阅读说明：本技术 基于扩张状态观测器的永磁同步电流控制器的设计方法 (Design method of permanent magnet synchronous current controller based on extended state observer ) 是由 刘丙友 张峥峥 王力超 李兴 罗建 于 2019-10-10 设计创作，主要内容包括：本发明公开了基于扩张状态观测器的永磁同步电流控制器的设计方法,包括如下步骤：步骤SS1：搭建电流环自抗扰控制器闭环回路；步骤SS2：确定永磁同步电机电流环能够解近似耦线性化,通过电流传感器检测得到永磁同步电机的两相定子电流和经过Clarke变换和Park变化得到永磁同步电机的直轴电流和交轴电流,建立PMSM在两相旋转坐标系即d-q坐标系下的电流环数学模型；步骤SS3：根据交轴电流值,设计“参考电流变换率前馈”；步骤SS4：根据一阶改进型扩张状态观测器观测得到的系统总扰动的补偿模型,设计电流环的改进型自抗扰控制器。本发明彻底解决PMSM的电流波动更小,提高系统的抗动能力,增加电机的稳定性的技术需求。(The invention discloses a design method of a permanent magnet synchronous current controller based on an extended state observer, which comprises the following steps: step SS 1: building a current loop active disturbance rejection controller closed loop; step SS 2: determining that a current loop of the permanent magnet synchronous motor can be approximately decoupled and linearized, detecting by a current sensor to obtain two-phase stator current of the permanent magnet synchronous motor, obtaining direct-axis current and quadrature-axis current of the permanent magnet synchronous motor through Clarke transformation and Park transformation, and establishing a current loop mathematical model of the PMSM in a two-phase rotating coordinate system, namely a d-q coordinate system; step SS 3: designing 'reference current transformation rate feedforward' according to the quadrature axis current value; step SS 4: and designing an improved active disturbance rejection controller of a current loop according to a compensation model of the total system disturbance observed by the first-order improved extended state observer. The invention thoroughly solves the technical requirements that the current fluctuation of the PMSM is smaller, the anti-motion capability of the system is improved, and the stability of the motor is increased.)

1. The design method of the permanent magnet synchronous current controller based on the extended state observer is characterized by comprising the following steps of:

step SS 1: building a current loop active disturbance rejection controller closed loop;

step SS 2: determining that a current loop of the permanent magnet synchronous motor can be approximately decoupled and linearized, detecting by a current sensor to obtain two-phase stator current of the permanent magnet synchronous motor, obtaining direct-axis current and quadrature-axis current of the permanent magnet synchronous motor through Clarke transformation and Park transformation, and establishing a current loop mathematical model of the PMSM in a two-phase rotating coordinate system, namely a d-q coordinate system;

step SS 3: designing 'reference current transformation rate feedforward' according to the quadrature axis current value;

step SS 4: and designing an improved active disturbance rejection controller of a current loop according to a compensation model of the total system disturbance observed by the first-order improved extended state observer.

2. The design method of the permanent magnet synchronous current controller based on the extended state observer is characterized in that the mathematical model of the permanent magnet synchronous motor in the step SS2 on the dq axis is as follows:

the stator voltage equation is as follows:

u in the formulae (1-1) and (1-2)_d、u_qThe stator voltage d-axis component and the stator voltage q-axis component are respectively; i.e. i_d、i_qThe stator current d-axis component and the stator current q-axis component are respectively; Ψ_d、Ψ_qRespectively are a stator flux linkage d-axis component and a stator flux linkage q-axis component; ω is the rotor angular frequency;

the flux linkage equation is as follows:

Ψ_d＝L_di_d+Ψ_f(1-3)

Ψ_q＝L_qi_q(1-4)

l in the formulae (1-3) and (1-4)_d、L_qD-axis inductance and q-axis inductance of the stator winding are parameters irrelevant to the angular position theta of the rotor respectively; l is_d＝L_md+L₁,L_q＝L_mq+L₁Wherein L is_md、L_mqIs the d-axis mutual inductance, q-axis mutual inductance, L, between stator and rotor₁Is the stator leakage inductance;

the electromagnetic torque equation is as follows:

Τ_em＝p(Ψ_di_q-Ψ_qi_d) (1-5)

the mechanical equation of motion is as follows:

r in the formula (1-6)_ΩIs a resistance coefficient, T_LIs the load torque;

according to a stator voltage equation and a mechanical motion equation, obtaining a permanent magnet synchronous motor state equation under a d-q coordinate system:

the formulas (1-7) and (1-8) are the current loop state equations of the permanent magnet synchronous motor, wherein L_d＝L_q＝L_aR is the stator coil resistance; l is the inductance component of the q-axis; Ψ_rIs a flux linkage generated by the permanent magnet; u. of_qIs the voltage of the q-axis; ω is the motor rotor angular velocity.

3. The method for designing a permanent-magnet synchronous current controller based on an extended state observer according to claim 1, wherein the compensation model of the total system disturbance observed by the first-order modified extended state observer in step SS4 specifically includes:

when the system shown by the permanent magnet synchronous motor current loop state equation considers that the system does not know external disturbance, the input quantity U is selected to be [ U ═ U%_du_q]^ΤAnd the output quantity Y ═ i_di_q]^ΤState variable X₁＝[i_di_q]^ΤAnd obtaining a standard form of current loop state equation of the permanent magnet synchronous motor:

where w is the unknown external disturbance of the system,

as can be seen from the formula (2-2), i_dThe stator exciting current i is realized to a certain extent by the current control method of 0_dAnd torque current i_qDecoupling of (1); using d, q-axis armature voltages u_d、u_qControlling d and q axis armature currents i_d、i_qSince the position of the rotor magnetic pole of the permanent magnet synchronous motor can be detected, the d-axis and q-axis armature voltages u_d、u_qIs controllable; however, in (2-2), the inductance parameter L_aThere is a more severe perturbation of the parameters, and furthermore the perturbation term ω i_q、The existence of (2) also causes the characteristics of strong coupling and nonlinearity of the system; f (X)₁) And (3) regarding the system as internal disturbance, and taking the sum of internal disturbance and external disturbance of the system as an unknown part of the system and expanding the sum into a new state variable a (t): a (t) ═ f (i)_q,t)+w(t)；

The auto-disturbance rejection control model of the current loop can be expressed as:

i′_q＝a(t)+bu (1-12)

4. the method according to claim 1, wherein the closed loop of the current loop active disturbance rejection controller in step SS1 includes a tracking differential controller TD, a novel extended state observer ESO, a novel nonlinear error feedback control law NSEF, and a controlled object, an output of the tracking differential controller TD and an output of the novel extended state observer ESO are respectively connected to an input of the novel nonlinear error feedback control law NSEF, an output of the novel nonlinear error feedback control law NSEF and an output of the novel extended state observer ESO are respectively connected to an input of the controlled object, and an output of the controlled object is connected to an input of the novel extended state observer ESO.

5. The design method of permanent magnet synchronous current controller based on extended state observer as claimed in claim 4, wherein given current i_q ^*An output signal z of the tracking differential controller TD connected to an input terminal of the tracking differential controller TD₁₁With the output signal z of the novel extended state observer, ESO₂₁Comparing and outputting an error signal to the input end of the novel nonlinear error feedback control law NSEF, and outputting a signal z of the novel extended state observer ESO₂₂And a given current i_q ^*The differentiated compared output signal is divided by a compensation factor b₀Then comparing the output signal with the output signal of the novel nonlinear error feedback control law NSEF, outputting the output signal to a controlled object and outputting a controlled quantity i_qThe controlled quantity i_qAnd flows back to the input end of the ESO.

6. The method of claim 4, wherein the control function of the tracking derivative controller TD is:

wherein i_q ^*Setting a q-axis current loop of a permanent magnet synchronous motor system; z is a radical of₁₁Is i_q ^*The tracking signal of (2); r is₀Is velocity factor, z'₁₁Is i_q ^*The first derivative of the tracking signal of (1); h is₀Is a filter factor; r is₀And h₀To schedule the speed of the transient.

7. The extended state observer-based permanent magnet synchronous current controller design method according to claim 4, characterized in that the new extended state observer ESO calculation model is:

wherein z is₂₁To output i_qTracking signal of e₁For tracking error, z₂₂Is the observed value of the total disturbance signal w (t); β₁、β₂To extend the gain of the state observer α₀、α₁Is a non-linear factor;₁is the linear interval width of the nonlinear function; b₀Is an estimate of the compensation factor.

8. The design method of the permanent magnet synchronous current controller based on the extended state observer as claimed in claim 4, wherein the calculation model of the novel nonlinear error feedback control law NSEF is:

β₃gain for a novel nonlinear error feedback control rate, α₂Is a novel nonlinear error feedback control lawThe non-linear factor of (a) is,₂is a filter factor of a novel nonlinear error feedback control law.

9. The method for designing a permanent-magnet synchronous current controller based on an extended state observer according to claim 4, wherein the step SS2 specifically includes: increasing the "reference current transformation rate feed forward", perturbing f (i) according to the sum_qT) can be a first order nonlinear system of formula i'_qA (t) + bu is compensated to a "first order pure integrator-tandem system", i.e.:

i'_q＝u₀(1-16)

at a given current i_q ^*In the known case, the reference current transformation ratio, i.e. the set current i, can be determined first_q ^*And assigning this value to the intermediate control quantity u₀。

Technical Field

The invention relates to a design method of a permanent magnet synchronous current controller based on an extended state observer, and belongs to the technical field of servo control systems.

Background

In a high-precision servo system, a Permanent Magnet Synchronous Motor (PMSM) has excellent performance, and is widely applied to various industrial fields and high-performance servo systems, and gradually becomes the mainstream of a servo system execution motor. However, the permanent magnet synchronous motor is used as a controlled object with multivariable, nonlinear and strong coupling, in the actual operation process of a servo system, the parameters of the motor body can change, and meanwhile, the load object has uncertainty, mainly including moment of inertia change, load disturbance and the like; in addition, various disturbances often exist in the application environment of the servo system. These disturbance factors may adversely affect the desired servo performance of the servo system, such as dynamic and static characteristics, control accuracy and stability, and sometimes even cause the control quality to be seriously degraded, and the robustness may not be ensured. The traditional control theory has poor adaptability to system parameter change, is difficult to overcome the influence of disturbance factors such as system disturbance, parameter large-range change and the like on the system performance, has poor anti-interference capability and is difficult to meet the requirement of high-precision servo control. With the development of control theory, many advanced algorithms are applied to the control research of the permanent magnet synchronous motor, such as inner membrane control, fuzzy control, neural network control, sliding mode variable structure control and the like. However, many of the methods involve more mathematical knowledge, are more complex to calculate and implement, are only stopped in a numerical simulation stage, and have limited disturbance resistance. Therefore, aiming at the problems faced by the current servo control system, a servo control strategy which has better performance, strong disturbance rejection and easy realization needs to be sought to meet the increasingly urgent high-performance servo control requirement, so that the servo system has stronger disturbance rejection. The current loop is the innermost loop of the permanent magnet synchronous motor, and the main function of the current loop is to improve the dynamic performance of the whole system by improving the innermost loop performance of the system, so the performance of the current loop can directly influence the performance of the speed loop and the position loop, and the performance of the whole permanent magnet synchronous motor can be influenced.

The Active Disturbance Rejection Control (ADRC) technology does not depend on the internal mechanism and the external disturbance rule of a controlled object, and the real-time estimation and timely active compensation are carried out on the total disturbance quantity, so that the method has the characteristics of strong disturbance rejection capability, high precision, high response speed, simple structure and the like, and meanwhile, the algorithm is simple and easy to realize, and the uncertainty of the controlled system is not strictly limited, so that the method has incomparable advantages of other control strategies in the disturbance rejection capability of the permanent magnet synchronous servo system, and becomes a research hotspot of the control strategy of the PMSM servo control system. In a PMSM servo system using active disturbance rejection control, in order to obtain a good control effect, it is only necessary that the tracking effect of an observer is good, that is, the estimation accuracy of an Extended State Observer (ESO) needs to be high, and if the estimation capability of the ESO cannot meet the requirement of the control accuracy of the system, the performance of the active disturbance rejection control system is adversely affected. The disturbance terms estimated by the ESO include changes in rotational speed, torque, and rotational inertia and damping coefficients. During the operation of the permanent magnet synchronous motor, the parameters and the disturbance quantity change, and particularly when the load disturbance is large, the amplitude of the disturbance item is large. If the total sum of the disturbances is changed too much and too fast, the observer is obviously burdened by directly estimating the disturbances by the ESO, and the estimation of the disturbances by the ESO is difficult to ensure high precision, so that the system disturbances are difficult to accurately compensate by the active disturbance rejection controller, and the active disturbance rejection controller is limited to obtain better disturbance rejection capability and control performance.

The nonlinear function commonly used today is the fal (e, α,) function:

derivative the fal (e, α,) function at the segmentation point:

αe^α-1≠1/^1-α,e＝ (2-3)

it can be seen that the left and right derivative values are not the same at the segmentation point, and although the fal (e, α,) function is continuous at the origin and at the segmentation point, the fal (e, α,) function is not conducive and does not have good continuity and smoothness at the origin and at the segmentation point.

Disclosure of Invention

The invention aims to overcome the defects in the prior art, solve the technical problems of overlarge disturbance amplitude value, excessively violent change, low precision and insufficient active disturbance rejection estimated by the extended state observer, and provide a design method of a permanent magnet synchronous current controller based on the extended state observer, so that the current fluctuation of a PMSM is smaller, the anti-dynamic capability of a system is improved, and the stability of a motor is improved.

The invention adopts the following technical scheme: the design method of the permanent magnet synchronous current controller based on the extended state observer is characterized by comprising the following steps of:

step SS 1: building a current loop active disturbance rejection controller closed loop;

step SS 2: determining that a current loop of the permanent magnet synchronous motor can be approximately decoupled and linearized, detecting by a current sensor to obtain two-phase stator current of the permanent magnet synchronous motor, obtaining direct-axis current and quadrature-axis current of the permanent magnet synchronous motor through Clarke transformation and Park transformation, and establishing a current loop mathematical model of the PMSM in a two-phase rotating coordinate system, namely a d-q coordinate system;

step SS 3: designing 'reference current transformation rate feedforward' according to the quadrature axis current value;

step SS 4: and designing an improved active disturbance rejection controller of a current loop according to a compensation model of the total system disturbance observed by the first-order improved extended state observer.

As a preferred embodiment, the mathematical model of the permanent magnet synchronous motor in step SS2 on the d-q axis is:

the stator voltage equation is as follows:

u in the formulae (1-1) and (1-2)_d、u_qThe stator voltage d-axis component and the stator voltage q-axis component are respectively; i.e. i_d、 i_qThe stator current d-axis component and the stator current q-axis component are respectively; Ψ_d、Ψ_qRespectively are a stator flux linkage d-axis component and a stator flux linkage q-axis component; ω is the rotor angular frequency;

the flux linkage equation is as follows:

Ψ_d＝L_di_d+Ψ_f(2-6)

Ψ_q＝L_qi_q(2-7)

l in the formulae (1-3) and (1-4)_d、L_qD-axis inductance and q-axis inductance of the stator winding are parameters irrelevant to the angular position theta of the rotor respectively; l is_d＝L_md+L₁,L_q＝L_mq+L₁Wherein L is_md、 L_mqIs the d-axis mutual inductance, q-axis mutual inductance, L, between stator and rotor₁Is the stator leakage inductance;

the electromagnetic torque equation is as follows:

Τ_em＝p(Ψ_di_q-Ψ_qi_d) (2-8)

the mechanical equation of motion is as follows:

r in the formula (1-6)_ΩIs a resistance coefficient, T_LIs the load torque;

according to a stator voltage equation and a mechanical motion equation, obtaining a permanent magnet synchronous motor state equation under a d-q coordinate system:

the formulas (1-7) and (1-8) are the current loop state equations of the permanent magnet synchronous motor, wherein L_d＝L_q＝L_aR is the stator coil resistance; l is the inductance component of the q-axis; Ψ_rIs a flux linkage generated by the permanent magnet; u. of_qIs the voltage of the q-axis; ω is the motor rotor angular velocity.

As a preferred embodiment, the compensation model of the total system disturbance observed by the first-order modified extended state observer in step SS4 specifically includes:

when the system shown by the permanent magnet synchronous motor current loop state equation considers that the system does not know external disturbance, the input quantity U is selected to be [ U ═ U%_du_q]^ΤAnd the output quantity Y ═ i_di_q]^ΤState variable X₁＝[i_di_q]^ΤAnd obtaining a standard form of current loop state equation of the permanent magnet synchronous motor:

where w is the unknown external disturbance of the system,

as can be seen from the formula (2-2), i_dThe stator exciting current i is realized to a certain extent by the current control method of 0_dAnd torque current i_qDecoupling of (1); using d, q-axis armature voltages u_d、u_qControlling d and q axis armature currents i_d、i_qSince the position of the rotor magnetic pole of the permanent magnet synchronous motor can be detected, the d-axis and q-axis armature voltages u_d、u_qIs controllable; however, in (2-2), the inductance parameter L_aThere is a more severe perturbation of the parameters, and furthermore the perturbation term ω i_q、The existence of (2) also causes the characteristics of strong coupling and nonlinearity of the system; f (X)₁) And (3) regarding the system as internal disturbance, and taking the sum of internal disturbance and external disturbance of the system as an unknown part of the system and expanding the sum into a new state variable a (t): a (t) ═ f (i)_q,t)+w(t)；

The auto-disturbance rejection control model of the current loop can be expressed as:

i′_q＝a(t)+bu (2-15)

as a preferred embodiment, the current loop active disturbance rejection controller closed loop in step SS1 includes a tracking differential controller TD, a novel extended state observer ESO, a novel non-linear error feedback control law NSEF, and a controlled object, an output end of the tracking differential controller TD and an output end of the novel extended state observer ESO are respectively connected to an input end of the novel non-linear error feedback control law NSEF, an output end of the novel non-linear error feedback control law NSEF and an output end of the novel extended state observer ESO are respectively connected to an input end of the controlled object, and an output end of the controlled object is connected to an input end of the novel extended state observer ESO.

As a preferred embodiment, the current i is given_q ^*An output signal z of the tracking differential controller TD connected to an input terminal of the tracking differential controller TD₁₁With the output signal z of the novel extended state observer, ESO₂₁Comparing and outputting an error signal to the input end of the novel nonlinear error feedback control law NSEF, and outputting a signal z of the novel extended state observer ESO₂₂And a given current i_q ^*The differentiated compared output signal is divided by a compensation factor b₀Then comparing the output signal with the output signal of the novel nonlinear error feedback control law NSEF, outputting the output signal to a controlled object and outputting a controlled quantity i_qSaid quiltQuantity control i_qAnd flows back to the input end of the ESO.

As a preferred embodiment, the control function of the tracking derivative controller TD is:

wherein i_q ^*Setting a q-axis current loop of a permanent magnet synchronous motor system; z is a radical of₁₁Is i_q ^*The tracking signal of (2); r is₀Is a velocity factor; h is₀Is a filter factor; r is₀And h₀To schedule the speed of the transient; the tracking derivative controller TD implements a smooth approximation of the generalized derivative of the input signal using a non-linear function, which arranges the transition according to the constraints of the reference input and the controlled object, resulting in a smooth input signal.

As a preferred embodiment, fhan (z) in the tracking derivative controller₁₁-i_q ^*,v₂,r₀,h₀) For the fastest control function, the expression is as follows:

as a preferred embodiment, the calculation model of the new extended state observer ESO is:

wherein z is₂₁To output i_qTracking signal of e₁For tracking errors，z₂₂Is the observed value of the total disturbance signal w (t); β₁、β₂To extend the gain of the state observer α₀、α₁Is a non-linear factor;₁is the linear interval width of the nonlinear function; b₀Is an estimate of the compensation factor.

As a preferred example, nfal (e, α, γ) is expressed as follows:

wherein z is₂₁To output i_qTracking signal of e₁For tracking error, z₂₂Is the observed value of the total disturbance signal w (t); β₁、β₂To extend the gain of the state observer α₀、α₁Is a non-linear factor;₁is the linear interval width of the nonlinear function; b₀Is an estimate of the compensation factor.

As a preferred embodiment, the calculation model of the new nonlinear error feedback control law NSEF is:

β₃gain for a novel nonlinear error feedback control rate, α₂Is a nonlinear factor of a novel nonlinear error feedback control law,₂the method is a filter factor of a novel nonlinear error feedback control law, and the novel nonlinear error feedback control rate carries out nonlinear calculation on the proportion, the integral and the differential of an error signal, so that the control precision of the system is improved, and the immunity of the system is enhanced.

As a preferred embodiment, step SS2 specifically includes: increasing the "reference current transformation rate feed forward", perturbing f (i) according to the sum_qT) can be a first order nonlinear system of formula i'_qA (t) + bu is compensated to a "first order pure integrator-tandem system", i.e.:

i'_q＝u₀(2-23)

at a given current i_q ^*In the known case, the reference current transformation ratio, i.e. the set current i, can be determined first_q ^*And assigning this value to the intermediate control quantity u₀And thus the controlled quantity i_qI.e. the actual current, can track the given current i well_q ^*。

The invention achieves the following beneficial effects: firstly, aiming at solving the technical problems of overlarge disturbance amplitude, excessively violent change, low precision and insufficient active disturbance rejection capability of the extended state observer, the invention realizes the technical requirements of smaller current fluctuation of the PMSM, improvement of the system disturbance rejection capability and increase of the stability of the motor, and has better disturbance rejection capability compared with the unmodified active disturbance rejection controller while inheriting all the advantages of the active disturbance rejection controller; secondly, the estimation accuracy of the extended state observer on the system disturbance is improved; thirdly, on the basis of excellent anti-interference capability of the traditional active disturbance rejection controller, the invention increases the feedforward of the conversion rate of the reference current, improves the current tracking precision of the system and improves the capability of compensating uncertain disturbance; fourthly, the improved novel extended state observer is applied to the current control of the permanent magnet synchronous motor, so that the current loop has higher response speed, smaller fluctuation and higher control precision, and the performance of the current loop is comprehensively improved.

Drawings

FIG. 1 is a schematic diagram of the architecture of a permanent magnet synchronous current controller based on an extended state observer according to the present invention;

FIG. 2 is a response curve of a current loop at a step input;

fig. 3 is a graph of the tracking response of the current loop with a sinusoidal input.

Detailed Description

The invention is further described below with reference to the accompanying drawings. The following examples are only for illustrating the technical solutions of the present invention more clearly, and the protection scope of the present invention is not limited thereby.

As shown in fig. 1, the present invention provides a method for designing a permanent magnet synchronous current controller based on an extended state observer, wherein an improved extended state observer is designed based on a conventional active disturbance rejection controller, and a disturbance term of the extended state observer is compensated to an improved active disturbance rejection controller of a current loop, so that an anti-interference capability of a system and an estimation precision value of system disturbance are improved; the 'reference current transformation rate feedforward' is added, the current tracking precision of the system is improved, and the uncertain disturbance compensation capability is improved.

The invention specifically comprises the following steps:

step SS 1: building a current loop active disturbance rejection controller closed loop;

step SS 2: determining that a current loop of the permanent magnet synchronous motor can be approximately decoupled and linearized, detecting by a current sensor to obtain two-phase stator current of the permanent magnet synchronous motor, obtaining direct-axis current and quadrature-axis current of the permanent magnet synchronous motor through Clarke transformation and Park transformation, and establishing a current loop mathematical model of the PMSM in a two-phase rotating coordinate system, namely a d-q coordinate system;

step SS 3: designing 'reference current transformation rate feedforward' according to the quadrature axis current value;

step SS 4: and designing an improved active disturbance rejection controller of a current loop according to a compensation model of the total system disturbance observed by the first-order improved extended state observer.

As a preferred embodiment, the mathematical model of the permanent magnet synchronous motor in step SS2 on the d-q axis is:

the stator voltage equation is as follows:

u in the formulae (1-1) and (1-2)_d、u_qThe stator voltage d-axis component and the stator voltage q-axis component are respectively; i.e. i_d、 i_qThe stator current d-axis component and the stator current q-axis component are respectively; Ψ_d、Ψ_qRespectively are a stator flux linkage d-axis component and a stator flux linkage q-axis component; omega is electricityMachine rotor angular velocity;

the flux linkage equation is as follows:

Ψ_d＝L_di_d+Ψ_f(3-3)

Ψ_q＝L_qi_q(3-4)

l in the formulae (1-3) and (1-4)_d、L_qD-axis inductance and q-axis inductance of the stator winding are parameters irrelevant to the angular position theta of the rotor respectively; l is_d＝L_md+L₁,L_q＝L_mq+L₁Wherein L is_md、 L_mqIs the d-axis mutual inductance, q-axis mutual inductance, L, between stator and rotor₁Is the stator leakage inductance;

the electromagnetic torque equation is as follows:

Τ_em＝p(Ψ_di_q-Ψ_qi_d) (3-5)

the mechanical equation of motion is as follows:

r in the formula (1-6)_ΩIs a resistance coefficient, T_LIs the load torque;

according to a stator voltage equation and a mechanical motion equation, obtaining a permanent magnet synchronous motor state equation under a d-q coordinate system:

the formulas (1-7) and (1-8) are the current loop state equations of the permanent magnet synchronous motor, wherein L_d＝L_q＝L_aR is the stator coil resistance; l is the inductance component of the q-axis; Ψ_rIs a flux linkage generated by the permanent magnet; u. of_qIs the voltage of the q-axis; ω is the motor rotor angular velocity.

Servo control system for permanent magnet synchronous motorIn order to decouple the current, i is used_dThe vector control mode of the same or different from 0 can be obtained

Wherein R is the stator coil resistance; l is the inductance component of the q-axis; Ψ_rIs a flux linkage generated by the permanent magnet; u. of_qIs the voltage of the shaft; ω is the motor rotor angular velocity.

As a preferred embodiment, the compensation model of the total system disturbance observed by the first-order modified extended state observer in step SS4 specifically includes:

when the system shown by the permanent magnet synchronous motor current loop state equation considers that the system does not know external disturbance, the input quantity U is selected to be [ U ═ U%_du_q]^ΤAnd the output quantity Y ═ i_di_q]^ΤState variable X₁＝[i_di_q]^ΤAnd obtaining a standard form of current loop state equation of the permanent magnet synchronous motor:

where w is the unknown external disturbance of the system,

as can be seen from the formula (2-2), i_dThe stator exciting current i is realized to a certain extent by the current control method of 0_dAnd torque current i_qDecoupling of (1); using d, q-axis armature voltages u_d、u_qControlling d and q axis armature currents i_d、i_qSince the position of the rotor magnetic pole of the permanent magnet synchronous motor can be detected, the d-axis and q-axis armature voltages u_d、u_qIs controllable; however, in (2-2), the inductance parameter L_aThere is a more severe perturbation of the parameters, and furthermore the perturbation term ω i_q、

The existence of (2) also causes the characteristics of strong coupling and nonlinearity of the system; f (X)₁) And (3) regarding the system as internal disturbance, and taking the sum of internal disturbance and external disturbance of the system as an unknown part of the system and expanding the sum into a new state variable a (t): a (t) ═ f (i)_q,t)+w(t)；

The auto-disturbance rejection control model of the current loop can be expressed as:

i′_q＝a(t)+bu (3-13)

as a preferred embodiment, the current loop active disturbance rejection controller closed loop in step SS1 includes a tracking differential controller TD, a novel extended state observer ESO, a novel non-linear error feedback control law NSEF, and a controlled object, an output end of the tracking differential controller TD and an output end of the novel extended state observer ESO are respectively connected to an input end of the novel non-linear error feedback control law NSEF, an output end of the novel non-linear error feedback control law NSEF and an output end of the novel extended state observer ESO are respectively connected to an input end of the controlled object, and an output end of the controlled object is connected to an input end of the novel extended state observer ESO.

As a preferred embodiment, the current i is given_q ^*An output signal z of the tracking differential controller TD connected to an input terminal of the tracking differential controller TD₁₁With the output signal z of the novel extended state observer, ESO₂₁Comparing and outputting an error signal to the input end of the novel nonlinear error feedback control law NSEF, and outputting a signal z of the novel extended state observer ESO₂₂And a given current i_q ^*The differentiated compared output signal is divided by a compensation factor b₀Then comparing the output signal with the output signal of the novel nonlinear error feedback control law NSEF, outputting the output signal to a controlled object and outputting a controlled quantity i_qSaid controlled quantityi_qAnd flows back to the input end of the ESO.

As a preferred embodiment, the control function of the tracking derivative controller TD is:

wherein i_q ^*Setting a q-axis current loop of a permanent magnet synchronous motor system; z is a radical of₁₁Is i_q ^*The tracking signal of (2); r is₀Is a velocity factor; h is₀Is a filter factor; r is₀And h₀To schedule the speed of the transient.

As a preferred embodiment, the calculation model of the new extended state observer ESO is:

wherein z is₂₁To output i_qTracking signal of e₁For tracking error, z₂₂Is the observed value of the total disturbance signal w (t); β₁、β₂To extend the gain of the state observer α₀、α₁Is a non-linear factor;₁is the linear interval width of the nonlinear function; b₀Is an estimate of the compensation factor.

As a preferred embodiment, the calculation model of the new nonlinear error feedback control law NSEF is:

β₃gain for a novel nonlinear error feedback control rate, α₂Is a nonlinear factor of a novel nonlinear error feedback control law,₂is a filter factor of a novel nonlinear error feedback control law. The nonlinear error feedback control rate performs nonlinear calculation on the proportion, the integral and the differential of the error signal, thereby improving the control precision of the systemAnd the noise immunity of the system is enhanced.

As a preferred embodiment, step SS2 specifically includes: increasing the "reference current transformation rate feed forward", perturbing f (i) according to the sum_qT) can be a first order nonlinear system of formula i'_qA (t) + bu is compensated to a "first order pure integrator-tandem system", i.e.:

i'_q＝u₀(3-17)

at a given current i_q ^*In the known case, the reference current transformation ratio, i.e. the set current i, can be determined first_q ^*And assigning this value to the intermediate control quantity u₀And thus the controlled quantity i_qI.e. the actual current, can track the given current i well_q ^*。

In this example, the following subjects were subjected to simulink modeling and simulation studies using an auto-disturbance rejection controller. The parameters of the improved active disturbance rejection controller of the present embodiment are shown in table 1.

TABLE 1 parameters of ADRC

In simulation, the current control system of the permanent magnet synchronous motor is compared between the traditional active disturbance rejection control and the improved active disturbance rejection control, and fig. 2 and 3 respectively show a response curve of a current loop at step input and a tracking response curve of the current loop under the action of sine input.

The above description is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, several modifications and variations can be made without departing from the technical principle of the present invention, and these modifications and variations should also be regarded as the protection scope of the present invention.