Double-digital-valve redundancy control system

Abstract

The invention provides a double-digital-valve redundancy control system. The double-digital-valve redundancy control system comprises a first channel digital valve, a first channel switch element, a first channel execution element, a second channel execution element, a second channel switch element, a second channel digital valve, a Master host, a Slave1 slave and a Slave2 slave. According to the invention, through differential model design, dual innovation of structure redundancy and algorithm isomerism is realized, cost is reduced by using the same hardware, diversity and adaptability of control strategies are improved through different models, and the technical bottleneck of a traditional redundant system is broken through in principle.

Description

Technical Field

[0001] The present invention relates to the technical field of wind power generation, and in particular to a dual digital valve redundant control system. Background Art

[0002] Wind is one of the pollution-free energy sources. Wind power generation is very environmentally friendly and has huge wind energy reserves.

[0003] Digital hydraulics can be directly connected to a computer, eliminating the need for intermediate steps like digital-to-analog conversion. Compared to traditional proportional and servo technologies, digital hydraulics offer a simpler structure, lower requirements for fluid precision and operating temperature, and are relatively inexpensive. Furthermore, they offer high repeatability, stability, and reliability, while requiring minimal drive power, making them ideally suited for large wind turbines.

[0004] However, unstable wind speeds, seasonal climate fluctuations, and other unpredictable weather factors pose significant challenges to wind turbines. Hydraulic control components, actuators, and feedback devices are often exposed to high and low temperatures, vibration, and long-term operation. These components are susceptible to aging and damage, leading to equipment failure. To ensure safe and long-term stable operation of the wind turbine, the control system requires redundancy. Summary of the Invention

[0005] The present invention aims to provide a dual digital valve redundant control system, which improves system reliability and ensures safe and long-term stable operation of wind turbines by making the two digital valves mutually redundant and working in coordination.

[0006] The present invention provides a dual digital valve redundant control system, comprising a first channel digital valve, a first channel switch element, a first channel actuator, a second channel actuator, a second channel switch element, a second channel digital valve, a Master host, a Slave 1 slave, and a Slave 2 slave;

[0007] The first channel digital valve is connected to the first channel switch element, and the first channel switch element is connected to the first channel actuator;

[0008] The second channel digital valve is connected to the second channel switch element, and the second channel switch element is connected to the second channel actuator;

[0009] The first channel actuator and the second channel actuator are rigidly synchronized through a mechanical connection;

[0010] The P circuits of the first channel digital valve and the second channel digital valve are both connected to the oil source high-pressure pipeline, and the T circuits of the first channel digital valve and the second channel digital valve are both connected to the oil source return pipeline, and the T circuits are always open to return oil;

[0011] The Master host controls the first channel digital valve and the first channel switch element through the Slave 1 slave, and the Master host controls the second channel digital valve and the second channel switch element through the Slave 2 slave.

[0012] According to a dual digital valve redundant control system provided by the present invention, through the control of the Master host, the first channel digital valve and the second channel digital valve can achieve the initial state, the first channel digital valve single working state, the second channel digital valve single working state and the dual-channel digital valve joint working state.

[0013] According to a dual digital valve redundant control system provided by the present invention, the Master host drives the parameters of the Slave 1 slave through a first control model to achieve control of the first channel digital valve and the first channel switch element. The first control model is:

[0014]

[0015] Among them, U1(t) is the control output voltage of Slave 1 at time t, which directly drives the action of the first channel digital valve and the first channel switch element; e1(t) is the deviation between the target position and the actual position of the first channel digital valve, reflecting the error of the system control; e1(τ) represents the deviation between the target position and the actual position of the first channel digital valve at time point τ, and its physical meaning is consistent with e1(t), which is used to accumulate the historical deviation from time 0 to time t; e1(λ) represents the deviation between the target position and the actual position of the first channel digital valve at time point λ, and its physical meaning is consistent with e1(t), which is used to accumulate the historical deviation from time 0 to time τ; K p1 K is the proportional control coefficient, which is used to amplify the control effect of the current deviation. The larger the coefficient, the more sensitive the response to the deviation. i1 K is the integral control coefficient, which is used to eliminate static deviation and achieve zero-error control by accumulating historical deviations; d1 is the differential control coefficient, which is used to suppress the rate of change of the deviation and reduce system overshoot and oscillation; a n1 is the amplitude of the nth harmonic, which is used to superimpose periodic disturbance compensation and suppress the natural frequency vibration of the hydraulic system; ω1 is the fundamental angular frequency, which is determined by the system control period; The phase angle of the nth harmonic adjusts the time phase of the harmonic component to match the system delay characteristics; N is the upper limit of the harmonic order, which is used to limit the frequency band range of harmonic compensation and balance the calculation complexity and control accuracy;

[0016] The first control model outputs U1(t), and based on U1(t), the operation of the Slave 1 slave is driven.

[0017] According to a dual digital valve redundant control system provided by the present invention, when the first channel digital valve is working alone, the first control model is constrained by a first constraint model; the first constraint model is:

[0018]

[0019] Among them, K p10 is the base proportional coefficient, representing the basic control strength when the deviation is 0, which is determined by the system hardware characteristics; E 10 is the reference deviation value, which is used to standardize the deviation. becomes a dimensionless coefficient to avoid calculation overflow due to excessive deviation; α1 is the adjustment index used to control K p1 The nonlinear degree of the deviation, and α1>0; β1 is the angular frequency parameter, which determines K p1 The frequency of oscillation over time is used to match the periodicity of wind fluctuations; t is time;

[0020] When the first channel digital valve is in a single working state, the first constraint model is associated with the first control model to obtain an output U1 (t).

[0021] According to a dual digital valve redundant control system provided by the present invention, the Master host drives the parameters of the Slave 2 slave through a second control model to achieve control of the second channel digital valve and the second channel switch element; the second control model is:

[0022]

[0023] Where U2(t) is the control output voltage of Slave 2 at time t, which directly drives the operation of the second-channel digital valve and the second-channel switch element; e2(t) is the deviation between the target position and the actual position of the second-channel digital valve, reflecting the error of the system control; b m2 is the amplitude of the mth pulse component, which is used to compensate for the instantaneous impact or high-frequency vibration of the hydraulic system; m2 is the time center of the mth pulse, indicating the moment of pulse action; σ m2 is the width parameter of the mth pulse, which determines the duration of the pulse action. The smaller the value, the steeper the pulse and the more concentrated the action. M is the number of pulse components, which reflects the number of vibration frequency points that the system needs to compensate, and is determined by spectrum analysis. K p2 is the proportional control coefficient, which is multiplied by the deviation e2(τ) to form the basic control quantity; E 20 It is the reference deviation value, which is used to perform nonlinear normalization on the deviation to avoid saturation of the control quantity when the deviation is large;

[0024] The second control model outputs U2(t), and the action of the Slave 2 slave is driven based on U2(t).

[0025] According to a dual digital valve redundant control system provided by the present invention, when the second channel digital valve is working alone, the second control model is constrained by a second constraint model; the second constraint model is:

[0026]

[0027] Among them, b m20 is the reference amplitude of the mth pulse, representing the basic compensation strength when there is no deviation, which is determined by the system hardware characteristics and historical vibration data; e2(tt m2 ) is the deviation function, which represents the difference between the current time t and the pulse center time t m2 The deviation value at the time of the time difference reflects the hysteresis of the deviation on the pulse; γ2 is the pulse modulation index, which is used to control the nonlinear degree of the pulse amplitude changing with the deviation. When -γ2>0, the larger the deviation, the greater the b m2 The faster the decay; it is a sign function used to determine that the pulse direction is opposite to the deviation direction;

[0028] When the second channel digital valve is in a single working state, the second constraint model is associated with the second control model to obtain an output U2(t).

[0029] According to a dual digital valve redundant control system provided by the present invention, when the dual-channel digital valves are working together, the Master host constrains the first constraint model and the second constraint model through a collaborative constraint model. The collaborative constraint model is:

[0030]

[0031] Among them, U 1max and U 2max is the maximum control output voltage of the two slaves, which is determined by the hardware circuit and is used to standardize the control quantity; |e1(t)-e2(t)| is the absolute value of the deviation between the two channels, which is used to measure the consistency of the control state of the two channels; E c is the collaborative deviation threshold, which is used to standardize the deviation difference and determine the response sensitivity of the nonlinear term on the right side of the formula; exp(·) is an exponential function, which forms an S-shaped curve with the denominator, giving the formula a nonlinear transition characteristic;

[0032] When the dual-channel digital valve is in a joint working state, the collaborative constraint model is associated with the first control model and the second control model to obtain outputs U1(t) and U2(t).

[0033] According to a dual digital valve redundant control system provided by the present invention, the first channel switching element includes two components, which respectively control the on and off of the A and B circuits of the first channel digital valve; the second channel switching element includes two components, which respectively control the on and off of the A and B circuits of the second channel digital valve.

[0034] According to a dual digital valve redundant control system provided by the present invention, the T-circuits of the first channel digital valve and the second channel digital valve are normally open to return oil, ensuring that the valve core is in oil.

[0035] According to a dual digital valve redundant control system provided by the present invention, the first channel actuator and the second channel actuator are rigidly synchronized through a mechanical connection and simultaneously drive the actuator to operate.

[0036] Compared with the prior art, the present invention has the following advantages:

[0037] The two digital valves of this application are redundant with each other. Each digital valve can work independently, and the other valve serves as a safety redundant backup. The two digital valves can also work simultaneously to increase the system flow and enable the actuator to run quickly, thereby improving the reliability of the system and ensuring the safe and long-term stable operation of the entire wind turbine. At the same time, this application achieves dual innovations of structural redundancy and algorithm heterogeneity through differentiated model design, which not only reduces costs by using the same hardware, but also improves the diversity and adaptability of control strategies through different models, breaking through the technical bottleneck of traditional redundant systems in principle.

[0038] Other features and advantages of the present invention will be described in the following description, and in part will become apparent from the description, or will be understood by practicing the present invention. The purpose and other advantages of the present invention can be realized and obtained by the structures particularly pointed out in the written description and the accompanying drawings.

[0039] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] The accompanying drawings are used to provide further understanding of the present invention and constitute a part of the specification. They are used to explain the present invention together with the embodiments of the present invention and do not constitute a limitation of the present invention.

[0041] In the attached figure:

[0042] Figure 1 1 is a schematic structural diagram of a dual digital valve redundant control system in an initial state provided by an embodiment of the present invention;

[0043] Figure 2 This is a structural diagram of a dual digital valve redundant control system provided by an embodiment of the present invention, in which the first channel digital valve is working alone;

[0044] Figure 3 1 is a structural diagram of a dual digital valve redundant control system provided by an embodiment of the present invention, in which the second channel digital valve is working alone;

[0045] Figure 4 The present invention provides a structural diagram of a dual digital valve redundant control system in a dual-channel digital valve working state.

[0046] Description of the drawings: 1. First channel digital valve; 2. First channel switching element; 3. First channel actuator; 4. Second channel actuator; 5. Second channel switching element; 6. Second channel digital valve; 7. Slave 2; 8. Master; 9. Slave 1. DETAILED DESCRIPTION

[0047] The preferred embodiments of the present invention are described below with reference to the accompanying drawings. It should be understood that the preferred embodiments described herein are only used to illustrate and explain the present invention, and are not used to limit the present invention.

[0048] Example 1:

[0049] The embodiment of the present invention provides a dual digital valve redundant control system, please refer to Figure 1-4 ,include:

[0050] First channel digital valve 1, first channel switching element 2, first channel actuator 3, second channel actuator 4, second channel switching element 5, second channel digital valve 6, Master host 8, Slave 1 slave 9 and Slave 2 slave 7;

[0051] The first channel digital valve 1 is connected to the first channel switch element 2, and the first channel switch element 2 is connected to the first channel actuator 3;

[0052] The second channel digital valve 6 is connected to the second channel switch element 5, and the second channel switch element 5 is connected to the second channel actuator 4;

[0053] The first channel actuator 3 and the second channel actuator 4 are rigidly synchronized through mechanical connection;

[0054] The P circuits of the first channel digital valve 1 and the second channel digital valve 6 are both connected to the oil source high-pressure pipeline, and the T circuits of the first channel digital valve 1 and the second channel digital valve 6 are both connected to the oil source return pipeline, and the T circuits are always open to return oil;

[0055] The Master host 8 controls the first channel digital valve 1 and the first channel switch element 2 through the Slave 1 slave 9 , and the Master host 8 controls the second channel digital valve 6 and the second channel switch element 5 through the Slave 2 slave 7 .

[0056] Through the control of the Master host 8, the first channel digital valve 1 and the second channel digital valve 6 can achieve the initial state, the first channel digital valve 1 working state alone, the second channel digital valve 6 working state alone and the dual-channel digital valve working state.

[0057] The first channel switch element 2 includes two components, which respectively control the on and off of the A and B circuits of the first channel digital valve 1; the second channel switch element 5 includes two components, which respectively control the on and off of the A and B circuits of the second channel digital valve 6.

[0058] The T circuits of the first channel digital valve 1 and the second channel digital valve 6 are normally open to return oil, ensuring that the valve core is in the oil.

[0059] The first channel actuator 3 and the second channel actuator 4 are rigidly synchronized through mechanical connection and simultaneously drive the actuator to move.

[0060] It should be noted that the first channel switch element 2 and the second channel switch element 5 can be, but are not limited to, solenoid valves and ball valves; the first channel actuator 3 and the second channel actuator 4 can be cylinders and motors.

[0061] Example 2:

[0062] See also Figure 2 , the Master drives the parameters of the Slave 1 slave 9 through the first control model to realize the control of the first channel digital valve 1 and the first channel switch element 2. The first control model is:

[0063]

[0064] Among them, U1(t) is the control output voltage of Slave 1 slave machine 9 at time t, which directly drives the action of the first channel digital valve 1 and the first channel switch element 2; e1(t) is the deviation between the target position and the actual position of the first channel digital valve 1, reflecting the error amount of system control; e1(τ) represents the deviation between the target position and the actual position of the first channel digital valve 1 at time point τ, and its physical meaning is consistent with e1(t), and is used to accumulate historical deviations from time 0 to time t; e1(λ) represents the deviation between the target position and the actual position of the first channel digital valve 1 at time point λ, and its physical meaning is consistent with e1(t), and is used to accumulate historical deviations from time 0 to time τ; K p1K is the proportional control coefficient, which is used to amplify the control effect of the current deviation. The larger the coefficient, the more sensitive the response to the deviation. i1 K is the integral control coefficient, which is used to eliminate static deviation and achieve zero-error control by accumulating historical deviations; d1 is the differential control coefficient, which is used to suppress the rate of change of the deviation and reduce system overshoot and oscillation; a n1 is the amplitude of the nth harmonic, which is used to superimpose periodic disturbance compensation and suppress the natural frequency vibration of the hydraulic system; ω1 is the fundamental angular frequency, which is determined by the system control period; The phase angle of the nth harmonic adjusts the time phase of the harmonic component to match the system delay characteristics; N is the upper limit of the harmonic order, which is used to limit the frequency band range of harmonic compensation and balance the calculation complexity and control accuracy;

[0065] The first control model outputs U1(t), and the operation of the slave machine Slave 1 9 is driven based on U1(t).

[0066] When the first channel digital valve 1 is working alone, the first control model is constrained by the first constraint model; the first constraint model is:

[0067]

[0068] Among them, K p10 is the base proportional coefficient, representing the basic control strength when the deviation is 0, which is determined by the system hardware characteristics; E 10 is the reference deviation value, which is used to standardize the deviation. becomes a dimensionless coefficient to avoid calculation overflow due to excessive deviation; α1 is the adjustment index used to control K p1 The nonlinear degree of the deviation, and α1>0; β1 is the angular frequency parameter, which determines K p1 The frequency of oscillation over time is used to match the periodicity of wind fluctuations; t is time;

[0069] When the first channel digital valve 1 is working alone, the first constraint model is associated with the first control model to obtain the output U1 (t).

[0070] It should be noted that the first control model achieves past-present-future three-dimensional error control by accumulating historical deviations through the integral term and predicting the deviation change trend through the differential term. When the deviation increases, K p1The e1(τ) term enhances the real-time adjustment force; when the deviation persists, the integral term gradually accumulates to eliminate static errors; when the rate of change of the deviation increases, the differential term suppresses excessively fast actions to avoid overshoot; the combination of the harmonic term and PID control gives the system frequency self-sensing capability: traditional PID can only adapt to fixed-frequency disturbances by adjusting coefficients, while this formula can simultaneously compensate for vibrations of multiple frequencies such as blade rotation frequency and tower resonance frequency through harmonic superposition; for example, under strong wind conditions, wind speed fluctuations will cause high-frequency vibrations in the hydraulic system. At this time, the high-order harmonic components are automatically enhanced to suppress high-frequency noise in a targeted manner; the smoothness of integral control combined with the accuracy of harmonic compensation can reduce the energy loss of the hydraulic system: avoiding the overshoot-callback energy waste caused by the fixed coefficients of traditional PID; harmonic compensation uses precise inversion to offset the maximum vibration amplitude with the minimum control energy, similar to the energy optimization of the lever principle.

[0071] The first constraint model is passed The larger the deviation, the stronger the gain of the nonlinear control. When the deviation is small, e1(t) is less than E 10 , K p1 Approaching K p10 cos(β1t), the control amount is smooth to avoid system jitter; when the deviation is large, such as strong wind causing the actuator position to deviate, K p1 Rapidly increase according to the power function, accelerate the deviation correction, similar to the characteristics of emergency braking. The time-varying frequency adaptive cos(β1t) term makes K p1 Adjust periodically over time. The principle is as follows: In wind power generation, the wind speed often fluctuates in a sinusoidal pattern, such as the wind speed change caused by the temperature difference between day and night. After β1 matches the fluctuation frequency, K p1 The gain intensity will change synchronously with the wind speed. When the wind speed increases, the cos(β1t) value increases. p1 Enhanced, improve the system's anti-interference ability; when the wind speed decreases, K p1 Automatically weaken to avoid excessive sensitivity of the control quantity. α1 controls the nonlinearity of the deviation gain to avoid the problem of large overshoot and energy waste in traditional linear PID when the deviation is large; β1 controls the time oscillation frequency to make K p1 Automatically adjust at the peaks and troughs of wind speed fluctuations to achieve maximum deviation correction efficiency with minimum control energy.

[0072] The methods for obtaining the above parameters are existing technical means and will not be explained one by one here.

[0073] Example 3:

[0074] See also Figure 3 The Master host 8 drives the parameters of the Slave 2 slave 7 through the second control model to achieve control of the second channel digital valve 6 and the second channel switch element 5; the second control model is:

[0075]

[0076] Wherein, U2(t) is the control output voltage of Slave 2 7 at time t, which directly drives the operation of the second channel digital valve 6 and the second channel switch element 5; e2(t) is the deviation between the target position and the actual position of the second channel digital valve 6, reflecting the error of the system control; m2 is the amplitude of the mth pulse component, which is used to compensate for the instantaneous impact or high-frequency vibration of the hydraulic system; m2 is the time center of the mth pulse, indicating the moment of pulse action; σ m2 is the width parameter of the mth pulse, which determines the duration of the pulse action. The smaller the value, the steeper the pulse and the more concentrated the action. M is the number of pulse components, which reflects the number of vibration frequency points that the system needs to compensate, and is determined by spectrum analysis. K p2 is the proportional control coefficient, which is multiplied by the deviation e2(τ) to form the basic control quantity; E 20 It is the reference deviation value, which is used to perform nonlinear normalization on the deviation to avoid saturation of the control quantity when the deviation is large;

[0077] The second control model outputs U2(t), and the operation of the slave machine Sla2 7 is driven based on U2(t).

[0078] When the second channel digital valve 6 is working alone, the second control model is constrained by the second constraint model; the second constraint model is:

[0079]

[0080] Among them, b m20 is the reference amplitude of the mth pulse, representing the basic compensation strength when there is no deviation, which is determined by the system hardware characteristics and historical vibration data; e2(tt m2 ) is the deviation function, which represents the difference between the current time t and the pulse center time t m2 The deviation value at the time of the time difference reflects the hysteresis of the deviation on the pulse; γ2 is the pulse modulation index, which is used to control the nonlinear degree of the pulse amplitude changing with the deviation. When -γ2>0, the larger the deviation, the greater the b m2 The faster the decay; it is a sign function used to determine that the pulse direction is opposite to the deviation direction;

[0081] When the second channel digital valve 6 is in a single working state, the second constraint model is associated with the second control model to obtain the output U2 (t).

[0082] It should be noted that the second control model It is a Gaussian pulse function, characterized by the fact that at t=t m2The amplitude is the largest at t, and decays to both sides according to the normal distribution, ensuring that the pulse only works near a specific time point; the value of its parameters can be obtained by collecting the hydraulic system operation data through the vibration sensor, performing fast Fourier transform FFT, and identifying the time t corresponding to the vibration peak m2 and frequency; σ m2 Determined according to the duration of vibration; b m2 Determined by the anti-phase compensation principle, the larger the vibration amplitude, the greater the b m2 The larger the absolute value, and the sign is opposite to the vibration direction, such as when vibrating upward, the pulse voltage causes the digital valve to move downward; The essence is a nonlinear correction of the traditional proportional term. When |e2(τ)| is less than E 20 When |e2(τ)| is greater than E 20 When the denominator approaches The control quantity approaches K p2 E 20 , avoid saturation; through the superposition of multiple Gaussian pulses, accurate positioning of vibration and targeted energy offset are achieved: the nonlinear integral term makes the control amount saturated but smooth when the deviation is large through the square root function of the denominator: the traditional proportional control increases the control amount linearly when the deviation is large, which can easily lead to sudden changes in hydraulic system pressure such as full valve opening. In this formula, when |e2(τ)|=E 20 When the control quantity is As the deviation increases, it gradually approaches K p2 E 20 , avoiding hard impact on the actuator; the number of pulse components M can be expanded to multiple vibration frequency bands, while the integral term covers the deviation accumulation of the entire time period. The combination of the two realizes frequency domain-time domain joint control. The pulse term handles high-frequency transient vibrations such as hydraulic shock caused by sudden wind speed changes; the integral term handles low-frequency steady-state deviations such as position offset caused by long-term blade yaw;

[0083] The second constraint model formula is The logic that the larger the deviation, the weaker the pulse compensation is realized. When the deviation is small, the pulse compensation intensity is close to the reference value, and small vibrations are suppressed in time. When the deviation is large, such as when the system is in strong wind conditions, the actuator deviates significantly from the target position, and the pulse amplitude decays according to the power function with the deviation, avoiding the superposition of too many pulses under large deviations, which may cause oscillation of the controlled quantity. m2 )] is to make the pulse direction always opposite to the deviation direction: if the deviation is positive and the actuator position exceeds the target value, sgn = 1, the pulse amplitude is positive, and the digital valve is driven in the reverse direction; if the deviation is negative, sgn = -1, the pulse amplitude sign is flipped to ensure that the compensation direction is always correct, similar to the reverse thrust during vibration; e2(tt m2 ) in the time difference tt m2It reflects the lag between deviation measurement and pulse action. There is a delay from the generation of deviation to sensor feedback in the hydraulic system. The formula is tt m2 Automatically correct the pulse amplitude to match the actual deviation state, avoiding compensation dislocation caused by delay. If the deviation has been reduced, the pulse is still output at the original deviation intensity.

[0084] By adding b m2 The second control model provides basic pulse compensation, covering typical vibration scenarios. The second constraint model adjusts the pulse amplitude and direction in real time based on the current deviation to accommodate atypical operating conditions, such as sudden changes in wind speed that cause deviation and vibration coupling.

[0085] Example 4:

[0086] See also Figure 4 , when the dual-channel digital valve works together, the Master host 8 constrains the first constraint model and the second constraint model through the collaborative constraint model. The collaborative constraint model is:

[0087]

[0088] Among them, U 1max and U 2max is the maximum control output voltage of the two slaves, which is determined by the hardware circuit and is used to standardize the control quantity; |e1(t)-e2(t)| is the absolute value of the deviation between the two channels, which is used to measure the consistency of the control state of the two channels; E c is the collaborative deviation threshold, which is used to standardize the deviation difference and determine the response sensitivity of the nonlinear term on the right side of the formula; exp(·) is an exponential function, which forms an S-shaped curve with the denominator, giving the formula a nonlinear transition characteristic;

[0089] When the dual-channel digital valve works together, the collaborative constraint model is associated with the first control model and the second control model to obtain outputs U1(t) and U2(t).

[0090] It should be noted that the collaborative constraint model uses an S-shaped function to achieve intelligent coordination, superimposing flows when deviations are consistent and limiting flows when deviations conflict. This results in a smooth S-shaped curve for the total control variable as the deviations change, rather than abruptly. This avoids the system shock caused by traditional on-off logic, such as a sudden switching of control strategies when deviations exceed a threshold, and improves control smoothness. Although the actuators are mechanically synchronized, the control deviations of the two-channel digital valves may desynchronize due to hydraulic leakage, friction differences, and other factors. The model dynamically adjusts the control variable allocation between the two channels by monitoring the e1(t)-e2(t) in real time, implementing an adaptive mechanism that provides hydraulic compensation when mechanical synchronization is insufficient and hydraulic enhancement when mechanical synchronization is sufficient.

[0091] It should also be noted that in this dual digital valve redundant control system, two valves with the same structure use different control models. This is mainly based on the comprehensive consideration of system redundancy design goals, operating condition adaptability, and control strategy optimization. The specific reasons are as follows:

[0092] Although the two valves have the same structure, in single-channel working state, if the first channel or the second channel operates independently, the control characteristics and interference sources of each channel need to be independently optimized:

[0093] The first control model uses a PID integral and harmonic superposition structure, which is suitable for suppressing the periodic vibration of the hydraulic system, such as steady-state disturbances caused by blade rotation. Its harmonic terms can match the natural frequency of the system.

[0094] The second control model uses Gaussian pulses and nonlinear integral structures, which is more suitable for handling transient shocks such as hydraulic shock caused by sudden changes in wind speed. The pulse term can compensate for sudden vibrations in real time.

[0095] This differentiated design enables the two channels to specifically address different types of interference when working independently, improving the reliability of single-channel operation;

[0096] When the system switches from the first channel to the second channel or vice versa, different models can achieve a smooth transition of the control quantity through parameter matching. The integral characteristic of the first model makes the control quantity change smoothly, avoiding the impact during switching. The pulse modulation characteristic of the second model can dynamically adjust the compensation intensity according to the deviation, ensuring rapid adaptation to the new working conditions after switching.

[0097] When the two channels work together, the outputs of the two models are coupled through a collaborative constraint model to form a composite control system that combines steady-state control and transient compensation. The PID integral term of the first model provides a stable basic control variable to ensure the position accuracy of the actuator, while the pulse term of the second model offsets high-frequency vibrations in real time to improve control smoothness.

[0098] For example, in strong wind conditions, the first model suppresses the low-frequency vibration of blade rotation through harmonic compensation, while the second model compensates for the high-frequency impact of sudden wind speed changes through pulse compensation. The combination of the two achieves full-band interference suppression.

[0099] The collaborative constraint model dynamically adjusts the flow distribution based on the consistency of the two-channel deviation. That is, when the two-channel deviation is consistent, the outputs of the two models are superimposed, the flow is doubled, and the action of the actuator is accelerated. When the two-channel deviation conflicts, the model automatically limits the total flow to avoid conflicts in the flow direction of hydraulic oil.

[0100] This mechanism requires the two models to have different response characteristics. The first model focuses on linear integral control, while the second model focuses on nonlinear pulse modulation to achieve flexible adjustment of flow distribution.

[0101] In wind power generation, wind speed includes low-frequency trends such as diurnal variations and high-frequency pulsations such as gusts. Different models can specifically handle disturbances of different time scales. The angular frequency parameter in the first model can match low-frequency wind speed fluctuations and dynamically adjust the proportional coefficient through cosine oscillation. The pulse time center in the second model can capture the instantaneous impact of high-frequency gusts and compensate in real time through Gaussian pulses. The first model uses the α1 adjustment index to achieve nonlinear control with greater gain as the deviation increases, which is suitable for rapid correction under large deviation conditions. The second model uses the γ2 pulse modulation index to achieve the logic of faster pulse decay as the deviation increases, avoiding overcompensation under large deviation conditions.

[0102] This differentiated design allows the system to maintain control accuracy during small deviations, such as normal operation, and ensure stability during large deviations, such as failures or strong winds;

[0103] If a channel model causes control anomalies due to parameter drift, a different model in another channel can take over control through a collaborative constraint model, avoiding system failures caused by the failure of a single algorithm. For example, if the PID integral model of the first channel experiences integral saturation, the pulse model of the second channel can maintain control through an independent algorithm, improving system fault tolerance.

[0104] Furthermore, using different models in the two channels allows for the accumulation of multiple sets of control data, providing a comparative basis for subsequent algorithm optimization. By comparing the control effects of the two models under the same operating conditions, such as adjustment time and overshoot, parameters such as α1 and γ2 can be iteratively optimized to gradually improve system performance. This dual-model comparative learning mechanism is an innovation that cannot be achieved in traditional single-model control systems.

[0105] In traditional redundant control systems, redundant channels often use the same control model as the primary channel, which has the following drawbacks:

[0106] 1. Fault homology: If the primary channel model causes control errors due to parameter design flaws, the redundant channel may repeat the same error;

[0107] 2. The adaptability to a single working condition is limited; a single model cannot simultaneously take into account both low-frequency steady-state control and high-frequency transient compensation;

[0108] 3. Low collaborative efficiency. The superposition of outputs from the same model can easily lead to oscillation of the control volume, making intelligent traffic distribution impossible.

[0109] This solution achieves dual innovations in structural redundancy and algorithm heterogeneity through differentiated model design. It not only reduces costs by using the same hardware, but also improves the diversity and adaptability of control strategies through different models, breaking through the technical bottleneck of traditional redundant systems in principle.

[0110] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A dual digital valve redundant control system, characterized in that: It comprises a first channel digital valve (1), a first channel switch element (2), a first channel actuator (3), a second channel actuator (4), a second channel switch element (5), a second channel digital valve (6), a Master host (8), a Slave 1 slave (9) and a Slave 2 slave (7); The first channel digital valve (1) is connected to the first channel switch element (2), and the first channel switch element (2) is connected to the first channel actuator (3); The second channel digital valve (6) is connected to the second channel switch element (5), and the second channel switch element (5) is connected to the second channel actuator (4); The first channel actuator (3) and the second channel actuator (4) are rigidly synchronized through a mechanical connection; The P circuits of the first channel digital valve (1) and the second channel digital valve (6) are both connected to the oil source high-pressure pipeline, and the T circuits of the first channel digital valve (1) and the second channel digital valve (6) are both connected to the oil source return pipeline, and the T circuits are always open to return oil; The Master host (8) controls the first channel digital valve (1) and the first channel switch element (2) through the Slave 1 slave (9), and the Master host (8) controls the second channel digital valve (6) and the second channel switch element (5) through the Slave 2 slave (7).

2. A dual digital valve redundant control system according to claim 1, characterized in that: Through the control of the Master host (8), the first channel digital valve (1) and the second channel digital valve (6) can realize an initial state, a first channel digital valve (1) single working state, a second channel digital valve (6) single working state and a dual-channel digital valve joint working state.

3. A dual digital valve redundant control system according to claim 2, characterized in that: The Master drives the parameters of the Slave1 slave (9) through a first control model to control the first channel digital valve (1) and the first channel switch element (2). The first control model is: Among them, U1(t) is the control output voltage of Slave1 slave (9) at time t, which directly drives the action of the first channel digital valve (1) and the first channel switch element (2); e1(t) is the deviation between the target position and the actual position of the first channel digital valve (1), reflecting the error amount of system control; e1(τ) represents the deviation between the target position and the actual position of the first channel digital valve (1) at time point τ, and its physical meaning is consistent with e1(t), and is used to accumulate historical deviations from 0 to time t; e1(λ) represents the deviation between the target position and the actual position of the first channel digital valve (1) at time point λ, and its physical meaning is consistent with e1(t), and is used to accumulate historical deviations from 0 to time τ; K p1 K is the proportional control coefficient, which is used to amplify the control effect of the current deviation. The larger the coefficient, the more sensitive the response to the deviation. i1 K is the integral control coefficient, which is used to eliminate static deviation and achieve zero-error control by accumulating historical deviations; d1 is the differential control coefficient, which is used to suppress the rate of change of the deviation and reduce system overshoot and oscillation; a n1 is the amplitude of the nth harmonic, which is used to superimpose periodic disturbance compensation and suppress the natural frequency vibration of the hydraulic system; ω1 is the fundamental angular frequency, which is determined by the system control period; The phase angle of the nth harmonic adjusts the time phase of the harmonic component to match the system delay characteristics; N is the upper limit of the harmonic order, which is used to limit the frequency band range of harmonic compensation and balance the calculation complexity and control accuracy; The first control model outputs U1(t), and based on U1(t), the action of the Slave1 slave (9) is driven.

4. A dual digital valve redundant control system according to claim 3, characterized in that: When the first channel digital valve (1) is in a single working state, the first control model is constrained by a first constraint model; the first constraint model is: Among them, K p10 is the base proportional coefficient, representing the basic control strength when the deviation is 0, which is determined by the system hardware characteristics; E 10 is the reference deviation value, which is used to standardize the deviation. becomes a dimensionless coefficient to avoid calculation overflow due to excessive deviation; α1 is the adjustment index used to control K p1 The nonlinear degree of the deviation, and α1>0; β1 is the angular frequency parameter, which determines K p1 The frequency of oscillation over time is used to match the periodicity of wind fluctuations; t is time; When the first channel digital valve (1) is in a single working state, the first constraint model is associated with the first control model to obtain an output U1(t).

5. A dual digital valve redundant control system according to claim 4, characterized in that: The Master host (8) drives the parameters of the Slave 2 slave (7) through a second control model to achieve control of the second channel digital valve (6) and the second channel switch element (5); the second control model is: Wherein, U2(t) is the control output voltage of Slave 2 (7) at time t, which directly drives the operation of the second channel digital valve (6) and the second channel switch element (5); e2(t) is the deviation between the target position and the actual position of the second channel digital valve (6), reflecting the error of the system control; m2 is the amplitude of the mth pulse component, which is used to compensate for the instantaneous impact or high-frequency vibration of the hydraulic system; m2 is the time center of the mth pulse, indicating the moment of pulse action; σ m2 is the width parameter of the mth pulse, which determines the duration of the pulse action. The smaller the value, the steeper the pulse and the more concentrated the action. M is the number of pulse components, which reflects the number of vibration frequency points that the system needs to compensate, and is determined by spectrum analysis. K p2 is the proportional control coefficient, which is multiplied by the deviation e2(τ) to form the basic control quantity; E 20 It is the reference deviation value, which is used to perform nonlinear normalization on the deviation to avoid saturation of the control quantity when the deviation is large; The second control model outputs U2(t), and the action of the Slave 2 slave (7) is driven based on U2(t).

6. A dual digital valve redundant control system according to claim 5, characterized in that: When the second channel digital valve (6) is in a single working state, the second control model is constrained by a second constraint model; the second constraint model is: Among them, b m20 is the reference amplitude of the mth pulse, representing the basic compensation strength when there is no deviation, which is determined by the system hardware characteristics and historical vibration data; e2(tt m2 ) is the deviation function, which represents the difference between the current time t and the pulse center time t m2 The deviation value at the time of the time difference reflects the hysteresis of the deviation on the pulse; γ2 is the pulse modulation index, which is used to control the nonlinear degree of the pulse amplitude changing with the deviation. When -γ2>0, the larger the deviation, the greater the b m2 The faster the decay; it is a sign function used to determine that the pulse direction is opposite to the deviation direction; When the second channel digital valve (6) is in a single working state, the second constraint model is associated with the second control model to obtain an output U2(t).

7. A dual digital valve redundant control system according to claim 6, characterized in that: When the dual-channel digital valve is in a working state, the Master host (8) constrains the first constraint model and the second constraint model through a collaborative constraint model, and the collaborative constraint model is: Among them, U 1ma and U 2ma is the maximum control output voltage of the two slaves, which is determined by the hardware circuit and is used to standardize the control quantity; |e1(t)-e2(t)| is the absolute value of the deviation between the two channels, which is used to measure the consistency of the control state of the two channels; E c is the collaborative deviation threshold, which is used to standardize the deviation difference and determine the response sensitivity of the nonlinear term on the right side of the formula; exp(·) is an exponential function, which forms an S-shaped curve with the denominator, giving the formula a nonlinear transition characteristic; When the dual-channel digital valve is in a joint working state, the collaborative constraint model is associated with the first control model and the second control model to obtain outputs U1(t) and U2(t).

8. The dual digital valve redundant control system according to claim 1, characterized in that: The first channel switch element (2) comprises two components, respectively controlling the on / off of the A and B circuits of the first channel digital valve (1); the second channel switch element (5) comprises two components, respectively controlling the on / off of the A and B circuits of the second channel digital valve (6).

9. The dual digital valve redundant control system according to claim 1, characterized in that: The T circuits of the first channel digital valve (1) and the second channel digital valve (6) are always open to return oil, ensuring that the valve core is in the oil.

10. The dual digital valve redundant control system according to claim 1, characterized in that: The first channel actuator (3) and the second channel actuator (4) are mechanically connected to achieve rigid synchronization and simultaneously drive the actuator to operate.

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