Hydraulic yaw system and wind turbine generator set

Abstract

This disclosure provides a hydraulic yaw system and a wind turbine generator set. The hydraulic yaw system of the wind turbine generator set includes: at least one hydraulic motor for driving the nacelle of the wind turbine generator set to yaw; a first hydraulic circuit connected to a first port of each of the at least one hydraulic motor; a second hydraulic circuit connected to a second port of each of the at least one hydraulic motor; and a power-off yaw module connected between the first and second hydraulic circuits, which replenishes the hydraulic oil in the second hydraulic circuit to the first hydraulic circuit when the wind turbine generator set is completely powered off, so as to circulate the hydraulic oil supply to the at least one hydraulic motor.

Description

Technical Field

[0001] This disclosure pertains to the field of wind power, and more specifically, relates to a hydraulic yaw system and a wind turbine generator set. Background Technology

[0002] Current passive yaw technology can only achieve yaw when the wind turbine is powered (passive yaw is achieved through control). When the wind turbine is not powered, it cannot control valves such as solenoid valves, motors, etc. Therefore, passive yaw cannot be achieved when the wind turbine is not powered, and when the yaw angle of the wind turbine is not in the wind, yaw cannot be oriented towards the wind, which will cause vibration of the unit due to vortex-induced vibration.

[0003] Furthermore, when a wind turbine is without power for various reasons, it cannot actively yaw. Therefore, the nacelle remains at a fixed angle, resulting in a deviation in the yaw system's windward angle. Due to the turbine's characteristics, vibrations will occur, potentially leading to the turbine tower collapsing.

[0004] Additionally, during yaw, the hydraulic drive pump may suck in air due to external forces. Summary of the Invention

[0005] One of the purposes of this disclosure is to provide a hydraulic system capable of achieving passive yaw.

[0006] One of the purposes of this disclosure is to provide a hydraulic yaw system capable of passive yaw in the event of power failure.

[0007] One of the purposes of this disclosure is to provide a hydraulic yaw system that can achieve efficient oil replenishment.

[0008] According to a first aspect of this disclosure, a hydraulic yaw system for a wind turbine generator set is provided. The hydraulic yaw system includes: at least one hydraulic motor for driving the nacelle of the wind turbine generator set to yaw; a first hydraulic circuit connected to a first port of each of the at least one hydraulic motor; a second hydraulic circuit connected to a second port of each of the at least one hydraulic motor; and a power-off yaw module connected between the first and second hydraulic circuits, which replenishes the hydraulic oil in the second hydraulic circuit to the first hydraulic circuit when the wind turbine generator set is completely powered off, so as to circulate oil supply to the at least one hydraulic motor.

[0009] According to embodiments of this disclosure, the power-off yaw module may include: a hydraulic replenishing motor, wherein a first working port of the hydraulic replenishing motor is connected to a second hydraulic circuit, and a second working port of the hydraulic replenishing motor is connected to a first hydraulic circuit; and a replenishing pump, wherein the shaft of the replenishing pump is connected to the hydraulic replenishing motor, the inlet of the replenishing pump is connected to an oil tank, and the outlet of the replenishing pump is connected to the second working port.

[0010] According to embodiments of this disclosure, the power-off yaw module may further include a fuel replenishment throttle valve, and the two ends of the fuel replenishment throttle valve are respectively connected to a first working oil port and a second working oil port.

[0011] According to embodiments of this disclosure, the hydraulic yaw system may further include a first bridging valve assembly unit connected between the first hydraulic circuit and the second hydraulic circuit. The first bridging valve assembly unit includes: a first check valve, the output end of the power-off yaw module being connected to the input port of the first check valve, and the output port of the first check valve being connected to the first hydraulic circuit; and a second check valve, the output end of the power-off yaw module being connected to the input port of the second check valve, and the output port of the second check valve being connected to the second hydraulic circuit. One end of the power-off yaw module is connected to a first node between the first check valve and the second check valve, and the other end of the power-off yaw module is connected to the first hydraulic circuit and the second hydraulic circuit.

[0012] According to embodiments of this disclosure, the hydraulic yaw system may further include a second bridging valve group unit connected between the first hydraulic circuit and the second hydraulic circuit and in parallel with the first bridging valve group unit. The second bridging valve group unit includes: a third check valve, the input port of which is connected to the first hydraulic circuit; and a fourth check valve, the output port of which is connected to the output port of the fourth check valve, and the input port of the fourth check valve is connected to the second hydraulic circuit. One end of the power-off yaw module is connected to a second node between the third check valve and the fourth check valve via the first electrically controlled switch valve group module. The hydraulic yaw system forms a power-off passive yaw circulation circuit passing through one end of the power-off yaw module, the first check valve, the first hydraulic circuit, the hydraulic motor, the second hydraulic circuit, the fourth check valve, and the other end of the power-off yaw module, or forms a power-off passive yaw circulation circuit passing through one end of the power-off yaw module, the second check valve, the second hydraulic circuit, the hydraulic motor, the first hydraulic circuit, the third check valve, and the other end of the power-off yaw module.

[0013] According to embodiments of this disclosure, the first electrically controlled switching valve assembly module may include a first electrically controlled switching valve and a first throttle valve connected in series with each other.

[0014] According to embodiments of this disclosure, the first node and the second node may be connected via a first overflow valve, and the first node may be connected to the oil tank via a second overflow valve.

[0015] According to embodiments of this disclosure, the hydraulic yaw system may further include a heat dissipation module, which includes: a fan motor, the output terminal of the power-off yaw module being connected to a first working port of the fan motor, a radiator, a second working port of the fan motor being connected to the first working port of the radiator, and the second working port of the radiator being connected to an oil tank.

[0016] According to embodiments of this disclosure, the hydraulic yaw system may further include: a hydraulic drive module, a directional valve, the hydraulic drive module being connected to a first hydraulic circuit via the directional valve and a second electrically controlled switch valve, and the second hydraulic circuit being connected to an oil tank via a third electrically controlled switch valve and the directional valve, and the passive yaw return oil outlet of the directional valve being connected to the output terminal of the power-off yaw module.

[0017] According to a second aspect of this disclosure, a hydraulic yaw system for a wind turbine generator set is provided. The hydraulic yaw system includes: at least one hydraulic motor for driving the nacelle of the wind turbine generator set to yaw; a hydraulic drive module for supplying hydraulic oil to the at least one hydraulic motor; a first hydraulic oil passage connected to a first port of each of the at least one hydraulic motor; a second hydraulic oil passage connected to a second port of each of the at least one hydraulic motor; a bridging valve unit bridging the first hydraulic oil passage and the second hydraulic oil passage for circulating hydraulic oil from the other hydraulic oil passage (which is the return oil side) to the supply oil side when the supply oil side of the first hydraulic oil passage and the second hydraulic oil passage needs replenishment; and a reversing valve, wherein the hydraulic drive module is connected to the first hydraulic oil passage via the reversing valve, and the second hydraulic oil passage is connected to an oil tank via the reversing valve, wherein the return oil outlet of the reversing valve is connected to the bridging valve unit to achieve circulating replenishment.

[0018] According to embodiments of this disclosure, a bridging valve assembly unit may include a first bridging valve assembly unit, the first bridging valve assembly unit including: a first check valve, the return oil outlet of the directional valve being connected to the input port of the first check valve, and the output port of the first check valve being connected to a first hydraulic circuit; and a second check valve, the return oil outlet of the directional valve being connected to the input port of the second check valve, and the output port of the second check valve being connected to a second hydraulic circuit, wherein the return oil outlet of the directional valve is connected to a first node between the input port of the first check valve and the input port of the second check valve.

[0019] According to embodiments of this disclosure, the bridging valve assembly unit may further include a second bridging valve assembly unit, the second bridging valve assembly unit including: a third check valve, the input port of the third check valve being connected to a first hydraulic circuit; a fourth check valve, the output port of the third check valve being connected to the output port of the fourth check valve, and the input port of the fourth check valve being connected to a second hydraulic circuit, wherein a second node between the third check valve and the fourth check valve is connected to a first node via a first relief valve, and the first node is connected to an oil tank via a second relief valve.

[0020] According to embodiments of this disclosure, the hydraulic yaw system may further include a fourth electrically controlled switching valve, which is connected between the hydraulic drive module and the second relief valve.

[0021] According to embodiments of this disclosure, the directional valve may include a first working port, a second working port, a third working port, and a fourth working port. The first working port is connected to the hydraulic drive module, the second working port is connected to the first node as a return oil outlet, the third working port is connected to the first hydraulic circuit via a second electrically controlled switch valve, and the fourth working port is connected to the second hydraulic circuit via a third electrically controlled switch valve.

[0022] According to a third aspect of this disclosure, a wind turbine generator set is provided, comprising: a tower; a nacelle movably connected to the tower via a yaw bearing; a hydraulic yaw system, the hydraulic yaw system being as described above; and a yaw controller for controlling the hydraulic yaw system to drive the nacelle to yaw rotation, wherein a hydraulic motor of the hydraulic yaw system is mounted on the base of the nacelle and is connected to a retaining ring of the yaw bearing.

[0023] The hydraulic yaw system according to embodiments of this disclosure can improve system safety.

[0024] The hydraulic yaw system according to the embodiments of this disclosure can realize the passive yaw function when power is cut off. When there is no power supply, when the wind speed is high enough, the wind can blow the nacelle of the wind turbine to face away from the wind direction. By facing away from the wind, the vibration of the unit is eliminated and the safety of the unit is protected. Attached Figure Description

[0025] These and / or other aspects and advantages of this disclosure will become clearer and more readily understood from the following description of embodiments, taken in conjunction with the accompanying drawings, wherein: Figure 1 This is a schematic diagram of a hydraulic yaw system according to an embodiment of the present disclosure; Figure 2 The direction of hydraulic oil flow under a power-off passive yaw condition according to an embodiment of the present disclosure is shown. Figure 3 The direction of hydraulic oil flow under passive yaw conditions according to embodiments of the present disclosure is shown. Figure 4 The direction of hydraulic oil flow is shown in the passive yaw thrust reverse condition according to an embodiment of the present disclosure; Figure 5 The direction of hydraulic oil flow under active yaw conditions according to embodiments of the present disclosure is shown. Figure 6 The hydraulic oil flow direction is shown in the active yaw being towed under the condition according to an embodiment of the present disclosure; Figure 7 The direction of hydraulic oil flow is shown in the active yaw reverse-dragging condition according to an embodiment of the present disclosure. Detailed Implementation

[0026] The following detailed description is provided to aid in obtaining a full understanding of the methods, apparatus, and / or systems described herein. However, the order of operations described herein is merely illustrative and is not limited to those orders set forth herein; equivalent substitutions or changes may be made, except for operations that must occur or be performed in a specific order. Furthermore, for clarity and conciseness, descriptions of content well-known in the art will be omitted or simplified.

[0027] Unless otherwise defined, all terms used herein (including technical and scientific terms) shall have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure pertains upon understanding this disclosure. Unless expressly defined herein, terms (such as those defined in a general dictionary) shall be interpreted as having a meaning consistent with their meaning in the context of the relevant field and in this disclosure, and shall not be interpreted in an idealized or overly formalistic manner.

[0028] Unless otherwise specified, the same reference numerals generally refer to the same elements (e.g., components, steps, and methods). Reference numerals described in previous embodiments that reappear in later embodiments may be omitted. Furthermore, technical features described in different or the same embodiments can be combined in any way, as long as the combined embodiment or technical solution is complete and can solve the technical problems of this application or achieve the technical effects described or not described in this disclosure but which can be determined based on the complete technical solution described above.

[0029] In this disclosure, "connection" or "connection" encompasses not only physical, direct, rigid connections but also extends to the connectivity between fluid pathways. For example, it refers not only to the physical connection between two components via rigid pipes, hoses, or integrated blocks but also to the state where the fluid medium can flow freely. When "connection" is mentioned, it includes not only the physical connections mentioned above but also logical connections. This means that even if components are not physically directly connected, as long as they can indirectly form a fluid pathway through control elements (such as valves) or other functional components (such as filters, accumulators, etc.), they can be considered to be in a "connected" state. For example, a solenoid directional valve can be used to switch the fluid flow direction under different operating conditions, thereby changing the operating mode of the actuator.

[0030] Similar to the statement that A and B are connected or linked, it can include the case where A and B are directly connected or linked, as well as the case where A and B are connected or linked through at least one other intermediate component. The connection or link between a port or end of the same component and another component usually means that the hydraulic oil flowing through that port or end flows through that other component.

[0031] The hydraulic yaw system disclosed herein can achieve passive yaw even when the unit is completely de-energized. Here, "complete de-energization" means that the controller, pumps, valves, etc. of the wind turbine's hydraulic yaw system cannot receive power (e.g., cannot receive power from the external power grid, cannot receive power from other components of the wind turbine, etc.). This can prevent the unit from experiencing vortex-induced vibration due to yaw not being in the wind, avoid the risk of wind turbine tower collapse, and protect the safety of the wind turbine.

[0032] The following is a detailed description of the embodiments of this disclosure.

[0033] Figure 1 This is a schematic diagram of a hydraulic yaw system according to an embodiment of the present disclosure. Figure 2 The hydraulic oil flow direction under a power-off passive yaw condition according to an embodiment of the present disclosure is shown. Figure 3 The direction of hydraulic oil flow under passive yaw conditions according to embodiments of the present disclosure is shown. Figure 4 The hydraulic oil flow direction is shown in the passive yaw thrust reverse condition according to an embodiment of the present disclosure. Figure 5 The hydraulic oil flow direction under active yaw conditions according to embodiments of the present disclosure is shown. Figure 6 The hydraulic oil flow direction under active yaw and forward towing conditions according to embodiments of the present disclosure is shown. Figure 7 The direction of hydraulic oil flow is shown in the active yaw reverse-dragging condition according to an embodiment of the present disclosure.

[0034] Reference Figures 1 to 7 The hydraulic yaw system disclosed herein may include at least one hydraulic motor 10.1, 10.2, 10.3 and 10.4, a first hydraulic circuit, a second hydraulic circuit and a power-off yaw module 11, 12 and 13.

[0035] At least one hydraulic motor 10.1, 10.2, 10.3 and 10.4 can drive the nacelle of the wind turbine generator to yaw.

[0036] As an example, the number of hydraulic motors can be at least one; for example, wind turbine generators are typically configured with 2 to 6 hydraulic motors, such as 2 or 4, to ensure uniform distribution of driving force and improve system reliability and redundancy. The type of hydraulic motor disclosed herein is not specifically limited.

[0037] At least one hydraulic motor 10.1, 10.2, 10.3, and 10.4 may be symmetrically mounted around the yaw bearing between the bottom of the nacelle and the top of the tower, i.e., distributed circumferentially around the yaw slewing bearing. Each hydraulic motor is connected to the outer gear ring of the yaw bearing via a gear transmission mechanism, wherein the output shaft of the hydraulic motor drives the pinion to rotate, and the pinion meshes with the large gear ring of the yaw bearing fixed to the top of the tower, thereby converting hydraulic energy into mechanical rotation and driving the entire nacelle to rotate around the tower axis.

[0038] At least one hydraulic motor can be supplied with oil by a unified hydraulic pump station. Its rotation direction and speed can be adjusted by controlling the opening of the control valve group and the speed of the pump, so as to realize the left yaw or right yaw action of the engine room.

[0039] During yaw, the wind turbine's main control system can determine and activate the system based on data collected by wind direction sensors. When the wind direction continuously deviates from the front of the turbine by a certain angle, the control system can activate the corresponding hydraulic motors to drive the nacelle to rotate smoothly and slowly to the windward direction. As an example, the yaw system can also be equipped with a yaw damper or brake to lock the nacelle position in the non-yaw state, preventing swaying caused by wind disturbances and ensuring stable and safe operation.

[0040] At least one of the hydraulic motors 10.1, 10.2, 10.3 and 10.4 disclosed herein may have an oil inlet and an oil outlet. Under normal circumstances, the oil inlet is connected to high-pressure oil, and the hydraulic oil after the hydraulic motor has performed work flows out from the oil outlet and returns to the oil tank of the hydraulic system or continues to flow to the next hydraulic component.

[0041] The oil inlet of at least one hydraulic motor 10.1, 10.2, 10.3, and 10.4 can be connected to one of the first hydraulic circuit and the second hydraulic circuit, and the oil outlet of at least one hydraulic motor 10.1, 10.2, 10.3, and 10.4 can be connected to the other of the first hydraulic circuit and the second hydraulic circuit. Various valves and other components may be installed in the first hydraulic circuit and the second hydraulic circuit.

[0042] Reference Figures 1 to 7The hydraulic yaw system may have power-off yaw modules 11, 12, and 13. These modules are connected between the first and second hydraulic circuits, meaning they bridge the high-pressure and low-pressure circuits. When the wind turbine generator is completely powered off, they replenish the hydraulic oil in the second hydraulic circuit to the first hydraulic circuit, circulating oil to at least one hydraulic motor 10.1, 10.2, 10.3, and 10.4. When the first hydraulic circuit is a high-pressure circuit (i.e., the supply circuit), the second hydraulic circuit is a low-pressure circuit (i.e., the return circuit). Conversely, when the first hydraulic circuit is a low-pressure circuit (i.e., the return circuit), the second hydraulic circuit is a high-pressure circuit (i.e., the return circuit). The specific type can be determined by the direction of the yaw force during passive yaw in the event of a power outage.

[0043] As mentioned above, when a wind turbine is without power supply for various reasons, it cannot perform active yaw. The power-off passive yaw module disclosed herein can use wind power to move the nacelle of the wind turbine to face away from the wind direction when there is no power supply and the wind speed is high enough. By having the turbine head face away from the wind, the vibration of the unit can be eliminated, and the safety of the unit can be protected.

[0044] Reference Figure 1 and Figure 2 The power failure yaw modules 11, 12 and 13 disclosed herein may include a hydraulic replenishing motor 12 and a replenishing pump 13.

[0045] The first working port of the hydraulic replenishing motor 12 is connected to the second hydraulic circuit, and the second working port of the hydraulic replenishing motor 12 is connected to the first hydraulic circuit. The shaft of the replenishing pump 13 is connected to the hydraulic replenishing motor 12, the oil inlet of the replenishing pump 13 is connected to the oil tank, and the oil outlet of the replenishing pump 13 is connected to the second working port.

[0046] As an example, the power failure yaw modules 11, 12 and 13 of this disclosure also include a replenishing throttle valve 11, and the two ends of the replenishing throttle valve 11 are respectively connected to the first working oil port and the second working oil port of the hydraulic replenishing motor.

[0047] When the motor speed is high, if all the return oil passes through the hydraulic replenishing motor 12, the total flow rate is very large, causing the hydraulic replenishing motor 12 to rotate very fast, which can easily damage it. By connecting the replenishing throttle valve 11 in parallel with the hydraulic replenishing motor 12, the speed of multiple hydraulic replenishing motors 12 fluctuates greatly due to wind load when passively yawing without power. The parallel design of the replenishing throttle valve 11 diverts a portion of the flow. When the hydraulic replenishing motor 12 has a high speed and large flow rate, the diversion of the replenishing throttle valve 11 is also large; conversely, when the hydraulic replenishing motor 12 has a low speed and low flow rate, the diversion of the replenishing throttle valve 11 is small. This reduces the flow rate through the replenishing motor and lowers the speed of the hydraulic replenishing motor 12.

[0048] Therefore, the replenishing throttle valve 11 can change the flow rate of hydraulic oil entering the hydraulic motor, thereby controlling the speed of the hydraulic replenishing motor 12. When it is necessary to reduce the speed of the hydraulic replenishing motor 12, the opening of the throttle valve can be increased, the flow of the throttle valve can be increased, the flow rate through the hydraulic replenishing motor 12 can be reduced, and the speed of the replenishing motor 12 can be reduced. Conversely, the opening of the replenishing throttle valve 11 can be reduced, the flow rate through the hydraulic replenishing motor 12 can be increased, and the speed of the replenishing motor 12 can be increased. The replenishing throttle valve 11 can improve the reliability of the power failure yaw module and the system safety.

[0049] The power failure yaw module disclosed herein can achieve passive yaw in the event of a complete power failure, and does not require components such as accumulators, motors, or pumps, but instead utilizes external force to achieve passive yaw during power failure.

[0050] The configuration of the power-off yaw module disclosed herein is not limited to this. In addition to the replenishing throttle valve 11, the hydraulic replenishing motor 12 and the replenishing pump 13, the power-off yaw module disclosed herein may also include other auxiliary hydraulic components.

[0051] Reference Figures 1 to 7 The hydraulic yaw system disclosed herein also includes various bridging valve assembly units connected between the first hydraulic circuit and the second hydraulic circuit. The bridging valve assembly units may include first bridging valve assembly units 7.1 and 7.2, and the first bridging valve assembly units 7.1 and 7.2 may include a first check valve 7.1 and a second check valve 7.2.

[0052] The first bridging valve units 7.1 and 7.2 can be connected between the first hydraulic circuit and the second hydraulic circuit to circulate hydraulic oil from the other hydraulic circuit (which is the return side of the first and second hydraulic circuits) to the supply side when the supply side of the first and second hydraulic circuits needs to be replenished.

[0053] The output terminals of the power-off yaw modules 11, 12 and 13 are connected to the input port of the first check valve 7.1, the output port of the first check valve 7.1 is connected to the first hydraulic circuit, the output terminals of the power-off yaw modules 11, 12 and 13 are connected to the input port of the second check valve 7.2, and the output port of the second check valve 7.2 is connected to the second hydraulic circuit.

[0054] One end of the power-off yaw modules 11, 12 and 13 is connected to the first node between the first check valve 7.1 and the second check valve 7.2, and the other end of the power-off yaw modules 11, 12 and 13 is connected to the first hydraulic circuit and the second hydraulic circuit.

[0055] Additionally, the bridging valve assembly unit of the hydraulic yaw system disclosed herein may further include second bridging valve assembly units 7.3 and 7.4, which are connected in parallel with the first bridging valve assembly units 7.1 and 7.2 and are bridging the first hydraulic circuit and the second hydraulic circuit. The second bridging valve assembly units 7.3 and 7.4 may include a third check valve 7.3 and a fourth check valve 7.4. The input port of the third check valve 7.3 is connected to the first hydraulic circuit, the output port of the third check valve 7.3 is connected to the output port of the fourth check valve 7.4, and the input port of the fourth check valve 7.4 is connected to the second hydraulic circuit.

[0056] The first bridging valve group units 7.1 and 7.2 can be implemented using normally open electrically controlled switching valves; however, the configuration of the first bridging valve group units 7.1 and 7.2 is not limited to this.

[0057] As an example, one end of the power-off yaw modules 11, 12, and 13 can be connected to a second node between the third check valve 7.3 and the fourth check valve 7.4 via the first electrically controlled switch valve group modules 8 and 9. The hydraulic yaw system forms a power-off passive yaw circulation circuit passing through one end of the power-off yaw modules 11, 12, and 13, the first check valve 7.1, the first hydraulic circuit, the hydraulic motor, the second hydraulic circuit, the fourth check valve 7.4, and the other end of the power-off yaw modules 11, 12, and 13, or forms a power-off passive yaw circulation circuit passing through one end of the power-off yaw modules 11, 12, and 13, the second check valve 7.2, the second hydraulic circuit, the hydraulic motor, the first hydraulic circuit, the third check valve 7.3, and the other end of the power-off yaw modules 11, 12, and 13. The first electrically controlled switch valve group modules 8 and 9 can be normally open valve group modules. When the power is off, the first electrically controlled switch valve group modules 8 and 9 can be opened, and hydraulic oil can pass through the first electrically controlled switch valve group modules 8 and 9.

[0058] The second bridging valve group units 7.3 and 7.4 can both be implemented by normally open electrically controlled switching valves; however, the configuration of the second bridging valve group units 7.3 and 7.4 is not limited to this.

[0059] As an example, the first electrically controlled switch valve group modules 8 and 9 may include a first electrically controlled switch valve 9, and may also include a first throttle valve 8 connected in series with the first electrically controlled switch valve 9. The first electrically controlled switch valve 9 may be a two-position two-way solenoid valve, and the first electrically controlled switch valve group module may also have other structures, as long as the first electrically controlled switch valve group module can be opened when power is off, and can be opened and closed as needed when power is supplied.

[0060] Although Figure 2 The illustration shows the case where the passive yaw force is directed to the right; however, the embodiments of this disclosure are not limited to this, and the passive yaw force can be directed in any direction other than that. Figure 2 Conversely, as shown, the first and second hydraulic circuits can have opposite hydraulic oil flow directions.

[0061] Reference Figures 1 to 7 The first node between the first check valve 7.1 and the second check valve 7.2, and the second node between the third check valve 7.3 and the fourth check valve 7.4, can be connected via a first relief valve 10. The first relief valve 10 can be activated when the oil pressure between the first node and the second node exceeds a safety threshold. For example, in the passive yaw reverse towing condition described below, the high-pressure oil overflows through the first relief valve 10 and becomes low-pressure oil, which then merges with the hydraulic oil supplied by the replenishment path (e.g., the T-port return oil of the directional valve) and replenishes the low-pressure side of the hydraulic motor. In addition, the first node can be connected to the oil tank via a second relief valve 16, which can provide the back pressure required for replenishment, thereby improving system safety.

[0062] As an example, the hydraulic yaw system of this disclosure may further include heat dissipation modules 14 and 15, which include a fan motor 14 and a radiator 15. The output terminals of the power-off yaw modules 11, 12, and 13 are connected to the first working port of the fan motor 14, and the second working port of the fan motor 14 is connected to the first working port of the radiator 15. The second working port of the radiator 15 is connected to an oil tank. The fan motor 14 can blow air onto the radiator 15 under the action of hydraulic oil.

[0063] As an example, the hydraulic yaw system of this disclosure may also include hydraulic drive modules 1, 2 and 3 and a directional valve 5. The hydraulic drive modules 1, 2 and 3 are connected to a first hydraulic circuit via the directional valve 5, and the second hydraulic circuit is connected to an oil tank via the directional valve 5. The return oil outlet (e.g., T-port return oil) of the directional valve 5 is connected to a bridging valve group unit to achieve cyclic oil replenishment.

[0064] As an example, hydraulic drive modules 1, 2, and 3 are connected to a first hydraulic circuit via directional control valve 5 and a second electrically controlled switching valve 6.1. The second hydraulic circuit is connected to a hydraulic tank via a third electrically controlled switching valve 6.2 and directional control valve 5. The passive yaw return outlet of directional control valve 5 is connected to the output of power-off yaw modules 11, 12, and 13. As an example, directional control valve 5 can be a proportional directional control valve, such as a proportional solenoid directional control valve. The return outlet of directional control valve 5 is connected to the first bridging valve group units 7.1 and 7.2 to achieve cyclic oil replenishment. Additionally, the return outlet of directional control valve 5 is connected to the input port of the first check valve 7.1, and the output port of the first check valve 7.1 is connected to the first hydraulic circuit. The return outlet of directional control valve 5 is connected to the input port of the second check valve 7.2, and the output port of the second check valve 7.2 is connected to the second hydraulic circuit. The return outlet of directional control valve 5 is connected to the node between the input port of the first check valve 7.1 and the second check valve 7.2.

[0065] Hydraulic drive modules 1, 2 and 3 may include a motor 1 and a pump 2, and may also include a check valve 3. The motor 1 can drive the pump 2 to rotate, and the pump 2 can pump hydraulic oil from the hydraulic oil tank to the hydraulic oil circuit.

[0066] As an example, the directional control valve 5 can be a solenoid directional control valve, but its construction is not limited to this. In one example, the directional control valve 5 may have a first working port P, a second working port T, a third working port A, and a fourth working port B. The first working port P can be connected to a second electrically controlled switching valve 6.1, and the fourth working port B can be connected to a third electrically controlled switching valve 6.2. The first working port P is connected to hydraulic drive modules 1, 2, and 3, and the second working port T can be connected to heat dissipation modules 14 and 15. The second working port T serves as a return oil outlet connected to the first node between the first check valve 7.1 and the second check valve 7.2. The third working port A is connected to the first hydraulic circuit via the second electrically controlled switching valve 6.1, and the fourth working port B is connected to the second hydraulic circuit via the third electrically controlled switching valve 6.2.

[0067] Additionally, the hydraulic yaw system of this disclosure may further include a fourth electrically controlled switching valve 4, which can be connected between the output port of the one-way valve 3 and the second relief valve 16. Each electrically controlled switching valve in this disclosure can be a solenoid valve. The fourth electrically controlled switching valve 4 can be used in both forward and reverse towing situations during yaw. In the accompanying drawings of this disclosure, colored lines indicate hydraulic oil flowing through corresponding components, and black lines indicate hydraulic oil not flowing through corresponding components.

[0068] Passive yaw during power failure Reference Figure 2 Driven by the wind, the nacelle rotates, and the wind force is transmitted to the yaw gear ring, then to the yaw reducer, and finally drives the hydraulic motor to rotate.

[0069] like Figure 2 As shown, when clockwise rotation occurs, at least one hydraulic motor draws oil from the oil circuit on the left. In the absence of power supply, all solenoid valves in the system are in a de-energized state. The on / off state of the solenoid valves in the de-energized state can be selected according to the oil circuit conditions under different operating circumstances.

[0070] like Figure 2 As shown, hydraulic oil cannot flow at the second solenoid valve 6.1 and the third solenoid valve 6.2, and the first solenoid valve 9 is de-energized, allowing hydraulic oil to flow through its orifice. When the hydraulic oil passes through the first throttle valve 8, according to the principles of hydraulic fluid dynamics, it encounters resistance as it passes through a small orifice. When the wind speed is high, i.e., the wind load is large, at least one hydraulic motor (10.1, 10.2, 10.3, and 10.4) rotates at high speed, resulting in a large total hydraulic oil flow. Based on the characteristics of the throttle valve, a larger flow rate leads to higher pressure at the inlet of the first throttle valve 8, generating a greater reaction force. Consequently, the speed of at least one hydraulic motor decreases, reducing the yaw speed. Under different wind loads, the hydraulic system passively generates different pressures and wind load balances, i.e., different yaw speed balances. By selecting the appropriate specifications for the first throttle valve 8, the working pressure of the hydraulic system does not exceed the maximum withstand pressure under maximum wind load (maximum speed).

[0071] Reference Figure 2 The return oil from the hydraulic replenishing motor 12 and the discharge oil from the replenishing pump 13 are combined and supplied to the left oil circuit (i.e., the first hydraulic circuit) of at least one hydraulic motor 10.1, 10.2, 10.3 and 10.4. Since the leakage of at least one hydraulic motor 10.1, 10.2, 10.3 and 10.4 is uncertain, the combined oil flow may be greater than the leakage. Therefore, excess hydraulic oil can be discharged to prevent the pressure in the right oil circuit (i.e., the second hydraulic circuit) of the hydraulic motor from being too high. The second relief valve 16 can ensure that the hydraulic oil on the right side is both sufficient and not too high.

[0072] Reference Figure 2 High-pressure oil flows sequentially through the fourth check valve 7.4 and the first throttle valve 8 before entering the power-off yaw modules 11, 12, and 13, driving the hydraulic replenishing motor 12. The hydraulic replenishing motor 12 is connected to the shaft of the replenishing pump 13. As the hydraulic replenishing motor 12 rotates, it drives the replenishing pump 13 to rotate as well. The replenishing pump 13 draws oil from the oil tank. The return oil from the hydraulic replenishing motor 12 and the discharge oil from the replenishing pump 13 are combined, passing through check valve 7.5, and then through the first check valve 7.1 to the left oil circuit of the motor. Figure 2 The oil circuit on the left side shown is the low-pressure oil circuit. Additionally, the output port of the one-way valve 7.5 can be connected to the second relief valve 16.

[0073] During power failure and yaw, the inlet of the first throttle valve 8 is under high pressure. After passing through the first throttle valve 8, the pressure decreases, thus increasing the temperature of the outlet oil. Therefore, it is best to cool the hydraulic oil. However, due to the lack of power supply, cooling cannot be achieved using an electric cooling fan.

[0074] This disclosure utilizes a heat dissipation module including a fan motor for heat dissipation. The hydraulic oil flowing out of the first throttle valve 8 passes through the fan motor 14, which drives the fan to rotate. The fan blows air onto the radiator 15, thereby achieving heat dissipation of the hydraulic oil.

[0075] Although the above description uses a passive yaw force reversed in a clockwise direction as an example, the embodiments of this disclosure are not limited to this. For example, when the passive yaw force is reversed in a counterclockwise direction, the left oil circuit of at least one hydraulic motor 10.1, 10.2, 10.3 and 10.4 becomes a high-pressure oil circuit, and the right oil circuit of at least one hydraulic motor 10.1, 10.2, 10.3 and 10.4 becomes a low-pressure oil circuit. The second check valve 7.2 is open, the first check valve 7.1 is closed, the third check valve 7.3 is open, and the fourth check valve 7.4 is closed. The flow direction of hydraulic oil in other oil circuits can be as described above, and will not be repeated here.

[0076] Although not shown, but except Figure 2 In addition to the components shown that flow along the direction of hydraulic oil flow, the power-off yaw oil circuit of this disclosure may also include other auxiliary components.

[0077] Furthermore, the valve assembly modules disposed on the left and right sides of at least one hydraulic motor can be connected to the first hydraulic circuit and the second hydraulic circuit, respectively. Hydraulic oil replenished by the power-off yaw modules 11, 12, and 13 can be supplied to at least one hydraulic motor through these valve assembly modules, and the return oil from at least one hydraulic motor can also be returned to the power-off yaw modules 11, 12, and 13 through these valve assembly modules. Additionally, hydraulic oil from the hydraulic drive modules 1, 2, and 3 can be supplied to at least one hydraulic motor through these valve assembly modules, and the return oil from at least one hydraulic motor can also be recovered to the oil tank through these valve assembly modules. The valve group modules disposed on the left and right sides of at least one hydraulic motor as shown in the figure may include a third check valve 7.3, a fourth check valve 7.4, a second check valve 7.2, a first check valve 7.1, first electrically controlled switch valve group modules 8 and 9, a first relief valve 10, a second electrically controlled switch valve 6.1, a third electrically controlled switch valve 6.2, and a directional valve 5. However, the configuration of the valve group modules disposed on the left and right sides of at least one hydraulic motor is not limited to the configuration described above, as long as it can circulate the hydraulic oil supplied by the power-off yaw module to the hydraulic motor in the absence of power supply. In addition, the valve group modules can meet the requirements of other different yaw conditions as needed.

[0078] Passive yaw (unit not disconnected from power) The passive yaw scheme of the hydraulic yaw system of wind turbine generator set is as follows: Figure 3 As shown.

[0079] In passive yaw mode, when the hydraulic yaw system receives a passive yaw command, such as a right yaw command, motor 1 starts and rotates, which in turn drives pump 2 to rotate.

[0080] The fourth electrically controlled switch valve 4 is not energized. When driven by external force, the hydraulic motor... Figure 3 Rotate in the direction shown, and the hydraulic oil in the right-side pipeline will follow... Figure 3 The flow direction is as shown. At the reversing valve 5, port B and port T are connected. Due to the instability of the external driving force generated by the wind, the rotation speed of at least one hydraulic motor 10.1, 10.2, 10.3, and 10.4 is unstable. When the yaw controller detects that the yaw speed exceeds the normal speed through the sensor, it increases the resistance (i.e., controls the amount of oil replenishment) by reducing the opening of the reversing valve 5. The rotation speed (i.e., yaw speed) of at least one hydraulic motor 10.1, 10.2, 10.3, and 10.4 will decrease. The opening size of the reversing valve 5 can be dynamically adjusted by the yaw controller. The pressure in the oil circuit on the right side of the motor can be adjusted by adjusting the opening of the reversing valve 5. That is, when the external force drives the hydraulic motor to rotate, it provides resistance to the hydraulic motor, thereby realizing passive yaw speed control and stabilizing the passive yaw speed. The yaw controller of the wind turbine generator can accept the external wind speed, wind direction, and yaw speed, and can determine the corresponding mode, thereby controlling the pumps, various control solenoid valves, and / or reversing valves in the yaw hydraulic system.

[0081] Oil returns from the T port of the directional valve 5. At the same time, the T port of the directional valve 5 is connected to the node between the second relief valve 16 and the first check valve 7.1 and the second check valve 7.2, thereby creating back pressure at the second relief valve 16. Meanwhile, the pump 2 continues to supply hydraulic oil, thus ensuring that the hydraulic oil in the left oil circuit of the hydraulic motor is sufficient. After the hydraulic oil exceeds the hydraulic oil required by the right oil circuit of the hydraulic motor, the excess hydraulic oil can pass through the radiator and / or the second relief valve 16 and finally return to the oil tank.

[0082] In the hydraulic yaw system disclosed herein, the return oil from the T port of the directional valve 5 is compensated to the oil port of the hydraulic motor through the first check valve 7.1 and the second check valve 7.2, ensuring that the hydraulic oil in the hydraulic motor pipeline remains sufficient. Additionally, refer to... Figure 3 Alternatively, oil replenishment can be performed using an alternative replenishment path that bypasses the reversing valve 5. For example, when oil replenishment is required for passive yaw, the fourth electronically controlled switch valve 4 is de-energized and energized. Hydraulic drive modules 1, 2, and 3 are connected to the first node between the first check valve 7.1 and the second check valve 7.2 via the fourth electronically controlled switch valve 4, and are connected to the hydraulic oil tank via the second relief valve 16.

[0083] In addition, due to the uncertainty of wind speed, when the wind speed is low, the external force generated by the wind cannot achieve passive yaw. In order to prevent the yaw system from deviating too much from the wind, the hydraulic yaw system needs to provide active driving force. For example, the fourth electronically controlled switch valve 4 can be energized. At this time, the hydraulic oil cannot flow through the fourth electronically controlled switch valve 4 to the second overflow valve 16 or the heat dissipation module, and the system can thus provide active driving force.

[0084] Therefore, under passive yaw conditions, the return oil path can be formed sequentially as follows: high-pressure side of hydraulic cylinder → third solenoid valve 6.2 → port B of directional valve 5 → port T of directional valve 5; supply oil path can be formed sequentially as follows as follows as follows as follows as follows as follows as follows as follows: hydraulic drive modules 1, 2 and 3 → port P of directional valve 5 → port A of directional valve 5 → second solenoid valve 6.1 → low-pressure side of hydraulic cylinder; replenishment oil path can be formed sequentially as follows as follows as follows as follows as follows as follows as follows as follows: hydraulic drive modules 1, 2 and 3 → fourth solenoid valve 4 → first node B → first check valve 7.1.

[0085] Although not shown, when the direction of the passive yaw force is opposite to... Figure 3 When the directions are reversed, ports P and B of the reversing valve 5 are connected, and ports A and T are connected. That is, the left side of at least one hydraulic motor becomes the high-pressure side, and the right side of at least one hydraulic motor becomes the low-pressure side. The low-pressure side can be replenished with oil through the second check valve 7.2. The specific flow direction of the hydraulic oil in this case will not be described in detail.

[0086] Passive yaw being towed When a wind turbine performs passive yaw using wind power, the wind load is unstable and the direction may change in real time. During passive yaw, it is desirable to rotate in one direction and minimize frequent changes in direction. Figure 4 As shown, the oil circuit is under low pressure, and when an abnormal directional load occurs, at least one hydraulic motor 10.1, 10.2, 10.3 and 10.4 is dragged in the opposite direction.

[0087] The second electrically controlled switch valve 6.1 is de-energized. When the external load in the abnormal direction does not exceed the driving capacity, the first relief valve 10 is not opened, so the yaw will not reverse and no control intervention is required, thus avoiding frequent directional changes. When the external load in the abnormal direction exceeds the driving capacity, the system will overflow, and the yaw will reverse. Therefore, the first relief valve 10 can ensure the safety of the system.

[0088] like Figure 4As shown, the passive yaw direction is clockwise, and the abnormal load direction is counterclockwise. The left side of at least one hydraulic motor 10.1, 10.2, 10.3, and 10.4 is the high-pressure side. High-pressure oil is supplied to the low-pressure side sequentially via the third check valve 7.3, the first relief valve 10, and the second check valve 7.2. Additionally, the hydraulic oil on the low-pressure side flows to node B via the third electrically controlled switch valve 6.2 and the B and T ports of the directional valve 5, or flows to the hydraulic oil tank via the second relief valve 16. Furthermore, the hydraulic oil from hydraulic drive modules 1, 2, and 3 can flow to the first node via the fourth electrically controlled switch valve 4 or to the hydraulic oil tank via the second relief valve 16.

[0089] Therefore, under the condition of passive yaw being reverse-drag, the return oil path can be formed sequentially from the high-pressure side of the hydraulic cylinder → the third check valve 7.3 → the first relief valve 10, and sequentially from the low-pressure side of the hydraulic cylinder → the third solenoid valve 6.2 → the B port of the directional valve 5 → the T port of the directional valve 5. Furthermore, the replenishment oil path can be formed sequentially from the T port of the directional valve 5 → the first node B → the second check valve 7.2, as well as the replenishment oil path from hydraulic drive modules 1, 2 and 3 → the fourth solenoid valve 4 → the first node B → the second check valve 7.2.

[0090] Additionally, although not shown, when the passive yaw direction is counterclockwise and the abnormal load is clockwise, the right side of at least one hydraulic motor 10.1, 10.2, 10.3, and 10.4 becomes the high-pressure side, and a circulating oil replenishment path can be formed via the fourth check valve 7.4, the first relief valve 10, the first check valve 7.1, etc. Further details are omitted here.

[0091] Active yaw like Figure 5 As shown, the hydraulic yaw system of the wind turbine generator set achieves active yaw.

[0092] When the hydraulic yaw system receives an active yaw command, such as a right yaw command, motor 1 starts and rotates, driving pump 2 to rotate.

[0093] When the fourth solenoid valve 4 is energized, hydraulic oil cannot pass through the fourth solenoid valve 4, thereby establishing high pressure and driving the hydraulic oil to flow to the directional valve 5.

[0094] For example, the control signal for directional valve 5 (e.g., a proportional directional valve) can be -10V to +10V, such as... Figure 5 As shown, when a +10V control signal is supplied to the directional control valve, the right-side solenoid valve of the directional control valve is energized, and port P (i.e., the first working oil port) is connected to port A (i.e., the third working oil port), and port B (i.e., the fourth working port) is connected to port T (i.e., the second working oil port or return oil outlet). During yaw, a corresponding control signal is supplied to the directional control valve 5 according to the yaw speed requirements.

[0095] Reference Figure 5 The hydraulic oil flows from port P to port A of the directional control valve, and then passes through the second electrically controlled switch valve 6.1. During right yaw, the second electrically controlled switch valve 6.1 is de-energized, allowing hydraulic oil to flow from port P to port A, but not from port A to port P. This prevents back drag caused by internal leakage in the directional control valve 5 under external instantaneous large loads.

[0096] After the hydraulic oil passes through the second electrically controlled switch valve 6.1, it drives at least one hydraulic motor 10.1, 10.2, 10.3 and 10.4 to rotate. The output shaft of the hydraulic motor is connected to the reducer, thereby driving the small gear of the reducer to rotate, ultimately driving the engine room to yaw.

[0097] After the hydraulic oil passes through at least one hydraulic motor 10.1, 10.2, 10.3 and 10.4, the return oil passes through the third solenoid valve 6.2. The third solenoid valve 6.2 is energized, and the hydraulic oil can pass through the third solenoid valve 6.2.

[0098] Hydraulic oil flows from port B to port T of directional valve 5. The return oil at port T is simultaneously connected to the node of hydraulic motor / fan motor 14, first check valve 7.1, and second check valve 7.2. Under normal active yaw conditions, since the pressure on the left side of first check valve 7.1 and the pressure on the right side of second check valve 7.2 are both higher than the return oil pressure at port T, hydraulic oil flows from port T of directional valve 5 to fan motor 14. After passing through fan motor 14, it enters radiator 15 to dissipate heat from the hydraulic oil.

[0099] In addition, a second relief valve 16 is connected in parallel at the oil port of the fan motor 14. The second relief valve 16 can have a certain opening pressure. When the oil port pressure of the fan motor 14 is higher than the pressure set by the second relief valve 16, the second relief valve 16 opens to overflow, so that the oil port pressure of the fan motor 14 will not be too high. This can also ensure that the T port of the reversing valve 5 has a certain back pressure for oil return.

[0100] Additionally, although not shown, when it is necessary to communicate with Figure 5 When yawing in the opposite direction, as shown, the control signal for directional control valve 5 can be between -10V and 0V. At this point, the solenoid valve on the left side of directional control valve 5 is energized, connecting port P to port B and port A to port T. The valve opening is maximum at -10V and closed at 0V. The opening degree of the directional control valve's port is directly proportional to the magnitude of the control signal, thus enabling [the desired yaw direction]. Figure 5 The opposite direction of the indicated yaw is reversed.

[0101] Active yaw being towed Due to the uncertainty of wind speed, when a sudden strong wind occurs, exceeding the driving capacity of the hydraulic yaw system, the hydraulic motor may be dragged in the opposite direction. Conversely, when an abnormal external load force is in the same direction as the active yaw driving force, the hydraulic motor may be dragged in the forward direction. In this case, the hydraulic circuit will behave as follows: Figure 6 As shown.

[0102] When an abnormal external load force is in the same direction as the active yaw drive force, the speed of the hydraulic motor exceeds the rated speed of the active yaw drive supplied by the hydraulic pump. When the sensor detects that the yaw speed exceeds the normal speed limit, the resistance is increased by reducing the opening of the directional valve 5. At this time, the speed of at least one hydraulic motor (i.e., the yaw speed) will decrease.

[0103] Since the force generated by the wind is dynamically changing, the yaw speed is unstable when the yaw is being towed. The yaw speed can be monitored by a yaw speed sensor, and the opening size of the reversing valve 5 can be dynamically adjusted by the controller to stabilize the yaw speed.

[0104] like Figure 6 As shown, due to insufficient oil supply in the left oil circuit (i.e., the first hydraulic oil circuit), the pressure on the left side of the hydraulic motor will decrease, and the hydraulic oil in the right oil circuit (i.e., the second hydraulic oil circuit) will pass through the reversing valve 5. The return oil from the T port of the reversing valve 5 is connected to the connection between the first check valve 7.1 and the second check valve 7.2. At this time, because the pressure on the left side of the first check valve 7.1 is low, the hydraulic oil can enter the left oil circuit of the motor through the first check valve 7.1.

[0105] The faster the hydraulic motor is driven in the forward direction, the greater the flow rate of hydraulic oil through port B to port T of the directional valve. Simultaneously, more hydraulic oil enters the oil circuit on the left side of the motor through the first check valve 7.1. Furthermore, pump 2 continuously supplies oil, ensuring sufficient hydraulic oil in the pipeline when the hydraulic motor is driven in the forward direction, preventing the hydraulic motor from sucking in cavitation.

[0106] Hydraulic oil exceeding the requirements of the left-side pipeline of the hydraulic motor will eventually return to the oil tank via the radiator and the second relief valve 16.

[0107] Additionally, although not shown, when the active yaw drive force and Figure 6 The direction of the active yaw driving force shown is opposite to that of the abnormal external load force, and the direction of the abnormal external load force is also opposite to that shown. Figure 6 When the abnormal external load force shown is in the opposite direction, the left side of at least one hydraulic motor becomes the high-pressure side and the right side becomes the low-pressure side. The solenoid valve on the left side of the reversing valve 5 is energized, and port P is connected to port B and port A is connected to port T, thus forming different hydraulic oil flow directions.

[0108] Active yaw was reversed Due to the unpredictability of wind speed, when a sudden strong wind occurs, exceeding the driving capacity of the hydraulic yaw system, the hydraulic motor may be dragged in the opposite direction. For details, please refer to... Figure 7 .

[0109] When an abnormal external load force exceeds the active yaw drive force, such as Figure 7 As shown, the pressure in the oil circuit on the left side of the hydraulic motor will increase.

[0110] As described above, due to the first relief valve 10, when the pressure on the left side of at least one hydraulic motor exceeds the set pressure of the first relief valve 10, the first relief valve 10 opens, and the system pressure will no longer increase. At this time, the hydraulic motor will be driven in the reverse direction. The second electrically controlled switch valve 6.1 connected to the left oil circuit of the hydraulic motor is not energized, and the hydraulic oil cannot flow from top to bottom, but must flow through the third check valve 7.3. When the hydraulic motor is driven in the reverse direction, its left oil circuit is high pressure, and its right oil circuit is low pressure. The high-pressure oil supplied by pump 2 and the high-pressure oil when the motor is driven in the reverse direction merge at position 1, and after passing through the third check valve 7.3, flow to the first relief valve 10.

[0111] When the hydraulic motor is dragged in the opposite direction, the hydraulic system operates in overflow mode for a long time, with the left oil circuit continuously supplying high-pressure oil to resist external load forces.

[0112] In conventional motor yaw systems, when the motor is overloaded, the motor current increases, triggering a trip within seconds. After the motor trips, it cannot provide driving force, and the yaw system will be dragged back to a very high speed, leading to component failure. In this disclosure, the oil flowing from the first relief valve 10 reaches the connection between the first check valve 7.1 and the second check valve 7.2, and then enters the right-side oil circuit of the hydraulic motor through the second check valve 7.2. The oil in the right-side oil circuit of the hydraulic motor passes through the third electrically controlled switch valve 6.2, the B port to the T port of the reversing valve 5, the return oil from the T port of the reversing valve 5, and the outlet of the first relief valve 10, converging at position 2. Hydraulic oil exceeding the demand of the right-side pipeline of the hydraulic motor passes through the radiator and the second relief valve, and finally returns to the oil tank. This ensures the safe operation of all components in the oil circuit.

[0113] Additionally, although not shown, when the active yaw drive force and Figure 7 The direction of the active yaw driving force shown is opposite to that of the abnormal external load force, and the direction of the abnormal external load force is also opposite to that shown. Figure 7 When the abnormal external load force shown is in the opposite direction, the right side of at least one hydraulic motor becomes the high-pressure side and the left side becomes the low-pressure side. The specific oil circuit will not be described in detail here.

[0114] The hydraulic yaw system disclosed herein is used for yaw of a wind turbine generator set. A wind turbine generator set according to embodiments of this disclosure may include a tower, a nacelle, a yaw controller, and a hydraulic yaw system. The nacelle is movably connected to the tower via a yaw bearing. The hydraulic motor of the hydraulic yaw system is mounted on the base of the nacelle and connected to a fixed ring (e.g., an outer ring) of the yaw bearing. The yaw controller controls the hydraulic yaw system to drive the nacelle of the wind turbine generator set to yaw rotation; the yaw controller may be part of a main controller. As an example, in active yaw conditions and in the incomplete power outage condition during passive yaw, based on changes in external wind conditions, the yaw controller can control various controllable components (e.g., pumps and various valves) in the hydraulic yaw system to drive the nacelle of the wind turbine generator set to yaw rotation.

[0115] The hydraulic yaw system according to embodiments of this disclosure can improve system safety.

[0116] The yaw controller of the hydraulic yaw system according to embodiments of the present disclosure (e.g., the main controller of the unit) can control the switching between active yaw and passive yaw modes.

[0117] The hydraulic yaw system according to the embodiments of this disclosure can switch freely between active yaw or passive yaw in forward and reverse towing when the power is on, and the original normal active yaw. This allows for more precise and accurate yaw control for working conditions with uncertain wind.

[0118] The hydraulic yaw system according to the embodiments of this disclosure can realize the passive yaw function when power is cut off. When there is no power supply, when the wind speed is high enough, the wind can blow the nacelle of the wind turbine to face away from the wind direction. By facing away from the wind, the vibration of the unit is eliminated and the safety of the unit is protected.

[0119] The above description is merely a preferred embodiment of this disclosure, but the scope of protection of this disclosure is not limited thereto. Any changes or substitutions that are easily conceived by those skilled in the art within the scope of the technology disclosed in this disclosure should be included within the scope of protection of this disclosure. Therefore, the scope of protection of this disclosure should be determined by the scope of the claims.

Claims

1. A hydraulic yaw system for a wind turbine generator set, characterized in that, include: At least one hydraulic motor drives the nacelle of the wind turbine to yaw. A first hydraulic circuit is connected to the first port of each of at least one hydraulic motor; A second hydraulic circuit is connected to the second port of each of the at least one hydraulic motor; The power-off yaw module is connected between the first hydraulic circuit and the second hydraulic circuit, and when the wind turbine generator is completely powered off, it replenishes the hydraulic oil in the second hydraulic circuit into the first hydraulic circuit to circulate oil supply to the at least one hydraulic motor.

2. The hydraulic yaw system of the wind turbine generator set according to claim 1, characterized in that, The power failure yaw module includes: A hydraulic oil replenishing motor, wherein the first working oil port of the hydraulic oil replenishing motor is connected to the second hydraulic oil circuit, and the second working oil port of the hydraulic oil replenishing motor is connected to the first hydraulic oil circuit; The oil replenishing pump has its shaft connected to the hydraulic oil replenishing motor, its inlet connected to the oil tank, and its outlet connected to the second working oil port.

3. The hydraulic yaw system of the wind turbine generator set according to claim 2, characterized in that, The power failure yaw module also includes a fuel replenishment throttle valve, and the two ends of the fuel replenishment throttle valve are respectively connected to the first working oil port and the second working oil port.

4. The hydraulic yaw system of the wind turbine generator set according to claim 1, characterized in that, The hydraulic yaw system further includes a first bridging valve assembly unit connected between the first hydraulic circuit and the second hydraulic circuit, the first bridging valve assembly unit comprising: The first check valve, the output end of the power-off yaw module is connected to the input port of the first check valve, and the output port of the first check valve is connected to the first hydraulic oil circuit; The second check valve is connected to the input port of the power-off yaw module, and the output port of the second check valve is connected to the second hydraulic circuit. The power-off yaw module is connected at one end to the first node between the first check valve and the second check valve, and at the other end to the first hydraulic circuit and the second hydraulic circuit.

5. The hydraulic yaw system of the wind turbine generator set according to claim 4, characterized in that, The hydraulic yaw system further includes a second bridging valve assembly unit connected between the first hydraulic circuit and the second hydraulic circuit and in parallel with the first bridging valve assembly unit. The second bridging valve assembly unit includes: A third check valve, the input port of which is connected to the first hydraulic circuit. The fourth check valve is connected to the output port of the third check valve, and the input port of the fourth check valve is connected to the second hydraulic circuit. Wherein, one end of the power-off yaw module is connected to the second node between the third check valve and the fourth check valve via the first electronically controlled switch valve group module, and the hydraulic yaw system forms a power-off passive yaw circulation circuit passing through one end of the power-off yaw module, the first check valve, the first hydraulic oil circuit, the hydraulic motor, the second hydraulic oil circuit, the fourth check valve, and the other end of the power-off yaw module, or forms a power-off passive yaw circulation circuit passing through one end of the power-off yaw module, the second check valve, the second hydraulic oil circuit, the hydraulic motor, the first hydraulic oil circuit, the third check valve, and the other end of the power-off yaw module.

6. The hydraulic yaw system of the wind turbine generator set according to claim 5, characterized in that, The first electrically controlled switch valve module includes a first electrically controlled switch valve and a first throttle valve connected in series with each other.

7. The hydraulic yaw system of the wind turbine generator set according to claim 6, characterized in that, The first node and the second node are connected via a first overflow valve, and the first node is connected to the oil tank via a second overflow valve.

8. The hydraulic yaw system of the wind turbine generator set according to claim 1, characterized in that, The hydraulic yaw system also includes a heat dissipation module, which comprises: The output terminal of the power-off yaw module is connected to the first working port of the fan motor. The radiator has a second working port connected to the first working port of the fan motor, and the second working port of the radiator is connected to the oil tank.

9. The hydraulic yaw system of a wind turbine generator set according to any one of claims 1 to 8, characterized in that, The hydraulic yaw system also includes: Hydraulic drive module, The hydraulic drive module is connected to the first hydraulic circuit via the reversing valve and the second electrically controlled switch valve, and the second hydraulic circuit is connected to the oil tank via the third electrically controlled switch valve and the reversing valve. The passive yaw return oil outlet of the reversing valve is connected to the output terminal of the power-off yaw module.

10. A hydraulic yaw system for a wind turbine generator set, characterized in that, include: At least one hydraulic motor drives the nacelle of the wind turbine to yaw. The hydraulic drive module supplies hydraulic oil to the at least one hydraulic motor; A first hydraulic circuit is connected to the first port of each of at least one hydraulic motor; A second hydraulic circuit is connected to the second port of each of the at least one hydraulic motor; A bridging valve unit is connected between the first hydraulic circuit and the second hydraulic circuit to circulate hydraulic oil from the other hydraulic circuit (which is the return side of the first hydraulic circuit and the second hydraulic circuit) to the supply side when the supply side of the first hydraulic circuit and the second hydraulic circuit needs to be replenished. as well as A directional control valve is provided, through which the hydraulic drive module is connected to the first hydraulic circuit, and the second hydraulic circuit is connected to the oil tank via the directional control valve. The return oil outlet of the reversing valve is connected to the bridging valve group unit to achieve circulating oil replenishment.

11. The hydraulic yaw system of the wind turbine generator set according to claim 10, characterized in that, The bridging valve assembly unit includes a first bridging valve assembly unit, the first bridging valve assembly unit comprising: The first check valve, wherein the return oil outlet of the reversing valve is connected to the input port of the first check valve, and the output port of the first check valve is connected to the first hydraulic oil circuit; The second check valve has its return oil outlet connected to the input port of the directional valve, and its output port connected to the second hydraulic circuit. The return oil outlet of the reversing valve is connected to a first node between the input port of the first check valve and the input port of the second check valve.

12. The hydraulic yaw system of the wind turbine generator set according to claim 11, characterized in that, The bridging valve assembly unit further includes a second bridging valve assembly unit, the second bridging valve assembly unit comprising: A third check valve, the input port of which is connected to the first hydraulic circuit. The fourth check valve is connected to the output port of the third check valve, and the input port of the fourth check valve is connected to the second hydraulic circuit. The second node between the third check valve and the fourth check valve is connected to the first node via a first relief valve, and the first node is connected to the oil tank via a second relief valve.

13. The hydraulic yaw system of the wind turbine generator set according to claim 12, characterized in that, The hydraulic yaw system also includes a fourth electrically controlled switching valve, which is connected between the hydraulic drive module and the second relief valve.

14. The hydraulic yaw system of the wind turbine generator set according to claim 11, characterized in that, The reversing valve includes a first working port, a second working port, a third working port, and a fourth working port. The first working port is connected to the hydraulic drive module, the second working port is connected to the first node as the return oil outlet, the third working port is connected to the first hydraulic circuit via a second electrically controlled switch valve, and the fourth working port is connected to the second hydraulic circuit via a third electrically controlled switch valve.

15. A wind turbine generator set, characterized in that, include: Tower; The nacelle is movably connected to the tower via a yaw bearing; A hydraulic yaw system, wherein the hydraulic yaw system is the hydraulic yaw system according to any one of claims 1-14; The yaw controller controls the hydraulic yaw system to drive the nacelle to yaw rotation. The hydraulic motor of the hydraulic yaw system is mounted on the base of the engine room, and the hydraulic motor is connected to the retaining ring of the yaw bearing.

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