1. Rotating speed

There are two measuring points for the speed of a wind turbine: the generator speed and the rotor speed. The speed measurement signal is used to control the connection and disconnection of the wind turbine generator. It can also be used to start the overspeed protection system. When the rotor speed exceeds the set value n1 or the generator speed exceeds the set value n2, the overspeed protection action, the wind turbine Stopped.

Wind turbine speed and generator speed can be mutually verified. If they do not match, the wind turbine is faulty.

2. temperature

There are 8 points of temperature measured to reflect the operating conditions of the wind turbine system. These 8 points include: 1 gearbox oil temperature; 2 high speed bearing temperature; 3 large generator temperature; 4 small generator temperature; 5 front main bearing temperature; 6 rear main bearing temperature; 7 control panel temperature (mainly thyristor Temperature); 8 controller ambient temperature.

Because the wind turbine is out of operation due to overheating temperature, the wind turbine generator can still be started automatically when the temperature drops to the allowable value.

3. Cabin vibration

In order to detect the abnormal vibration of the unit, a vibration sensor should be installed on the nacelle. The sensor consists of a ball connected to the microswitch and its support. When abnormal vibration occurs, the steel ball drops from the ring that supports it, pulling the micro switch and causing a safety shutdown. When restarting, the ball must be reinstalled.

There is also a blade vibration detector (TAC84 system) at the rear of the nacelle. Excessive vibration will cause a normal shutdown.

4. Cable twist

Since the generator cable and all electrical and communication cables are directly introduced into the tower from the nacelle, it is up to the ground control cabinet. If the nacelle often yaws in one direction, it will cause serious cable twisting. Therefore, the yaw system should also have the function of torsion cable protection. A separate counting sensor is mounted on the yaw gear to record the number of teeth rotated relative to the initial position. When the wind turbine continues to yaw in one direction to the set value, it indicates that the cable has been twisted to a dangerous degree and the controller will issue a stop command and display a fault. The wind turbine is shut down and performs a cable unwinding operation in a clockwise or counterclockwise direction. In order to improve reliability, at the cable introduction tower (ie the top of the tower), a trip switch is also installed. The trip switch contacts are connected to the cable. When the cable is twisted to a certain extent, the trip switch can be directly pulled to cause a safety shutdown.

In order to facilitate the understanding of the current state of the yaw system, the controller may record the deflection angle of the current azimuth and the initial azimuth of the nacelle and the direction of the yaw in response to the yaw count sensor report to record the number of teeth rotated relative to the initial orientation.

5. Mechanical brake condition

A brake wear indicator is installed in the mechanical brake system. If the brake pad wears to a certain extent, the controller will display a fault signal. In this case, the brake pad must be replaced to start the wind turbine.

Between two consecutive actions, there is a preset time interval to allow sufficient cooling time for the brakes to avoid overheating the brake discs. According to different models of wind turbines, temperature sensors can also be used instead of setting delay programs. At this time, the temperature of the brake disc must be lower than the preset temperature to start the wind turbine.

6. Oil level

The wind turbine's oil level includes lubricating oil level and hydraulic system oil level.

(iv) Detection of various feedback signals The controller shall receive the feedback signal of the actions performed within the set time after the following commands are issued: 1Recover the tip spoiler; 2Release the mechanical brake; 3Release the yaw brake ; 4 generators off the net and off the network after the speed drop signal. Otherwise, a corresponding fault signal will appear and a safe shutdown will be performed.