阅读说明：本技术 一种风力发电机组液压控制系统及其控制方法 (Hydraulic control system of wind generating set and control method thereof ) 是由 张洪溢 黄金余 文茂诗 贺国凌 胡浩 李瑚 于 2020-05-06 设计创作，主要内容包括：本发明涉及风力发电机组液压系统领域,具体涉及一种风力发电机组液压控制系统及其控制方法。本发明在保证偏航制动系统不变的情况下,通过液压系统偏航制动力矩分级与偏航驱动启动时间配合,来渡过“偏航启动真空期”,并在渡过“偏航启动真空期”后,降低偏航过程中的制动力矩,从而使得偏航制动力矩保持在一个较低水平,达到降低噪音、振动、延长刹车片寿命的目的。(The invention relates to the field of hydraulic systems of wind generating sets, in particular to a hydraulic control system of a wind generating set and a control method thereof. Under the condition of ensuring that a yaw brake system is not changed, the yaw brake moment grading of the hydraulic system is matched with the yaw drive starting time to live through a yaw starting vacuum period, and after the yaw starting vacuum period is live through, the brake moment in the yaw process is reduced, so that the yaw brake moment is kept at a lower level, and the purposes of reducing noise and vibration and prolonging the service life of a brake pad are achieved.)

1. The hydraulic control system of the wind generating set is characterized in that: the system comprises an oil tank (1), an oil pump (2), a yaw brake (3) and a hydraulic system control loop; the hydraulic system control circuit comprises a first pressure circuit, a second pressure circuit and a third pressure circuit which are arranged in parallel, the pressure value of the first pressure circuit is larger than that of the second pressure circuit, and the third pressure circuit has no pressure; the hydraulic system is characterized in that the oil tank (1), the oil pump (2) and the yaw brake (3) are sequentially communicated, an oil return port of the hydraulic system control loop is communicated with the yaw brake (3), and an oil drainage port of the hydraulic system control loop is communicated with the oil tank (1).

2. The hydraulic control system of the wind generating set according to claim 1, wherein: the first pressure loop comprises a first electromagnetic valve (4) and a first overflow valve (5) which are sequentially communicated, the first electromagnetic valve (4) is arranged between the yaw brake (3) and the first overflow valve (5), and the first overflow valve (5) is arranged between the first electromagnetic valve (4) and the oil tank (1).

3. The hydraulic control system of the wind generating set according to claim 1, wherein: the second pressure loop comprises a second electromagnetic valve (6) and a second overflow valve (7) which are sequentially communicated, the second electromagnetic valve (6) is arranged between the yaw brake (3) and the second overflow valve (7), and the second overflow valve (7) is arranged between the second electromagnetic valve (6) and the oil tank (1).

4. The hydraulic control system of the wind generating set according to claim 1, wherein: the third pressure circuit comprises a third solenoid valve (8), the third solenoid valve (8) being arranged between the yaw brake (3) and the oil tank (1).

5. The hydraulic control system of a wind turbine generator system according to any one of claims 1 to 4, wherein: the ratio of the pressure value of the first pressure loop to the pressure value of the second pressure loop is 5: 2-10: 3.

6. The hydraulic control system of the wind generating set according to claim 5, wherein: the hydraulic system control circuit is characterized by further comprising a safety valve (9), one end of the safety valve (9) is communicated with the oil tank (1), and the other end of the safety valve (9) is communicated with an oil drainage port of the hydraulic system control circuit.

7. The hydraulic control system of the wind generating set according to claim 6, wherein: the yaw brake system is characterized by further comprising a filter (10), one end of the filter (10) is communicated with the yaw brake (3), and the other end of the filter (10) is communicated with an oil return port of the hydraulic system control circuit.

8. A control method of a hydraulic control system of a wind generating set is characterized by comprising the following steps:

s1, controlling the yaw brake to generate and maintain the first yaw brake torque;

s2, controlling the yaw driving electric brake to release and start the yaw motor to generate yaw driving torque at the first moment, and reaching the yaw driving rated torque at the second moment so that the wind generating set starts yawing;

and S3, when the wind generating set starts to yaw, controlling the yaw brake to gradually reduce the brake torque so as to obtain a second yaw brake torque at the third moment and keep the second yaw brake torque until the yaw is finished.

9. The hydraulic control system of a wind generating set according to claim 8, wherein: the second yaw braking torque is 20-30% of the first yaw braking torque.

Technical Field

The invention relates to the field of hydraulic systems of wind generating sets, in particular to a hydraulic control system of a wind generating set and a control method thereof.

Background

Before the wind generating set carries out the yawing action, the yawing drive electric brake is released firstly, then the driving motor is started to reach the rated torque, and the set starts yawing, and during the time when the yawing motor is started to reach the rated torque, the yawing drive can not provide enough torque, which is called as a vacuum period. Referring to fig. 3, to ensure the safety of the unit during the vacuum period, the yaw brake needs a large braking torque until the whole yaw motion is completed. With the megawatt grade lifting of the wind generating set, the holding torque required by the yaw vacuum period of the set is greatly lifted, if the yaw brake configuration is not changed (the brake is not added), in the whole yaw process, if the yaw brake always keeps the brake torque of the vacuum period, the problems of noise, vibration, rapid brake pad abrasion and the like of the set are caused due to the overlarge holding torque.

Disclosure of Invention

Aiming at the defects in the prior art, the invention provides a hydraulic control system of a wind generating set and a control method thereof, which aim to solve the technical problems that if a yaw brake keeps larger moment all the time, the noise and vibration of the set and the brake pad are induced to be quickly worn in the whole yaw process.

In order to achieve the purpose, the invention is realized by the following technical scheme:

a hydraulic control system of a wind generating set comprises an oil tank, an oil pump, a yaw brake and a hydraulic system control loop; the hydraulic system control circuit comprises a first pressure circuit, a second pressure circuit and a third pressure circuit which are arranged in parallel, the pressure value of the first pressure circuit is larger than that of the second pressure circuit, and the third pressure circuit has no pressure; the oil tank, the oil pump and the yaw brake are sequentially communicated, an oil return port of the hydraulic system control loop is communicated with the yaw brake, and an oil drainage port of the hydraulic system control loop is communicated with the oil tank.

Optionally, the first pressure circuit includes a first electromagnetic valve and a first overflow valve that are sequentially communicated, the first electromagnetic valve is disposed between the yaw brake and the first overflow valve, and the first overflow valve is disposed between the first electromagnetic valve and the oil tank.

Optionally, the second pressure circuit includes a second electromagnetic valve and a second overflow valve that are sequentially communicated, the second electromagnetic valve is disposed between the yaw brake and the second overflow valve, and the second overflow valve is disposed between the second electromagnetic valve and the oil tank.

Optionally, the third pressure circuit comprises a third solenoid valve, the third solenoid valve being arranged between the yaw brake and the oil tank.

Optionally, the ratio of the pressure value of the first pressure circuit to the pressure value of the second pressure circuit is 5: 2-10: 3.

Optionally, the hydraulic system further comprises a safety valve, one end of the safety valve is communicated with the oil tank, and the other end of the safety valve is communicated with the oil drainage port of the hydraulic system control circuit.

Optionally, the system further comprises a filter, one end of the filter is communicated with the yaw brake, and the other end of the filter is communicated with an oil return port of the hydraulic system control circuit.

A control method of a hydraulic control system of a wind generating set comprises the following steps:

s1, controlling the yaw brake to generate and maintain the first yaw brake torque;

s2, controlling the yaw driving electric brake to release and start the yaw motor to generate yaw driving torque at the first moment, and reaching the yaw driving rated torque at the second moment so that the wind generating set starts yawing;

and S3, when the wind generating set starts to yaw, controlling the yaw brake to gradually reduce the brake torque so as to obtain a second yaw brake torque at the third moment and keep the second yaw brake torque until the yaw is finished.

According to the technical scheme, the invention has the beneficial effects that:

in a first aspect, the invention provides a hydraulic control system of a wind generating set, which comprises an oil tank, an oil pump, a yaw brake and a hydraulic system control loop; the hydraulic system control circuit comprises a first pressure circuit, a second pressure circuit and a third pressure circuit which are arranged in parallel, the pressure value of the first pressure circuit is larger than that of the second pressure circuit, and the third pressure circuit has no pressure; the oil tank, the oil pump and the yaw brake are sequentially communicated, an oil return port of the hydraulic system control loop is communicated with the yaw brake, and an oil drainage port of the hydraulic system control loop is communicated with the oil tank. Under the condition that a yaw brake system is not changed (the cost is not increased), the yaw brake moment grading of the hydraulic system is matched with the yaw drive starting time to live through a yaw starting vacuum period, and after the yaw starting vacuum period is live through, the brake moment in the yaw process is reduced, so that the yaw brake moment is kept at a lower level, and the purposes of reducing noise and vibration and prolonging the service life of a brake pad are achieved.

In a second aspect, the invention provides a control method for a hydraulic control system of a wind generating set, which comprises the following steps: controlling the yaw brake to generate and maintain a first yaw brake torque; controlling the yaw driving electric brake to be released at a first moment to generate yaw driving torque, and reaching the yaw driving rated torque at a second moment to enable the wind generating set to start yawing; and when the wind generating set starts to yaw, controlling the yaw brake to gradually reduce the brake torque so as to obtain a second yaw brake torque at a third moment and keeping the second yaw brake torque until the yaw is finished. The 'yaw starting vacuum period' is passed through the matching of the hydraulic system yaw braking torque grading and the yaw driving starting time, and the braking torque in the yaw process is reduced after the 'yaw starting vacuum period' is passed, so that the yaw braking torque is kept at a lower level, and the purposes of reducing noise and vibration and prolonging the service life of a brake pad are achieved.

Drawings

In order to more clearly illustrate the detailed description of the invention or the technical solutions in the prior art, the drawings that are needed in the detailed description of the invention or the prior art will be briefly described below. Throughout the drawings, like elements or portions are generally identified by like reference numerals. In the drawings, elements or portions are not necessarily drawn to scale.

FIG. 1 is a schematic diagram of a hydraulic control system of a 10MW wind generating set;

FIG. 2 is a flow chart of a control method of a hydraulic control system of a wind generating set;

FIG. 3 is a graph of torque variation during a yaw state of a conventional wind turbine generator system;

FIG. 4 is a torque variation graph in a yaw state of the improved wind generating set;

reference numerals:

1-oil tank, 2-oil pump, 3-yaw brake, 4-first solenoid valve, 5-first overflow valve, 6-second solenoid valve, 7-second overflow valve, 8-third solenoid valve, 9-safety valve and 10-filter.

Detailed Description

Embodiments of the present invention will be described in detail below with reference to the accompanying drawings. The following examples are only for illustrating the technical solutions of the present invention more clearly, and therefore are only examples, and the protection scope of the present invention is not limited thereby.

It is to be noted that, unless otherwise specified, technical or scientific terms used herein shall have the ordinary meaning as understood by those skilled in the art to which the invention pertains.

Referring to fig. 1, the hydraulic control system of a wind turbine generator system provided by the present invention includes an oil tank 1, an oil pump 2, a yaw brake 3, and a hydraulic system control circuit. The hydraulic system control circuit comprises a first pressure circuit, a second pressure circuit and a third pressure circuit which are arranged in parallel, the pressure value of the first pressure circuit is larger than that of the second pressure circuit, and the third pressure circuit has no pressure. Specifically, the ratio of the pressure value of the first pressure circuit to the pressure value of the second pressure circuit is 5: 2-10: 3, namely the first pressure circuit is a high-pressure circuit, the second pressure circuit is a low-pressure circuit, and the hydraulic system yaw braking moment grading is achieved through switching of the first pressure circuit, the second pressure circuit and the third pressure circuit. The first pressure circuit and the second pressure circuit are both used for the yaw state of the wind generating set, and the third pressure circuit is used for the cable releasing state of the wind generating set. The hydraulic system comprises an oil tank 1, an oil pump 2 and a yaw brake 3 which are sequentially communicated, an oil return port of a hydraulic system control loop is communicated with the yaw brake 3, and an oil drainage port of the hydraulic system control loop is communicated with the oil tank 1 to form hydraulic oil circuit circulation. Specifically, the first pressure circuit comprises a first electromagnetic valve 4 and a first overflow valve 5 which are sequentially communicated, the first electromagnetic valve 4 is arranged between the yaw brake 3 and the first overflow valve 5, and the first overflow valve 5 is arranged between the first electromagnetic valve 4 and the oil tank 1; the second pressure loop comprises a second electromagnetic valve 6 and a second overflow valve 7 which are sequentially communicated, the second electromagnetic valve 6 is arranged between the yaw brake 3 and the second overflow valve 7, and the second overflow valve 7 is arranged between the second electromagnetic valve 6 and the oil tank 1; the third pressure circuit comprises a third solenoid valve 8, which third solenoid valve 8 is arranged between the yaw brake 3 and the oil tank 1. The 'yaw starting vacuum period' is passed through the matching of the hydraulic system yaw braking torque grading and the yaw driving starting time, and the braking torque in the yaw process is reduced after the 'yaw starting vacuum period' is passed, so that the yaw braking torque is kept at a lower level, and the purposes of reducing noise and vibration and prolonging the service life of a brake pad are achieved.

As a further improvement to the above scheme, the hydraulic control system further comprises a safety valve 9, one end of the safety valve 9 is communicated with the oil tank 1, and the other end of the safety valve 9 is communicated with an oil drainage port of the hydraulic system control circuit. In the oil source conveying process, when the pressure on a system pipeline is greater than a set threshold value, the safety valve 9 is opened to release the pressure, the system is protected from running safely, and safety accidents are avoided.

As a further improvement to the scheme, the yaw brake system further comprises a filter 10, one end of the filter 10 is communicated with the yaw brake 3, and the other end of the filter 10 is communicated with an oil return port of the hydraulic system control circuit. In the oil source conveying process, the filter 10 is used for filtering the oil source in the pipeline, so that the situation that the electromagnetic valve is blocked by the oil source in the pipeline, and the hydraulic system cannot work normally is avoided.

Referring to fig. 2, the present invention further provides a control method of a hydraulic control system of a wind turbine generator system, including the following steps:

s1, controlling the yaw brake 3 to generate and maintain the first yaw brake torque;

s2, controlling the yaw driving electric brake to release and start the yaw motor at the first moment to generate yaw driving torque, and reaching the yaw driving rated torque at the second moment to enable the wind generating set to start yawing;

and S3, when the wind generating set starts to yaw, controlling the yaw brake 3 to gradually reduce the brake torque so as to obtain a second yaw brake torque at the third moment and keep the second yaw brake torque until the yaw is finished.

Specifically, the second yaw brake torque is 20-30% of the first yaw brake torque.

In one embodiment, referring to fig. 4, before the wind turbine generator system starts yawing, the yaw brake 3 is controlled to generate and maintain a yaw brake torque of 80 kn.m, specifically, the first electromagnetic valve 4 is controlled to be opened, the second electromagnetic valve 6 and the third electromagnetic valve 8 are controlled to be closed, and the yaw brake 3 torque is adjusted through the first overflow valve 5. Controlling the yaw driving electric brake to release and start the yaw motor at the 5 th s to generate yaw driving torque, and reaching the yaw driving rated torque at the 6 th s to enable the wind generating set to start yawing; and meanwhile, controlling the yaw brake torque to drop to a second stage of 20kN.m, finishing the dropping at a 7s, and then keeping the yaw brake torque of 20kN.m until the yaw is finished, specifically, controlling the second electromagnetic valve 6 to be opened, closing the first electromagnetic valve 4 and the third electromagnetic valve 8, and regulating the torque of the yaw brake 3 through the second overflow valve 7. And the yaw state of the wind generating set is finished at the 16 th s, at the moment, the first electromagnetic valve 4, the second electromagnetic valve 6 and the third electromagnetic valve 8 are controlled to be closed, and oil is continuously supplied through the oil pump to enable the yaw braking torque to rise to 165kN.m so as to enter the braking state of the wind generating set. When the wind generating set needs to be untwisted, the third electromagnetic valve 8 is controlled to be opened, and the first electromagnetic valve 4 and the second electromagnetic valve 6 are controlled to be closed, so that oil is drained from the yaw brake 3 to the oil tank 1, and the pressure value is reduced to the minimum. Load analysis shows that when the yaw drive reaches rated torque, the holding torque of the yaw brake 3 can be reduced, namely, after the yaw vacuum period is bridged, the holding torque can be stably switched to a lower level through an optimized control strategy and a hydraulic system, so that the purposes of reducing noise and vibration and prolonging the service life of a brake pad are achieved.

Finally, it should be noted that: the above embodiments are only used to illustrate the technical solution of the present invention, and not to limit the same; while the invention has been described in detail and with reference to the foregoing embodiments, it will be understood by those skilled in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some or all of the technical features may be equivalently replaced; such modifications and substitutions do not depart from the spirit and scope of the present invention, and they should be construed as being included in the following claims and description.