Variable pitch motor control system applied to GE unit

Abstract

The invention provides a variable pitch motor control system applied to a GE unit, and the system comprises a main control communication unit which is used for building data connection with a main control system of a wind turbine unit; the wind condition detection unit is connected with the main control communication unit; the priority scheduling unit is connected with the wind condition detection unit; the motor driving control unit is connected with the priority scheduling unit; the state acquisition unit is connected with the motor driving control unit and is used for acquiring current position information, rotating speed information and current change data of the motor in a high-frequency mode; according to the method, priority scheduling based on sudden change wind regime identification is constructed, prediction compensation control and a fuzzy self-adaptive PID adjustment strategy are combined, on one hand, a wind regime sudden change identification unit can rapidly position abnormal wind speed changes within 300ms and trigger scheduling priority adjustment, and an adjustment path is prevented from being occupied by a low-priority task; on the other hand, feedforward correction is carried out on the wind speed change trend and the motor response delay through prediction compensation, and the actual response time is shortened.

Description

Technical Field

[0001] The present invention relates to the technical field of wind power control systems, and in particular to a variable pitch motor control system applied to GE units. Background Art

[0002] As a renewable energy source, wind power generation has been widely used in power systems around the world. Large wind turbines (such as the GE series) usually adopt variable pitch control technology, which adjusts the pitch angle of the wind turbine blades to adapt to energy capture and system stability requirements under different wind speed conditions. The variable pitch control system is the core subsystem of the wind turbine. Its operating stability and response speed directly affect the safety and power generation efficiency of the wind turbine under extreme working conditions such as sudden wind speed changes.

[0003] Traditionally, GE wind turbine pitch systems have used electric servo control, using a servo motor to drive a gearbox to achieve real-time adjustment of the blade pitch angle. Common control methods include PID control methods based on a combination of speed feedback and position closed-loop control. Some systems also integrate limited redundant control logic to cope with abnormal wind conditions.

[0004] However, in actual applications, sudden gusts of wind or severe convective weather place higher demands on the system response speed. Traditional variable pitch motor control systems often have problems with response hysteresis, control delay or accumulated action errors when dealing with such extreme wind conditions. There is a time delay in the perception and response of the control system to wind speed changes, which causes the pitch adjustment action to lag behind the actual wind load changes, which can easily lead to abnormal blade force and even trigger the whole machine shutdown or blade damage risk. Therefore, a variable pitch motor control system for GE units is proposed. Summary of the Invention

[0005] A control system for a pitch motor of a GE turbine, the control system comprising:

[0006] The main control communication unit is used to establish a data connection with the main control system of the wind turbine generator set and receive wind speed data, rotation speed information and pitch target value;

[0007] A wind condition detection unit, connected to the main control communication unit, is used to analyze the received wind speed change data in real time to determine whether there is a sudden gust of wind or a sudden change in wind speed;

[0008] a priority scheduling unit connected to the wind condition detection unit, configured to assign an adjustment priority to the pitch adjustment task when a sudden change in wind condition is detected, and to adjust the control logic path of the pitch target value;

[0009] a motor drive control unit connected to the priority scheduling unit, configured to generate a motor control signal according to the scheduling result and drive the pitch servo motor to perform a pitch adjustment operation;

[0010] A state acquisition unit, connected to the motor drive control unit, for acquiring current position information, speed information and current change data of the motor in a high-frequency manner;

[0011] A prediction and compensation unit, connected to both the state acquisition unit and the wind condition detection unit, for performing feedforward compensation of the control signal according to the acquired motor state and wind speed change trend, predicting the motor response delay and adjusting the control target in advance;

[0012] a parameter adjustment unit connected to the motor drive control unit and the prediction compensation unit, and configured to automatically adjust the control parameters according to the real-time control error;

[0013] A fault protection unit is connected to the parameter adjustment unit and the motor drive control unit, and is used to switch to a safe mode of operation when feedback delay, execution failure or current abnormality is detected.

[0014] Further preferably, the wind condition detection unit includes a mutation recognition unit and a wind speed change rate calculation unit. The mutation recognition unit performs differential calculation on the wind speed input sequence within the sliding time window T, which has a value range of 500ms to 1500ms, to obtain the wind speed change rate ΔV / Δt; when the absolute value of ΔV / Δt exceeds 3.5m / s 2 , and the duration exceeds 300ms, it is determined to be a sudden change in wind conditions event, and a sudden change signal is output for the priority scheduling unit to prioritize the current adjustment instruction.

[0015] Further preferably, the priority scheduling unit constructs a scheduling priority factor P according to the wind speed change ΔV, the power generation power proportion Pa, and the blade torque estimation value Tb, and the calculation formula is: P = α·|ΔV|+β·Pa+γ·Tb, where Pa represents the current power generation power proportion of 0% to 100%, and α, β, and γ are weighting coefficients;

[0016] The scheduling priority factor P is divided into three levels of response areas, corresponding to the "immediate interrupt execution", "priority queue execution" and "regular queue execution" paths respectively.

[0017] Further preferably, the motor drive control unit generates a target pitch response curve using a segmented control strategy, including:

[0018] The first stage is the high deviation fast response area Δθ≥5°, and the control system is at 1.5° / s 2 Start with acceleration and limit the maximum speed to no more than 3° / s;

[0019] The second stage is to approach the buffer zone Δθ∈[1°, 5°] and gradually reduce the speed by linear interpolation;

[0020] The third stage is to lock the tracking area Δθ < 1°, maintain a low-speed fine-tuning of 0.5° / s, and monitor the current at the same time. If the current amplitude is greater than 1.3 times the average value, it enters the current limiting path to limit the fluctuation of the motor load response.

[0021] Further preferably, the state acquisition unit includes a position encoder, a three-phase current sensor and a high-speed sampling scheduling unit. The resolution of the position encoder is not less than 0.01°, and the sampling frequency is adaptively adjusted between 100Hz and 200Hz. The current sensor uses a Hall element combined with an ADC for sampling and is configured with a dual DMA cache structure.

[0022] Further preferably, the prediction compensation unit constructs the pitch error advance Δθ p The estimation model includes:

[0023] S61, calculating the slope Sv of the change curve using the current five frames of wind speed samples;

[0024] S62, obtaining the response delay time τm in the previous adjustment process;

[0025] S63. Calculate prediction error Δθ p =Sv×τm×Kp, where Kp is the adjustable compensation coefficient;

[0026] The estimated Δθ p It is added to the pitch target value as a feedforward to form an advance-corrected control output.

[0027] Further preferably, the parameter adjustment unit adopts a fuzzy adaptive PID control method, the fuzzy inputs are the pitch error Δθ, the error change rate Δθ′ and the wind speed change rate ΔV, and the outputs are PID adjustment parameters ΔKp, ΔTi and ΔTd.

[0028] Further preferably, the fault protection unit includes:

[0029] S81, delay timeout monitoring unit, triggers a "response hysteresis" event if no feedback is received within 100ms after sending a control signal;

[0030] S82, current overload monitoring unit, if the servo current exceeds 1.5 times the rated value for three consecutive cycles, an "overload event" is triggered;

[0031] S83, angular position abnormality monitoring unit, triggers a "control failure event" when the deviation between the adjustment target and the feedback angle exceeds 3° for more than 200ms;

[0032] When any of the three types of events is triggered, it automatically switches to the safety control state and outputs a fixed pitch angle command.

[0033] Further preferably, the main control communication unit is connected to the main control system of the wind turbine generator set via a CAN communication interface, for receiving pitch target values, wind speed data and control instructions, and feeding back motor state parameters to the main control system with a period not exceeding 100ms.

[0034] Further preferably, the control system adopts an integrated embedded installation structure and is integrated into the pitch control box of the wind turbine.

[0035] The embodiment of the present invention adopts the above technical solution, which has the following advantages:

[0036] The present invention constructs a priority scheduling based on the identification of sudden wind conditions, combines predictive compensation control with fuzzy adaptive PID adjustment strategy, so that the pitch control has stronger dynamic response capability. On the one hand, the wind condition sudden change identification unit can quickly locate abnormal wind speed changes within 300ms and trigger scheduling priority adjustment to avoid the adjustment path being occupied by low-priority tasks; on the other hand, the wind speed change trend and motor response delay are feedforward corrected through predictive compensation, so that the adjustment instruction can reach the target position in advance, shortening the actual response time; the state acquisition and control parameter linkage can adaptively adjust the PID control strategy according to the motor execution deviation, thereby suppressing oscillation or overshoot in the adjustment process, effectively reducing the risk of blade damage due to delayed force, and improving the operation stability and safety of the wind turbine under extreme wind conditions.

[0037] The above summary is for illustrative purposes only and is not intended to be limiting in any way. In addition to the illustrative aspects, embodiments and features described above, further aspects, embodiments and features of the present invention will be readily apparent by reference to the accompanying drawings and the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0039] Figure 1 This is a system architecture diagram of the present invention. DETAILED DESCRIPTION

[0040] Hereinafter, only certain exemplary embodiments are briefly described. As will be appreciated by those skilled in the art, the described embodiments may be modified in various ways without departing from the spirit or scope of the present invention. Therefore, the drawings and description are to be considered as illustrative in nature and not restrictive.

[0041] The embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0042] like Figure 1 As shown, an embodiment of the present invention provides a pitch motor control system for a GE unit, comprising:

[0043] The wind condition detection unit is used to identify sudden wind condition changes in real time from the wind speed data obtained from the main control communication unit. It consists of two subunits: a sudden change recognition unit and a wind speed change rate calculation unit;

[0044] The wind speed change rate calculation unit uses a sliding window difference algorithm, sets the sampling period to 100ms, and the window length T can be configured to 500 ms to 1500 ms , by processing the wind speed sequence of each cycle in the form of average difference, the approximate first-order derivative ΔV / Δt is obtained, and the calculation formula is as follows: ΔV / Δt=(Vc-Vp) / Δt, where Vc is the current wind speed value, Vp is the wind speed value at the start time of the window, and Δt is the window length;

[0045] The mutation recognition unit compares the above change rate with the set threshold value. If the threshold condition is met for three consecutive cycles and the cumulative duration exceeds 300ms, it outputs a mutation event trigger signal for the priority scheduling unit to call.

[0046] After receiving the sudden event identification signal from the wind condition detection unit, the priority scheduling unit assigns a priority tag to the pitch adjustment task in the sudden scenario and changes its response level in the task queue. This priority scheduling unit mainly consists of a scheduling factor calculation unit and a response queue management unit.

[0047] The dispatch factor is calculated based on three factors: wind speed change ΔV, current blade force index Tb (inferred from the drive current and pitch angle), and current power generation Pa (in %). It is calculated using the following formula: P = α·|ΔV|+β·Pa+γ·Tb;

[0048] Among them, α, β, and γ are weighted coefficients set by experience, which divide P into three levels of scheduling areas:

[0049] P>T1: Immediately interrupt the current task and inject a new adjustment task execution path;

[0050] T2<P≤T1: Insert to the front of the task queue as a high priority scheduler;

[0051] P≤T2: normal scheduling.

[0052] The response queue management unit uses double buffering to process multiple event sources in parallel, ensuring that high-priority tasks can be responded to quickly when wind conditions change drastically.

[0053] The motor drive control unit is used to convert the pitch target angle instruction from the priority scheduling unit into a specific drive signal to control the pitch servo motor to perform the action. The motor drive control unit includes a speed planning unit, a current modulation unit and a position closed-loop control unit;

[0054] The segmented speed planning method is adopted, which is divided into three stages according to the pitch deviation Δθ:

[0055] Fast response area (Δθ ≥ 5°): acceleration upper limit 1.5° / s2, target speed upper limit 3° / s;

[0056] Buffer adjustment area (1°≤Δθ<5°): the speed is slowly reduced by linear interpolation to ensure a smooth transition;

[0057] 3) Precision tracking area (Δθ<1°): Follow at a low speed of 0.5° / s and monitor the drive current in real time to prevent overshoot.

[0058] The current modulation adopts PWM control, combined with the current closed-loop feedback to dynamically adjust the duty cycle to achieve the matching of the dynamic output capability of the motor.

[0059] The state acquisition unit is responsible for collecting the current state of the motor from the drive system in real time for feedback control and predictive analysis. It includes a high-resolution position encoder, a three-phase current sampling unit, and a high-speed sampling manager.

[0060] The position encoder has a resolution of 0.01°, and the sampling frequency is adaptively adjusted to 100Hz to 200Hz. Resource allocation is automatically optimized according to the pitch change rate. Current sampling uses a combination of Hall elements and ADC conversion, and interference errors are eliminated through differential acquisition. The dual DMA cache channel structure is combined to reduce processing delays. All collected data is time-stamped and enters the control link for call by the prediction unit.

[0061] The prediction compensation unit makes feedforward corrections to the regulation target based on the current wind speed change trend and motor response to compensate for control delays in advance;

[0062] The forecasting process consists of three steps:

[0063] S61, extract the wind speed change samples of the past 5 frames and calculate the average change slope Sv;

[0064] S62, measuring the response delay τm according to the historical adjustment record;

[0065] S63: Calculate the predicted compensation amount Δθ p =Sv×τm×Kp, this value is superimposed on the current pitch target to form the final control instruction;

[0066] Among them, Kp is the empirical adjustment coefficient, the recommended initial value is 1.2, and it is adjusted according to the actual inertia parameters of the unit.

[0067] The parameter adjustment unit is substituted into a fuzzy adaptive PID controller. The fuzzy controller takes the pitch error Δθ, the error change rate Δθ′, and the wind speed change rate ΔV as input variables and outputs three sets of PID parameter correction values: ΔKp, ΔTi, and ΔTd. The PID controller has a built-in 49-rule matrix and uses the central average method for defuzzification.

[0068] For example:

[0069] If Δθ is large and ΔV is fast → Kp rises, Ti falls;

[0070] If Δθ is small and Δθ′ approaches 0→Kp decreases and Td increases.

[0071] The fault protection unit performs three-layer real-time monitoring of the stability of the execution link, including a delay timeout detection unit, a current overload detection unit, and an angular deviation detection unit;

[0072] The delay timeout unit starts the timer after sending a control signal. If there is no valid feedback within 100ms, it is judged as an abnormal response;

[0073] Current overload unit: If the current exceeds 1.5 times the rated value for three consecutive cycles, the protection signal will be triggered;

[0074] The angle deviation unit determines that the execution has failed if the deviation between the pitch target and the actual feedback value is continuously greater than 3° for more than 200ms.

[0075] When any abnormal event is triggered, the system switches to a safe pitch angle, interrupts the current control output, and enters a locked state until manually or remotely reset.

[0076] The main control communication unit is connected to the main control platform of the entire machine through the CAN communication interface. The interface adopts a fixed frame structure and supports 100ms cycle communication. The main control system sends wind speed data, pitch target and power data; the control system returns motor status, control deviation and fault code; the entire control system adopts an integrated embedded installation structure, and all units are integrated into a standard 19-inch variable pitch electric control box at the PCB board level, providing a standard industrial Ethernet / serial port maintenance interface.

[0077] When the present invention is working: when the wind turbine is in operation, the main control communication unit receives wind speed, rotation speed and pitch setting information from the wind turbine main control system at a fixed period, the wind condition detection unit monitors the wind speed change rate in real time, and if a sudden wind condition exceeding the threshold is detected, the sudden change event identifier of the wind condition is immediately issued through the sudden change recognition unit, the priority scheduling unit calculates the scheduling priority based on the sudden signal in combination with the current power generation power and the blade force level, assigns a high priority label to the pitch adjustment task, inserts it into the front end of the control queue or directly interrupts the current pitch execution task, after the task enters the execution chain, the motor drive control unit plans the execution rate and acceleration in sections according to the current pitch deviation Δθ, and at the same time combines PWM closed-loop current control to drive the variable pitch servo motor to efficiently complete the angle adjustment, during the execution process, the state acquisition unit collects the position, speed and current information of the servo motor in real time at a frequency of 100-200Hz, and uploads it to the control core through the data cache with a timestamp for closed-loop feedback and feedforward prediction, and the prediction compensation unit calculates the compensation angle Δθ in real time based on the wind speed slope and the historical response delay. p And it is superimposed on the pitch target value in advance, effectively reducing the adjustment deviation caused by control delay. The parameter adjustment unit dynamically corrects the PID parameter group under the fuzzy rule system according to the three elements of the system's current control error, error change rate and wind speed change rate, so that the system can automatically balance between high-speed response and stable control; the entire execution process is monitored in parallel by the fault protection unit. If the system has a response timeout, current overload or target execution deviation, it will immediately switch to a safe pitch angle and suspend operation. During operation, each unit communicates and coordinates with the controller through the internal CAN bus, and maintains periodic command reception and feedback externally through the CAN link with the main control system to achieve closed-loop control of the entire system process.

[0078] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any person skilled in the art can easily conceive of various modifications and substitutions within the technical scope disclosed in the present invention, and such modifications and substitutions are intended to be within the scope of protection of the present invention. Therefore, the scope of protection of the present invention shall be subject to the scope of protection of the claims.

Claims

1. A control system for a pitch motor of a GE turbine, characterized in that: The control system includes: The main control communication unit is used to establish a data connection with the main control system of the wind turbine generator set and receive wind speed data, rotation speed information and pitch target value; A wind condition detection unit, connected to the main control communication unit, is used to analyze the received wind speed change data in real time to determine whether there is a sudden gust of wind or a sudden change in wind speed; a priority scheduling unit connected to the wind condition detection unit, configured to assign an adjustment priority to the pitch adjustment task when a sudden change in wind condition is detected, and to adjust the control logic path of the pitch target value; a motor drive control unit connected to the priority scheduling unit, configured to generate a motor control signal according to the scheduling result and drive the pitch servo motor to perform a pitch adjustment operation; A state acquisition unit, connected to the motor drive control unit, for acquiring current position information, speed information and current change data of the motor in a high-frequency manner; A prediction and compensation unit, connected to both the state acquisition unit and the wind condition detection unit, for performing feedforward compensation of the control signal according to the acquired motor state and wind speed change trend, predicting the motor response delay and adjusting the control target in advance; a parameter adjustment unit connected to the motor drive control unit and the prediction compensation unit, and configured to automatically adjust the control parameters according to the real-time control error; A fault protection unit is connected to the parameter adjustment unit and the motor drive control unit, and is used to switch to a safe mode of operation when feedback delay, execution failure or current abnormality is detected.

2. The pitch motor control system for GE turbines according to claim 1, characterized in that: The wind condition detection unit includes a mutation recognition unit and a wind speed change rate calculation unit. The mutation recognition unit performs differential calculation on the wind speed input sequence within the sliding time window T, which has a value range of 500ms to 1500ms, to obtain the wind speed change rate ΔV / Δt; when the absolute value of ΔV / Δt exceeds 3.5m / s 2 , and the duration exceeds 300ms, it is determined to be a sudden change in wind conditions event, and a sudden change signal is output for the priority scheduling unit to prioritize the current adjustment instruction.

3. The pitch motor control system for GE turbines according to claim 1, characterized in that: The priority scheduling unit constructs a scheduling priority factor P based on the wind speed change ΔV, the power generation proportion Pa, and the blade torque estimation value Tb. The calculation formula is: P = α·|ΔV|+β·Pa+γ·Tb, where Pa represents the current power generation proportion of 0% to 100%, and α, β, and γ are weighting coefficients; The scheduling priority factor P is divided into three levels of response areas, corresponding to the "immediate interrupt execution", "priority queue execution" and "regular queue execution" paths respectively.

4. The pitch motor control system for GE turbines according to claim 1, characterized in that: The motor drive control unit generates a target pitch response curve using a segmented control strategy, including: The first stage is the high deviation fast response area Δθ≥5°, and the control system is at 1.5° / s 2 Start with acceleration and limit the maximum speed to no more than 3° / s; The second stage is to approach the buffer zone Δθ∈[1°,5°] and gradually reduce the speed by linear interpolation; The third stage is to lock the tracking area Δθ < 1°, maintain a low-speed fine-tuning of 0.5° / s, and monitor the current at the same time. If the current amplitude is greater than 1.3 times the average value, it enters the current limiting path to limit the fluctuation of the motor load response.

5. The pitch motor control system for GE turbines according to claim 1, characterized in that: The state acquisition unit includes a position encoder, a three-phase current sensor and a high-speed sampling scheduling unit. The resolution of the position encoder is not less than 0.01°, and the sampling frequency is adaptively adjusted between 100Hz and 200Hz. The current sensor uses a Hall element combined with an ADC for sampling and is configured with a dual DMA cache structure.

6. The pitch motor control system for GE turbines according to claim 1, characterized in that: The prediction compensation unit constructs the pitch error advance value Δθ p The estimation model includes: S61, calculating the slope Sv of the change curve using the current five frames of wind speed samples; S62, obtaining the response delay time τm in the previous adjustment process; S63. Calculate prediction error Δθ p =Sv×τm×Kp, where Kp is the adjustable compensation coefficient; The estimated Δθ p It is added to the pitch target value as a feedforward to form an advance-corrected control output.

7. The pitch motor control system for GE turbines according to claim 1, characterized in that: The parameter adjustment unit adopts a fuzzy adaptive PID control method, the fuzzy inputs are the pitch error Δθ, the error change rate Δθ′ and the wind speed change rate ΔV, and the outputs are PID adjustment parameters ΔKp, ΔTi and ΔTd.

8. The pitch motor control system for GE turbines according to claim 1, characterized in that: The fault protection unit includes: S81, delay timeout monitoring unit, triggers a "response delay" event if no feedback is received within 100ms after sending a control signal; S82, current overload monitoring unit, if the servo current exceeds 1.5 times the rated value for three consecutive cycles, an "overload event" is triggered; S83, angular position abnormality monitoring unit: When the deviation between the adjustment target and the feedback angle exceeds 3° for more than 200ms, a "control failure event" is triggered; When any of the three types of events is triggered, it automatically switches to the safety control state and outputs a fixed pitch angle command.

9. The pitch motor control system for GE turbines according to claim 1, characterized in that: The main control communication unit is connected to the main control system of the wind turbine generator set through a CAN communication interface, and is used to receive pitch target values, wind speed data and control instructions, and feed back motor state parameters to the main control system with a period of no more than 100ms.

10. The pitch motor control system for GE turbines according to claim 1, characterized in that: The control system adopts an integrated embedded installation structure and is integrated into the pitch control box of the wind turbine generator set.

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