CN111379675B

CN111379675B - Hydraulic driving system of wind generating set barring gear and control method

Info

Publication number: CN111379675B
Application number: CN201811640010.6A
Authority: CN
Inventors: 章钟伟; 张竹; 李红峰
Original assignee: Fujian Goldwind Technology Co ltd
Current assignee: Fujian Goldwind Technology Co ltd
Priority date: 2018-12-29
Filing date: 2018-12-29
Publication date: 2021-06-25
Anticipated expiration: 2038-12-29
Also published as: CN111379675A

Abstract

The invention relates to a hydraulic driving system and a control method of a barring gear of a wind generating set, wherein the hydraulic driving system comprises a control device, at least two main hydraulic cylinders and a force balancing device; the main hydraulic cylinder comprises a rod cavity, a rodless cavity and a control valve module; the force balancing device comprises a rod cavity balancing oil way and a rodless cavity balancing oil way; the control device controls the oil quantity entering the rod cavity and the rodless cavity through the control valve module, monitors the driving force of each main hydraulic cylinder in real time and calculates the average driving force, and if the deviation between the driving force of the main hydraulic cylinders and the average driving force exceeds a preset range, the control device controls the oil quantity entering the rod cavity through the rod cavity balance oil circuit and/or the oil quantity entering the rodless cavity through the rodless cavity balance oil circuit according to the deviation until the deviation is within the preset range. The hydraulic driving system can adjust the oil pressure of each main hydraulic cylinder, so that the driving force of each main hydraulic cylinder is consistent, the synchronism of each main hydraulic cylinder is ensured, and the electromagnetic air gap of the generator is prevented from being influenced by larger deformation of the generator.

Description

Hydraulic driving system of wind generating set barring gear and control method

Technical Field

The invention relates to the field of wind driven generators, in particular to a hydraulic driving system of a barring gear of a wind driven generator set and a control method.

Background

The wind driven generator is a device for converting wind energy into electric energy, and mainly comprises a cabin, a generator, an impeller and the like. The impeller consists of a hub and blades. A wind turbine is mounted by first mounting a hub to a nacelle and then mounting blades to the hub one by one. Specifically, the hub needs to be rotated to a corresponding position, and then one blade is installed, and then the hub is rotated to the next installation position, and the next blade is installed.

The double-fed generator can drive the hub to rotate through the gear box of the double-fed generator, the hub of the direct-drive generator is directly connected with a generator rotor, the gear box is not arranged inside the double-fed generator, and the controlled rotation of the generator rotor cannot be realized in the installation stage.

The diameter of the large megawatt direct-drive wind power generator is far larger than that of the double-fed wind power generator, and the diameter of the large megawatt direct-drive wind power generator is usually 3m to 6 m. When only one blade is mounted on the hub, the resistance torque exerted on the generator rotor by the gravity of the single blade and the wind load of the blade is large, so that the required torque for driving the generator rotor to rotate is also large. If the motor is adopted for driving, the required motor power and the required reducer have larger volume, and the direct-drive generator does not have enough space. In addition, the diameter of the generator of the large megawatt direct drive unit is as high as more than 3m, even 6m, if a gear transmission mode is adopted, driving torque needs to be applied to the rotor of the generator, so that the generator (particularly an outer rotor inner stator generator) is easy to generate large deformation to influence the electromagnetic air gap of the generator, and the generator is damaged. In addition, the generator rotor cannot be controlled to rotate when the direct-drive wind driven generator is maintained.

Disclosure of Invention

The invention aims to provide a hydraulic driving system and a control method of a barring gear of a wind generating set, which can adjust the oil pressure of each main hydraulic cylinder, make the driving force of each main hydraulic cylinder consistent, ensure the synchronism of each main hydraulic cylinder, avoid the influence of the electromagnetic air gap of a generator caused by the larger deformation of the generator and avoid the damage of the generator.

In order to solve the technical problem, the invention provides a hydraulic driving system of a barring gear of a wind generating set, which comprises a control device, at least two main hydraulic cylinders and a force balancing device corresponding to each main hydraulic cylinder; the main hydraulic cylinder is used for driving a generator rotor to rotate and comprises a rod cavity and a rodless cavity, and the rod cavity oil circuit and the rodless cavity oil circuit of each main hydraulic cylinder are controlled by a control valve module; the force balancing device comprises a rod cavity balancing oil way communicated with the rod cavity and a rodless cavity balancing oil way communicated with the rodless cavity; the control device controls the oil quantity entering the rod cavity and the rodless cavity of each main hydraulic cylinder through the control valve module, monitors the driving force of each main hydraulic cylinder in real time and calculates the average driving force, and if the deviation between the driving force of the main hydraulic cylinder and the average driving force exceeds a preset range, the control device controls the oil quantity entering the rod cavity through the rod cavity balance oil circuit and/or the oil quantity entering the rodless cavity through the rodless cavity balance oil circuit according to the deviation until the deviation is within the preset range.

That is, the control device supplies oil to the rod chamber and the rodless chamber of each master cylinder through the master oil passage, so that the driving forces of the master cylinders are theoretically uniform (i.e., the driving force is the same as the average driving force), but the performance characteristics may differ due to the difference of the hydraulic components themselves. For example, under the same conditions, pressure losses of the same valves are different, and hydraulic oil is lost in the flowing process due to different lengths of oil paths of the master cylinders, so that the driving forces provided by the master cylinders are different, the synchronism of the master cylinders is poor, and the strokes and the forces of the master cylinders are deviated. The force balancing device can balance and adjust the driving force of each master cylinder and balance the stroke and stress of each master cylinder in the turning process, and the deviation between the driving force and the average driving force of each master cylinder is in a preset range, so that the conditions that the generator is deformed greatly, the electromagnetic air gap of the generator is influenced, and the generator is damaged are avoided.

Specifically, the driving force of the master cylinder to the generator rotor may be a pushing force or a pulling force, and the following describes in detail the force balance adjustment process of the driving device to each master cylinder through the force balancing device for two cases, namely, a pushing force hydraulic cylinder (the master cylinder that drives the generator rotor to rotate through the pushing force) and a pulling force hydraulic cylinder (the master cylinder that drives the generator rotor to rotate through the pulling force).

If the deviation between the driving force F1 of a certain thrust hydraulic cylinder and the average driving force exceeds a preset range and F1 is larger than F, the control device increases the oil amount of the rod cavity through the rod cavity balance oil way until the deviation between the driving force F1 of the certain thrust hydraulic cylinder and the average driving force F is within the preset range, and if the deviation between the driving force F1 of the certain thrust hydraulic cylinder and the average driving force is beyond the preset range and F1 is smaller than F, the control device increases the oil amount of the rodless cavity through the rodless cavity balance oil way until the deviation between the driving force F1 of the certain thrust hydraulic cylinder and the average driving force F is within the preset range.

If the deviation between the driving force F1 of a certain tension hydraulic cylinder and the average driving force exceeds a preset range and F1 is larger than F, the control device increases the oil quantity of the rodless cavity through the rodless cavity balance oil way until the deviation between the driving force F1 of the certain tension hydraulic cylinder and the average driving force F is within the preset range, and if the deviation between the driving force F1 of the certain tension hydraulic cylinder and the average driving force is beyond the preset range and F1 is smaller than F, the control device increases the oil quantity of the rod cavity through the rod cavity balance oil way until the deviation between the driving force F1 of the certain tension hydraulic cylinder and the average driving force F is within the preset range.

In addition, the arrangement of the force balancing device can also enable the system to be suitable for the condition that the torque reversal direction changes suddenly, for example, when the blade rotates to the vertical position, the gravity of the blade changes suddenly to the torque direction of the impeller, the control device controls the oil pressure in the rod cavity and/or the rodless cavity of the main hydraulic cylinder through the force balancing device so as to change the torque direction of the main hydraulic cylinder, namely, a resistance is exerted in advance, and therefore the capacity of the system for resisting the load sudden change is improved, and the system is relatively stable in the process of overload of the load sudden change.

Optionally, each of the master cylinders is provided with a first pressure sensor and a second pressure sensor, respectively, the first pressure sensor is configured to detect a pressure of the rodless cavity, and the second pressure sensor is configured to detect a pressure of the rod cavity; the control device calculates the driving force and the average driving force of the master cylinder in real time according to the feedback of the first pressure sensor and the second pressure sensor.

Optionally, each of the master cylinders is provided with a displacement sensor for detecting a displacement of a piston rod of each of the master cylinders.

Optionally, the control device controls the amount of oil entering the rod chamber through the rod chamber balancing oil passage and the amount of oil entering the rodless chamber through the rodless chamber balancing oil passage by a flow control valve.

Alternatively, the flow control valve is a proportional directional valve that can be switched to communicate the oil source with the rod chamber balanced oil passage or the rodless chamber balanced oil passage, and the control device may control the opening degree of the proportional directional valve according to a detected deviation of the driving force and the average driving force of the hydraulic cylinder.

Optionally, the force balancing device further includes two zero-leakage electromagnetic valves, and the two electromagnetic valves are respectively disposed in the rod cavity balancing oil path and the rodless cavity balancing oil path.

Optionally, the oil source is a hydraulic station, and the hydraulic station is provided with a first working pipeline, a second working pipeline and a pressure pipeline; the first working pipeline is respectively communicated with the rodless cavity oil passages of the main hydraulic cylinders, and the second working pipeline is respectively communicated with the rod cavity oil passages of the main hydraulic cylinders; the pressure pipeline is communicated with the proportional directional valve.

Optionally, the first working line is provided with a first total balance valve, and the second working line is provided with a second total balance valve, when the pressure in the working line is lower than the opening pressure of the total balance valve, the total balance valve is closed.

Optionally, the hydraulic station comprises an oil tank, a variable displacement pump, a flow compensation valve and a pump side valve block; the first working pipeline and the second working pipeline are respectively communicated with a variable pump, the pump side valve block is arranged between the two working pipelines and the variable pump and used for switching and controlling the output quantities of the first working pipeline and the second working pipeline, and the flow compensation valve can feed back the flow required by the pump side valve block to the variable pump so as to adjust the output flow of the variable pump to the flow required by the pump side valve block; the hydraulic station further includes a shuttle valve and a pressure setting valve, and the pump-side valve block sets a maximum working pressure through the shuttle valve and the pressure setting valve.

Alternatively, the number of the variable displacement pumps is two, and the two variable displacement pumps may be used for oil supply at the same time or either one of the variable displacement pumps may be used for oil supply.

Optionally, the hydraulic station further comprises a balancing valve block arranged in parallel with the pump-side valve block for controlling the output of the pressure line.

Optionally, the force balancing apparatus further comprises an accumulator in communication between the pressure line and the proportional reversing valve.

Optionally, at least two of the master cylinders include at least one set of a thrust cylinder and a tension cylinder with opposite piston rods.

Optionally, each control valve module includes a pressure reducing valve disposed in the rodless cavity oil path and a check valve connected in parallel with the pressure reducing valve.

Optionally, a first load balancing valve is respectively arranged in a rod cavity oil path of each main hydraulic cylinder, and the first load balancing valve is opened by high-pressure oil in the rodless cavity oil path; and a second load balance valve is arranged in each rodless cavity oil way of the main hydraulic cylinder and is opened through high-pressure oil in the rod cavity oil way.

In addition, the invention also provides a hydraulic control method of the barring gear of the wind generating set, and based on the hydraulic driving system, the hydraulic control method comprises the following steps:

determining the rotation direction and the target rotation angle of the generator rotor;

after the master cylinders simultaneously drive the generator rotor to rotate for a preset angle along the rotating direction, the generator rotor is kept at the current position, the piston of each master cylinder is retreated to the initial position, the generator rotor is re-driven to rotate for the preset angle along the rotating direction until the generator rotor rotates to the target rotating angle, meanwhile, the driving force of each master cylinder is monitored in real time, the average driving force of each master cylinder is calculated, and the deviation between the driving force of each master cylinder and the average driving force is adjusted to be within a preset range through a force balancing device.

The hydraulic control method based on the hydraulic drive system has similar technical effects to those of the hydraulic drive system, and is not repeated herein for saving space.

Optionally, calculating the driving force of the master cylinder and the average driving force of each master cylinder according to the pressure of the rodless cavity and the pressure of the rod cavity of the master cylinder monitored in real time; if the deviation of the driving force of the main hydraulic cylinder and the average driving force exceeds a preset range, adjusting the oil quantity of a rod cavity of the main hydraulic cylinder through a rod cavity balance oil circuit of the force balancing device according to the deviation, and/or adjusting the oil quantity of a rodless cavity of the main hydraulic cylinder through a rodless cavity balance oil circuit of the force balancing device until the deviation is within the preset range.

Optionally, the retracting the piston of each master cylinder to the initial position comprises: and backing each master cylinder one by one, monitoring the driving force of each master cylinder in real time and calculating the average driving force during the backing process of one master cylinder, and adjusting the deviation of the driving force of each master cylinder and the average driving force to the preset range through a force balancing device.

The hydraulic driving system and the control method of the barring gear of the wind generating set can achieve the effect of dynamic balance in the stages of starting, running at a constant speed and stopping at a deceleration, namely ensure that the driving forces of the main hydraulic cylinders are the same and ensure the synchronism of the main hydraulic cylinders.

Drawings

Fig. 1 is a schematic structural diagram of an overall hydraulic drive system of a barring gear according to an embodiment of the present invention;

FIG. 2 is a schematic diagram of the control principle of the barring hydraulic drive system in FIG. 1;

FIG. 3 is a schematic diagram of the first master cylinder and its control unit of FIG. 2;

FIG. 4 is a schematic diagram of the second master cylinder and its control unit of FIG. 2;

FIG. 5 is a schematic diagram of the hydraulic station of FIG. 2;

FIG. 6 is a schematic diagram of the pump side valve block of FIG. 5;

fig. 7 is a block flow diagram of a hydraulic driving method of a barring gear according to an embodiment of the present invention;

fig. 8 is a block diagram showing a detailed flow of the barring driving method shown in fig. 7.

In the accompanying fig. 1-8, the reference numerals are illustrated as follows:

1-a first variable pump; 11-a second variable pump;

20-a flow compensation valve; 40-a fuel tank; 50-return pipe check valve; 52-a shuttle valve; 55-pressure setting valve block; 60-pump side valve block, 62-balance valve block;

100-a first control unit; 200-a second control unit; 300-a third control unit; 400-a fourth control unit; 500-a fifth control unit; 900-hydraulic station;

401-first master cylinder; 402-a second master cylinder; 403-third master cylinder; 404-fourth master cylinder; 405-a fifth master cylinder; 406-a first locking cylinder; 407-a second locking hydraulic cylinder; 408-a third locking hydraulic cylinder; 409-a fourth locking hydraulic cylinder; 410-a fifth locking hydraulic cylinder;

501-displacement sensor; 502-a first pressure sensor; 503-a first load balancing valve; 504-one-way valve; 505-a pressure relief valve; 507-a first directional valve;

521-a second pressure sensor; 523-second load balancing valve; 524-a second direction valve; 525-a first safety valve; 526-a third directional valve; 527-second safety valve; 528-a fourth directional valve;

531-a first electromagnetic valve, 532-a second electromagnetic valve, 533-a proportional reversing valve;

551-first total balance valve; 552-a second gross balance valve;

601-a first cylinder side valve block; 602-a second cylinder side valve block, 603-a third cylinder side valve block, 604-a fourth cylinder side valve block, 605-a fifth cylinder side valve block;

700-turning gear main structure;

701-a first support; 702-a first carriage; 703-a second slide; 704-a second support; 705-a third slide; 706-a third support; 707-a fourth carriage; 708-a fifth carriage; 709-a fourth support;

800-a base; 801-generator rotor; 802-locking hole;

901-quick plug of oil pipe oil inlet; 904-quick plug of oil pipe oil inlet.

Detailed Description

In order to make the technical solutions of the present invention better understood by those skilled in the art, the present invention will be further described in detail with reference to the accompanying drawings and specific embodiments.

Referring to fig. 1 and 2, fig. 1 is a schematic diagram illustrating an overall structure of a hydraulic drive system of a barring gear according to an embodiment of the present invention; fig. 2 is a schematic diagram of the control principle of the barring hydraulic drive system in fig. 1.

The embodiment of the invention provides a hydraulic driving system of a barring gear of a wind generating set, which is suitable for a direct-drive wind generating set and comprises a control device, at least two main hydraulic cylinders and force balancing devices corresponding to the main hydraulic cylinders, wherein the main hydraulic cylinders are used for driving (pushing or pulling) a generator rotor 801 to rotate; the force balancing device comprises a rod cavity balancing oil way communicated with the rod cavity and a rodless cavity balancing oil way communicated with the rodless cavity; the control device controls the oil mass entering the rod cavity and the rodless cavity of each main hydraulic cylinder through the control valve module, monitors the driving force of each main hydraulic cylinder in real time and calculates the average driving force, and if the deviation between the driving force of the main hydraulic cylinders and the average driving force exceeds a preset range, the control device controls the oil mass entering the rod cavity through the rod cavity balance oil circuit and/or the oil mass entering the rodless cavity through the rodless cavity balance oil circuit according to the deviation until the deviation is within the preset range.

The real-time monitoring can be continuous monitoring or once every several seconds, specific monitoring frequency can be set according to specific conditions, specific limitation is not made, when deviation is within a preset range, when each main hydraulic cylinder simultaneously drives the generator rotor 801 to rotate, deformation of the generator rotor 801 is controllable, an electromagnetic air gap of a generator cannot be influenced, damage to the generator is avoided, the specific preset range can be set according to actual conditions of the generator, and specific requirements are not made.

That is, in this embodiment, the control device supplies oil to the rod chamber and the rodless chamber of each master cylinder through the master oil passage, so that the driving forces of the master cylinders are theoretically the same (i.e., the driving force is the same as the average driving force), but the performance characteristics may differ due to the difference in the hydraulic components themselves. For example, under the same conditions, pressure losses of the same valves are different, and hydraulic oil is lost in the flowing process due to different lengths of oil paths of the master cylinders, so that the driving forces provided by the master cylinders are different, the synchronism of the master cylinders is poor, and the strokes and the forces of the master cylinders are deviated. The force balancing device can balance and adjust the driving force of each master cylinder and balance the stroke and stress of each master cylinder in the turning process, and the deviation between the driving force and the average driving force of each master cylinder is in a preset range, so that the conditions that the generator is deformed greatly, the electromagnetic air gap of the generator is influenced, and the generator is damaged are avoided.

Specifically, the driving force of the master cylinder to the generator rotor 801 may be a pushing force or a pulling force, and the following describes in detail the force balance adjustment process of the driving device to each master cylinder by the force balance device for both the pushing force hydraulic cylinder (the master cylinder that drives the generator rotor 801 to rotate by the pushing force) and the pulling force hydraulic cylinder (the master cylinder that drives the generator rotor 801 to rotate by the pulling force).

In the above embodiment, as shown with reference to fig. 3 and 4, each master cylinder is provided with the first pressure sensor 502 and the second pressure sensor 521, respectively, wherein the first pressure sensor 502 is used for detecting the pressure P1 of the rodless chamber, and the second pressure sensor 521 is used for detecting the pressure P2 of the rod chamber. The control device calculates the driving force F1 of the master cylinder based on the feedback of P1 and P2 from the first pressure sensor 502 and the second pressure sensor 521 in real time. The control device calculates the average driving force F of the five master cylinders from the driving forces F1 of the five master cylinders, and adjusts the driving force F1 of each group of master cylinders to the average driving force F.

Further, each master cylinder is provided with a displacement sensor 501, and the displacement sensor 501 is used to detect the displacement of the piston rod, and since the drive stroke of the master cylinder is limited, the hydraulic drive system cannot rotate the generator rotor 801 to its target rotation angle at one time, but is realized by a plurality of drive cycles. That is, after the master cylinders drive the generator rotor 801 to rotate by a preset angle, the piston rods of the master cylinders need to be retracted to the initial positions and then the next driving cycle is performed. The displacement sensor 501 may record the position of the piston rod of the master cylinder, facilitating the retraction of the piston rod of the master cylinder to an initial position after the end of a drive cycle.

In addition, after the generator rotor 801 rotates to the target rotation angle, due to the small leakage of the hydraulic valve, the pistons in the master cylinders also have a small internal leakage phenomenon, and particularly after the pistons receive the gravity action of a single blade on the impeller and the blades receive a large wind load, the length and the pressure of the piston rod of the master cylinder change after a period of time, so that the angular position of the generator rotor 801 changes. Therefore, the control device compares the displacement signal fed back by the displacement sensor 501 with the previously recorded displacement to monitor the displacement change of the piston rod of each master cylinder in real time, and simultaneously compares the pressure signals fed back by the two pressure sensors with the previously recorded pressure, if the difference exceeds a set value (the set value is a range value, and can be specifically set according to experimental measurement), the control device performs fine adjustment oil supplement action on the master cylinder to reduce the difference. When the difference is smaller than the set value, the oil supplementing action is stopped, and the corresponding control valve signal is closed. Further, the generator rotor 801 can be kept to change within a slight angle range after rotating to the target rotation angle, and the situation that the position change amount of the generator rotor 801 is too large and danger is brought to the blade installation work is avoided.

In the above embodiment, the control device controls the amount of oil entering the rod chamber through the rod chamber balancing oil passage and the amount of oil entering the rodless chamber through the rodless chamber balancing oil passage by the flow control valve. Or in this embodiment, the control device may further control the oil inlet amount of the rod cavity balance oil path and the rodless cavity balance oil path through the flow pump. Compared with a flow pump, the flow control valve can simplify the whole structure and is good in economical efficiency.

In the above embodiment, the flow control valve is the proportional directional valve 533, the proportional directional valve 533 can conduct the oil source and the rod chamber balanced oil passage or the rodless chamber balanced oil passage by switching, and the control device can control the opening degree of the proportional directional valve 533 in accordance with the deviation of the driving force of the master cylinder from the average driving force. The control device calculates the force deviation and outputs corresponding current to adjust the opening of the proportional directional valve 533, and hydraulic oil of the oil source reaches the rodless cavity/rod cavity of the oil cylinder through the proportional directional valve 533 to achieve the function of adjusting the force balance. Of course, in this embodiment, flow control valves may be respectively disposed in the rod cavity balanced oil path and the rodless cavity balanced oil path, and the proportional directional valve 533 may reduce the number of components while satisfying the flow control, thereby simplifying the overall structure.

In the above embodiment, the force balancing apparatus further includes the first solenoid valve 531 and the second solenoid valve 532, wherein the first solenoid valve 531 is disposed in the rodless chamber balancing oil path, the second solenoid valve 532 is disposed in the rod chamber balancing oil path, and both the first solenoid valve 531 and the second solenoid valve 532 are zero-leakage solenoid valves. The two solenoid valves can function as safety valves. When the oil pressure in the rod cavity and/or the rodless cavity does not need to be adjusted through the force balancing device, the corresponding solenoid valve is in a closed state, so that the situation that the oil pressure in the rod cavity or the rodless cavity is influenced by leakage of the proportional directional valve 533 can be avoided, and the driving force of each main hydraulic cylinder is ensured to be the same as the average driving force.

Specifically, when the deviation between the driving force F1 of a certain master cylinder and the average driving force F exceeds a preset range, the control device controls the opening degree of the proportional directional valve 533 according to the deviation, simultaneously opens the first solenoid valve 531, supplies oil to the rod cavity oil passage of the master cylinder through the rod cavity balance oil passage, and/or controls the opening degree of the proportional directional valve 533 according to the deviation, simultaneously opens the second solenoid valve 532, supplies oil to the rod cavity oil passage of the master cylinder through the rod cavity balance oil passage, until the deviation between the driving force F1 of the master cylinder and the average driving force F is within the preset range.

As shown in fig. 5, in the above embodiment, the oil source is a hydraulic station 900, and the hydraulic station 900 is provided with a first working line a, a second working line B, a leakage line D, and a pressure line P; the first working pipeline A is respectively communicated with the rodless cavity oil passages of the hydraulic cylinders, and the second working pipeline B is respectively communicated with the rod cavity oil passages of the hydraulic cylinders; the leakage pipeline D is respectively communicated with the overflow valve with the rod cavity and the overflow valve without the rod cavity of each hydraulic cylinder to form a leakage loop; the pressure line P communicates with a proportional directional valve 533. That is, in the present embodiment, the force balancing device and each master cylinder share the oil source, and the action of the oil source on the force balancing device and the action on the master cylinder are not affected by each other, so that the overall structure can be simplified, the occupied space can be reduced, and the economy can be improved, compared to the case where the force balancing device is combined with a separate oil source.

In the above embodiment, the first working line a is provided with the first total balance valve 551, and the second working line B is provided with the second total balance valve 552, so that when the pressure in the working line is reduced and lower than the minimum opening pressure of the total balance valve due to a broken line or the like, the total balance valve is in a closed state, so that the pressure of the oil path in the hydraulic circuit on the master cylinder side is not lost, thereby improving the safety of the system.

Specifically, in this embodiment, the first total balance valve 551 and the second total balance valve 552 are integrated in the first cylinder side valve block 601, and the oil inlet pipeline of each master cylinder is connected in series behind the first total balance valve 551 and the second total balance valve 552, so that the two total balance valves can ensure the system safety of each control unit.

In the above embodiment, the hydraulic station 900 includes the oil tank 40, the variable displacement pump, the flow rate compensation valve 20, and the pump-side valve block 60. Specifically, a first working pipeline a and a second working pipeline B are respectively communicated with the variable pump, a pump side valve block 60 is arranged between the first working pipeline a and the second working pipeline B and the variable pump, a proportional servo reversing valve is arranged in the pump side valve block 60 and used for switching the first working pipeline a and the second working pipeline B as required and controlling the output quantity of the first working pipeline a and the second working pipeline B, and the flow compensation valve 20 can feed back the output flow (i.e. the flow required by the load) required by the pump side valve block 60 to the variable pump so as to adjust the output flow of the variable pump to the output flow required by the pump side valve block 60, so that the output flow of the variable pump is matched with the flow required by the system, the power consumption of the system is reduced, the heat productivity is reduced, and the efficiency is improved.

The hydraulic station also includes a shuttle valve 52, a pressure setting valve 55 and a return line check valve 50, and a pump side valve block 60 sets the maximum operating pressure of the system through two different relief circuits inside the shuttle valve 52 and the pressure setting valve 55. The extension or contraction speed of the piston rod of each master cylinder is calculated according to the designed controlled rotation speed of the generator rotor 801, the opening size of the pump side valve block 60 is prestored by the control device, and the oil supply amount of the two working pipelines is adjusted by sending corresponding control signals to the pump side valve block 60.

Specifically, the rotational speed of the generator rotor 801 is controlled by controlling the speed of each master cylinder. The control device differentiates the displacement signal of the main hydraulic cylinder into a speed which is compared with the calculated extension or contraction speed of the piston rod of the main hydraulic cylinder, calculates the adjustment amount of the opening of the proportional reversing valve of the pump side valve block 60 according to the difference value, sends an adjustment signal to the opening of the proportional reversing valve of the pump side valve block 60, and adjusts the flow of the hydraulic system to enable the difference value between the speed of the hydraulic cylinder and the set value to be within a certain range.

In the above embodiment, the number of the variable pumps is two, and the variable pumps are respectively the first variable pump 1 and the second variable pump 11, and both the variable pumps are load-sensitive variable pumps, and the two variable pumps can be used for supplying oil to the system at the same time, or any one of the two variable pumps can be used for supplying oil to the system, and the two variable pumps are mutually standby. When one variable pump fails, the other variable pump can provide half of the flow required by the normal work of the system, and the system can continue to work in a mode of reducing the rotation speed of the generator rotor 801, so that the reliability of the system is improved, and the safety of the direct-drive wind turbine generator set during single-blade hoisting in a turning mode is guaranteed.

In the above embodiment, the hydraulic station 900 further includes a balancing valve block 62 disposed in parallel with the pump-side valve block 60 for controlling the output of the pressure line P. Specifically, the balance valve block 62 is used to finely adjust the output flow rate of the pressure line P, and the proportional directional valve 533 is used to finely adjust the driving force of each master cylinder. Specifically, the balancing valve block 62 may be a load-sensitive valve or a common switching-value solenoid valve, which is not limited herein.

In the above embodiment, the force balancing device further comprises an accumulator 66 connected between the pressure line P and the proportional directional valve 533, the accumulator 66 being used for storing hydraulic oil for fast response of the force balancing device to a ram pressure. Because the force balancing device is mainly used for adjusting the oil quantity of the rod cavity and the rodless cavity of the main hydraulic cylinder, the control device monitors the driving force of each main hydraulic cylinder in real time or regularly, and timely acquires the force deviation and adjusts the force in time, and the energy accumulator 66 is arranged so that the adjustment can be more timely and rapid. Specifically, in the present embodiment, the accumulator 66 is a piston-type accumulator, but may be other types of accumulators, and is not limited herein.

In the above embodiment, the at least two master cylinders include at least one set of a thrust cylinder and a tension cylinder, where the piston rods of the at least two master cylinders are disposed opposite to each other, and specifically, the piston cylinders of the two master cylinders are disposed opposite to each other, one of the two master cylinders drives the generator rotor 801 to rotate through the thrust, and the other master cylinder drives the generator rotor 801 to rotate through the tension, and the directions of the driving forces of the two master cylinders are the. In the process of driving the generator rotor 801 to rotate, the piston rods of the thrust hydraulic cylinders extend out, the piston rods of the tension hydraulic cylinders retract, and one of the two oppositely arranged piston rods extends out and retracts, namely, the piston rods of the two oppositely arranged thrust hydraulic cylinders or tension hydraulic cylinders can share a stroke space, so that the reserved space prepared for the movement of the piston rods of each main hydraulic cylinder is reduced, more main hydraulic cylinders can be arranged in a limited space, and sufficient driving force is guaranteed.

In the above embodiment, the barring hydraulic drive system further includes the same number of locking hydraulic cylinders as the number of master cylinders, and the generator rotor 801 is provided with the locking hole 802 for driving the locking pin to fix the piston rod of the master cylinder with the locking hole 802.

In the above embodiment, each control valve module includes a pressure reducing valve 505 disposed in a rodless cavity oil path and a check valve 504 connected in parallel with the pressure reducing valve 505, where the pressure reducing valve 505 opens the check valve 504 to close when oil is fed into the rodless cavity oil path, and the pressure reducing valve 505 closes the check valve 504 to open when the rodless cavity oil path returns to reduce the pressure of high-pressure oil entering the rodless cavity side, so that the thrust provided by the master cylinder can be the same as the driving force of the other master cylinders, thereby ensuring that the master cylinders can generate the same force regardless of being in a pushing state or a pulling state, and preventing the deformation of the generator end cover from being inconsistent due to different driving forces acting on the generator rotor 801.

In addition, when the pressure of the rod cavity or the rodless cavity of the master cylinder is too high, the pressure can overflow to the oil tank through the bypass overflow valve inside the first load balance valve 503 or the second load balance valve 523, and the system safety is ensured.

In the above embodiment, the rod chamber oil path of each master cylinder is provided with the first load balancing valve 503, and the first load balancing valve 503 is opened by the high pressure oil in the rod chamber oil path, the rod chamber oil path of each master cylinder is provided with the second load balancing valve 523, and the second load balancing valve 523 is opened by the high pressure oil in the rod chamber oil path. When the system pressure is lower than the opening pressure of the first load balance valve 503 and the second load balance valve 523 due to leakage of the oil path, the two valves are closed, so that hydraulic oil in each hydraulic cylinder (including each main hydraulic cylinder and each locking hydraulic cylinder) cannot be removed, the position of the rotor of the generator is kept unchanged, major accidents such as blade breakage are avoided, time is gained for removing faults, and the safety of the system is improved.

That is, the first main balance valve 551 and the second main balance valve 552 determine based on the total oil pressure of the system and close from the working line side, and can block the oil passages of the respective hydraulic cylinders timely and quickly to avoid the accidents caused by the reduction of the oil pressure in the working line due to the rupture of the working line, and the first load balance valve 503 and the second load balance valve 523 determine based on the oil pressures entering the rod chamber oil passages and the rodless chamber oil passages of the respective master hydraulic cylinders and close in the rod chamber oil passages and the rodless chamber oil passages of the respective master hydraulic cylinders to avoid the accidents caused by the reduction of the oil pressure in the working line due to the rupture of the lines between the main balance valves and the load balance valves, and thus, the double insurance and the safety are higher.

Specifically, as shown in fig. 1, taking the example of five master cylinders, the hydraulic drive system further includes a turning gear main structure 700, four supports, five sliders, and five locking cylinders.

Turning gear main structure 700 is the installation base member, can be integrated as an organic whole with other spare parts of hydraulic drive system, and the hoist and mount installation of being convenient for. The barring gear main structure 700 is an annular structure, and a plurality of sections of spaced rails are arranged on the outer edge of the ring. The barring gear main structure 700 may be fixed to the base 800 and disposed coaxially with the generator rotor 801.

The four supports are respectively a first support 701, a second support 704, a third support 706 and a fourth support 709, the four supports are sequentially distributed on the outer edge of the ring of the turning gear main structure 700, and the top ends of the supports radially protrude along the ring.

The five carriages are a first carriage 702, a second carriage 703, a third carriage 705, a fourth carriage 707, and a fifth carriage 708, respectively. Five sliders are slidably disposed on the rails of the barring device main structure 700, and top ends of the five sliders respectively protrude in a radial direction of the barring device main structure 700.

The first slider 702 is located on the clockwise side of the first carriage 701. The first master cylinder 401 is disposed between the first support 701 and the first slide carriage 702, and the cylinder body thereof is hinged to the top end of the first support 701, and the first piston rod is hinged to the top end of the first slide carriage 702, so that the first piston rod can be driven to extend out

The first slider 702 slides along a rail of the barring gear main structure 700.

The second sliding base 703 is arranged on the counterclockwise side of the second support 704, the cylinder body of the second master cylinder 402 is hinged to the second support 704, the second piston rod is hinged to the second sliding base 703, and the second piston rod can drive the second sliding base 703 to slide along the guide rail of the barring device main structure 700 when retracting.

The third slider 705 is disposed on the clockwise side of the second holder 704, and the third master cylinder 403 is connected therebetween. A fourth carriage 707 is provided on the clockwise side of the third support 706, and a fourth master cylinder 404 is connected therebetween. The fifth slider 708 is disposed on the counterclockwise side of the fourth support 709, and the fifth master cylinder 405 is connected therebetween. The third master cylinder 403, the fourth master cylinder 404, and the fifth master cylinder 405 can be connected in a specific manner as described above with reference to the connection of the first master cylinder 401 or the second master cylinder 402.

The five locking cylinders are a first locking cylinder 406, a second locking cylinder 407, a third locking cylinder 408, a fourth locking cylinder 409 and a fifth locking cylinder 410. Five locking hydraulic cylinders are connected in series at the top of the first carriage 702, the second carriage 703, the third carriage 705, the fourth carriage 707 and the fifth carriage 708. The extension and retraction directions of the five locking hydraulic cylinders are along the axial direction of the generator rotor 801, and the piston rods of the locking hydraulic cylinders can drive the locking pins to enter and exit from the locking holes 802 on the end face of the generator rotor 801. When the locking pin enters the locking hole 802 on the end face of the generator rotor 801, the five main hydraulic cylinders can respectively drive the five sliding bases to slide along the guide rail of the turning gear main structure 700, and meanwhile, the generator rotor 801 is driven to rotate through the five locking hydraulic cylinders. In this embodiment, the hydraulic cylinder for driving the generator rotor 801 to rotate is a servo hydraulic cylinder.

Of course, in this embodiment, the specific number of the master cylinders is not limited, and may be two, three, four, six, and the like, and the specific number may be set according to the conditions such as space.

The first master cylinder 401 is provided with a first cylinder side valve block 601, the second master cylinder 402 is provided with a second cylinder side valve block 602, the third master cylinder 403 is provided with a third cylinder side valve block 603, the fourth master cylinder 404 is provided with a fourth cylinder side valve block 604, and the fifth master cylinder 405 is provided with a fifth cylinder side valve block 605. The five cylinder side valve blocks are used for installing and connecting valves such as the reversing valve and the balance valve, and form control units for controlling the respective master cylinders, that is, a first control unit 100, a second control unit 200, a third control unit 300, a fourth control unit 400 and a fifth control unit 500 shown in fig. 2, respectively, and the hydraulic station 900 is used for supplying hydraulic oil to the respective control units.

The control principle of the hydraulic drive system will be described below with reference to fig. 3 to 6.

FIG. 3 is a schematic diagram of the first master cylinder and its control unit of FIG. 2; FIG. 4 is a schematic diagram of the second master cylinder and its control unit of FIG. 2; FIG. 5 is a schematic diagram of the hydraulic station of FIG. 2; FIG. 6 is a schematic diagram of the pump side valve block of FIG. 5; the driving process of the first master cylinder will be described in detail by taking the first master cylinder as an example.

The first main balance valve 551, the first reversing valve 507, the pressure reducing valve 505 and the first load balance valve 503 are connected in sequence to form an oil path on the rodless cavity side of the first main hydraulic cylinder 401; the second master balance valve 552, the second direction switching valve 524, and the second load balance valve 523 are connected in sequence to form an oil path on the rod cavity side of the first master cylinder 401. A check valve 504 is also connected in parallel to the pressure reducing valve 505. In addition, a first pressure sensor 502 is provided on the rodless cavity side of the first master cylinder 401, a second pressure sensor 521 is provided on the rod cavity side, and a displacement sensor 501 is provided on the cylinder body. The first direction valve 507 and the second direction valve 524 are two-position four-way electromagnetic direction valves.

The proportional directional valve 533 and the first solenoid valve 531 are connected in sequence to form a rod chamber-less balanced oil path of the first master cylinder 401, and the proportional directional valve 533 and the second solenoid valve 532 are connected in sequence to form a rod chamber balanced oil path of the first master cylinder 401.

The third direction switching valve 526, the fourth direction switching valve 528, the first relief valve 525, the second relief valve 527, the first total balance valve 551, and the second total balance valve 552 are connected to form a control oil passage of the first lock cylinder 406. The first relief valve 525 and the second relief valve 527 are both relief valves, and when the pressure in the rod chamber or the rod-free chamber of the first locking hydraulic cylinder 406 is too high, relief can be realized through one of the two relief valves, and the relief oil can flow back to the oil tank through the leakage pipeline D.

The valves are attached and connected by a first cylinder side valve block 601. The first cylinder side valve block 601 is connected with the hydraulic station 900 through a first working pipeline a, a second working pipeline B, a leakage pipeline D and a pressure pipeline P, and the pipeline connection is connected through an oil pipe oil inlet quick plug 901 and an oil pipe oil inlet quick plug 904. The quick plug 901 for the oil inlet of the oil pipe and the quick plug 904 for the oil inlet of the oil pipe are favorable for quick on-site installation and disassembly, the working efficiency is improved, and meanwhile, the leakage of oil liquid during installation and disassembly is reduced, so that the environmental pollution is caused.

In this embodiment, two total balance valves are integrated in the first cylinder side valve block 601, but the positions of the two total balance valves are not required, and they may be integrated in the first cylinder side valve block and the master cylinder. The second control unit 200 of the second master cylinder 402 is substantially the same as the first control unit 100 except that the second cylinder side valve block 602 is not provided with the first total balance valve 551 and the second total balance valve 552. The third control unit 300, the fourth control unit 400, and the fifth control unit 500 have the same structure as the second control unit 200, that is, the second cylinder side valve block 602, the third cylinder side valve block 603, the fourth cylinder side valve block 604, and the fifth cylinder side valve block 605 have the same structure.

The control of the second 407, third 408, fourth 409 and fifth 410 locking cylinders is similar to the control of the first 406 locking cylinder.

The operation of each master cylinder will be described below by taking the operation of the first master cylinder 401 and the first locking cylinder 406 as an example.

The piston rod extension control hydraulic circuit of the first master cylinder 401 is as follows: the hydraulic station 900 supplies oil to the first working pipeline a, high-pressure oil of the first working pipeline a enters the first cylinder side valve block 601 through the check valve at the right position of the first total balance valve 551, and simultaneously the high-pressure oil triggers the second total balance valve 552 to act, so that the second total balance valve 552 is switched to the left position. At this time, the coil of the first direction switching valve 507 is energized, and the high-pressure oil passes through the right position thereof, passes through the pressure reducing valve 505, is reduced in pressure, and then enters the rodless chamber of the first master cylinder 401 through the right position of the first load balancing valve 503, thereby driving the piston rod to extend. Meanwhile, the high-pressure oil decompressed by the decompression valve 505 triggers the second load balance valve 523 to operate, so that the second load balance valve is shifted to the left position, and the return oil in the rod cavity of the first master cylinder 401 is allowed to pass through. Specifically, the return oil passes through the left position of the second load balancing valve 523 and the left position of the second reversing valve 524, and finally returns to the oil tank through the leakage pipeline D.

The piston rod retraction control hydraulic circuit of the first master cylinder 401 is as follows: the hydraulic station 900 supplies oil to the second working pipeline B, the high-pressure oil in the second working pipeline B enters the first cylinder side valve block 601 through the check valve in the right position of the second total balance valve 552, and simultaneously the high-pressure oil triggers the first total balance valve 551 to act, so that the first total balance valve 551 is switched to the left position. At this time, the coil of the second switching valve 524 is energized, and the high-pressure oil passes through the right position thereof. The high pressure oil then passes through the rod chamber of the first master cylinder 401 to the right of the second load balancing valve 523, pushing the piston rod to retract. Meanwhile, the high-pressure oil passing through the second direction-changing valve 524 triggers the first load balancing valve 503 to operate, so that it is switched to the left position, and oil in the rodless cavity of the first master cylinder 401 is allowed to return. Specifically, the return oil flows back to the tank via the first load balancing valve 503, the non return valve 504 and the leakage line D.

The hydraulic station 900 supplies oil to the pressure pipeline P, the energy accumulator 66 is communicated with the pressure pipeline P to store high-pressure oil, and when the control device replenishes hydraulic oil into the rodless cavity of the first main hydraulic cylinder 401 through the force balancing device, the high-pressure oil in the energy accumulator 66 passes through the proportional directional valve 533 and the first electromagnetic valve 531 and enters the rodless cavity along the rodless cavity balancing oil path; when the control means supplies hydraulic oil to the rod chamber of the first master cylinder 401 through the force balancing means, the high-pressure oil in the accumulator 66 passes through the proportional directional valve 533 and the second solenoid valve 532, and enters the rod chamber along the rod chamber balancing oil path.

The lock operation of the first lock cylinder 406 controls the hydraulic circuit as follows: the proportional directional valve in the pump-side valve block 60 is switched to enable high-pressure oil to enter the first working pipeline a, then the electromagnetic coil of the fourth directional valve 528 is electrified, and the high-pressure oil in the first working pipeline a enters the rodless cavity of the first locking hydraulic cylinder 406 through the right position of the fourth directional valve 528, so that the piston rod is driven to extend and is inserted into the locking hole 802 on the end face of the generator rotor 801. At the same time, the rod chamber oil can return to the tank through the leak line D via the left position of the third directional control valve 526.

The pulling-out operation of the first locking cylinder 406 controls the hydraulic circuit as follows: high-pressure oil is introduced into the second working pipeline B, after the electromagnetic coil of the third reversing valve 526 is electrified, the high-pressure oil enters the rod cavity from the right position of the third reversing valve 526, the piston rod is contracted, and the locking pin is pulled out. The rodless chamber oil returns to the tank through the left position of the fourth directional valve 528 and the leak line D. The first relief valve 525 and the second relief valve 527 are relief valves capable of ensuring the safety of the lock pin hydraulic circuit, that is, when the oil passage pressure on the rod chamber-free side or the rod chamber-containing side is too high, hydraulic oil may overflow through one of the two relief valves and return to the oil tank through the leak line D.

The first control unit 100, the second control unit 200, the third control unit 300, the fourth control unit 400 and the fifth control unit 500 are sequentially connected in series with the hydraulic station 900, the control device controls the hydraulic station 900 to supply oil to five master cylinders according to the calculated average driving force, in a static balance state, as the five control units are connected in series with the hydraulic station 900, the driving force provided by the five master cylinders should be the same, but particularly in the process that each master cylinder drives the generator rotor 1 to rotate, when the control device controls the hydraulic station 900 to adjust the oil amount of the rod cavity and the oil amount of the rodless cavity of each master cylinder through the first working pipeline A and the second working pipeline B, as shown in FIG. 2, the oil lines of each master cylinder have different lengths, so that the hydraulic oil is lost in the flowing process, and meanwhile, as the difference of each master cylinder itself, the driving force provided by each hydraulic cylinder is different, resulting in poor synchronicity of the master cylinders.

The force balancing device provided by the embodiment can realize the dynamic balance effect at the starting, uniform-speed running and deceleration stopping stages of each master cylinder, namely, the driving forces of the master cylinders are ensured to be the same, the synchronism of the master cylinders is ensured, and the phenomenon that the generator is greatly deformed and the electromagnetic air gap of the generator is influenced due to the different driving forces of the master cylinders is avoided, so that the generator is damaged.

Referring to fig. 7 to 8, fig. 7 is a block flow diagram of a hydraulic driving method of a barring device according to an embodiment of the present invention; fig. 8 is a block diagram showing a detailed flow of the barring driving method shown in fig. 7.

In addition, an embodiment of the present invention further provides a hydraulic control method for a barring gear of a wind turbine generator system based on the hydraulic control system, where the hydraulic control method is controllable by the control device, the control device may be a PLC or a single chip microcomputer, and specifically, the hydraulic control method includes the following steps:

determining a rotation direction and a target rotation angle of a generator rotor (801);

after the master cylinders simultaneously drive the generator rotor (801) to rotate by a preset angle along the rotating direction, the generator rotor (801) is kept at the current position, the piston of each master cylinder is retracted to the initial position, the generator rotor (801) is re-driven to rotate by the preset angle along the rotating direction until the generator rotor (801) rotates to the target rotating angle, meanwhile, the driving force of each master cylinder is monitored in real time, the average driving force of each master cylinder is calculated, and the driving force of each master cylinder is adjusted to be balanced force through a force balancing device.

Specifically, when the master cylinders include a thrust cylinder and a tension cylinder, the operation mode of each master cylinder is determined according to the rotation direction of the motor generator rotor 801 and the installation position of each master cylinder, as shown in fig. 1, when the master cylinders are rotated counterclockwise from the base 800, the first master cylinder 401, the third master cylinder 403, and the fourth master cylinder 404 are tension cylinders, and the second master cylinder 402 and the fifth master cylinder 405 are thrust cylinders; when rotating clockwise, the first master cylinder 401, the third master cylinder 403, and the fourth master cylinder 404 are thrust hydraulic cylinders, and the second master cylinder 402 and the fifth master cylinder 405 are tension hydraulic cylinders.

The angle of rotation required is calculated and the direction of rotation is determined by the initial angular position of the generator rotor 801 fed back by the angular position sensor mounted on the generator, and at the same time, the control device records the initial displacement amount of each master cylinder by the displacement sensor 501 mounted on each master cylinder. Since the master cylinder has a limited drive stroke, the hydraulic drive system cannot rotate the generator rotor 801 to its target rotation angle at once, but rather through multiple drive cycles.

The method includes that a preset angle is formed by driving a generator rotor 801 to rotate by each main hydraulic cylinder, a plurality of driving cycles are needed when the generator rotor 801 is driven to rotate to a target rotation angle, the rotating angle of each driving cycle generator rotor 801 is the preset angle, when a next driving cycle needs to be started after one driving cycle is finished, the generator rotor 801 keeps the current position, piston rods of the main hydraulic cylinders are retracted to the initial position, then the next driving cycle is started, namely the generator rotor 801 is driven to rotate by the preset angle again until the generator rotor 801 rotates to the target rotation angle.

In the process, the driving force of each master cylinder is monitored in real time, the average driving force of each master cylinder is calculated, if the deviation between the driving force of a certain master cylinder and the average driving force exceeds a preset range, the oil pressure oil quantity of a rod cavity and/or a rodless cavity of the master cylinder is adjusted through a force balancing device, so that the deviation between the driving force of the master cylinder and the average driving force is in the preset range, the driving force of each master cylinder is ensured to be the same, the deformation consistency of a generator end cover is ensured, and the deformation of a generator is further reduced.

Specifically, when the number of master cylinders is five, the average driving force F of the five master cylinders is calculated according to the driving forces F1 of the five master cylinders monitored in real time, and the driving force F1 of each group of master cylinders is adjusted to the average driving force F. The rodless cavity of the first master cylinder 401 is provided with a first pressure sensor 502, the rod cavity is provided with a second pressure sensor 521, the pressure P1 of the rodless cavity is detected in real time by the first pressure sensor 502, the pressure P2 of the rod cavity is detected in real time by the second pressure sensor 521, the driving force F1 of the first master cylinder is calculated, and meanwhile, the driving force F1 of the four master cylinders and the average driving force F of the five master cylinders are calculated.

When the first master cylinder 401 is a thrust hydraulic cylinder, the oil pressures of the rod chamber and the rodless chamber thereof are adjusted by the above-described force balance adjustment process for the thrust hydraulic cylinder, and when the first hydraulic cylinder 401 is a tension hydraulic cylinder, the oil pressures of the rod chamber and the rodless chamber thereof are adjusted by the above-described force balance adjustment process for the tension hydraulic cylinder, so that the deviation between the driving force F1 and the average driving force F of the first master cylinder 401 is within a preset range. The other four groups of main hydraulic cylinders have the same function.

After a single cycle is finished, the current displacement information monitored by the displacement sensor 501 mounted on the master cylinder is compared with the displacement of the master cylinder in the initial state to obtain the relative displacement, and the relative displacement is compared with the preset relative displacement. If the preset relative displacement is reached, the proportional directional valve in the pump side valve block 60 is closed, and the first directional valve 507 and the second directional valve 524 in the master cylinder control valve module are closed, so that the master cylinder stops moving. At this time, since the first load balance valve 503 at the outlet of the rodless chamber and the second load balance valve 523 at the outlet of the rod chamber of the master cylinder are both in a closed state, the hydraulic oil is enclosed in the cylinder, and thus the load generated by the impeller (the hub may be provided with one, two or three blades, or no blade), the load generated by the gravity of the generator, and the load generated by the blades on the impeller due to wind can be resisted.

In the above embodiment, retracting the piston of each master cylinder to the initial position includes: and in the process of retracting, one master cylinder is regulated by a force balancing device so as to uniformly distribute the average driving force of the master cylinders in the retracting process to the rest master cylinders in the working state.

Specifically, when a single drive cycle is completed, each master cylinder stops moving, the cycle number register in the control unit increments by 1, and each master cylinder retracts in sequence to prepare for the next generator rotor 801 drive cycle. Only one master cylinder is retracted at a time to maintain the position of generator rotor 801. The retracted position is determined by the primary hydraulic pressure initial displacement recorded in the control device. Only the control valve module of the main hydraulic cylinder needing to be retracted is opened each time, and other control valve modules without the hydraulic cylinder needing to be retracted are in a closed state. When each master cylinder is retracted to the position, the next drive cycle is started.

When one master cylinder retracts, the other master cylinders need to keep loads, the loads originally acting on the retracted master cylinders are distributed to the other master cylinders, the force balancing device acts at the moment, the states of the other master cylinders are respectively adjusted, the excessive loads are uniformly distributed, and the same force application of each master cylinder is kept. Specifically, five master cylinders drive the generator rotor 801 to rotate, when one master cylinder retracts, the total load is borne by the remaining four master cylinders, the driving forces F2 of the four master cylinders which are still in the working state are monitored in real time, the average driving force F 'is calculated, and the driving forces F2 of the four master cylinders which are in the working state are adjusted through the force balancing device, so that the deviation between the driving force F2 of each master cylinder and the average driving force F' is within a preset range at the moment. Similarly, when the retracted master cylinders are retracted to the right position, all the five master cylinders are in working states, and at the moment, the driving force F of each master cylinder is adjusted by the force balancing device, so that the deviation between the driving force F and the new average driving force is within a preset range.

The foregoing is only a preferred embodiment of the present invention, and it should be noted that it is obvious to those skilled in the art that various modifications and improvements can be made without departing from the principle of the present invention, and these modifications and improvements should also be considered as the protection scope of the present invention.

Claims

1. A hydraulic driving system of a barring gear of a wind generating set is characterized by comprising a control device, at least two main hydraulic cylinders and force balancing devices corresponding to the main hydraulic cylinders;

the master hydraulic cylinder is used for driving a generator rotor (801) to rotate, the master hydraulic cylinder comprises a rod cavity and a rodless cavity, and an oil circuit of the rod cavity and an oil circuit of the rodless cavity of each master hydraulic cylinder are controlled by a control valve module;

the force balancing device comprises a rod cavity balancing oil way communicated with the rod cavity and a rodless cavity balancing oil way communicated with the rodless cavity;

the control device controls the oil quantity entering the rod cavity and the rodless cavity of each main hydraulic cylinder through the control valve module, monitors the driving force of each main hydraulic cylinder in real time and calculates the average driving force, and if the deviation between the driving force of the main hydraulic cylinder and the average driving force exceeds a preset range, the control device controls the oil quantity entering the rod cavity through the rod cavity balance oil circuit and/or the oil quantity entering the rodless cavity through the rodless cavity balance oil circuit according to the deviation until the deviation is within the preset range.

2. The hydraulic drive system of claim 1, wherein each of the master cylinders is provided with a first pressure sensor (502) and a second pressure sensor (521), respectively, the first pressure sensor (502) being configured to detect the pressure of the rodless chamber, the second pressure sensor (521) being configured to detect the pressure of the rod chamber;

the control device calculates the driving force and the average driving force of the master cylinder in real time according to the feedback of the first pressure sensor (502) and the second pressure sensor (521).

3. A hydraulic drive system according to claim 2, wherein each of said master cylinders is provided with a displacement sensor (501) and said displacement sensor (501) is adapted to detect displacement of a piston rod of each of said master cylinders.

4. A hydraulic drive system according to any one of claims 1 to 3 wherein said control means controls the amount of oil entering said rod chamber through said rod chamber balance oil passage and the amount of oil entering said rodless chamber through said rodless chamber balance oil passage by means of a flow control valve.

5. A hydraulic drive system according to claim 4, wherein the flow control valve is a proportional directional control valve (533), the proportional directional control valve (533) being switchable to communicate the oil source with the rod chamber balanced oil passage or the rodless chamber balanced oil passage, the control means being operable to control the opening degree of the proportional directional control valve (533) in accordance with the detected deviation of the driving force of the hydraulic cylinder from the average driving force.

6. The hydraulic drive system of claim 5, wherein the force balancing device further comprises two zero-leak solenoid valves disposed in the rod chamber balancing oil passage and the rodless chamber balancing oil passage, respectively.

7. The hydraulic drive system according to claim 5, wherein said oil source is a hydraulic station (900), said hydraulic station (900) being provided with a first working line, a second working line and a pressure line;

the first working pipeline is respectively communicated with the rodless cavity oil passages of the main hydraulic cylinders, and the second working pipeline is respectively communicated with the rod cavity oil passages of the main hydraulic cylinders;

the pressure line is in communication with the proportional directional valve (533).

8. A hydraulic drive system according to claim 7, characterized in that the first working line is provided with a first total balancing valve (551) and the second working line is provided with a second total balancing valve (552), which is closed when the pressure in the working line is lower than the opening pressure of the total balancing valve.

9. The hydraulic drive system of claim 7, wherein the hydraulic station includes a tank (40), a variable displacement pump, a flow compensated valve (20), and a pump side valve block (60);

the first working pipeline and the second working pipeline are respectively communicated with a variable pump, the pump side valve block (60) is arranged between the two working pipelines and the variable pump and used for switching the first working pipeline and the second working pipeline and controlling the output quantities of the first working pipeline and the second working pipeline, and the flow compensation valve (20) can feed back the flow required by the pump side valve block (60) to the variable pump so as to adjust the output flow of the variable pump to the flow required by the pump side valve block (60);

the hydraulic station (900) further includes a shuttle valve (52) and a pressure setting valve (55), and the pump-side valve block (60) sets a maximum working pressure through the shuttle valve (52) and the pressure setting valve (55).

10. The hydraulic drive system of claim 9 wherein the variable displacement pumps are two in number and both variable displacement pumps can be used for oil supply simultaneously or either can be used for oil supply.

11. A hydraulic drive system according to claim 9, wherein said hydraulic station (900) further comprises a balancing valve block (62) arranged in parallel with said pump side valve block (60) for controlling the output of said pressure line.

12. The hydraulic drive system of claim 11, wherein the force balancing device further includes an accumulator (66) in communication between the pressure line and the proportional reversing valve (533).

13. A hydraulic drive system according to any one of claims 1 to 3 wherein at least two of said master cylinders comprise at least one set of thrust and tension cylinders having their piston rods arranged in opposition.

14. A hydraulic drive system according to any one of claims 1-3, wherein each of said control valve modules comprises a pressure reducing valve (505) arranged in said rodless chamber oil circuit and a check valve (504) connected in parallel with said pressure reducing valve (505).

15. A hydraulic drive system according to any one of claims 1-3, wherein a first load balancing valve (503) is provided in each of the rod chamber oil passages of the main hydraulic cylinders, the first load balancing valves (503) being opened by high pressure oil in the rod chamber oil passages;

and a second load balance valve (523) is respectively arranged in a rodless cavity oil way of each main hydraulic cylinder, and the second load balance valve (523) is opened through high-pressure oil in the rod cavity oil way.

16. A hydraulic control method of a barring gear of a wind generating set based on the hydraulic driving system of the barring gear according to any one of claims 1 to 15, characterized by comprising the steps of:

after the master cylinders simultaneously drive the generator rotor (801) to rotate by a preset angle along the rotation direction, the generator rotor (801) is kept at the current position, the piston of each master cylinder is retracted to the initial position, the generator rotor (801) is re-driven to rotate by the preset angle along the rotation direction until the generator rotor (801) rotates to the target rotation angle, meanwhile, the driving force of each master cylinder is monitored in real time, the average driving force of each master cylinder is calculated, and the deviation of the driving force of each master cylinder and the average driving force is adjusted to be within a preset range through a force balancing device.

17. The hydraulic control method according to claim 16, wherein the driving force of the master cylinder and the average driving force of each master cylinder are calculated based on the pressures of the rodless chamber and the rod chamber of the master cylinder monitored in real time;

if the deviation of the driving force of the main hydraulic cylinder and the average driving force exceeds a preset range, adjusting the oil quantity of a rod cavity of the main hydraulic cylinder through a rod cavity balance oil circuit of the force balancing device according to the deviation, and/or adjusting the oil quantity of a rodless cavity of the main hydraulic cylinder through a rodless cavity balance oil circuit of the force balancing device until the deviation is within the preset range.

18. The hydraulic control method according to claim 16, wherein the retracting the piston of each master cylinder to an initial position includes: and retracting the piston rods of the main hydraulic cylinders one by one, monitoring the driving force of each main hydraulic cylinder in real time and calculating the average driving force during the retraction process of the piston rod of one main hydraulic cylinder, and adjusting the deviation of the driving force of each main hydraulic cylinder and the average driving force to be within the preset range through a force balancing device.