normally open electromagnetic reversing valve 5.1 and the second normally open electromagnetic reversing valve 5.2, so that hydraulic oil flows through the first normally open electromagnetic reversing valve 5.1 and the first throttle valve 6 into the rodless chamber 12.1 of the pitch cylinder assembly 12, pushing the piston rod to extend quickly, driving the blades to feather. Step 3.2: During emergency feathering, the hydraulic oil in the rod chamber 12.2 of the pitch cylinder group 12 flows back to the pressure oil tank 2 through the second normally open electromagnetic reversing valve 5.2 and the second throttle valve 11.

[0042] Example 2 The accumulator assembly 1 of the present invention is the system's primary power source, providing high-pressure hydraulic oil for feathering, opening, and emergency feathering operations. The pressure oil tank 2 of the present invention stores excess hydraulic oil. The interior of the tank is isolated from the outside air, and a spring compresses the hydraulic oil against the hydraulic oil port. The sealed tank 2 rotates with the wind turbine hub, preventing hydraulic oil leakage and ensuring that the hydraulic pitch control system can be integrated into the hub.

[0043] The variable pitch cylinder group 12 is composed of two hydraulic cylinders. When the piston rod of the variable pitch cylinder group 12 is extended, the blades are aligned. The state in which the piston rod of the variable pitch cylinder group 12 retracts to a predetermined position according to the control signal of the control device is called the wind turbine blade open state.

[0044] When the electromagnets of the first normally open solenoid reversing valve 5.1 and the second normally open solenoid reversing valve 5.2 are energized, the valves close and prevent hydraulic oil from flowing through. When the electromagnets are de-energized, the valves open and allow hydraulic oil to flow through. During normal pitch control, the electromagnets 5.1 and 5.2 are energized, and the corresponding oil circuits are disconnected. During emergency pitch feathering, the electromagnets are de-energized, and the oil circuits open, allowing emergency pitch feathering.

[0045] The first throttle valve 6 and the second throttle valve 11 controlled by the control device are used to adjust the flow rate of the hydraulic oil. The larger the opening of the throttle valve, the greater the flow rate; the smaller the opening, the smaller the flow rate.

[0046] When the electromagnets of the first and second normally closed solenoid reversing valves 7.1 and 7.2 are energized, the valves are connected, allowing hydraulic oil to flow through them. When the electromagnets are de-energized, the valves close, preventing hydraulic oil from flowing through them. During normal pitch control, the electromagnets 7.1 and 7.2 are energized, ensuring normal connection between the high-pressure port P of the proportional reversing valve and the first output port A, allowing the pitch control device to both feather and open the propellers. During emergency pitch control, the electromagnets of the first and second normally closed solenoid reversing valves 7.1 and 7.2 are de-energized, disconnecting the oil path between the high-pressure port P of the proportional reversing valve and the first output port A. Even if the proportional reversing valves receive an input signal for reversing, the pitch control device will not malfunction.

[0047] The proportional reversing valve 8 is the core component of the pitch system. It changes the position of the valve core according to the control signal input by the control device to control the opening and closing of the pitch device. At the same time, the position of the valve core can be adjusted according to the size of the control electrical signal to change the opening size of each throttle valve, control the flow rate, and then control the pitch speed.

[0048] The first one-way valve 9.1 ensures that hydraulic oil can only flow from the first normally open electromagnetic reversing valve 5.1 to the first throttle valve 6, and cannot flow in the opposite direction. The second one-way valve 9.2 ensures that hydraulic oil can only flow from the rod chamber of the pitch cylinder group to the first normally closed electromagnetic reversing valve 7.1, and cannot flow in the opposite direction.

[0049] The overflow valve 10 sets the pressure of the high-pressure oil of the entire pitch device to reach a set threshold.

[0050] The servo motor 13 drives the hydraulic pump to rotate, injecting the hydraulic oil into the hydraulic oil pipeline in a high-pressure hydraulic oil state.

[0051] Typically, when a wind turbine rotor is shut down, the blades are perpendicular to the wind direction, a condition known as wind turbine blade feathering. Emergency feathering occurs when a wind turbine malfunctions or wind speeds exceed a predetermined blade operating threshold. A control device rapidly feathers the blades, halting the turbine. Example 3

[0052] Feathering operation The control device energizes the first normally closed solenoid reversing valve 7.1, the second normally closed solenoid reversing valve 7.2 and the proportional reversing valve 8. The pressure oil provided by the hydraulic pump 3 or the accumulator group 1 is output from the first output port A of the proportional reversing valve 8 through the high-pressure port P of the first normally closed solenoid reversing valve 7.1 and the proportional reversing valve 8, and is injected into the rodless chamber 12.1 of the pitch cylinder group 12 through the second normally closed solenoid reversing valve 7.2, and the piston rod is extended; the opening size of the proportional reversing valve 8 is adjusted to control the flow rate to control the speed of the piston rod extension, thereby driving the blades to feather.

[0053] The oil in the rod chamber of the pitch cylinder group 12 flows through the second one-way valve 9.2 to the high-pressure port P of the proportional reversing valve 8 and flows back to the rodless chamber, increasing the speed of the piston rod extension and forming a differential circuit.

[0054] Paddle operation The control device energizes the first normally closed electromagnetic reversing valve 7.1, the second normally closed electromagnetic reversing valve 7.2 and the proportional reversing valve 8. The pressure oil provided by the accumulator group 1 or the hydraulic pump 3 passes through the high-pressure port P of the first normally closed electromagnetic reversing valve 7.1 and the proportional reversing valve 8, and is injected into the rod chamber 12.2 of the variable pitch cylinder group 12 through the second output port B of the proportional reversing valve 8. The control device adjusts the opening size of the proportional reversing valve 8, controls the flow, pushes the piston rod to retract, and drives the blades to open; the oil in the rod chamber 12.2 of the variable pitch cylinder group 12 flows back to the hydraulic oil port of the pressure oil tank 2 through the second normally closed electromagnetic reversing valve 7.2, the first output port A of the proportional reversing valve 8 and the low-pressure port T.

[0055] Emergency feathering operation During emergency feathering operation, the hydraulic pump 3 does not work, the first normally open electromagnetic reversing valve 5.1 and the second normally open electromagnetic reversing valve 5.2 are powered off, and the high-pressure oil stored in the accumulator group 1 is injected into the rodless chamber of the pitch cylinder group 12 through the first normally open electromagnetic reversing valve 5.1, the first one-way valve 9.1, and the first throttle valve 6, pushing the piston rod to extend and drive the blades to feather; the oil in the rod chamber of the pitch cylinder group 12 flows back to the hydraulic oil port of the pressure oil tank 2 through the second normally open electromagnetic reversing valve 5.2 and the second throttle valve 11.

[0056] Although the present invention has been described in detail above using general descriptions and specific embodiments, it will be apparent to those skilled in the art that modifications and improvements may be made thereto. Therefore, such modifications and improvements, without departing from the spirit of the present invention, are intended to be within the scope of protection claimed herein.

Claims

1. An integrated wind power hydraulic pitch device, characterized in that: The integrated wind power hydraulic pitch control device is completely installed inside the wind turbine hub, and comprises: an accumulator group (1), a hydraulic pump (3), a pressure oil tank (2), a pitch control cylinder group (12), and a valve group connected via a plurality of pressure-bearing hydraulic oil pipelines; The pitch cylinder group (12) includes multiple groups of pitch cylinders, each of which includes a rodless cavity (12.1) and a rod cavity (12.2); a piston rod in the rod cavity (12.2) is connected to a wind turbine blade; The accumulator group (1) comprises a plurality of high-pressure oil storage chambers for storing hydraulic oil; the accumulator group (1) provides high-pressure hydraulic oil to the pitch cylinder group (12); the hydraulic oil drives the movement of the piston rod of the pitch cylinder group (12); the movement of the piston rod drives the wind turbine blades to rotate to change the windward angle of the wind turbine blades; The hydraulic oil port of the pressure oil tank (2) is connected to the pressure-bearing hydraulic oil pipeline through the hydraulic pump (3); The valve group comprises: a safety relief valve (4), a first normally open electromagnetic reversing valve (5.1), a second normally open electromagnetic reversing valve (5.2), a first throttle valve (6), a first normally closed electromagnetic reversing valve (7.1), a second normally closed electromagnetic reversing valve (7.2), a proportional reversing valve (8), a first one-way valve (9.1), a second one-way valve (9.2), a second relief valve (10) and a second throttle valve (11).

2. The hydraulic pitch device according to claim 1, characterized in that: The integrated wind power hydraulic pitch device further includes a control device, which controls the opening or closing of each valve of the valve group; The proportional reversing valve (8) comprises four ports: a low-pressure port, a high-pressure port, a first output port and a second output port; The first normally open electromagnetic reversing valve (5.1), the second normally open electromagnetic reversing valve (5.2), the first normally closed electromagnetic reversing valve (7.1), the second normally closed electromagnetic reversing valve (7.2), the first throttle valve (6), the second throttle valve (11), the first one-way valve (9.1) and the second one-way valve (9.2) each comprise an input port and an output port.

3. The hydraulic pitch device according to claim 2, characterized in that: The outlet of the accumulator group (1) is connected to the high-pressure port of the hydraulic pump (3), the output port of the safety relief valve (4) and the high-pressure port of the proportional reversing valve (8) through a pressure-bearing hydraulic oil pipeline; The first output port of the proportional reversing valve (8) is connected to the rodless chamber (12.1) of the pitch cylinder group (12) via a pressure-bearing hydraulic oil pipeline; The second output port of the proportional reversing valve (8) is connected to the input port of the second normally open electromagnetic reversing valve (5.2) and the rod chamber (12.2) of the pitch cylinder group (12) through a pressure-bearing hydraulic oil pipeline; The output port of the second normally open electromagnetic reversing valve (5.2) is connected to the input port of the second relief valve (10) through a pressure-bearing hydraulic oil pipeline and a second throttle valve (11); the input port of the second relief valve (10) is also connected to the hydraulic oil port of the pressure oil tank (2).

4. The hydraulic pitch device according to claim 3, characterized in that: The first output port of the proportional reversing valve (8) is connected to the input port of the second normally closed electromagnetic reversing valve (7.2) via a pressure-bearing hydraulic oil pipeline, and the output port of the second normally closed electromagnetic reversing valve (7.2) is connected to the rodless chamber (12.1) of the pitch cylinder group (12) via a pressure-bearing hydraulic oil pipeline; The outlet of the accumulator group (1) is connected to the input port of the first normally closed electromagnetic reversing valve (7.1) through a pressure-bearing hydraulic oil pipeline; the output port of the first normally closed electromagnetic reversing valve (7.1) is connected to the output port of the second one-way valve (9) of the pressure-bearing hydraulic oil pipeline and the high-pressure port of the proportional reversing valve (8); the input port of the second one-way valve (9.2) is connected to the rod chamber (12.2) of the pitch cylinder group (12) through a pressure-bearing hydraulic oil pipeline.

5. The hydraulic pitch device according to claim 3, characterized in that: The outlet of the accumulator group (1) is connected to the input port of the first normally open electromagnetic reversing valve (5.1) through a pressurized hydraulic oil pipeline, the output port of the first normally open electromagnetic reversing valve (5.1) is connected to the input port of the first one-way valve (9.1) through a pressurized hydraulic oil pipeline, and the input port of the first one-way valve (9.1) is connected to the output port of the first throttle valve (6); the input port of the first throttle valve (6) is connected to the rodless chamber (12.1) of the pitch cylinder group (12) and the input port of the safety relief valve (4) through a pressurized hydraulic oil pipeline.

6. The hydraulic pitch device according to claim 1, characterized in that: The pressure oil tank (2) is a fully enclosed structure; The hydraulic oil port of the pressure oil tank (2) is connected to the oil extraction port of the hydraulic pump (3); An elastic device is used inside the pressure oil tank (2) to keep the hydraulic oil port of the pressure oil tank (2) always in a full oil state.

7. The operating method of the hydraulic pitch device according to any one of claims 1 to 6, characterized in that: The method comprises the following steps: Step 1: The control device of the integrated wind power hydraulic pitch device obtains surrounding wind force and wind direction data through sensors, and controls the angle change of the blades according to the obtained wind force and wind direction data; Step 2: The control device obtains hydraulic oil pressure data inside the accumulator group (1) through a sensor. When the hydraulic oil pressure is lower than a predetermined oil pressure threshold, the control device starts the hydraulic pump (3) to replenish hydraulic oil from the pressure oil tank (2) to the accumulator group (1), so that the hydraulic oil pressure inside the accumulator group (1) reaches or exceeds the predetermined oil pressure threshold; Step 3: When the wind force data exceeds a predetermined wind force threshold, the control device controls the wind turbine blades to feather and stop generating electricity.

8. The method according to claim 7, wherein Step 1 includes sub-steps Step 1.1, feathering action, the control device energizes the first normally closed electromagnetic reversing valve (7.1), the second normally closed electromagnetic reversing valve (7.2) and the proportional reversing valve (8), so that the hydraulic oil inside the accumulator group (1) is injected into the rodless chamber (12.1) of the pitch cylinder group (12) through the first normally closed electromagnetic reversing valve (7.1) and the proportional reversing valve (8), pushing the piston rod to extend, and the piston rod drives the wind turbine blade to feather; Step 1.2, the blade opening action, the control device energizes the first normally closed electromagnetic reversing valve (7.1), the second normally closed electromagnetic reversing valve (7.2) and the proportional reversing valve (8), so that the hydraulic oil inside the accumulator group (1) is injected into the rod chamber (12.2) of the pitch cylinder group (12) through the first normally closed electromagnetic reversing valve (7.1) and the proportional reversing valve (8), driving the piston rod to retract, and the piston rod drives the wind turbine blades to open.

9. The method according to claim 8, wherein Step 1.1 also includes sub-steps: Step 1.11, the control device controls the flow of hydraulic oil to adjust the movement speed of the piston rod by adjusting the opening size of the proportional reversing valve (8); In step 1.12, the control device controls the second one-way valve (9.2) to adjust the flow ratio of the hydraulic oil in the rod chamber (12.2) of the pitch cylinder group (12) to the high-pressure port of the proportional reversing valve (8) through the second one-way valve (9.2), thereby increasing the speed at which the piston rod extends.

10. The method according to claim 9, wherein Step 3 includes the emergency feathering procedure: In step 3.1, the control device cuts off the power to the first normally open electromagnetic reversing valve (5.1) and the second normally open electromagnetic reversing valve (5.2), so that the hydraulic oil inside the accumulator group (1) is injected into the rodless chamber (12.1) of the pitch cylinder group (12) through the first normally open electromagnetic reversing valve (5.1), the first one-way valve (9.1), and the first throttle valve (6), pushing the piston rod to extend and driving the blade to feather; Step 3.2, during emergency feathering, the hydraulic oil in the rod chamber (12.2) of the pitch cylinder group (12) flows back to the pressure oil tank (2) through the second normally open electromagnetic reversing valve (5.2) and the second throttle valve (11).

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