CN115681002A - Control strategy for limit switch safety bypass of wind power pitch control system - Google Patents

Abstract

The invention relates to a control strategy of a limit switch safety bypass of a wind power pitch control system, which comprises the following steps: s1: the master control sends a limit switch bypass signal to the variable pitch control system, judges whether a 96-degree limit switch is triggered, if so, enters the step S2, and if not, does not execute any operation; s2, the variable pitch driver controls the bypass relay to be switched on, whether the motor continues to run away and rotate is judged, if not, the step S3 is carried out, and if yes, the step S5 is carried out; s3: the variable pitch driver controls the motor to reversely rotate at a low speed to separate from a 96-degree limit switch, whether the feedback angle of the encoder is continuously reduced is judged, if yes, the step S4 is executed, and if not, the step S5 is executed; s4: judging whether the position is separated from a 96-degree limit switch, if not, returning to the step S3, and if so, entering the step S5; s5: the bypass relay is opened. The invention remotely solves the problem that the pitch control system triggers the limit switch of 96 degrees, avoids time waste caused by the fault removal when maintenance personnel go out of the offshore tower and improves the operation efficiency.

Description

Control strategy for limit switch safety bypass of wind power pitch control system

Technical Field

The invention relates to the technical field of wind power generation, in particular to a control strategy of a limit switch safety bypass of a wind power pitch control system.

Background

Wind energy is a novel and renewable environment-friendly energy source, and a wind power generation project is a key project actively supported by national industrial policies. The variable pitch system is one of core systems of the wind generating set, and has higher requirements on the reliability, the safety and the rationality of fault treatment.

At present, limit switches are arranged on each blade surface of most of variable-pitch systems in the market at two positions of 91 degrees and 96 degrees of the blades as safety protection measures. The paddle runs to 91 degrees to trigger the first limit switch and then the motor is controlled by software to stop, and if the stop fails, the paddle continuously rotates to 96 degrees to trigger the second limit switch. And the normally closed contact of the 96-degree limit switch and the hardware enabling signal of the variable pitch system driver are directly connected in series in a loop, and when the 96-degree limit switch is triggered, the normally closed contact is disconnected, the enabling loop of the driver is opened, and the driver is forcibly stopped. This measure aims at ensuring the safety of the pitch system, but it also has one significant drawback: once the fault is triggered, whether the fault reason is eliminated or not, maintenance personnel must enter the tower barrel cabin, the variable pitch system is switched to a manual mode, and then the blade is driven out to be separated from the limit switch of 96 degrees. For the offshore unit, due to uncertainty of the sea time, once such a fault is triggered, the unit can be shut down for a long time, and the power generation efficiency of the unit is seriously influenced.

Disclosure of Invention

Aiming at the defects of the prior art, the technical problem to be solved by the application of the patent is how to provide a control strategy for a limit switch safety bypass of a wind power pitch control system, the fault that the pitch system triggers a 96-degree limit switch can be solved remotely by sending an instruction through a master control under the condition of ensuring the safety of the pitch system, the time waste caused by the fact that a maintainer goes out of an offshore tower to remove the fault is avoided, and the operating efficiency of a wind generating set is improved.

In order to solve the technical problems, the invention adopts the following technical scheme:

a control strategy for a limit switch safety bypass of a wind power pitch control system comprises the following steps:

s1: the master control sends a limit switch bypass signal to the variable pitch control system, judges whether a 96-degree limit switch is triggered, if so, enters the step S2, and if not, does not execute any operation;

s2, the variable pitch driver controls the bypass relay to be switched on, whether the motor continues to run away and rotate is judged, if not, the step S3 is carried out, and if yes, the step S5 is carried out;

s3: the variable pitch driver controls the motor to reversely rotate at a low speed to separate from a 96-degree limit switch, whether the feedback angle of the encoder is continuously reduced is judged, if yes, the step S4 is executed, and if not, the step S5 is executed;

s4: judging whether the position is separated from a 96-degree limit switch, if not, returning to the step S3, and if so, entering the step S5;

s5: the bypass relay is opened.

The invention discloses a bypass control strategy of a limit switch of a variable pitch control system, which is characterized in that a normally closed signal of a 96-degree limit switch of the variable pitch system is connected into a hardware of a driver for enabling, and simultaneously, a loop controlled to be switched on and off by a relay is connected in parallel to form a bypass, and the driver realizes the bypass function of the limit switch by controlling the switching on and off of the relay. When the pitch system fails and is stopped at the limit switch of 96 degrees in feathering, if the failure is remotely eliminated, the main control can send a bypass signal to the pitch system to start the bypass function, then the actual condition of the blade is comprehensively judged by the pitch driver, and the bypass relay is switched on under the condition of ensuring the safety of the system, so that the blade is automatically operated to the safety position under the control of the pitch system and is separated from the limit switch of 96 degrees. The invention can remotely solve the problem that the pitch system triggers the limit switch of 96 degrees by sending the command through the master control under the condition of ensuring the safety of the pitch system, thereby avoiding the time waste caused by the maintenance personnel getting out of the offshore tower to eliminate the fault and improving the operation efficiency of the wind generating set.

In conclusion, the invention has the following beneficial effects:

1. the invention can remotely solve the problem that the pitch control system triggers the limit switch of 96 degrees, avoid the time waste caused by the maintenance personnel getting out of the offshore tower to eliminate the fault and improve the operation efficiency of the wind generating set.

2. The control strategy related by the invention is rigorous and reliable, and the bypass function of the limit switch can be realized under the condition of ensuring safety.

Drawings

FIG. 1 is a control strategy flow chart of a limit switch safety bypass of a wind power pitch control system according to the invention.

Detailed Description

The present invention will be described in further detail with reference to the accompanying drawings. In the description of the present invention, it is to be understood that the orientation or positional relationship indicated by the orientation words such as "upper, lower" and "top, bottom" etc. are usually based on the orientation or positional relationship shown in the drawings, and are only for convenience of description and simplicity of description, and in the case of not making a reverse description, these orientation words do not indicate and imply that the device or element referred to must have a specific orientation or be constructed and operated in a specific orientation, and therefore, should not be interpreted as limiting the scope of the present invention; the terms "inner and outer" refer to the inner and outer relative to the profile of the respective component itself.

As shown in fig. 1, a control strategy for a limit switch safety bypass of a wind power pitch control system includes the following steps:

s1: the master control sends a limit switch bypass signal to the variable pitch control system, judges whether a 96-degree limit switch is triggered, if so, enters the step S2, and if not, does not execute any operation;

s2, the variable pitch driver controls the bypass relay to be switched on, whether the motor continues to run away and rotate is judged, if not, the step S3 is carried out, and if yes, the step S5 is carried out;

s3: the variable pitch driver controls the motor to slowly rotate reversely to separate from a 96-degree limit switch, whether the feedback angle of the encoder is continuously reduced is judged, if yes, the step S4 is executed, and if not, the step S5 is executed;

s4: judging whether the position is separated from a 96-degree limit switch, if not, returning to the step S3, and if so, entering the step S5;

s5: the bypass relay is opened.

During specific implementation, if the motor is out of control in the process of triggering fault feathering by a variable pitch system, the blade can continue to feather until the limit switch of 96 degrees is triggered, and at the moment, the motor is forced to stop due to the fact that the enabling signal of the driver hardware is disconnected. After the fault occurs, the master control firstly eliminates the corresponding fault and resets, then sends a limit switch bypass signal to the variable pitch system through communication, and the variable pitch system firstly judges whether the limit switch of 96 degrees is triggered after receiving the signal, so as to avoid the situation that the master control mistakenly sends the signal to influence the system safety. When the limit switch of 96 degrees is in a trigger state, the variable pitch driver controls the bypass relay to be switched on, and simultaneously gives a motor stop command. At the moment, if the motor is still in an out-of-control state and continues to rotate forwards, the driver immediately disconnects the bypass relay, and the motor is forced to stop due to the fact that the hardware enabling signal is lost, so that the safety of the system is guaranteed. If the motor returns to normal, the driver will give a slow reverse command and then monitor the encoder for angular feedback: if the angle of the encoder is not continuously reduced, the system still has serious faults, and a bypass relay is immediately disconnected for ensuring the safety system; if the angle of the encoder is continuously reduced, the motor executes a reverse rotation command, and after the paddle is separated from the 96-degree limit switch, the bypass relay is switched off, the normally closed signal of the 96-degree limit switch is switched on, the driver cannot lose the hardware enabling signal, and the motor can continue to operate normally.

In specific implementation, the operation is as follows:

1. and the wiring and the pitch variation of related hardware and the replacement of a main control program are completed, and the control feedback of newly added signals is ensured to be normal.

2. And under the condition that the variable pitch system is in a manual mode, the blade is opened to a position of a 96-degree limit switch and stopped, and the condition that a motor of the blade is out of control and stopped at the position of the 96-degree limit switch is simulated.

3. And switching the variable pitch system into an automatic mode, and then sending a limit switch bypass signal to the variable pitch system by the master control.

4. After the variable pitch system receives the signal, the bypass relay is switched on, the driver recovers the hardware enabling signal, and the motor starts to rotate reversely at a low speed.

5. And after the paddle rotates reversely to be separated from the 96-degree limit switch, the motor stops running, the bypass relay is disconnected, and the main control cancels the bypass signal.

6. And the master control resets the system failure, sends out a start instruction, and drives the blades to the specified start angle.

Finally, it should be noted that: various modifications and alterations of this invention may be made by those skilled in the art without departing from the spirit and scope of this invention. Thus, it is intended that the present invention cover the modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents.

Claims (1)

1. A control strategy for a limit switch safety bypass of a wind power pitch control system is characterized by comprising the following steps:

s1: the master control sends a limit switch bypass signal to the variable pitch control system, judges whether a 96-degree limit switch is triggered, if so, enters the step S2, and if not, does not execute any operation;

s2, the variable pitch driver controls the bypass relay to be switched on, whether the motor continues to run away and rotate is judged, if not, the step S3 is carried out, and if yes, the step S5 is carried out;

s3: the variable pitch driver controls the motor to reversely rotate at a low speed to separate from a 96-degree limit switch, whether the feedback angle of the encoder is continuously reduced is judged, if yes, the step S4 is executed, and if not, the step S5 is executed;

s4: judging whether the position is separated from a 96-degree limit switch, if not, returning to the step S3, and if so, entering the step S5;

s5: the bypass relay is opened.

Images