Cascade optimization control system and method for deceleration strip magnetic lead screw power generation system based on energy conversion integration platform

Abstract

The invention discloses a cascade optimization control system and method of a deceleration strip magnetic lead screw power generation system based on an energy conversion integration platform, and belongs to the technical field of deceleration strip power generation, and the control system comprises an obtaining module which is used for obtaining the three-phase current and the three-phase voltage of a magnetic lead screw composite motor; the I-stage module is used for respectively acquiring an angular velocity estimated value and an angular position estimated value of the magnetic composite motor by adopting a dynamic sliding mode control method based on a sigmoid function according to the three-phase current and the three-phase voltage; the II-level module is used for acquiring a quadrature-direct axis reference current instruction by adopting an anti-disturbance extended state observer and a fractional order sliding mode controller according to the three-phase current, the load torque and the angular velocity estimated value; and the III-level module is used for performing decoupling according to the quadrature-direct axis reference current instruction, the three-phase current and the constructed open-loop transfer function to generate a quadrature-direct axis reference voltage instruction. The system can be accurately tracked and observed, and the external disturbance resistance is high.

Description

Technical Field

[0001] The present invention belongs to the technical field of speed reduction belt power generation, and in particular relates to a cascade optimization control system and method for a speed reduction belt magnetic screw power generation system based on an energy conversion integrated platform. Background Art

[0002] With the rapid growth of the global economy and the continuous increase in population, the demand for energy is rising. In this context, the speed bump energy recovery system, as an emerging energy recovery technology, has attracted widespread attention from the society. This system uses the mechanical energy generated by the mechanical movement of the vehicle and converts it into electrical energy, providing a new sustainable energy solution for the industrial and transportation fields.

[0003] The existing speed bump power generation system connects the speed bump with a magnetic screw generator. The efficient transmission performance of the magnetic screw fully converts the mechanical energy of the vehicle's mechanical movement into electrical energy through the continuous secondary transmission of the power generation system, thereby realizing energy utilization and recovery. However, how to develop a speed bump power generation system that can integrate strong anti-external disturbance capabilities, precise tracking and observation, and efficient and stable operation under desired conditions has become a problem that needs to be solved urgently in the world today. Summary of the invention

[0004] In view of the deficiencies in the prior art, the present invention provides a cascade optimization control system and method for a speed-reducing belt magnetic screw power generation system based on an energy conversion integrated platform, which can accurately track and observe and has a strong ability to resist external disturbances, so that the speed-reducing belt power generation system can operate efficiently and stably under desired conditions.

[0005] The present invention provides the following technical solutions:

[0006] In the first aspect, a cascade optimization control system of a speed reduction belt magnetic screw power generation system based on an energy conversion integrated platform is provided, wherein the speed reduction belt magnetic screw power generation system comprises a speed reduction belt and a magnetic screw composite motor connected to the speed reduction belt through a transmission rod, and when the speed reduction belt drives the transmission rod to move linearly, the magnetic screw composite motor generates electrical energy, and the control system comprises:

[0007] Acquisition module, used to obtain the three-phase current I of the magnetic screw composite motor gen And the three-phase voltage V gen ;

[0008] I-level module is used to gen And the three-phase voltage V gen , the dynamic sliding mode control method based on the sigmoid function is used to obtain the angular velocity estimation value of the magnetic compound motor and the angular position estimate

[0009] Class II module, used to gen , the collected load torque T of the magnetic screw composite motor L And the angular velocity estimate The anti-disturbance extended state observer and fractional-order sliding mode controller are used to obtain the quadrature axis reference current command. and direct axis reference current command

[0010] Class III module for quadrature axis reference current command Direct axis reference current command Three-phase current I gen And the constructed open-loop transfer function, decoupling to generate the quadrature axis reference voltage command and direct axis reference voltage command To control the operating state of the magnetic screw compound motor.

[0011] Optionally, the acquisition module acquires the three-phase current I of the magnetic screw composite motor based on the established power generation model of the vehicle and the speed bump magnetic screw power generation system. gen And the three-phase voltage V gen , specifically including the following steps:

[0012] A quarter vehicle model is selected as a reference benchmark to construct an equivalent motion model of the speed bump magnetic screw generator system to obtain the driving force F input to the speed bump magnetic screw generator system. MLS ;

[0013] Driving force F MLS Energy is converted into active power P output by magnetic screw compound motor out ;

[0014] According to the output active power P out , three-phase current I gen And the three-phase voltage V gen The relationship between the three-phase current I of the magnetic screw compound motor is obtained. gen .

[0015] Optionally, the motion equation of the equivalent motion model is expressed as:

[0016]

[0017] Among them, m s is the vehicle equivalent mass, k t is the vehicle suspension stiffness, k fd is the buffer coefficient, F MLS is the driving force of the magnetic screw generator system input to the speed reducer, z u is the displacement of the contact point between the vehicle and the upper surface of the speed bump, zs is the displacement of the lower surface of the speed bump, z r is the vehicle displacement, represents the equivalent acceleration of the vehicle model;

[0018] The magnetic screw composite motor outputs active power P out for:

[0019]

[0020] in, is the transmission ratio of the magnetic screw compound motor, τ is the lead, η gen is the electromagnetic conversion efficiency of the magnetic screw compound motor, V gen is the three-phase voltage output by the magnetic screw compound motor, I gen is the three-phase current of the magnetic screw compound motor.

[0021] Optionally, in the level I module, the dynamic sliding mode control method based on the sigmoid function is used to obtain the angular velocity estimation value of the magnetic composite motor respectively. and the angular position estimate The specific steps include:

[0022] The three-phase current I gen And the three-phase voltage V gen After Clark transformation, the current component I in the α-axis direction in the αβ stationary coordinate system is obtained α and voltage component V α , and the current component I in the β-axis direction β and voltage component V β ;

[0023] Establish the stator current state equation of the magnetic screw composite motor;

[0024]

[0025] Among them, p is the differential operator, R s and L s are the stator winding resistance and inductance of the magnetic screw composite motor, e α and e β They are the two components of the induced back electromotive force in the αβ stationary coordinate system;

[0026] The dynamic sliding mode observation equations for estimating current and back electromotive force are obtained by using the stator current state equation and the sigmoid function based on angular velocity estimation.

[0027]

[0028]

[0029] in, and They are the two estimated current components in the αβ stationary coordinate system, K h is the dynamic gain, H(x) is the sigmoid function based on angular velocity estimation;

[0030] Based on the dynamic sliding mode observation equation, the angular velocity estimate is obtained and the angular position estimate

[0031]

[0032]

[0033] in, and represents the estimated back EMF in the induced αβ stationary frame;

[0034] The estimated angular velocity obtained Perform high-frequency noise elimination and use the denoised angular velocity estimate Update the sigmoid function based on angular velocity estimation;

[0035] Using the updated sigmoid function based on angular velocity estimation, the estimated current is continuously adjusted to optimize the angular velocity estimation value. and the angular position estimate

[0036] Optionally, a low frequency filter is used to estimate the angular velocity Perform high frequency noise elimination;

[0037] The expression of the sigmoid function H(x) based on angular velocity estimation is:

[0038]

[0039] Where a is the acceleration slope of the sigmoid function.

[0040] Optionally, in the level II module, the direct axis reference current instruction Directional control equals 0;

[0041] The quadrature axis reference current instruction is obtained The specific steps include:

[0042] The three-phase current I gen After park transformation, the quadrature axis current component I is obtained q and the direct axis current component I d ;

[0043] Using the quadrature axis current component I q and the direct axis current component I d , establish the operation equation of the magnetic screw compound motor considering internal and external disturbances;

[0044] Using nonlinear function f nl Design a disturbance-resistant extended state observer to obtain two mismatch terms Z1 and Z2 that vary with time and internal and external disturbances;

[0045] The nonlinear function f nl The expression is:

[0046]

[0047] Among them, f nl is a two-variable continuous differentiable function, ρ b is the boundary layer thickness, ρ b >0, y is the input variable;

[0048] The mismatched terms Z1 and Z2 are input into the fractional-order sliding mode controller to obtain the angular velocity estimate. and angular velocity preset values Speed ​​error x e ;

[0049] In the quadrature axis control loop, according to the speed error x e Design nonlinear proportional integral sliding surface function;

[0050] The nonlinear proportional integral sliding surface function is:

[0051]

[0052] Among them, b and c are the two coefficients of the nonlinear sliding surface, is the speed error;

[0053] According to the operation equation of the magnetic screw composite motor, the nonlinear proportional integral sliding surface function and the collected load torque T of the magnetic screw composite motor L , get the quadrature axis reference current command

[0054]

[0055]

[0056]

[0057] Among them, n p , fand J are the pole pairs, permanent magnet flux and moment of inertia of the magnetic screw compound motor respectively, m and n are disturbance terms, is the estimated value of m, |x| represents the distance of the system state variable relative to the sliding surface, and is a fractional-order operator, r1 and r2 are orders, f on (s a ) is a switching function based on the inverse sine trigonometric function, s a is the independent variable of the switching function, k is the reaching law coefficient, ξ is the state coefficient, and χ is the reaching term index.

[0058] Optionally, the operation equation of the magnetic screw composite motor is:

[0059]

[0060]

[0061] Among them, ω r is the rotor angular velocity, Represents ω r First-order derivative, B m is the viscous friction coefficient, Δx1 and Δx2 are the two internal parameter changes of the magnetic screw compound motor.

[0062] Optionally, in the level III module, the generating quadrature axis reference voltage instruction and direct axis reference voltage command The specific steps include:

[0063] The three-phase current I gen After park transformation, the quadrature axis current component I is obtained q and the direct axis current component I d ;

[0064] Based on the first-order transfer function of the magnetic screw composite motor and the universal transfer function of the fractional-order proportional-integral controller obtained by Laplace transformation, the open-loop transfer function of the speed reducer magnetic screw power generation system is constructed.

[0065] The optimal adjustment parameters of the open-loop transfer function are obtained by using a frequency band complex number calculation method; the optimal adjustment parameters include the optimal adjustment gain K pr , integral gain K in and the optimal adjustment order α0 of the fractional-order controller;

[0066] Based on the best adjustment parameters, through the open-loop transfer function, quadrature axis reference current command Direct axis reference current command Cross-axis current I q and the direct axis current I d, decoupling to generate quadrature axis reference voltage command and direct axis reference voltage command

[0067] The quadrature axis reference voltage command and direct axis reference voltage command After the Park inverse transformation, it is transmitted to the space vector modulation module to generate a pulse signal for switching control of the machine-side converter of the magnetic screw compound motor.

[0068] Optionally, the open-loop transfer function of the speed reducer magnetic screw power generation system is:

[0069]

[0070] Among them, K pr and K in are the proportional adjustment gain and integral adjustment gain of the controller respectively, is the fractional calculus frequency domain operator, α i represents the order, J is the moment of inertia of the magnetic screw composite motor, B m is the viscous friction coefficient, s is the complex frequency variable in the Laplace transform;

[0071] The quadrature axis reference voltage command and direct axis reference voltage command They are:

[0072]

[0073]

[0074]

[0075] Among them, L d and L q are the inductance components of the stator winding of the magnetic screw composite motor on the orthogonal axis, n p The number of pole pairs of the magnetic screw compound motor, ψ f It is the permanent magnet flux of the magnetic screw compound motor.

[0076] In a second aspect, a cascade optimization control method for a speed reduction belt magnetic screw power generation system based on an energy conversion integrated platform is provided, wherein the speed reduction belt magnetic screw power generation system comprises a speed reduction belt and a magnetic screw composite motor connected to the speed reduction belt through a transmission rod, and when the speed reduction belt drives the transmission rod to move linearly, the magnetic screw composite motor generates electrical energy, and the control method comprises:

[0077] Get the three-phase current I of the magnetic screw compound motor gen And the three-phase voltage V gen ;

[0078] According to the three-phase current I gen And the three-phase voltage V gen , the dynamic sliding mode control method based on the sigmoid function is used to obtain the angular velocity estimation value of the magnetic compound motor and the angular position estimate

[0079] According to the three-phase current I gen , the collected load torque T of the magnetic screw composite motor L And the angular velocity estimate The anti-disturbance extended state observer and fractional-order sliding mode controller are used to obtain the quadrature axis reference current command. and direct axis reference current command

[0080] According to the quadrature axis reference current command Direct axis reference current command Three-phase current I gen And the constructed open-loop transfer function, decoupling to generate the quadrature axis reference voltage command and direct axis reference voltage command To control the operating state of the magnetic screw compound motor.

[0081] Compared with the prior art, the present invention has the following beneficial effects:

[0082] The present invention makes in-depth innovation based on the basic sliding mode control theory, divides the cascade control system into three-level modules, and has significant advantages in many aspects such as accurate acquisition of the angular velocity and position of the magnetic screw composite motor in prediction, anti-disturbance capability in response to external and internal interference when the speed belt power generation system is running, and stable operation following expected conditions; the present invention effectively improves the stability and response speed of the magnetic screw composite motor when the speed belt power generation system is running, which not only helps to enhance the working efficiency and reduce energy loss in the power generation process, but also improves the reliability and stability of the power generation system and prolongs the service life of the equipment; at the same time, through the regulation of the control loop, the dynamic characteristics of the speed belt magnetic screw power generation system are finely adjusted, which effectively reduces the steady-state error and dynamic response time of the traditional integer-order controller, and can adaptively adjust the control parameters while meeting the expected operating conditions, adapt to the parameter changes that may occur in the system during the speed belt operation, and ensure the stable operation of the power generation system. The present invention has broad application prospects and economic benefits. BRIEF DESCRIPTION OF THE DRAWINGS

[0083] Figure 1 It is the overall control framework diagram of the cascade optimization system of the present invention.

[0084] Figure 2It is an equivalent motion coupling model of the vehicle and the speed bump power generation system of the present invention.

[0085] Figure 3 It is the overall control flow chart of the level I module of the present invention.

[0086] Figure 4 It is a schematic diagram of the convergence performance of the sigmoid function based on the variable acceleration slope method in the level I module of the present invention.

[0087] Figure 5 It is the overall control flow chart of the level II module of the present invention.

[0088] Figure 6 It is the overall control flow chart of the level III module of the present invention.

[0089] Figure 7 It is a schematic diagram of the energy conversion process of the vehicle and the speed bump power generation system of the present invention.

[0090] In the figure, 100 is a speed reduction belt, 200 is a buffer, 300 is a transmission rod, and 400 is a magnetic screw composite motor. DETAILED DESCRIPTION

[0091] The present invention will be further described below in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present invention, and cannot be used to limit the protection scope of the present invention.

[0092] It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0093] Example 1

[0094] like Figure 1 and 2 As shown, a cascade optimization control system of a speed reducer magnetic screw power generation system based on an energy conversion integrated platform is provided, comprising an acquisition module, a level I module, a level II module and a level III module.

[0095] The speed-reducing belt magnetic screw power generation system of the present invention comprises a speed-reducing belt and an internal mechanical energy conversion component; when a vehicle passes through the speed-reducing belt 100, the internal energy conversion component converts the downward pressure generated by squeezing the speed-reducing belt 100 when the vehicle moves into the high-speed rotational motion of the permanent magnet synchronous generator rotor nested outside through the linear motion of the magnetic screw mover, thereby generating electrical energy and entering the process of power transmission or being stored in an energy storage device.

[0096] The present invention adopts a magnetic screw composite motor 400 as an internal mechanical energy conversion component. The device is mainly composed of a magnetic screw transmission structure and a permanent magnet synchronous generator. The bottom of the speed reduction belt 100 is connected to the transmission rod 300 through a buffer 200, and the permanent magnet synchronous generator is nested on the outside of the transmission rod 300. The transmission rod 300 serves as a mover unit of the magnetic screw transmission structure. The motor rotor is coaxially connected to the transmission rod 300. The bottom end of the speed reduction belt 100 is placed flush with the ground to facilitate the interaction between the tire and the surface module when the vehicle passes by, and to achieve a good buffering effect. It is worth noting that The connection method of each component of the present application can refer to the existing technology; the internal mechanical energy conversion components and the protective outer frame are embedded in the ground, and at the same time, excessive contact stress caused by heavy-loaded vehicles is prevented from causing damage to the device; compared with the traditional speed reduction belt power generation system, the present invention abandons the previous gear set transmission structure, and couples the speed reduction belt with the magnetic screw composite generator. The magnetic screw transmission structure greatly avoids mechanical friction loss. At the same time, under the same input conditions, the system can provide a greater torque density, which solves the problem of large friction loss and inability to recover a large amount of energy in the traditional speed reduction power generation system.

[0097] The cascade optimization control system of the speed reducer magnetic screw power generation system includes:

[0098] Acquisition module, used to obtain the three-phase current I of the magnetic screw composite motor gen And the three-phase voltage V gen .

[0099] The three-phase current I of the magnetic screw composite motor is obtained based on the power generation model of the vehicle and speed bump magnetic screw power generation system. gen And the three-phase voltage V gen Of course, in some other embodiments, a three-phase power collector or other monitoring equipment can also be used to obtain the three-phase current I of the magnetic screw composite motor. gen And the three-phase voltage V gen .

[0100] In this application, the three-phase current I of the magnetic screw composite motor is obtained gen And the three-phase voltage V gen , specifically including the following steps:

[0101] S11: Select a quarter vehicle model as a reference benchmark to construct an equivalent motion model of the speed bump magnetic screw generator system to obtain the driving force F input to the speed bump magnetic screw generator system MLS .

[0102] When analyzing the vehicle model, in order to best reflect the vertical dynamics involved in the downward pressure of the vehicle, a quarter model of the vehicle is selected as the reference benchmark, and the vehicle is simplified to a total mass of m s , an equivalent model consisting of the suspension system and the contact points between the wheels and the speed bump surface. This equivalence helps to quickly evaluate the dynamic response between the vehicle and the speed bump, while greatly reducing the computational complexity.

[0103] The suspension system is an important component connecting the wheels and the vehicle body. Its structure is mainly composed of a strong spring and a vibration reduction device. In the present invention, the equivalent stiffness is k t The impact-resistant structure of the vehicle passes by the speed bump surface, and the energy begins to be converted through the magnetic screw transmission structure due to the change in the position of the contact point between the wheel and the speed bump surface. The body, contact point and the lower surface of the speed bump will produce different degrees of displacement. Based on the dynamics theory, the motion equation describing the equivalent quarter vehicle and speed bump model can be obtained as follows:

[0104]

[0105] Among them, m s is the vehicle equivalent mass, k t is the vehicle suspension stiffness, k s is the buffer coefficient, F MLS is the driving force of the magnetic screw generator system input to the speed reducer, z u is the displacement of the contact point between the vehicle and the upper surface of the speed bump, z s is the displacement of the lower surface of the speed bump, z r is the vehicle displacement, represents the equivalent acceleration of the vehicle model. The driving force F can be obtained according to formula (1): MLS .

[0106] S12: Driving force F MLS Energy is converted into active power P output by magnetic screw compound motor out .

[0107] S13: According to the output active power P out , three-phase current I gen And the three-phase voltage V gen The relationship between the three-phase current I of the magnetic screw compound motor is obtained. gen .

[0108] Specifically, Figure 2 and 7 As shown, when the vehicle is at V s When the vehicle passes by at a speed of s Based on the basic structure of the magnetic screw transmission device, due to the principle of magnetic coupling, the movement of the rotor and the mover of the magnetic screw composite motor is always synchronized, and the driving force F MLS When the actuator is driven by the speed reduction belt to make linear motion input, the transmission ratio equation of the magnetic screw composite motor can be obtained:

[0109]

[0110] Among them, T e is the output electromagnetic torque on the rotor of the magnetic screw composite motor, G and τ are the transmission ratio and lead of the magnetic screw composite motor. At this time, the buffer installed at the interface plays the role of transmitting energy and preventing energy loss to the greatest extent; in the present invention, assuming that energy passes through the conversion process with minimal loss, the magnetic screw composite motor converts the mechanical energy E involved in energy conversion when the vehicle passes through the speed bump s It is approximately the displacement difference between the contact point and the lower surface of the speed bump and the driving force F MLS The product of s At the same time, it is converted into the rotational energy E of the magnetic screw composite motor rotor rot , the conversion relations are:

[0111] E rot =G·E s (3)

[0112] This process is the first level of energy conversion in energy conversion; according to the power generation working principle of the magnetic screw composite motor, as the rotor rotates, part of the energy is lost in the form of heat energy, and the rotational energy E rot Then the formula for the second-level energy conversion is as follows:

[0113] P out =η gen ·E rot (4)

[0114] Among them, P out is the output active power of the magnetic screw compound motor, η gen is the electromagnetic conversion efficiency of the magnetic screw compound motor.

[0115] Combining formulas (2) to (4), we can get the approximate three-phase current I at the machine end: gen The sizes are as follows:

[0116]

[0117] Among them, Vgen is the three-phase voltage output by the compound motor, I gen is the three-phase current at the machine end.

[0118] I-level module is used to gen And the three-phase voltage V gen , the dynamic sliding mode control method based on the sigmoid function is used to obtain the angular velocity estimation value of the magnetic compound motor and the angular position estimate

[0119] In the power generation process of highway speed bump system, the control of the angular velocity of the generator rotor is often an important link that cannot be ignored. In particular, the accurate detection of the speed and position of the rotor is crucial. Normally, the speed and position of the rotor can be predicted by high-precision mechanical sensors such as encoders. However, mechanical sensors are very expensive and very sensitive to changes in the external environment. In order to overcome these known problems, the present invention proposes a dynamic sliding mode control method based on a sigmoid function in the I-level module to predict the angular velocity and prediction of the magnetic screw compound motor, and combines the variable acceleration slope control method to make the predicted value approach the actual value.

[0120] like Figure 3 As shown in the figure, the dynamic sliding mode control method based on the sigmoid function is used to obtain the angular velocity estimation value of the magnetic compound motor. and the angular position estimate The specific steps include:

[0121] S21: The three-phase current I gen And the three-phase voltage V gen After Clark transformation, the current component I in the α-axis direction in the αβ stationary coordinate system is obtained α and voltage component V α , and the current component I in the β-axis direction β and voltage component V β .

[0122] Specifically, the a-axis coincides with the α-axis, while the b-axis and the c-axis are mapped to the α-axis and the β-axis through a specific linear combination of the prior art, with the three-phase current I gen For example, the transformation formula has a matrix transformation form as follows:

[0123]

[0124] Among them, I α ,I β is the current component in the αβ stationary coordinate system, I0 is the zero-sequence equivalent current, I a ,I b ,Ic are the currents of the three phases abc respectively.

[0125] S22: Establishing the stator current state equation of the magnetic screw composite motor;

[0126] Specifically, the voltage and current components in the αβ stationary coordinate system obtained by the Clark transformation of equation (6) are transmitted to the I-level module. By analyzing the state of the magnetic screw composite motor in the stationary coordinate system, the stator current state equation of the magnetic screw composite motor can be established as follows:

[0127]

[0128] Among them, p is the differential operator, R s , L s is the stator winding resistance and inductance of the magnetic screw composite motor, e α and e β is the induced back electromotive force in the αβ stationary coordinate system.

[0129] S23: using the stator current state equation and the sigmoid function based on angular velocity estimation, the dynamic sliding mode observation equation of the estimated current and back electromotive force is obtained;

[0130] A general dynamic sliding mode function will produce a large jitter phenomenon when switching the output of the surface, resulting in an unchangeable deviation in the result. At this time, the introduction of the sigmoid function can effectively prevent the occurrence of this situation; however, when there is no low-pass filter, although the sigmoid function can suppress the delay compensation of the low-pass filter, due to the influence of the acceleration slope a, the performance of the estimated result is not constant according to the change of the system operating speed range. When a is larger, the convergence speed is accelerated and the output fluctuation will also increase. Although a smaller a can reduce the jitter, the convergence speed is also correspondingly slowed down, resulting in a decrease in operating reliability. In order to maintain the prediction performance in the absence of a sensor, the present invention proposes a variable acceleration control method.

[0131] The sigmoid function based on speed estimation is introduced, and combined with the screening performance of the low-pass filter, after gradually removing the high-frequency noise, the result is accurately output through repeated iterations. The sigmoid function based on speed estimation is shown as follows:

[0132]

[0133]

[0134] Where a is the acceleration slope of the sigmoid function, is the velocity estimate after the low-frequency filter removes the noise, is the previous velocity estimate.u is the cut-off frequency of the low-pass filter, and μ is the delay coefficient.

[0135] The convergence performance of the sigmoid function based on the variable acceleration slope method is as follows: Figure 4 As shown, the convergence slope is estimated by the speed Real-time adjustment: In low-speed areas, slow acceleration is used to improve the vibration suppression effect; in high-speed areas, fast acceleration can improve convergence performance; The change in directional state, from curve a to curve c, the convergence performance becomes faster and faster, at this time the estimated value of the system can converge close to the actual value.

[0136] Based on the comprehensive analysis of equations (7) to (9), it can be seen that the current and back EMF estimation equations can be given by the following equations:

[0137]

[0138]

[0139] in, and is the current estimation in the αβ stationary coordinate system, and is the estimated back EMF of the induced αβ stationary coordinate system, K h is the dynamic gain, and H(x) represents the sigmoid function based on speed estimation.

[0140] S24: Obtain angular velocity estimation based on dynamic sliding mode observation equation and the angular position estimate

[0141]

[0142]

[0143] in, and represents the estimated back EMF in the induced αβ stationary coordinate system, tan -1 Represents the inverse tangent operation.

[0144] S25: Obtain the estimated angular velocity value Perform high-frequency noise elimination and use the denoised angular velocity estimate Update the sigmoid function based on the angular velocity estimate.

[0145] S26: Using the updated sigmoid function based on angular velocity estimation, the estimated current is continuously adjusted to optimize the angular velocity estimation value and the angular position estimate

[0146] Specifically, after removing the high-frequency noise signal, a new velocity estimate is obtained. Then it is transmitted to the dynamic sliding mode control again, and steps S21 to S26 are repeated to finally obtain the estimated values ​​of angular velocity and angular position close to the true value. and

[0147] like Figure 5 As shown, the Class II module is used to gen , the collected load torque T of the magnetic screw composite motor L And the angular velocity estimate The anti-disturbance extended state observer and fractional-order sliding mode controller are used to obtain the quadrature axis reference current command. and direct axis reference current command

[0148] Specifically, the direct axis reference current command Directional control equals 0.

[0149] Get the quadrature axis reference current command Specifically include:

[0150] S31: The three-phase current I gen After park transformation, the quadrature axis current component I is obtained q and the direct axis current component I d .

[0151] S32: Using the quadrature axis current component I q and the direct axis current component I d , the operating equation of the magnetic screw compound motor considering internal and external disturbances is established.

[0152] Specifically, the load torque T is obtained from the speed reduction belt power generation system. L And the AC and DC axis current components I obtained by park transformation d ,I q , establish the load operation equation of the magnetic screw compound motor:

[0153]

[0154] Among them, n p , f and J are the pole pairs, permanent magnet flux and moment of inertia of the magnetic screw composite motor, respectively. e is the electromagnetic power, B m is the viscous friction coefficient, ω r is the rotor angular velocity, Represents ω r The first derivative of .

[0155] When considering the internal and external disturbances of the magnetic screw composite motor, the load operation equation can be derived from equation (14) in another form:

[0156]

[0157] in, Δx1 and Δx2 are the changes in the internal parameters of the magnetic screw compound motor. Indicates the quadrature-axis reference current command value.

[0158] S33: Using nonlinear function f nl A disturbance-resistant extended state observer is designed to obtain two mismatch terms Z1 and Z2 that vary with time and internal and external disturbances.

[0159] Specifically, the disturbance term parameters m and n are defined as:

[0160]

[0161] Combined with formula (16), formula (15) can be simplified into a simplified form with disturbance term parameters m and n:

[0162]

[0163] In order to obtain the quadrature axis reference current command value The estimation of the disturbance terms m and n is essential. At this time, the extended state observer of the nonlinear function is combined with the adaptive formula. First, consider establishing a typical first-order system:

[0164]

[0165] Among them, R1(t) is the state variable, T(t) is the system output variable, is the time derivative of the state change R1(t) in the first-order system, is the external disturbance signal, u2(t) is the control input signal, p2 is the coefficient of adjusting the control input signal and p2>0; this system reflects that the state variable R1(t) is limited by the external disturbance The external control input signal u2(t) and a coefficient p2 that adjusts these effects work together; in order to more intuitively and simply get the mismatch terms Z1 and Z2, define At the same time, R2(t) is selected as the new extended state variable. At this time, the first-order system established by equation (18) can be expanded to become a second-order system as shown below:

[0166]

[0167] Furthermore, in order to improve the control error caused by system chattering due to external interference, the present invention adopts a nonlinear function f nl As the filter function of the interference-resistant extended state observer, the nonlinear function f nl is a continuous differentiable function, and its expression is as follows:

[0168]

[0169] Among them, f nl is a two-variable continuous differentiable function, ρ b is the boundary layer thickness, ρ b >0; then define Through analysis, the basic observation expression of the disturbance-resistant extended state observer is obtained as follows:

[0170]

[0171] Where e1 is the estimated speed in the Level I module The error between the actual value and the actual value; η1 and η2 are both adjusting nonlinear functions f nl The coefficients of and are all greater than zero, Z1(t) and Z2(t) are two mismatched terms that change with time and internal and external disturbances, the superscript represents the first-order derivative, ω r (t) is the angular velocity of the magnetic screw compound motor that changes with time.

[0172] The speed feedback signal of the magnetic screw composite motor is monitored by Z1, and the disturbance term of the system is obtained by transmitting it to the fractional-order proportional-integral sliding mode controller by Z2. After obtaining the mismatch term Z1, the calculated deviation from the preset value satisfied by the expected power generation system operation is fed back to the controller together with Z2.

[0173] S34: Input the mismatch terms Z1 and Z2 into the fractional order sliding mode controller to obtain the angular velocity estimate and angular velocity preset values Speed ​​error x e .

[0174] S35: In the quadrature axis control loop, according to the speed error x e Design nonlinear proportional-integral sliding surface function.

[0175] Specifically, the fractional-order proportional-integral sliding mode controller can better cope with the uncertainty caused by unknown nonlinear disturbances. Under the same number of parameter designs and conditional constraints, the fractional-order sliding mode control method used ensures the robustness to loop gain changes and the desired control performance. In the analysis process of the control loop combined with the level III module, based on the field-oriented control theory, the fractional-order proportional-integral control is performed on the quadrature axis, where the fractional-order calculus is defined as follows:

[0176]

[0177] in, represents the fractional order operator, r q represents the order of the fractional operator, t0 and t represent the operation time limit that determines the domain of the fractional operator; the inverse sine trigonometric function is used as the switching function to weaken the chattering phenomenon of the system, and the expression is as follows:

[0178]

[0179] Among them, ρ a is the boundary layer thickness and ρ a > 0. Since the value of the disturbance parameter m is related to the change of the parameters of the magnetic screw composite motor itself, it is difficult to obtain a specific value. The adaptive formula can be used for estimation:

[0180]

[0181] Where θ is the adjustment coefficient and θ>0; s n is the sliding surface function in the fractional-order proportional-integral sliding mode controller.

[0182] Although the traditional calculus sliding surface can be used as a conventional sliding surface to design a sliding mode controller, when the speed error is large, its control performance obviously cannot reach the expected effect. Based on this problem, the speed error function is replaced by the nonlinear function f described in formula (20): nl (y,ρ b ) instead. This function f nl (y,ρ b ) can greatly reduce the speed error, so that the system can be driven to the desired condition even in the case of serious disturbance error. Therefore, in the fractional-order proportional-integral sliding mode controller, a new nonlinear proportional-integral sliding mode function s is designed based on the traditional integral sliding mode surface. n As shown below:

[0183]

[0184] Where b and c are nonlinear sliding surface coefficients and b>0, c>0, ρ b is the boundary layer thickness and ρ b >0, is the speed error.

[0185] S36: Based on the operation equation of the magnetic screw composite motor, the nonlinear proportional integral sliding surface function and the collected load torque T of the magnetic screw composite motor L , get the quadrature axis reference current command

[0186]

[0187] in, n p , f and J are the pole pairs, permanent magnet flux and moment of inertia of the magnetic screw compound motor, respectively. m and n are disturbance terms, the superscript m is the estimated value, |x| is the distance of the system state variable relative to the sliding surface, T L is the load torque, and is a fractional-order operator, r1 and r2 are orders, f on (s a ) is a switching function based on the inverse sine trigonometric function, s a is the independent variable of the switching function, k is the reaching law coefficient, ε is the state coefficient, and χ is the reaching term index.

[0188] like Figure 6 As shown, the Class III module is used to generate a quadrature axis reference current command. Direct axis reference current command Three-phase current I gen And the constructed open-loop transfer function, decoupling to generate the quadrature axis reference voltage command and direct axis reference voltage command To control the operating state of the magnetic screw compound motor.

[0189] Generate quadrature axis reference voltage command and direct axis reference voltage command The specific steps include:

[0190] S41: The three-phase current I gen After park transformation, the quadrature axis current component I is obtained q and the direct axis current component I d .

[0191] S42: Based on the first-order transfer function of the magnetic screw composite motor and the universal transfer function of the fractional-order proportional-integral controller obtained by Laplace transformation, the open-loop transfer function of the speed reducer magnetic screw power generation system is constructed.

[0192] A simplified first-order transfer function model of the magnetic screw compound motor is established given by the following equation:

[0193]

[0194] Where, J is the moment of inertia of the magnetic screw composite motor, B m is the viscous friction coefficient, and the transfer function is in the form after Laplace transformation. Then in [ω b ,ωh ] frequency band realizes the rational approximation of the frequency of the fractional calculus frequency domain operator, where the approximate transfer function based on Oustaloup is given by the following formula:

[0195]

[0196] Among them, ω b With ω h are the upper and lower limits of the frequency band, α i is the order of the frequency domain operator of fractional calculus, N is a positive integer, ω′ n and ω n is the transition frequency, It represents the product of integers starting from -N and multiplied by N, where: A comprehensive analysis is conducted on the differential equation form used in the time domain of the fractional-order proportional-integral controller, and the general transfer function of the fractional-order proportional-integral controller and the conventional proportional-integral controller can be obtained by Laplace transform:

[0197]

[0198]

[0199] Wherein, C(s) is the universal transfer function of the fractional-order proportional-integral controller of the II-level module of the present invention, E(s) is the universal transfer function of the conventional proportional-integral controller, K pr , K in They are the proportional adjustment gain and integral adjustment gain of the controller respectively.

[0200] After applying the fractional-order proportional-integral controller, the general form of the open-loop transfer function G(s) is as follows:

[0201]

[0202] S43: Obtain the best adjustment parameters of the open-loop transfer function using a frequency band complex number calculation method; the best adjustment parameters include the best adjustment gain K pr , integral gain K in and the optimal adjustment order α0 of the fractional-order controller.

[0203] Specifically, in order to ensure the robustness of the cascade optimization control framework, the frequency band complex number calculation method used in the level III module of the present invention is inseparable from three constraints:

[0204] [1] Phase margin constraints:

[0205] Arg[G(jω c )]=Arg[C(jω c)F(jω c )]=-π+φ m (32)

[0206] [2], gain crossover frequency constraint:

[0207] |G(jω c )|dB=|C(jω c )F(jω c )|dB=0 (33)

[0208] [3] The robustness of the speed bump generator system to gain changes requires that the derivative of the phase with respect to frequency is equal to zero:

[0209]

[0210] Among them, ω c represents the gain crossover frequency, φ m represents phase margin, dB represents decibel, G(jω c ) represents the gain crossover frequency ω c The frequency response under c ) represents the gain crossover frequency ω c The transfer function response of the fractional-order proportional-integral controller under c ) represents the gain crossover frequency ω c Simplified first-order transfer function response of the magnetic screw compound motor under , Arg(z) represents the complex argument operation. The satisfaction of constraint [3] means that the overshoot value of the system response is almost the same and robustness is achieved.

[0211] The frequency response can be obtained from the open loop of G(s) as follows:

[0212]

[0213] in, As described in the constraint [1] of the phase margin, we can obtain:

[0214]

[0215] Where arctan(x) represents the inverse tangent function of x. K can be established by equation (36): in With α i The relationship is:

[0216]

[0217] When the constraint [3] is related to the robustness of the object to changes in the environmental gain, the following equation is obtained:

[0218]

[0219] At the same time, from formula (38), we can establish the relationship between K in Another equation for is as follows:

[0220]

[0221] in, At this time K pr The equivalent equation of can be established from the constraints [2]:

[0222]

[0223] Combining equations (37), (38), and (40), we can solve the optimal adjustment gain K pr , K in and the optimal adjustment order α0.

[0224] S44: Based on the best adjustment parameters, through the open-loop transfer function, quadrature axis reference current command Direct axis reference current command Cross-axis current I q and the direct axis current I d , decoupling to generate quadrature axis reference voltage command and direct axis reference voltage command

[0225] Specifically, the open-loop transfer function designed using the obtained optimal adjustment parameters can significantly and efficiently improve the stability of the speed bump power generation system and improve the power generation efficiency.

[0226] AC and DC axis reference control voltage command and

[0227]

[0228] Among them, ψ f is the permanent magnet flux of the magnetic screw compound motor, I d ,I q is the orthogonal axis current component obtained by Park transformation of the three-phase current collected from the magnetic screw compound motor. d The current control loop is set is equal to zero, After calculation, we get: is the estimated angular velocity obtained from equations (12) and (13) in the level I module Multiply by the number of pole pairs n p Delai, L d , L q They are the inductance components of the stator winding of the magnetic screw composite motor on the orthogonal axis respectively.

[0229] S45: Set the quadrature axis reference voltage command and direct axis reference voltage command After the Park inverse transformation, it is transmitted to the space vector modulation module to generate a pulse signal for switching control of the machine-side converter of the magnetic screw compound motor.

[0230] and After Park inverse transformation, it is transmitted to the space vector modulation module (SVPWM), and then used as input to generate a pulse signal to control the switching of the machine side converter (MSC) to achieve the ultimate goal of comprehensively enhancing the control performance of the full-process closed-loop system through cascade optimization control.

[0231] Based on the field oriented control, the feedforward control method proposed in the present invention consists of two control loops, which are used to track the reference current command input by the II-level module and adjust the stator AC and DC axis components I d and I q , especially in the quadrature axis feedforward loop, the fractional-order control method is used as the output signal of the fractional-order proportional-integral controller of the previous module. In order to obtain the quadrature and direct axis reference control voltage and The size of is inseparable from obtaining the specific values ​​of the adjustment parameters in the controller. In order to enhance the stable operation of the speed bump power generation system, the frequency band complex number calculation method is adopted in the level III module of the present invention to calculate the optimal adjustment parameters of the fractional-order proportional-integral controller in the level III module.

[0232] Example 2

[0233] A cascade optimization control method for a speed reduction belt magnetic screw power generation system based on an energy conversion integrated platform is provided. The speed reduction belt magnetic screw power generation system comprises a speed reduction belt and a magnetic screw composite motor connected to the speed reduction belt through a transmission rod. When the speed reduction belt drives the transmission rod to move linearly, the magnetic screw composite motor generates electrical energy. The control method comprises:

[0234] Get the three-phase current I of the magnetic screw compound motor gen And the three-phase voltage V gen ;

[0235] According to the three-phase current I gen And the three-phase voltage V gen , the dynamic sliding mode control method based on the sigmoid function is used to obtain the angular velocity estimation value of the magnetic compound motor and the angular position estimate

[0236] According to the three-phase current I gen , the collected load torque T of the magnetic screw composite motorL And the angular velocity estimate The anti-disturbance extended state observer and fractional-order sliding mode controller are used to obtain the quadrature axis reference current command. and direct axis reference current command

[0237] Used to follow the quadrature axis reference current command Direct axis reference current command Three-phase current I gen And the constructed open-loop transfer function, decoupling to generate the quadrature axis reference voltage command and direct axis reference voltage command To control the operating state of the magnetic screw compound motor.

[0238] The cascade optimization control method described in the present invention uses a regionalized control process, from the prediction link to the anti-interference processing link to the instruction calculation link, and the multi-level modules are coordinated and connected, which not only improves the control accuracy and adaptability of the system, but also enhances the system's ability to resist various internal and external interferences and to perform dynamic adjustments based on disturbances.

[0239] For more specific processes of the above method, please refer to the corresponding contents disclosed in the aforementioned embodiments, which will not be repeated here.

[0240] The various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referenced to each other.

[0241] Those skilled in the art can clearly understand that the technology in the embodiments of the present invention can be implemented by means of software plus a necessary general hardware platform. Based on this understanding, the technical solution in the embodiments of the present invention is essentially or the part that contributes to the prior art can be embodied in the form of a software product, which can be stored in a storage medium such as ROM / RAM, a disk, an optical disk, etc., and includes a number of instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to execute the methods described in each embodiment of the present invention or some parts of the embodiments.

[0242] The above are only preferred embodiments of the present invention, and the protection scope of the present invention is not limited to the above embodiments. All technical solutions under the concept of the present invention belong to the protection scope of the present invention. It should be pointed out that for ordinary technicians in this technical field, some improvements and modifications without departing from the principle of the present invention should be regarded as the protection scope of the present invention.

Claims

1. A cascade optimization control system for a speed reduction belt magnetic screw power generation system based on an energy conversion integrated platform, wherein the speed reduction belt magnetic screw power generation system comprises a speed reduction belt and a magnetic screw composite motor connected to the speed reduction belt through a transmission rod. When the speed reduction belt drives the transmission rod to move linearly, the magnetic screw composite motor generates electrical energy, characterized in that: The control system comprises: Acquisition module, used to obtain the three-phase current I of the magnetic screw composite motor gen And the three-phase voltage V gen ; Class I module, used to calculate the current according to the three-phase current I gen And the three-phase voltage V gen , the dynamic sliding mode control method based on the sigmoid function is used to obtain the angular velocity estimation value of the magnetic compound motor and the angular position estimate Level II module is used to calculate the three-phase current I gen , the collected load torque T of the magnetic screw composite motor L And the angular velocity estimate The anti-disturbance extended state observer and fractional-order sliding mode controller are used to obtain the quadrature axis reference current command. and direct axis reference current command Level III module, used to generate a quadrature axis reference current command Direct axis reference current command Three-phase current I gen And the constructed open-loop transfer function, decoupling to generate the quadrature axis reference voltage command and direct axis reference voltage command To control the operating state of the magnetic screw compound motor.

2. The cascade optimization control system of the speed reduction belt magnetic screw power generation system based on the energy conversion integrated platform according to claim 1 is characterized in that: The acquisition module acquires the three-phase current I of the magnetic screw composite motor based on the established power generation model of the vehicle and the speed bump magnetic screw power generation system. gen And the three-phase voltage V gen , specifically including the following steps: A quarter vehicle model is selected as a reference benchmark to construct an equivalent motion model of the speed bump magnetic screw generator system to obtain the driving force F input to the speed bump magnetic screw generator system. MLS ; Driving force F MLS Energy is converted into active power P output by magnetic screw compound motor out ; According to the output active power P out , three-phase current I gen And the three-phase voltage V gen The relationship between the three-phase current I of the magnetic screw compound motor is obtained. gen .

3. The cascade optimization control system of the speed reduction belt magnetic screw power generation system based on the energy conversion integrated platform according to claim 2 is characterized in that: The motion equation of the equivalent motion model is expressed as: Among them, m s is the vehicle equivalent mass, k t is the vehicle suspension stiffness, k fd is the buffer coefficient, F MLS is the driving force of the magnetic screw generator system input to the speed reducer, z u is the displacement of the contact point between the vehicle and the upper surface of the speed bump, z s is the displacement of the lower surface of the speed bump, z r is the vehicle displacement, represents the equivalent acceleration of the vehicle model; The magnetic screw composite motor outputs active power P out for: in, is the transmission ratio of the magnetic screw compound motor, τ is the lead, η gen is the electromagnetic conversion efficiency of the magnetic screw compound motor, V gen is the three-phase voltage of the magnetic screw compound motor, I gen is the three-phase current of the magnetic screw compound motor.

4. The cascade optimization control system of the speed reduction belt magnetic screw power generation system based on the energy conversion integrated platform according to claim 1 is characterized in that: In the level I module, the dynamic sliding mode control method based on the sigmoid function is used to obtain the angular velocity estimation value of the magnetic composite motor. and the angular position estimate The specific steps include: The three-phase current I gen And the three-phase voltage V gen After Clark transformation, the current component I in the α-axis direction in the αβ stationary coordinate system is obtained α and the voltage component V α , and the current component I in the β-axis direction β and the voltage component V β ; Establish the stator current state equation of the magnetic screw composite motor; Among them, p is the differential operator, R s and L s are the stator winding resistance and inductance of the magnetic screw composite motor, e α and e β They are the two components of the induced back electromotive force in the αβ stationary coordinate system; The dynamic sliding mode observation equations for estimating current and back electromotive force are obtained by using the stator current state equation and the sigmoid function based on angular velocity estimation. in, and They are the two estimated current components in the αβ stationary coordinate system, K h is the dynamic gain, H(x) is the sigmoid function based on angular velocity estimation; Based on the dynamic sliding mode observation equation, the angular velocity estimate is obtained and the angular position estimate in, and represents the estimated back EMF in the induced αβ stationary frame; The estimated angular velocity obtained Perform high-frequency noise elimination and use the denoised angular velocity estimate Update the sigmoid function based on angular velocity estimation; Using the updated sigmoid function based on angular velocity estimation, the estimated current is continuously adjusted to optimize the angular velocity estimation value. and the angular position estimate 5. The cascade optimization control system of the speed reduction belt magnetic screw power generation system based on the energy conversion integrated platform according to claim 4 is characterized in that: Angular velocity estimation using low frequency filter Perform high frequency noise elimination; The expression of the sigmoid function H(x) based on angular velocity estimation is: Where a is the acceleration slope of the sigmoid function.

6. The cascade optimization control system of the speed reduction belt magnetic screw power generation system based on the energy conversion integrated platform according to claim 1 is characterized in that: In the level II module, the direct axis reference current instruction Directional control equals 0; The quadrature axis reference current instruction is obtained The specific steps include: The three-phase current I gen After park transformation, the quadrature axis current component I is obtained q and the direct axis current component I d ; Using the quadrature axis current component I q and the direct axis current component I d , establish the operation equation of the magnetic screw compound motor considering internal and external disturbances; Using nonlinear function f nl Design a disturbance-resistant extended state observer to obtain two mismatch terms Z1 and Z2 that vary with time and internal and external disturbances; The nonlinear function f nl The expression is: Among them, f nl is a two-variable continuous differentiable function, ρ b is the boundary layer thickness, ρ b >0, y is the input variable; The mismatched terms Z1 and Z2 are input into the fractional-order sliding mode controller to obtain the angular velocity estimate. and angular velocity preset values Speed ​​error x e ; In the quadrature axis control loop, according to the speed error x e Design nonlinear proportional integral sliding surface function; The nonlinear proportional integral sliding surface function is: Among them, b and c are the two coefficients of the nonlinear sliding surface, is the speed error; According to the operation equation of the magnetic screw composite motor, the nonlinear proportional integral sliding surface function and the collected load torque T of the magnetic screw composite motor L , get the quadrature axis reference current command Among them, n p , f and J are the pole pairs, permanent magnet flux and moment of inertia of the magnetic screw compound motor respectively, m and n are disturbance terms, is the estimated value of m, |x| represents the distance of the system state variable relative to the sliding surface, and is a fractional-order operator, r1 and r2 are orders, f on (s a ) is a switching function based on the inverse sine trigonometric function, s a is the independent variable of the switching function, k is the reaching law coefficient, ε is the state coefficient, and χ is the reaching term index.

7. The cascade optimization control system of the speed reduction belt magnetic screw power generation system based on the energy conversion integrated platform according to claim 6 is characterized in that: The operation equation of the magnetic screw composite motor is: Among them, ω r is the rotor angular velocity, Represents ω r First-order derivative, B m is the viscous friction coefficient, Δx1 and Δx2 are the two internal parameter changes of the magnetic screw compound motor.

8. The cascade optimization control system of the speed reduction belt magnetic screw power generation system based on the energy conversion integrated platform according to claim 1 is characterized in that: In the level III module, the quadrature axis reference voltage instruction is generated and direct axis reference voltage command The specific steps include: The three-phase current I gen After park transformation, the quadrature axis current component I is obtained q and the direct axis current component I d ; Based on the first-order transfer function of the magnetic screw composite motor and the universal transfer function of the fractional-order proportional-integral controller obtained by Laplace transformation, the open-loop transfer function of the speed reducer magnetic screw power generation system is constructed. The optimal adjustment parameters of the open-loop transfer function are obtained by using a frequency band complex number calculation method; the optimal adjustment parameters include the optimal adjustment gain K pr , integral gain K in and the optimal adjustment order α0 of the fractional-order controller; Based on the best adjustment parameters, through the open-loop transfer function, quadrature axis reference current command Direct axis reference current command Cross-axis current I q and the direct axis current I d , decoupling to generate quadrature axis reference voltage command and direct axis reference voltage command The quadrature axis reference voltage command and direct axis reference voltage command After the Park inverse transformation, it is transmitted to the space vector modulation module to generate a pulse signal for switching control of the machine-side converter of the magnetic screw compound motor.

9. The cascade optimization control system of the speed reduction belt magnetic screw power generation system based on the energy conversion integrated platform according to claim 8 is characterized in that: The open-loop transfer function of the speed reduction belt magnetic screw power generation system is: Among them, K pr and K in are the proportional adjustment gain and integral adjustment gain of the controller respectively, is the fractional calculus frequency domain operator, α i represents the order, J is the moment of inertia of the magnetic screw composite motor, B m is the viscous friction coefficient, s is the complex frequency variable in the Laplace transform; The quadrature axis reference voltage command and direct axis reference voltage command They are: Among them, L d and L q are the inductance components of the stator winding of the magnetic screw composite motor on the orthogonal axis, n p The number of pole pairs of the magnetic screw compound motor, ψ f It is the permanent magnet flux of the magnetic screw compound motor.

10. A cascade optimization control method for a speed reduction belt magnetic screw power generation system based on an energy conversion integrated platform, wherein the speed reduction belt magnetic screw power generation system comprises a speed reduction belt and a magnetic screw composite motor connected to the speed reduction belt through a transmission rod. When the speed reduction belt drives the transmission rod to move linearly, the magnetic screw composite motor generates electrical energy, characterized in that: The control method comprises: Get the three-phase current I of the magnetic screw compound motor gen And the three-phase voltage V gen ; According to the three-phase current I gen And the three-phase voltage V gen , the dynamic sliding mode control method based on the sigmoid function is used to obtain the angular velocity estimation value of the magnetic compound motor and the angular position estimate According to the three-phase current I gen , the collected load torque T of the magnetic screw composite motor L And the angular velocity estimate The anti-disturbance extended state observer and fractional-order sliding mode controller are used to obtain the quadrature axis reference current command. and direct axis reference current command According to the quadrature axis reference current command Direct axis reference current command Three-phase current I gen And the constructed open-loop transfer function, decoupling to generate the quadrature axis reference voltage command and direct axis reference voltage command To control the operating state of the magnetic screw compound motor.

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