A control method based on dual proximity switches to replace redundant encoders of variable pitch systems

Abstract

The present invention discloses a control method based on replacing redundant encoders of a pitch control system with dual proximity switches. A first proximity switch sensor and a second proximity switch sensor are used as redundant devices for position detection of the pitch control system, and are respectively close to the 0° position and the 90° position of the corresponding blades, so that each time the wind turbine opens and retracts the blades, the first proximity switch sensor and the second proximity switch sensor are triggered; upon each triggering, the position value recorded by the A-type encoder is compared with the angular position corresponding to the corresponding proximity switch sensor; if the angle deviation falls within a set allowable value range, it is determined that the angle measurement is normal; if the angle deviation exceeds the set allowable value range, it is determined that there is a problem with the angle measurement, and an alarm is issued to shut down the machine; the present invention greatly reduces the failure rate of the wind turbine while ensuring the safety of the wind turbine, and at the same time significantly reduces the use cost of the wind turbine.

Description

Technical Field

[0001] The present invention belongs to the field of variable pitch system control in wind power generation industry, and in particular relates to a control method based on replacing redundant encoders of variable pitch systems with dual proximity switches. Background Art

[0002] In the prior art, the position detection of the variable pitch system generally adopts the method of motor resolver combined redundant encoder. During the operation, the motor speed and position signal are collected through the motor resolver, and the absolute position signal of the motor is collected through the SSI redundant encoder, and compared with the resolver position signal in real time. However, since the redundant encoder of the variable pitch system (referred to as "SSI encoder") is a weak link in the variable pitch system, it is in a harsh working environment and is more easily damaged than other devices and is prone to communication failures. It is easy to damage, has low reliability and is expensive.

[0003] Therefore, the applicant hopes to seek technical solutions to improve the above technical problems. Summary of the invention

[0004] In view of this, the purpose of the present invention is to propose a control method based on replacing the redundant encoder of the pitch system with a dual proximity switch, which greatly reduces the failure rate of the wind turbine while ensuring the safety of the wind turbine, and significantly reduces the use cost of the wind turbine.

[0005] To this end, the technical solution adopted in the present invention is as follows:

[0006] A control method based on replacing redundant encoders of a pitch system with dual proximity switches, wherein a first proximity switch sensor and a second proximity switch sensor are respectively configured for each blade of the pitch system, and an A-type encoder in communication connection with each proximity switch sensor is installed on each blade of the pitch system; wherein the first proximity switch sensor and the second proximity switch sensor are used as redundant devices for position detection of the pitch system, and are respectively close to the 0° position and the 90° position of their corresponding blades, so that each time the wind turbine opens and retracts the blades, the first proximity switch sensor and the second proximity switch sensor are triggered; each time the wind turbine is triggered, the position value recorded by the A-type encoder is compared with the angular position corresponding to the corresponding proximity switch sensor;

[0007] If the angle deviation falls within the set allowable value range, the angle measurement is judged to be normal;

[0008] If the angle deviation exceeds the set allowable value range, it is determined that there is a problem with the angle measurement and an alarm is issued to shut down the machine.

[0009] Preferably, the first proximity switch sensor is installed at the 3-7° position of the blade, preferably at the 4-6° position; and / or the second proximity switch sensor is installed at the 83-87° position of the blade, preferably at the 84-86° position.

[0010] Preferably, the set allowable value range is ±1-3° of the angular position corresponding to the proximity switch sensor, and more preferably is ±1-2° of the angular position corresponding to the proximity switch sensor.

[0011] Preferably, in the initial debugging state of the pitch system unit, the trigger angle allowable value range of each corresponding proximity switch sensor is calibrated by the A-type encoder of each blade.

[0012] Preferably, the calibration process comprises the following steps:

[0013] S10), each blade is set at a preset limit position, and the following variables are cleared in advance:

[0014] The first variable: the first proximity switch_ON, represents the A encoder position value corresponding to when the first proximity switch sensor is at the upper limit of the trigger angle allowable range and is triggered;

[0015] The second variable: first proximity switch_OFF, represents the A encoder position value corresponding to when the first proximity switch sensor is at the lower limit of the trigger angle allowable range and is triggered;

[0016] The third variable: second proximity switch_ON, represents the A encoder position value corresponding to when the second proximity switch sensor is at the upper limit of the trigger angle allowable range and is triggered;

[0017] The fourth variable: second proximity switch_OFF, represents the A encoder position value corresponding to when the second proximity switch sensor is at the lower limit of the trigger angle allowable range and is triggered;

[0018] The fifth variable: the mark position, which represents the position value of the A encoder corresponding to the position of the blade;

[0019] All the above variables are power-off saved variables;

[0020] S20), manually controlling each blade shaft of the pitch system, respectively, and commanding each blade to move from the limit switch to an angle less than the preset limit position by a preset value, wherein:

[0021] When the second proximity switch sensor is at the upper limit of the trigger angle allowable range and is triggered, the A encoder position value is saved in the second proximity switch_ON;

[0022] When the second proximity switch sensor is at the lower limit of the trigger angle allowable range and is triggered, the A encoder position value is saved in the second proximity switch_OFF;

[0023] When the first proximity switch sensor is at the upper limit of the trigger angle allowable range and is triggered, the A encoder position value is saved in the first proximity switch_ON;

[0024] When the first proximity switch sensor is at the lower limit of the trigger angle allowable range and is triggered, the A encoder position value is saved in the first proximity switch_OFF;

[0025] When the first proximity switch_ON, the first proximity switch_OFF, the second proximity switch_ON, and the second proximity switch_OFF are all greater than 0, the flag position = 1;

[0026] S30), the blade is rotated back to the preset limit position, and the calibration process is completed.

[0027] Preferably, the preset limit position is 91°, and the preset value is 1-5°; in the step S20), when the mark position = 0, starting is not allowed.

[0028] Preferably, during normal operation, the trigger angle allowable range corresponding to each proximity switch corresponding to the A-type encoder is verified; wherein the verification process includes:

[0029] The trigger angle allowable range is defined as a first calibration value interval, an angle range less than a lower limit of the trigger angle allowable range is defined as a second calibration value interval, and an angle range greater than an upper limit of the trigger angle allowable range is defined as a third calibration value interval;

[0030] When the position value of encoder A falls within the first calibration value range, the corresponding proximity switch sensor is not triggered, and the system program alarms "proximity switch lost";

[0031] When the position value of encoder A does not fall within the first calibration value interval, the corresponding proximity switch sensor is triggered, and the system program alarms "proximity switch malfunction".

[0032] Preferably, during the verification process, the upper and lower limits of the allowable range of the trigger angle are respectively reduced by one position angle inward, and used as the first calibration value interval; the lower limit of the allowable range of the trigger angle is increased by one position angle outward, and used as the second calibration value interval; the upper limit of the allowable range of the trigger angle is increased by one position angle outward, and used as the third calibration value interval.

[0033] Preferably, the pitch control system comprises three blades, and when the angle deviation between every two blades deviates from a preset blade angle deviation range, the pitch control system alarms and shuts down.

[0034] Preferably, the blade angle deviation range is pre-set via a parameter interface of the pitch control system.

[0035] The present invention adopts a solution of setting two proximity switch sensors to replace the SSI redundant encoder used in the existing general solution, and develops a specific proximity switch position detection solution and proximity switch position detection logic, which greatly reduces the failure rate of the wind turbine while ensuring the safety of the wind turbine, and significantly reduces the use cost of the wind turbine. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 It is a schematic diagram of the installation position of the proximity switch sensor in the specific implementation mode of the present application;

[0037] Figure 2 This is a schematic diagram of the permissible range of trigger angles for a single proximity switch sensor;

[0038] Figure 3 is a schematic diagram of the range of each calibration value of the first proximity switch sensor;

[0039] Figure 4 It is a schematic diagram of the range of calibration values ​​of the second proximity switch sensor. DETAILED DESCRIPTION

[0040] An embodiment of the present invention discloses a control method based on replacing redundant encoders of a pitch system with dual proximity switches, wherein a first proximity switch sensor and a second proximity switch sensor are respectively configured for each blade of the pitch system, and an A-type encoder communicatively connected to each proximity switch sensor is installed on each blade of the pitch system; wherein the first proximity switch sensor and the second proximity switch sensor serve as redundant devices for position detection of the pitch system, and are respectively close to the 0° position and 90° position of their corresponding blades, so that each time the wind turbine opens and retracts the blades, the first proximity switch sensor and the second proximity switch sensor are triggered; upon each triggering, the position value recorded by the A-type encoder is compared with the angular position corresponding to the corresponding proximity switch sensor; if the angle deviation falls within the set allowable value range, it is determined that the angle measurement is normal; if the angle deviation exceeds the set allowable value range, it is determined that there is a problem with the angle measurement, and an alarm is issued to shut down the machine.

[0041] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0042] See also Figure 1 As shown, a control method based on replacing redundant encoders of a pitch system with dual proximity switches is provided, wherein a first proximity switch sensor ( Figure 1 labeled "5 degree proximity switch") and a second proximity switch sensor ( Figure 1 The first proximity switch sensor and the second proximity switch sensor are redundant devices for position detection of the pitch system, and are respectively close to the 0° position ( Figure 1 marked as "Blade 0 degrees") and the 90° position ( Figure 1 Marked as "blade 90 degrees"), so that each time the fan opens and retracts the blade, the first proximity switch sensor and the second proximity switch sensor are triggered; preferably, in this embodiment, the first proximity switch sensor is installed at the 3-7° position of the blade, preferably at the 4-6° position; and / or the second proximity switch sensor is installed at the 83-87° position of the blade, preferably at the 84-86° position, and specifically preferably, in this embodiment, the first proximity switch sensor is installed at the 5° position of the blade; the second proximity switch sensor is installed at the 85° position of the blade;

[0043] At each trigger, the position value recorded by the A-type encoder is compared with the angular position corresponding to the corresponding proximity switch sensor; if the angle deviation falls within the set allowable value range (i.e., the allowable value range of the trigger angle of the corresponding proximity switch sensor), the angle measurement is determined to be normal; if the angle deviation exceeds the set allowable value range, it is determined that there is a problem with the angle measurement, and an alarm is issued to shut down; further preferably, in the present embodiment, the set allowable value range is ±1-3° of the angular position corresponding to the proximity switch sensor, and more preferably, the angular position corresponding to the proximity switch sensor is ±1-3 degrees; specifically preferably, in the present embodiment, the set allowable value range is ±2° of the angular position corresponding to the proximity switch sensor, specifically, the allowable value range of the trigger angle of the first proximity switch sensor is 3-7°, and the allowable value range of the trigger angle of the second proximity switch sensor is 83-87°. In other embodiments, the allowable value range of each proximity switch sensor can also be specifically set according to actual control needs, and the present application does not make a unique limitation when implemented.

[0044] Preferably, in this embodiment, in the initial debugging state of the pitch system unit, the trigger angle allowable value range of each proximity switch sensor corresponding to each blade is set by the A-type encoder of each blade (see Figure 2 As shown, that is, the range between the upper limit ON and the lower limit OFF) is calibrated; wherein further preferably, in this embodiment, the calibration process includes the following steps:

[0045] S10), each blade is set at a preset limit position (in this embodiment, the preset limit position is set to 91°), and the following variables are cleared in advance:

[0046] The first variable: the first proximity switch_ON (also called "5° proximity switch_ON"), represents the A encoder position value corresponding to when the first proximity switch sensor is at the upper limit of the trigger angle allowable range and is triggered;

[0047] The second variable: the first proximity switch_OFF (also called "5° proximity switch_OFF"), represents the A encoder position value corresponding to when the first proximity switch sensor is at the lower limit of the trigger angle range;

[0048] The third variable: the second proximity switch_ON (also called "85° proximity switch_ON"), represents the A encoder position value corresponding to when the second proximity switch sensor is at the upper limit of the trigger angle allowable range and is triggered;

[0049] The fourth variable: the second proximity switch_OFF (also called "85° proximity switch_OFF") represents the A encoder position value corresponding to when the second proximity switch sensor is triggered at the lower limit of the trigger angle allowable range;

[0050] The fifth variable: the mark position, which represents the position value of the A encoder corresponding to the position of the blade;

[0051] It should be noted that all the above five variables are power-off preservation variables;

[0052] S20), manually controlling each blade shaft of the pitch system, respectively, and commanding each blade to move from the limit switch to an angle less than 91° by a preset value, it is recommended that the preset value be 1-5°, and in this embodiment is specifically set to 2°, that is, wherein each blade is commanded to move from the limit switch to a -2° position direction; wherein,

[0053] When the second proximity switch sensor is at the upper limit of the trigger angle allowable range and is triggered, the A encoder position value is saved in the second proximity switch_ON;

[0054] When the second proximity switch sensor is at the lower limit of the trigger angle allowable range and is triggered, the A encoder position value is saved in the second proximity switch_OFF;

[0055] When the first proximity switch sensor is at the upper limit of the trigger angle allowable range and is triggered, the A encoder position value is saved in the first proximity switch_ON;

[0056] When the first proximity switch sensor is at the lower limit of the trigger angle allowable range and is triggered, the A encoder position value is saved in the first proximity switch_OFF;

[0057] When the first proximity switch_ON, the first proximity switch_OFF, the second proximity switch_ON and the second proximity switch_OFF are all greater than 0, the flag position = 1; in this step S20), when the flag position = 0, starting is not allowed;

[0058] S30), the blade is rotated back to the preset limit position, and the calibration process is completed.

[0059] Preferably, in the present embodiment, during normal operation, the trigger angle allowable range corresponding to each proximity switch corresponding to the A-type encoder is verified; wherein the verification process includes: defining the trigger angle allowable range as a first calibration value interval, defining the angle range less than the lower limit of the trigger angle allowable range as a second calibration value interval, and defining the angle range greater than the upper limit of the trigger angle allowable range as a third calibration value interval; further preferably, in the present embodiment, in order to further improve the verification accuracy, during the verification process, the upper and lower limits of the trigger angle allowable range are respectively reduced inward by a position angle tolerance, which are used as the first calibration value interval; the lower limit of the trigger angle allowable range is increased outward by a position angle tolerance, which is used as the second calibration value interval; the upper limit of the trigger angle allowable range is increased outward by a position angle tolerance, which is used as the third calibration value interval; wherein in actual implementation, the setting of reducing the position angle tolerance inward or increasing the position angle tolerance outward can be directly set through the parameter interface of the variable pitch system;

[0060] For more details, please see Figure 3 As shown, the trigger angle allowable range of the first proximity switch sensor is 3-7° (i.e., the range between the upper limit ON and the lower limit OFF of the trigger angle of the first proximity switch sensor), the first calibration value interval a1 is 4-6°, the second calibration value interval a2 is less than 2°, and the third calibration value interval a3 is greater than 8°; please refer to Figure 4As shown, the trigger angle allowable range of the second proximity switch sensor is 83-87° (i.e., the range between the upper limit ON and the lower limit OFF of the trigger angle of the second proximity switch sensor), the first calibration value interval b1 is 84-86°, the second calibration value interval b2 is less than 82°, and the third calibration value interval b3 is greater than 88°;

[0061] When the position value of encoder A falls within the first calibration value range, the corresponding proximity switch sensor is not triggered, and the system program alarms "proximity switch lost";

[0062] When the position value of encoder A does not fall within the first calibration value interval, the corresponding proximity switch sensor is triggered, and the system program alarms "proximity switch malfunction".

[0063] Preferably, in this embodiment, the pitch system includes three blades (i.e., paddle blades), and when the angle deviation between every two blades deviates from the preset blade angle deviation range, the pitch system alarms and shuts down; preferably, the blade angle deviation range is pre-set through the parameter interface of the pitch system.

[0064] This embodiment adopts a solution of setting two proximity switch sensors to replace the SSI redundant encoder used in the existing general solution, and develops a specific proximity switch position detection solution and proximity switch position detection logic. While ensuring the safety of the wind turbine, the failure rate of the wind turbine is greatly reduced, and the use cost of the wind turbine is significantly reduced.

[0065] It will be apparent to those skilled in the art that the invention is not limited to the details of the exemplary embodiments described above and that the invention can be implemented in other specific forms without departing from the spirit or essential features of the invention. Therefore, the embodiments should be considered exemplary and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description, and it is intended that all variations falling within the meaning and scope of the equivalent elements of the claims be included in the invention. Any reference numeral in a claim should not be considered as limiting the claim to which it relates.

[0066] In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

Claims

1. A control method based on replacing redundant encoders of a pitch control system with dual proximity switches, characterized in that: A first proximity switch sensor and a second proximity switch sensor are respectively configured for each blade of the pitch system, and an A-type encoder in communication with each proximity switch sensor is installed on each blade of the pitch system; wherein the first proximity switch sensor and the second proximity switch sensor are used as redundant devices for position detection of the pitch system, and are respectively close to the 0° position and the 90° position of the corresponding blade, so that each time the wind turbine opens and retracts the blade, the first proximity switch sensor and the second proximity switch sensor are triggered; each time the wind turbine is triggered, the position value recorded by the A-type encoder is compared with the angular position corresponding to the corresponding proximity switch sensor; If the angle deviation falls within the set allowable value range, the angle measurement is judged to be normal; If the angle deviation exceeds the set allowable value range, it is determined that there is a problem with the angle measurement and an alarm is issued to shut down the machine; In the initial debugging state of the pitch system unit, the trigger angle allowable value range of each proximity switch sensor corresponding to each blade is calibrated through the A-type encoder of each blade; The calibration process includes the following steps: S10), each blade is set at a preset limit position, and the following variables are cleared in advance: The first variable: the first proximity switch_ON, represents the A encoder position value corresponding to when the first proximity switch sensor is at the upper limit of the trigger angle allowable range and is triggered; The second variable: first proximity switch_OFF, represents the A encoder position value corresponding to when the first proximity switch sensor is at the lower limit of the trigger angle allowable range and is triggered; The third variable: second proximity switch_ON, represents the A encoder position value corresponding to when the second proximity switch sensor is at the upper limit of the trigger angle allowable range and is triggered; The fourth variable: second proximity switch_OFF, represents the A encoder position value corresponding to when the second proximity switch sensor is at the lower limit of the trigger angle allowable range and is triggered; The fifth variable: the mark position, which represents the position value of the A encoder corresponding to the position of the blade; All the above variables are power-off saved variables; S20), manually controlling each blade shaft of the pitch system, respectively, and commanding each blade to move from the limit switch to an angle less than the preset limit position by a preset value, wherein: When the second proximity switch sensor is at the upper limit of the trigger angle allowable range and is triggered, the A encoder position value is saved in the second proximity switch_ON; When the second proximity switch sensor is at the lower limit of the trigger angle allowable range and is triggered, the A encoder position value is saved in the second proximity switch_OFF; When the first proximity switch sensor is at the upper limit of the trigger angle allowable range and is triggered, the A encoder position value is saved in the first proximity switch_ON; When the first proximity switch sensor is at the lower limit of the trigger angle allowable range and is triggered, the A encoder position value is saved in the first proximity switch_OFF; When the first proximity switch_ON, the first proximity switch_OFF, the second proximity switch_ON and the second proximity switch_OFF are all greater than 0, the flag position = 1; S30), rotating the blade back to the preset limit position, and the calibration process is completed; During normal operation, the A-type encoder and the corresponding trigger angle allowable range of each proximity switch are verified; wherein the verification process includes: The trigger angle allowable range is defined as a first calibration value interval, an angle range less than a lower limit of the trigger angle allowable range is defined as a second calibration value interval, and an angle range greater than an upper limit of the trigger angle allowable range is defined as a third calibration value interval; When the position value of encoder A falls within the first calibration value interval, the corresponding proximity switch sensor is not triggered, and the system program alarms "proximity switch lost"; When the position value of encoder A does not fall within the first calibration value interval, the corresponding proximity switch sensor is triggered, and the system program alarms "proximity switch malfunction".

2. According to claim 1, the control method based on replacing the redundant encoder of the pitch control system with dual proximity switches is characterized in that: The first proximity switch sensor is installed at a position of 3-7° of the blade; and / or the second proximity switch sensor is installed at a position of 83-87° of the blade.

3. The control method based on replacing redundant encoders of pitch control system with dual proximity switches according to claim 2 is characterized in that: The first proximity switch sensor is installed at the 4-6° position of the blade.

4. The control method based on replacing redundant encoders of a pitch control system with dual proximity switches according to claim 2 is characterized in that: The second proximity switch sensor is installed at the 84-86° position of the blade.

5. The control method based on replacing redundant encoders of a pitch control system with dual proximity switches according to claim 1, characterized in that: The allowable value range for setting is ±1-3° of the angular position corresponding to the proximity switch sensor.

6. The control method based on replacing redundant encoders of pitch control system with dual proximity switches according to claim 1 is characterized in that: The permissible value range for setting is ±1-2° of the angular position corresponding to the proximity switch sensor.

7. The control method based on replacing redundant encoders of a pitch control system with dual proximity switches according to claim 1, characterized in that: The preset limit position is 91°, and the preset value is 1-5°; in the step S20), when the mark position = 0, starting is not allowed.

8. The control method based on replacing redundant encoders of a pitch control system with dual proximity switches according to claim 1, characterized in that: During the verification process, the upper limit and the lower limit of the trigger angle allowable range are respectively reduced inward by one position angle, and used as the first calibration value interval; The lower limit of the trigger angle allowable range is increased by one position angle, and is used as the second calibration value interval; the upper limit of the trigger angle allowable range is increased by one position angle, and is used as the third calibration value interval.

9. The control method based on replacing redundant encoders of a pitch control system with dual proximity switches according to claim 1, characterized in that: The variable pitch system includes three blades. When the angle deviation between every two blades deviates from a preset blade angle deviation range, the variable pitch system alarms and shuts down.

10. The control method based on replacing redundant encoders of a pitch control system with dual proximity switches according to claim 9, characterized in that: The blade angle deviation range is preset through a parameter interface of the pitch control system.

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