阅读说明：本技术 一种风电变桨控制系统叶轮转速监测方法 (Method for monitoring rotating speed of impeller of wind power pitch control system ) 是由 谢敬朗 胡作 黄学静 张成万 易东 幸红燕 于 2019-11-06 设计创作，主要内容包括：本发明公开了一种风电变桨控制系统叶轮转速监测方法,包括：S1：在变桨控制系统内设置有三个加速度传感器,三个所述加速度传感器分别针对三个桨叶相同位置设置；S2：以三个加速度传感器所在圆的圆心定义为原点,以通过该原点竖直向下方向定义为Z轴；检测三个加速度传感器经过Z轴时的重力加速度为相同数值时,所经过的时间段；S3：计算叶轮转速S；S4：将叶轮转速S与叶轮超速限定值Smax比较,当S>Smax,变桨控制系统安全链断开,执行顺浆动作。可以对叶轮转速进行监测,提高监测实时性、可靠性以及响应速度,提高风机安全性能。(The invention discloses a method for monitoring the rotating speed of an impeller of a wind power variable pitch control system, which comprises the following steps: s1: three acceleration sensors are arranged in the variable-pitch control system, and the three acceleration sensors are respectively arranged aiming at the same positions of the three blades; s2: the center of a circle where the three acceleration sensors are located is defined as an origin, and a vertical downward direction passing through the origin is defined as a Z axis; detecting the time period when the gravity acceleration of the three acceleration sensors passing through the Z axis is the same value; s3: calculating the rotating speed S of the impeller; s4: and comparing the rotating speed S of the impeller with an overspeed limit value Smax of the impeller, and when S is larger than Smax, disconnecting a safety chain of a variable pitch control system and executing a feathering action. The impeller rotating speed can be monitored, the monitoring real-time performance, the reliability and the response speed are improved, and the safety performance of the fan is improved.)

1. A method for monitoring the rotating speed of an impeller of a wind power variable pitch control system is characterized by comprising the following steps:

s1: three acceleration sensors are arranged in the variable-pitch control system, and the three acceleration sensors are respectively arranged aiming at the same positions of the three blades;

s2: the center of a circle where the three acceleration sensors are located is defined as an origin, and a vertical downward direction passing through the origin is defined as a Z axis; detecting the time period when the gravity acceleration of the three acceleration sensors passing through the Z axis is the same value;

s3: calculating the rotating speed S of the impeller;

s4: and comparing the rotating speed S of the impeller with an overspeed limit value Smax of the impeller, and when S is larger than Smax, disconnecting a safety chain of a variable pitch control system and executing a feathering action.

2. The method for monitoring the rotating speed of the impeller of the wind power pitch control system according to claim 1, wherein in the step S2, the value of the gravitational acceleration is g ± 2%.

3. The method for monitoring the rotating speed of the impeller of the wind power pitch control system according to claim 1, wherein in step S2, the time period is located as follows: the time elapsed between the time when the acceleration sensor of one of the blades detects the value of the gravitational acceleration and the time when the acceleration sensor of the next blade in the rotational direction of the blades detects the value of the gravitational acceleration.

4. The method for monitoring the rotating speed of the impeller of the wind power pitch control system according to claim 1, wherein in the step S3, when the rotating speed S of the impeller is calculated, the following formula is used for performing:

wherein, t_nComprises the following steps: when the detection is initial, firstly, the time when the acceleration sensor of the Z axis detects the gravity acceleration is passed;

t_n+1comprises the following steps: the time when the second acceleration sensor passing through the Z axis detects the gravity acceleration along the rotation direction of the impeller;

t_n+2comprises the following steps: the time when the third acceleration sensor passing through the Z axis detects the gravity acceleration along the rotation direction of the impeller;

5. The method for monitoring the rotating speed of the impeller of the wind power pitch control system according to claim 1, wherein the acceleration sensor is an acceleration sensor arranged in a driver of the pitch control system.

6. The method for monitoring the rotating speed of the impeller of the wind power pitch control system according to claim 1, wherein the acceleration sensor is an acceleration sensor arranged in a controller of the pitch control system.

Technical Field

The invention relates to the technical field of wind power generation, in particular to a method for monitoring the rotating speed of an impeller of a wind power pitch control system.

Background

The pitch control system is one of core components of the wind generating set, and the reliable operation of the pitch control system is a powerful guarantee for the normal operation of the wind generating set. The traditional fan impeller rotating speed detection is carried out on the engine room side of a fan, a rotating speed detection device such as an encoder or a rotating speed sensor is arranged on a low-speed shaft for monitoring, monitoring data are uploaded to a main control system, the rotating speed of the impeller is judged in an overspeed mode, and the rotating speed is transmitted to a variable pitch control system through a sliding ring.

However, the encoder is easily interfered, so that the machine set is shut down due to frequent false alarm of impeller overspeed, the stability of the machine set is influenced, the encoder is expensive, the maintenance cost is high, and the test error of the encoder is large when the rotating speed is low; moreover, the slip ring is used for transmitting the signals to the variable-pitch control system, and when the slip ring goes wrong, the variable-pitch control system cannot judge the overspeed fault of the impeller, so that the safety of the fan is affected.

Disclosure of Invention

To the deficiency of the prior art, the technical problem to be solved by the present patent application is: how to provide a method for monitoring the rotating speed of an impeller of a wind power variable pitch control system, which is used for monitoring the rotating speed of the impeller, improving the real-time performance, reliability and response speed of monitoring, and improving the safety performance of a fan.

In order to achieve the purpose, the invention adopts the following technical scheme:

a method for monitoring the rotating speed of an impeller of a wind power variable pitch control system comprises the following steps:

s1: three acceleration sensors are arranged in the variable-pitch control system, and the three acceleration sensors are respectively arranged aiming at the same positions of the three blades;

s2: the center of a circle where the three acceleration sensors are located is defined as an origin, and a vertical downward direction passing through the origin is defined as a Z axis; detecting the time period when the gravity acceleration of the three acceleration sensors passing through the Z axis is the same value;

s3: calculating the rotating speed S of the impeller;

s4: and comparing the rotating speed S of the impeller with an overspeed limit value Smax of the impeller, and when S is larger than Smax, disconnecting a safety chain of a variable pitch control system and executing a feathering action.

Further, in step S2, the gravity acceleration is g ± 2%.

Further, in step S2, the time period is located as: the time elapsed between the time when the acceleration sensor of one of the blades detects the value of the gravitational acceleration and the time when the acceleration sensor of the next blade in the rotational direction of the blades detects the value of the gravitational acceleration.

Further, in step S3, the following equation is used to calculate the impeller rotation speed S:

wherein, t_nComprises the following steps: when the detection is initial, firstly, the time when the acceleration sensor of the Z axis detects the gravity acceleration is passed;

t_n+1comprises the following steps: the time when the second acceleration sensor passing through the Z axis detects the gravity acceleration along the rotation direction of the impeller;

t_n+2comprises the following steps: the time when the third acceleration sensor passing through the Z axis detects the gravity acceleration along the rotation direction of the impeller;

comprises the following steps: in the impeller rotation direction, the acceleration sensor passing through the Z axis first rotates again to the time when the gravitational acceleration is detected in the Z axis direction.

Further, the acceleration sensor is an acceleration sensor arranged in a driver of the pitch control system.

Further, the acceleration sensor is an acceleration sensor arranged in a controller of the pitch control system.

The invention has the following beneficial effects:

1. the variable pitch control system can directly judge the overspeed fault of the impeller so as to carry out feathering action, ensure the safety of the fan, and ensure quicker response, safer and more reliable.

2. The variable-pitch control system can be used for realizing the operation without adding hardware equipment, and has the advantages of simple structure, strong operability and low cost.

3. The method can complete the monitoring of the rotating speed of the impeller on the impeller side, and is more direct and more time-efficient.

4. The problem that the impeller overspeed fault cannot be judged by the variable-pitch control system when the slip ring fails can be effectively avoided, and the safety and reliability performance are improved.

Drawings

In FIG. 1, a is a time t when the acceleration sensor of 1# blade passing through the Z axis first detects the gravitational acceleration at the initial detection_n(ii) a b is expressed as the time t when the acceleration sensor of 2# blade passing through the Z axis detects the gravity acceleration along the rotation direction of the impeller_n+1(ii) a c is expressed as the time t when the acceleration sensor of the 3# blade passing through the Z axis detects the acceleration of gravity along the rotation direction of the impeller_n+2(ii) a d is the time when the acceleration of gravity is detected when the 1# blade passes the acceleration sensor of the Z axis and rotates again to the Z axis direction along the rotation direction of the impeller

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the following will clearly and completely describe the technical solutions in the embodiments of the present invention, and it is obvious that the described embodiments are some embodiments of the present invention, but not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments of the present invention without inventive step, are within the scope of the present invention.

In the description of the present invention, it should also be noted that, unless otherwise explicitly specified or limited, the terms "disposed," "mounted," "connected," and "connected" are to be construed broadly and may, for example, be fixedly connected, detachably connected, or integrally connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.