A method for preventing a wind turbine generator unit pitch system from being stuck

Abstract

The present application belongs to the field of wind power generation technology, and discloses a method for preventing wind turbine variable pitch system from being stuck. The method comprises the following steps: S1, adding a relay in the power supply circuit of the variable pitch brake of the wind turbine variable pitch system; S2, judging the power supply state of the variable pitch brake by using the state of the added relay; and S3, judging whether the state of the variable pitch brake is normal according to the opening and closing state of the relay. When the power supply circuit is powered, if the relay is closed, the power supply circuit of the variable pitch brake is normal, the variable pitch brake works normally, and the variable pitch system operates normally; if the relay is not closed, the power supply circuit of the variable pitch brake is abnormal, the state of the variable pitch brake is abnormal, and the variable pitch system cannot operate normally. The method for monitoring the state of the power supply circuit of the variable pitch brake of the wind turbine can effectively prevent the opening and closing state of the variable pitch brake from being abnormal due to abnormal power supply, so as to avoid the safety hazards such as stuck or abnormal opening of the variable pitch system.

Description

Technical Field

[0001] The present invention belongs to the technical field of wind power generation, and in particular relates to a method for preventing a wind turbine set's pitch control system from getting stuck. Background Art

[0002] As wind turbines age, components and parts of the turbine's pitch control system are prone to aging, loosening, and wear. Failures in the power supply circuit for the pitch brake can cause the brake to fail to open or close. When the wind turbine is shut down, the pitch brake closes without power, effectively preventing the blades from rotating toward the open position. When the wind turbine is started, the pitch brake must be energized and opened before pitch control can begin. However, current control systems do not monitor the status of the pitch brake. If the pitch brake fails to open, excessive pitch torque can cause the wind turbine to jam during pitch control, leading to overload and shutdown of the pitch motor and the inability to feather the blades. Furthermore, if a power supply circuit failure causes the brake to fail to close after opening, the blades could be blown away in the feathered position during shutdown, potentially causing a runaway accident. Therefore, for safe and stable turbine operation, addressing the current safety hazards of pitch brake jams or open blades is crucial. Summary of the Invention

[0003] The object of the present invention is to provide a method for preventing a wind turbine pitch control system from getting stuck, so as to solve the problems in the prior art.

[0004] In order to achieve the above object, the present invention provides the following technical solutions:

[0005] A method for preventing a wind turbine pitch control system from getting stuck, comprising:

[0006] S1: Add a relay to the power supply circuit of the pitch brake of the wind turbine pitch system;

[0007] S2: Use the status of the added relay to determine the power supply status of the pitch brake;

[0008] S3: Determine whether the status of the pitch brake is normal based on the opening and closing status of the relay. When the power supply circuit is energized, if the relay is closed, the power supply of the pitch brake power supply circuit is normal, the pitch brake works normally, and the pitch system works normally; if the relay is not closed, the power supply of the pitch brake power supply circuit is abnormal, the pitch brake status is abnormal, and the pitch system cannot operate normally.

[0009] Furthermore, the relay is connected in series in a power supply circuit of the pitch brake.

[0010] Furthermore, the relay is connected to a pitch control cabinet in the pitch brake power supply circuit.

[0011] Furthermore, a relay is added to each pitch control cabinet in the pitch brake power supply circuit of the pitch system.

[0012] Furthermore, the pitch brake power supply circuit includes a power supply, a slip ring, a hub, a main controller, a pitch control cabinet, a power supply control unit, a relay and a pitch brake, wherein:

[0013] The power supply is arranged at one end of the nacelle of the wind turbine generator set and is fixedly connected to the main controller via a wire;

[0014] The main controller is arranged in the cabin and fixedly connected to the cabin;

[0015] The slip ring is arranged in the nacelle of the wind turbine generator set and is connected to the main controller and the pitch control cabinet in the hub through wires;

[0016] The hub is arranged at the other end of the nacelle and is detachably connected to the other end of the nacelle;

[0017] The pitch control cabinet is arranged in the wheel hub and is fixedly connected to the wheel hub;

[0018] The power supply control unit is arranged in the pitch control cabinet and is connected to the relay through a wire;

[0019] The input interface of the pitch brake is connected to the output interface of the relay via a connecting line;

[0020] The relay is connected between the power supply control unit and the pitch brake through a wire.

[0021] Furthermore, whether the power supply circuit of the pitch brake is normal is judged according to the opening and closing state of the relay, including: when the main controller sends a pitch command to the pitch control cabinet, if the pitch control cabinet supplies power to the power supply circuit of the pitch brake normally, and the relay in the power supply circuit is not closed, then the power supply circuit is faulty, the pitch brake is in a closed state, and the pitch system is abnormal; if the pitch control cabinet supplies power to the power supply circuit of the pitch brake normally, and the relay in the power supply circuit is closed, then the power supply circuit is normal, the pitch brake is in an open state, and the pitch system is normal.

[0022] Furthermore, the power input current is 230V AC.

[0023] Furthermore, the pitch brake is a one-way normally closed brake.

[0024] Compared with the prior art, the advantages of the present invention are:

[0025] By adding a relay to the power supply circuit of the pitch brake of the pitch system, it is possible to determine whether the power supply circuit of the pitch brake is normal based on the open and closed state of the relay, thereby determining the open and closed state of the pitch brake, which can effectively reduce the pitch sticking failure and safety hazards of the wind turbine set caused by the pitch brake not opening as required. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The accompanying drawings, which constitute part of the present invention, are intended to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are intended to explain the present invention and do not constitute an undue limitation of the present invention. In the accompanying drawings:

[0027] Figure 1 This is a flow chart of a method for preventing a wind turbine pitch control system from getting stuck according to the present invention;

[0028] Figure 2 This is a structural diagram of a power supply circuit for a pitch brake in a method for preventing a wind turbine pitch system from getting stuck according to the present invention;

[0029] Figure 3 A diagram showing the working principle of a method for preventing a wind turbine pitch system from getting stuck according to the present invention; DETAILED DESCRIPTION

[0030] The present invention will be described in detail below with reference to the accompanying drawings and in combination with embodiments. It should be noted that, in the absence of conflict, the embodiments and features of the embodiments of the present invention can be combined with each other.

[0031] The following detailed description is an exemplary description and is intended to provide further detailed description of the present invention. Unless otherwise indicated, all technical terms used in the present invention have the same meaning as those generally understood by those skilled in the art to which the present invention belongs. The terms used in the present invention are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present invention.

[0032] like Figure 1 As shown, a method for preventing a wind turbine pitch system from getting stuck according to the present invention includes:

[0033] S1: Add a relay to the power supply circuit of the pitch brake of the wind turbine pitch system;

[0034] S2: Use the status of the added relay to determine the power supply status of the pitch brake;

[0035] S3: judging whether the state of the variable pitch brake is normal according to the opening and closing state of the relay, when the power supply circuit is powered, if the relay is closed, the power supply circuit of the variable pitch brake is normal, the variable pitch brake works normally, and the variable pitch system operates normally; when the power supply circuit is powered, if the relay is not closed, the power supply circuit of the variable pitch brake is abnormal, the state of the variable pitch brake is abnormal, and the variable pitch system cannot operate normally.

[0036] Specifically, a relay is added in each variable pitch control cabinet in the power supply circuit of the variable pitch brake of the variable pitch system, and each relay is connected in series in the power supply circuit of the variable pitch brake.

[0037] The method for preventing the wind turbine variable pitch system from being stuck can effectively prevent the opening and closing state of the variable pitch brake of the wind turbine from being abnormal due to abnormal power supply, thereby avoiding the safety hazards such as the variable pitch system being stuck or abnormally opened.

[0038] Further specifically, as shown in Figure 2 The variable pitch system of the wind turbine is used to control the windward angle of the blade, and mainly consists of a variable pitch bearing, a variable pitch motor, a variable pitch gearbox, a variable pitch control cabinet, a variable pitch brake, a backup power supply, a rotary encoder and the like. The variable pitch brake is a one-way brake, which only brakes the blade in the opening direction and does not brake the blade in the feathering direction. The one-way brake is usually in a normally closed state and is opened by power supply. The opening and closing of the variable pitch brake is realized by switching the power supply state of the power supply circuit thereof.

[0039] Further specifically, the power supply is arranged at one end of the nacelle of the wind turbine, is fixedly connected to the main controller through a wire, and the main controller and the slip ring are arranged in the nacelle of the wind turbine. The hub is arranged at the other end of the nacelle; wherein: the main controller is fixedly connected to the nacelle; the slip ring is connected to the main controller and the variable pitch control cabinet in the hub through a wire; the hub is detachably connected to the other end of the nacelle; the variable pitch control cabinet is arranged in the hub and is fixedly connected to the hub; the power supply control unit is arranged in the variable pitch control cabinet and is connected to the relay through a wire; the input interface of the variable pitch brake is connected to the output interface of the relay through a connecting wire; and the relay is connected between the power supply control unit and the variable pitch brake through a wire.

[0040] Further specifically, the variable pitch brake is a one-way normally closed brake.

[0041] Specifically, when the main controller issues a pitch command and sends it to the pitch control cabinet through the slip ring, the pitch control cabinet will supply power to the pitch brake so that the pitch brake will open after being energized. The pitch action can only be started after the pitch brake is opened. After the power supply circuit is powered normally, if the relay in series in the power supply circuit is not closed, the power supply circuit is faulty, the pitch brake is not powered to open, and the pitch system is abnormal; if the pitch control cabinet supplies power to the power supply circuit of the pitch brake normally, the relay in the power supply circuit is closed, the power supply circuit is normal, the pitch brake is in the energized and open state, and the pitch system is normal.

[0042] To be more specific, the start-up status of the wind turbine: the main control sends a start-up command, and after the pitch control cabinet receives the start-up command through the slip ring, it first supplies power to the pitch brake, which opens after being energized. Then the pitch control cabinet starts to control the operation of the pitch motor according to the pitch speed and pitch reference angle given by the main control. The pitch motor drives the pitch gearbox and pitch bearing, and finally drives the blades to rotate. During the rotation process, the rotary encoder will monitor the rotation angle of the blade in real time and feed it back to the pitch control cabinet. When the rotary encoder detects that the blade has rotated to the required position, the pitch control cabinet will control the pitch motor to stop running, and the pitch action is completed at this time.

[0043] When the wind turbine is in normal operation: After the wind turbine is started normally, the pitch brake is always in the open state and no longer participates in the pitch action. The main control will always send pitch signals to the pitch control cabinet. The pitch control cabinet controls the output of the pitch motor to achieve the main control's response requirements for pitch. In the non-pitch state, the pitch motor will always output power to maintain the position of the blades, and the pitch brake does not need to be involved.

[0044] When the wind turbine is in shutdown state: when external conditions trigger the shutdown judgment conditions, the main control will issue a shutdown command. After the pitch control cabinet receives the shutdown command, it will control the pitch motor to operate and rotate the blades to the position required for shutdown. After the rotary encoder detects that the blades have rotated into place, the pitch brake power supply circuit is de-energized and the brake is closed to prevent the blades from rotating to the working position.

[0045] As wind turbines age, components and parts of the turbine's pitch system experience aging, loosening, and wear. Failures in the pitch brake control circuit can cause the brake to fail to open or close. However, many early turbine designs failed to account for this operating condition. The main control unit lacked feedback on the pitch brake status. During startup, even after the main control unit signals the brake to open, without knowing whether the brake is engaged, it sends pitch-related commands to the pitch system. If the pitch brake fails to open, the pitch motor will overcome the brake force and force the blades to pitch. This excessive pitch torque can cause the pitch system to jam, the pitch motor to overload, and the blades to fail to feather. Another potential issue is when the turbine is shut down. After blade feathering is complete, the power supply circuit should be de-energized and the brake engaged. However, if a power supply circuit failure prevents the brake from engaging, the blades could be blown away in the feathered position. Both of these situations can ultimately lead to a runaway accident.

[0046] More specifically, a relay is added to each pitch control cabinet in the power supply circuit of the pitch brake of the pitch system. That is, the present invention installs a relay in each pitch control cabinet as a monitoring feedback point for the pitch brake of each blade. The relay is connected in series to the power supply circuit of the pitch brake to collect the power supply status of the pitch brake and then determine whether the power supply circuit of the pitch brake is normal. If the power supply circuit of the pitch brake fails, the input current of the relay is zero, the relay is disconnected, the pitch brake cannot be powered on and opened, and the state is abnormal; if the power supply circuit of the pitch brake is normal, the input current of the relay reaches the specified value, the relay is energized, the pitch brake is powered on and opened, and the state is normal. The newly added relay feedback points in the three pitch control cabinets are connected in parallel and introduced into the main control, so that the main control of the wind turbine can monitor the working status of the pitch brake.

[0047] Furthermore, if Figure 3 As shown, the wind turbine start-up status: the main control sends a start-up command, and the power supply circuit of the pitch brake supplies power to the pitch brake. If the power supply circuit is normal, the relay is energized and the signal is fed back to the main control, indicating that the pitch brake is opened normally. After the main control determines that the three pitch brakes are normal, it starts to send a start-up pitch command to the pitch control cabinet, and the subsequent pitch control process is the same as the above process; if there is a problem with any of the power supply circuits of the three pitch brakes, the relay will feed back the signal to the main control, and the main control can monitor it in time, and then determine that there is an abnormality in the pitch brake system. At this time, the fault is reported and the machine is shut down, and it will no longer be started, and the maintenance personnel will be notified to board the machine for maintenance.

[0048] Normal operation state of the wind turbine: In this state, the pitch strategy is executed normally, and the pitch brake does not participate in the control logic. Therefore, the pitch control logic process remains unchanged from before the change.

[0049] Wind turbine shutdown status: When external conditions trigger the shutdown judgment condition, the main control will issue a shutdown command. After receiving the shutdown command, the pitch control cabinet will control the pitch motor to rotate the blades to the shutdown position. After the rotary encoder detects that the blades have rotated into place, it will feedback the signal to the main control. After the main control receives the signal that the blades have reached the right pitch, it will issue a power supply circuit de-energized command to the pitch brake. After the power supply circuit is de-energized, the relay will be disconnected, and the pitch brake will be de-energized and closed. The relay will give feedback signal to the main control, which will determine whether the feedback signal is normal. If it is abnormal, it will alarm. At this time, it means that the pitch brake is not braking, and the blades may be blown to the working position by the wind, causing the unit to run away. There is a huge safety hazard, and personnel will be notified to board the machine for maintenance.

[0050] Furthermore, the pitch brake detection relay contacts can be connected in series to the original system safety chain. When a brake power supply anomaly is detected, the pitch brake safety chain is disconnected, achieving an emergency shutdown of the unit with rapid blade retraction. Furthermore, the pitch brake detection signal can be compared with the feedback information from the main control pitch control software to identify the abnormal pitch brake. The main control software can then classify the fault and clearly identify the fault location, facilitating maintenance work.

[0051] It is understood from common technical knowledge that the present invention may be implemented by other embodiments that do not depart from its spirit or essential features. Therefore, the embodiments disclosed above are, in all respects, merely illustrative and not exclusive. All modifications within the scope of the present invention or equivalent to the scope of the present invention are intended to be encompassed by the present invention.

[0052] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to the above embodiments, ordinary technicians in the field should understand that the specific implementation methods of the present invention can still be modified or replaced by equivalents. Any modification or equivalent replacement that does not depart from the spirit and scope of the present invention should be covered by the scope of protection of the claims of the present invention.

Claims

1. A method for preventing a wind turbine pitch control system from getting stuck, characterized in that: include: S1: adding a relay to the power supply circuit of the pitch brake of the wind turbine pitch system; wherein the relay is connected in series to the power supply circuit of the pitch brake; The pitch brake power supply circuit includes a power supply, a slip ring, a hub, a main controller, a pitch control cabinet, a power supply control unit, a relay and a pitch brake, wherein: The power supply is arranged at one end of the nacelle of the wind turbine generator set and is fixedly connected to the main controller via a wire; The main controller is arranged in the cabin and fixedly connected to the cabin; The slip ring is arranged in the nacelle of the wind turbine generator set and is connected to the main controller and the pitch control cabinet in the hub through wires; The hub is arranged at the other end of the nacelle and is detachably connected to the other end of the nacelle; The pitch control cabinet is arranged in the wheel hub and is fixedly connected to the wheel hub; The power supply control unit is arranged in the pitch control cabinet and is connected to the relay through a wire; The input interface of the pitch brake is connected to the output interface of the relay via a connecting line; The relay is connected between the power supply control unit and the pitch brake via a wire; S2: Use the status of the added relay to determine the power supply status of the pitch brake; S3: judging whether the state of the pitch brake is normal according to the on / off state of the relay; when the power supply circuit is energized, if the relay is closed, the power supply of the pitch brake power supply circuit is normal, the pitch brake operates normally, and the pitch system operates normally; if the relay is not closed, the power supply of the pitch brake power supply circuit is abnormal, the pitch brake state is abnormal, and the pitch system cannot operate normally; Judging whether the power supply circuit of the pitch brake is normal according to the on-off state of the relay includes: when the main controller sends a pitch command to the pitch control cabinet, if the pitch control cabinet supplies power to the power supply circuit of the pitch brake normally, and the relay in the power supply circuit is not closed, then the power supply circuit is faulty, the pitch brake is in a closed state, and the pitch system is abnormal; if the pitch control cabinet supplies power to the power supply circuit of the pitch brake normally, and the relay in the power supply circuit is closed, then the power supply circuit is normal, the pitch brake is in an open state, and the pitch system is normal; A relay is added to each pitch control cabinet in the pitch brake power supply circuit of the pitch system.

2. A method for preventing a wind turbine pitch control system from getting stuck according to claim 1, characterized in that: The relay is connected to a pitch control cabinet in the pitch brake power supply circuit.

3. The method for preventing a wind turbine pitch control system from getting stuck according to claim 1, wherein: The power input current is 230V AC.

4. The method for preventing a wind turbine pitch control system from getting stuck according to claim 1, wherein: The pitch brake is a one-way normally closed brake.

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