阅读说明：本技术 航空柱塞泵用内嵌式永磁同步电机的多重抗扰控制方法 (Multiple anti-interference control method of embedded permanent magnet synchronous motor for aviation plunger pump ) 是由 骆光照 王涛鸣 刘春强 黄晓东 陈寿洛 于 2021-08-31 设计创作，主要内容包括：本发明涉及一种航空柱塞泵用内嵌式永磁同步电机的多重抗扰控制方法,针对航空柱塞泵负载特性建立了离散域模型,并提出了泵用内嵌式永磁同步电机的高性能转速控制方法。本发明设计的泵电机转速控制器由自适应准比例积分谐振转速控制器和Luenberger动态带宽负载转矩观测器组成,能够分别解决航空柱塞泵周期脉动载荷造成的驱动电机稳态转速高频波动问题和航空柱塞泵非周期冲击载荷造成的驱动电机转速跟踪误差突增问题,具有系统高可靠性、高稳定性、强抗扰性等优点。(The invention relates to a multiple anti-interference control method of an embedded permanent magnet synchronous motor for an aviation plunger pump, which is used for establishing a discrete domain model aiming at the load characteristic of the aviation plunger pump and providing a high-performance rotating speed control method of the embedded permanent magnet synchronous motor for the pump. The pump motor rotating speed controller designed by the invention consists of an adaptive quasi-proportional-integral resonance rotating speed controller and a Luenberger dynamic bandwidth load torque observer, can respectively solve the problem of high-frequency fluctuation of the steady-state rotating speed of a driving motor caused by periodic pulsating load of an aviation plunger pump and the problem of sudden increase of the tracking error of the rotating speed of the driving motor caused by non-periodic impact load of the aviation plunger pump, and has the advantages of high reliability, high stability, strong interference resistance and the like of a system.)

1. A multiple anti-interference control method of an embedded permanent magnet synchronous motor for an aviation plunger pump is characterized by comprising the following steps:

step 1: collecting the rotor angular speed omega and the rotating speed angle theta of the permanent magnet synchronous motor and the stator three-phase current i of the motor_a、i_b、i_cPerforming coordinate transformation to obtain a current component i in a rotating coordinate system_d、i_qAnd calculating the electromagnetic torque value T_e；

Step 2: the load characteristics of an aviation plunger pump were modeled as:

wherein, T_total(k) Is the aviation plunger pump load characteristic;non-periodic impact load of the aviation plunger pump;the periodic pulsating load of the aviation plunger pump is provided;

step 3, designing a self-adaptive quasi proportional integral resonance controller: for the cyclic pulsating load of the aviation plunger pumpDesigning an adaptive quasi proportional integral resonance controller:

(3.1) calculating according to mechanical parameters of the aviation plunger pump to obtain the real-time resonant frequency of the periodic pulsating load of the aviation plunger pump:

wherein z is the number of plungers of the aviation plunger pump, omega is the rotation angular velocity of the aviation plunger pump, and f₁、f₂The real-time resonant frequencies of periodic pulsating loads of even number plungers and odd number plungers respectively;

(3.2) setting the angular speed omega and the angular speed omega of the rotor obtained in the step 1 to be given values^*Making a difference to obtain an angular velocity feedback error delta omega, and designing a self-adaptive quasi proportional integral resonance controller in an s domain, wherein the input of the controller is the angular velocity feedback error delta omega, and the output is a stator current given valueThe expression is as follows:

in the formula, the resonance angular frequency omega₀Can be calculated according to the real-time resonance frequency to obtain omega₀＝2πf_i,i＝1 or 2，K_pAs a proportional parameter, K_iAs integral parameter, K_rAs a resonance parameter, ω_bIn order to be a resonance bandwidth,setting a stator current value;

by controlling stator current set-pointRealize to the periodic pulsating load of the aviation plunger pumpThe control of (2) is, under steady state conditions,andthe relation of (A) is as follows:

in the formulaWherein p is the number of pole pairs of the motor,is a permanent magnet flux linkage;

and 4, step 4: needleTo the non-periodic impact load of the aviation plunger pumpDesigning a Luenberger dynamic bandwidth load torque observer to observe the load torque observer, wherein the expression of the observer is as follows:

in the formula (I), the compound is shown in the specification,respectively, an angular velocity observation and a load torque observation, J, B_mRespectively, the inertia coefficient and the friction coefficient of the permanent magnet synchronous motor, T_eIs an electromagnetic torque, k₁、k₂Is the observer gain coefficient;

observed value of aperiodic impact loadNamely the aperiodic impact load of the aviation plunger pump

And 5: obtained according to step 3 and step 4Andobtaining corrected stator current set value through calculation

Then will beObtaining a given value of dq axis stator current through MTPA operationAndwherein, MTPA operational formula is as follows:

in the formula (I), the compound is shown in the specification,is a permanent magnet flux linkage, L_q、L_dRespectively representing q-axis inductance and d-axis inductance, and sgn represents a sign function;

step 6: setting the dq axis stator current obtained in the step 5Andoutputting a dq-axis voltage set value through a current controllerAndobtaining the given voltage value under the static rotating coordinate system through coordinate transformationAndand will beAndand SVPWM is input for pulse width modulation, PWM waves are output for triggering an inverter, and multiple anti-interference control of the embedded permanent magnet synchronous motor for the aviation plunger pump is realized.

2. The multiple anti-interference control method of the embedded permanent magnet synchronous motor for the aviation plunger pump according to claim 1, is characterized in that: the periodic pulsation load of the aviation plunger pump in the step 2 is obtained by taking a derivative of instantaneous pulsation flow to time, and the expression of a discrete domain is as follows:in the formula, K is a proportionality coefficient,is a single-cycle pulsating flow change value and has the expression of Andrespectively representing the pulsating flow at time k and at time k-1, and deltat is the period interval time.

3. The multiple anti-interference control method of the embedded permanent magnet synchronous motor for the aviation plunger pump according to claim 1, is characterized in that: the discrete domain model of the aperiodic impact load in the step 2 is as follows: the aperiodic impact load of the aviation plunger pump is composed of an external impact main load and an internal additional load, wherein the internal additional load comprises a sliding friction load, a viscous friction load and a rolling friction load, and the expression is as follows:

wherein d (k) is the external impact main load of the aviation plunger pump, delta T_t(k) For the internal additional load, the expression Δ T_t(k)＝T_f(k)+T_v(k)+T_s(k) Wherein T is_f(k) For sliding friction loads, T_v(k) For viscous friction loads, T_s(k) Is a rolling friction load.

4. The multiple anti-interference control method of the embedded permanent magnet synchronous motor for the aviation plunger pump according to claim 1, is characterized in that: the gain coefficient k of the Luenberger dynamic bandwidth load torque observer in the step 4₁、k₂The acquisition mode is as follows:

1) establishing observer characteristic equationObtaining an initial gain coefficient k 'according to a characteristic equation'₁And k'₂Expression (c):

k′₁＝Jω‘

where ω' is the set observer bandwidth, B_mIs the friction coefficient of the motor, and J is the inertia coefficient of the motor;

2) according to the initial gain coefficient k'₁And k'₂Establishing a gain coefficient k based on a hyperbolic tangent function₁、k₂The expression is as follows:

in the formula, beta₁、β₂、c₁、c₂All the components are proportional coefficients and are provided with a constant,an error is estimated for the rotational speed of the observer.

Technical Field

The invention belongs to the technical field of motor drive control, and relates to a multiple anti-interference control method of an embedded permanent magnet synchronous motor for an aviation plunger pump.

Background

Aviation plunger pump motor system background: in order to ensure that the aero-engine runs smoothly and conducts high temperature generated by friction in time, the aero-lubricating oil system is required to convey aero-lubricating oil to an engine rotating part rapidly and uninterruptedly, so that the long-time fault-free operation of the engine is ensured. Because the plunger pump has the advantages of easy adjustment of discharge capacity, high power, high reliability and the like, the plunger pump is usually adopted as a main pressure supply pump source in a lubricating oil supply system. Under the influence of the concept of 'power by wire' of a multi-electric airplane, the current development trend is to use a permanent magnet synchronous motor with high power density and high reliability as a power source of a plunger pump. Compared with a centralized traditional mechanical pump system, the distributed motor pump system composed of the permanent magnet synchronous motor, the plunger pump, the digital controller and the high-performance control strategy avoids complex and lengthy couplers and motion conversion mechanisms, and has the advantages of saving construction cost and using space. However, considering that the plunger pump operates under high pressure and high speed conditions, any disturbance may damage the stability of the system, thereby causing serious aviation accidents, and therefore, in order to maintain the high-performance and high-reliability control characteristics of the embedded permanent magnet synchronous motor for the aviation plunger pump, a high-performance control strategy needs to be designed for the load characteristics of the aviation plunger pump.

The load characteristic and the control technical status of the plunger pump motor: the plunger of the plunger pump reciprocates in the plunger hole of the cylinder body to realize oil absorption and oil discharge. The instantaneous flow rate of the oil is related to the number of plungers and the rotation speed of the cylinder. The product of the cylinder body rotating speed and the time represents the cylinder body rotating angle, when the angle changes, the axial displacement distance and the moving speed of the plunger change correspondingly, and therefore the instantaneous output flow of the pump in one working period generates a periodic pulsation phenomenon along with the change of the rotating angle. The periodic flow pulsation reflects a high frequency load torque on the motor shaft. Meanwhile, the load characteristics of the plunger pump are classified into periodic pulsating load and non-periodic impact load in consideration of the influence of sudden displacement change and external disturbance caused by the inclination angle of the swash plate of the plunger pump. At present, the main solution of the periodic flow pulsation and the pressure pulsation of the plunger pump is realized by changing the mechanical structure of the plunger pump or adding a mechanical compensation device, the realization cost of the method is high, the power-weight ratio of the plunger pump is reduced, and the method is not beneficial to the system level design of aviation lubricating oil. In order to compensate the non-periodic impact load of the pump motor in real time and improve the anti-interference performance of a control system, a sliding mode controller, a fuzzy controller and other non-linear controllers are generally adopted. The sliding mode controller has quick response performance, and when the control parameters reach the sliding mode surface, the control parameters generate shaking around the sliding mode surface, so that the control parameters are not beneficial to stable control. In addition, the fuzzy controller needs to design the fuzzy rule based on experience, and the stability cannot be guaranteed.

The control strategy of the motor system of the aviation plunger pump has the following problems: 1) the method comprises the following steps of (1) modeling the load characteristics of the aviation plunger pump, 2) compensating the periodic pulsating load disturbance of the aviation plunger pump, and 3) compensating the non-periodic impact load disturbance of the aviation plunger pump.

Disclosure of Invention

Technical problem to be solved

In order to avoid the defects of the prior art, the invention provides a multiple anti-interference control method of an embedded permanent magnet synchronous motor for an aviation plunger pump, which aims to solve the following problems: 1) the method comprises the following steps of (1) modeling the load characteristics of the aviation plunger pump, 2) compensating the periodic pulsating load disturbance of the aviation plunger pump, and 3) compensating the non-periodic impact load disturbance of the aviation plunger pump.

Technical scheme

A multiple anti-interference control method of an embedded permanent magnet synchronous motor for an aviation plunger pump is characterized by comprising the following steps:

step 1: collecting the rotor angular speed omega and the rotating speed angle theta of the permanent magnet synchronous motor and the stator three-phase current i of the motor_a、i_b、i_cPerforming coordinate transformation to obtain a current component i in a rotating coordinate system_d、i_qAnd calculating the electromagnetic torque value T_e；

Step 2: because the instantaneous flow of the aviation plunger pump has a periodic pulsation characteristic, and the influence of instantaneous impact load is considered, the load characteristic of the aviation plunger pump is modeled as follows:

wherein, T_total(k) Is the aviation plunger pump load characteristic;non-periodic impact load of the aviation plunger pump;the periodic pulsating load of the aviation plunger pump is provided;

step 3, designing a self-adaptive quasi proportional integral resonance controller: calculating according to mechanical parameters of the aviation plunger pump to obtain real-time resonance frequency of periodic pulsating load, designing a self-adaptive quasi-proportional-integral resonance controller by using the real-time resonance frequency, and aiming at the periodic pulsating load of the aviation plunger pumpDesigning an adaptive quasi proportional integral resonance controller:

(3.1) calculating according to mechanical parameters of the aviation plunger pump to obtain the real-time resonant frequency of the periodic pulsating load of the aviation plunger pump:

wherein z is the number of plungers of the aviation plunger pump, omega is the rotation angular velocity of the aviation plunger pump, and f₁、f₂The real-time resonant frequencies of periodic pulsating loads of even number plungers and odd number plungers respectively;

(3.2) setting the angular speed omega and the angular speed omega of the rotor obtained in the step 1 to be given values^*Making a difference to obtain an angular velocity feedback error delta omega, and designing a self-adaptive quasi proportional integral resonance controller in an s domain, wherein the input of the controller is the angular velocity feedback error delta omega, and the output is a stator current given valueThe expression is as follows:

in the formula, the resonance angular frequency omega₀Can be calculated according to the real-time resonance frequency to obtain omega₀＝2πf_i,i＝1or 2，K_pAs a proportional parameter, K_iAs integral parameter, K_rAs a resonance parameter, ω_bIn order to be a resonance bandwidth,setting a stator current value;

by controlling stator current set-pointRealize to the periodic pulsating load of the aviation plunger pumpThe control of (2) is, under steady state conditions,andthe relation of (A) is as follows:

in the formulaWherein p is the number of pole pairs of the motor,is a permanent magnet flux linkage;

and 4, step 4: electromagnetic torque T obtained according to step 1_eDesigning an observer model by using a motion equation of the permanent magnet synchronous motor, and using the rotating speed observation error to drive gain change so as to obtain an observed value of the impact load and an observed value of the angular speed of the motor;

aiming at the non-periodic impact load of the aviation plunger pumpDesigning a Luenberger dynamic bandwidth load torque observer to observe the load torque observer, wherein the expression of the observer is as follows:

in the formula (I), the compound is shown in the specification,respectively, an angular velocity observation and a load torque observation, J, B_mRespectively, the inertia coefficient and the friction coefficient of the permanent magnet synchronous motor, T_eIs an electromagnetic torque, k₁、k₂Is the observer gain coefficient;

observed value of aperiodic impact loadNamely the aperiodic impact load of the aviation plunger pump

And 5: obtained according to step 3 and step 4Andobtaining corrected stator current set value through calculation

Then will beObtaining a given value of dq axis stator current through MTPA operationAndwherein, MTPA operational formula is as follows:

in the formula (I), the compound is shown in the specification,is a permanent magnet flux linkage, L_q、L_dRespectively representing q-axis inductance and d-axis inductance, and sgn represents a sign function;

step 6: setting the dq axis stator current obtained in the step 5Andoutputting a dq-axis voltage set value through a current controllerAndobtaining the given voltage value under the static rotating coordinate system through coordinate transformationAndand will beAndand SVPWM is input for pulse width modulation, PWM waves are output for triggering an inverter, and multiple anti-interference control of the embedded permanent magnet synchronous motor for the aviation plunger pump is realized.

The periodic pulsation load of the aviation plunger pump in the step 2 is obtained by taking a derivative of instantaneous pulsation flow to time, and the expression of a discrete domain is as follows:in the formula, K is a proportionality coefficient,is a single-cycle pulsating flow change value and has the expression of Andrespectively representing the pulsating flow at time k and at time k-1, and deltat is the period interval time.

The discrete domain model of the aperiodic impact load in the step 2 is as follows: the aperiodic impact load of the aviation plunger pump is composed of an external impact main load and an internal additional load, wherein the internal additional load comprises a sliding friction load, a viscous friction load and a rolling friction load, and the expression is as follows:

wherein d (k) is the external impact main load of the aviation plunger pump, delta T_t(k) For the internal additional load, the expression Δ T_t(k)＝T_f(k)+T_v(k)+T_s(k) Wherein T is_f(k) For sliding friction loads, T_v(k) For viscous friction loads, T_s(k) Is a rolling friction load.

The gain coefficient k of the Luenberger dynamic bandwidth load torque observer in the step 4₁、k₂The acquisition mode is as follows:

1) establishing observer characteristic equationObtaining an initial gain coefficient k 'according to a characteristic equation'₁And k'₂Expression (c):

k′₁＝Jω‘

where ω' is the set observer bandwidth, B_mIs the friction coefficient of the motor, and J is the inertia coefficient of the motor;

2) according to the initial gain coefficient k'₁And k'₂Establishing a gain coefficient k based on a hyperbolic tangent function₁、k₂The expression is as follows:

in the formula, beta₁、β₂、c₁、c₂All the components are proportional coefficients and are provided with a constant,an error is estimated for the rotational speed of the observer.

Advantageous effects

The invention provides a multiple anti-interference control method of an embedded permanent magnet synchronous motor for an aviation plunger pump, which establishes a discrete domain model aiming at the load characteristic of the aviation plunger pump and provides a high-performance rotating speed control method of the embedded permanent magnet synchronous motor for the pump. The pump motor rotating speed controller designed by the invention consists of an adaptive quasi-proportional-integral resonance rotating speed controller and a Luenberger dynamic bandwidth load torque observer, can respectively solve the problem of high-frequency fluctuation of the steady-state rotating speed of a driving motor caused by periodic pulsating load of an aviation plunger pump and the problem of sudden increase of the tracking error of the rotating speed of the driving motor caused by non-periodic impact load of the aviation plunger pump, and has the advantages of high reliability, high stability, strong interference resistance and the like of a system.

The method mainly divides the load characteristics into periodic pulsating load and aperiodic impact load according to the structure and the motion characteristics of the aviation plunger pump, so that a high-performance controller is designed in a targeted manner for compensation, and the strong stability, strong interference rejection and high reliability control of an aviation plunger pump motor system are realized.

Compared with the prior art, the method has the beneficial effects that:

(1) by combining the characteristics of the aviation plunger pump, the load torque of the drive motor for the pump is summarized into periodic pulsating load and non-periodic impact load, so that a high-performance controller can be conveniently designed according to different load characteristics.

(2) Aiming at the periodic pulsating load, the resonance frequency of the pulsating load is acquired in real time by using a self-adaptive method, and the rotation speed fluctuation of the pump motor caused by the periodic pulsating load is reduced by adopting a quasi-proportional-integral resonance controller, so that the operation reliability of the electric pump system is improved.

(3) Aiming at the non-periodic impact load, a Luenberger dynamic bandwidth load torque observer is designed, the non-periodic impact load of the pump motor is compensated in real time, and the rotating speed tracking performance and the anti-interference performance of the pump motor to the impact load are improved.

Drawings

FIG. 1: control framework of embedded permanent magnet synchronous motor for aviation plunger pump

FIG. 2: periodic pulsating load waveform of motor of aviation plunger pump

FIG. 3: quasi-proportional resonant controller Bode diagram

FIG. 4: driving motor steady state speed comparison

FIG. 5: gain change of dynamic bandwidth load torque observer based on hyperbolic tangent function

FIG. 6: estimated load torque waveform based on Luenberger dynamic bandwidth load torque observer

FIG. 7: comparison of rotation speed waveforms of starting and loading conditions of driving motor

FIG. 8: comparison of rotation speed waveforms during sudden interference of driving motor

Detailed Description

The invention will now be further described with reference to the following examples and drawings:

the control strategy of the motor system of the aviation plunger pump has the following problems: 1) the method comprises the following steps of (1) modeling the load characteristics of the aviation plunger pump, 2) compensating the periodic pulsating load disturbance of the aviation plunger pump, and 3) compensating the non-periodic impact load disturbance of the aviation plunger pump.

The multiple anti-interference control method of the motor for the aviation plunger pump is technically characterized by comprising the following aspects:

(1) and (3) modeling the load characteristic of the aviation plunger pump. The basic principle is as follows:

if the number of plungers of the axial plunger pump is z, the diameter of the plungers is D, the diameter of a distribution circle of plunger holes is D, the included angle between the axis of the swash plate and the axis of the cylinder body is beta, and when the cylinder body rotates for one circle, the displacement of the pump can be expressed as

From the equation, it can be seen that adjusting the displacement of the pump can only be achieved by changing the inclination angle of the swash plate. In a fixed displacement piston pump, the inclination of the swashplate does not change, so that β is assumed to be constant in the following derivation.

When the cylinder body turnsWhen the axial displacement S of the plunger is

The above formula is used for obtaining the derivative of the time variable t to obtain the instantaneous moving speed V of the plunger

So that the instantaneous flow rate of a single plunger is

As shown in (4), the instantaneous flow rate of the single plunger changes according to a sine law. When the hydraulic pump is provided with z plungers, the included angle between the plungers isThe instantaneous theoretical flow rate of each plunger of all the pressurized oil areas is

In the formula, q₁、q₂、q_mInstantaneous theoretical flow of each plunger in a pressure oil area; m is the number of plungers in the process of pressing oil.

The total instantaneous flow of the plunger pump is the sum of all plunger instantaneous flows of the pressurized oil zone. So that the total instantaneous flow rate is

Assuming a sinusoidal pulse functionAs can be seen from the simplification, when the number of the plungers is even, the instantaneous pulsating flow of the plunger pump is

When the number of the plungers is odd, the instantaneous pulsating flow of the plunger pump is

As can be seen from equation (6), the instantaneous flow rate is proportional to the angular velocity. By deriving the formula (7) or (8), it is possible to obtain

As can be seen from equation (9), the derivative of the instantaneous pulsating flow rate is proportional to the plunger pump cylinder angular acceleration a'. According to the rotation law, the periodic pulsating load is generated under the influence of the angular acceleration a' of the cylinder body of the plunger pump, and the angular acceleration and the pulsating load are in a proportional relation, so that a motor periodic pulsating load model can be established

Wherein K is a proportionality coefficient,the flow difference between adjacent time intervals is shown as Δ t.

The non-periodic impact load of the plunger pump has the characteristic of uncertain time and amplitude, and meanwhile, the non-periodic impact load of the aviation plunger pump is classified into an external impact main load and an internal additional load by considering the friction force between internal machinery and liquid of the plunger pump. Assuming that the impact load acting time is the kth sampling period, the expression of the non-periodic impact load of the pump motor based on the discrete domain is

Wherein d (k) is the external impact main load of the aviation plunger pump, delta T_t(k) For the internal additional load under the influence of said external impact, the expression Δ T_t(k)＝T_f(k)+T_v(k)+T_s(k) Wherein T is_f(k) For sliding friction loads, T_v(k) For viscous friction loads, T_s(k) Is a rolling friction load.

The periodic pulsating load is discretized by using an Euler equation, so that the total load torque of the aviation plunger pump motor in a discrete domain is expressed as

Single cycle pulsating flow variation valueΔ t is the interval time.

(2) According to modeling of load characteristics of the aviation plunger pump, the change frequency of the periodic pulsating load is in direct proportion to the mechanical angular speed of the motor, namely the faster the angular speed of the motor is, the faster the change frequency of the pulsating load is. Therefore, the motor rotor side is subjected to periodic pulsation load, and then periodic rotation speed fluctuation is generated, which tends to cause instability of a control system for driving the motor. In order to solve the problems, an adaptive quasi proportional integral resonance rotating speed controller of a rotating speed ring is designed for the periodic pulsating load of a plunger pump.

The motor periodic pulsating load compensation method for the aviation plunger pump based on the self-adaptive quasi-proportional-integral resonance controller has the following basic principle:

when the number of the plungers of the plunger pump is z and the angular velocity is omega, the resonant frequency of the periodic pulsating load of the plunger pump is

Considering that the ideal proportional resonant controller only acts on a single resonant angular frequency, and in practical application, the signal acquisition frequency is shifted by noise, circuit delay and other factors, an adaptive quasi-proportional resonant controller is designed around the main resonant frequency f, and the transfer function of the adaptive quasi-proportional resonant controller is

In the formula of omega_bFor the resonance bandwidth, the resonance frequency ω can be tuned₀Peripheral omega_bSignals in the frequency range play a role; k_pIs a proportionality coefficient; k_rIs the resonance coefficient. Wherein, referring to the periodic pulsating load characteristic of the plunger pump, the resonant frequency of the resonant controller is taken as omega₀＝2πf_i，i＝1 or 2。

In order to realize the static-error-free control of the rotating speed, the designed self-adaptive quasi-proportional resonant controller and the proportional-integral controller are combined into the self-adaptive quasi-proportional-integral resonant controller, and the transfer function of the self-adaptive quasi-proportional-integral resonant controller is

Wherein K_pAnd K_iProportional and integral coefficients of the controller, respectively.

The expression for establishing the adaptive quasi-proportional-integral resonance controller by the formula (15) is

Where delta omega is the error of the given speed and the feedback speed,the stator current is given. The adaptive quasi-proportional-integral resonance controller weakens the periodic pulsating load by controlling the given value of the stator currentThe influence on the rotating speed, under the steady state working condition, the relation between the given current value and the periodic pulsating load isK_tAre parameter items.

(3) A motor non-periodic impact load disturbance compensation method for an aviation plunger pump based on a Luenberger dynamic bandwidth load torque observer is based on the following principle:

as can be seen from equation (11), the non-periodic impact load of the plunger pump can be regarded as a step signal for the drive motor. In order to realize the strong tracking performance of small impact load and the strong anti-interference performance of large impact load, the Luenberger dynamic bandwidth load torque observer is designed to estimate load torque in real time and carry out feedforward compensation, so that the control performance of the electric pump system is improved.

The motor equation of motion is as follows:

wherein J is moment of inertia; omega is the mechanical angular speed of the motor; b is_mIs the coefficient of friction; t is_LIs the load torque; t is_eIs an electromagnetic torque. The relation between the angular speed omega of the motor and the mechanical position angle theta is

According to the motion equation, the following state equation is obtained by taking the motor load torque and the motor mechanical angular velocity as state variables and taking the speed as an output variable

Based on equation (17), a load torque observer model is established as follows

Wherein the observed value of the load torque is related to the non-periodic impact load

From the observed valueThe compensation value of the given value of the stator current can be deduced through a formula.

The observer error state equation obtained by subtracting the equations (18) and (19) is

The characteristic equation of the observer can be obtained as

Setting initial gain to k 'according to equation (20)'₁＝Jω‘，The stability of the observer is ensured. Since the amplitude and the application time of the impact load are unknown, the gains of the designed dynamic bandwidth observer are respectively as follows based on the initial gain coefficientb and c are coefficients, k'₁And k'₂Respectively, initial gain. The design has the advantages that the rotating speed error can be rapidly reduced under the condition of large impact load, and the large-load torque and strong anti-interference performance can be realized; the rotating speed overshoot is avoided under the condition of small impact load, the rotating speed tracking is kept, and the strong tracking control performance of the rotating speed is realized.

The invention will now be further described with reference to the accompanying drawings and examples:

since the periodic pulsation load is only related to the number of plungers and the flow pulsation frequency, the aviation plunger pump with the number of plungers being 10 is taken as a research object in the embodiment of the invention, specific parameters of the embedded permanent magnet synchronous motor for driving are shown in table 1, and a control system framework is shown in fig. 1.

TABLE 1 drive-used Embedded PMSM parameters

The embodiment comprises the following specific steps:

1. according to the formula (10), a discretized periodic pulsating load model of the aviation plunger pump is established as shown in the following formula

In the formulaAnd isΔt＝t(k)-t(k-1)。

If the given rotation speed of the drive motor is a piecewise linear function, as shown in the following equation, the periodic pulsating load variation waveform is shown in fig. 2.

2. From equation (13), the resonant frequency of the plunger pump in the k-th sampling period is as follows

Quasi-proportional resonant controller designed based on resonant frequency as follows

In the formula of omega₀＝2πf₁. Assuming a quasi-proportional resonant controller parameter of K_p＝5，K_r＝30，ω_b50. The Bode diagram of the controller is shown in fig. 3. The graph shows that the designed quasi-proportional resonant controller has larger amplitude at the resonant frequency and better harmonic suppression effect, and the system phase margin is-45 deg, thereby meeting the system stable phase margin of industrial requirements.

And adding the designed quasi-proportional resonant controller and the proportional-integral controller to obtain the self-adaptive quasi-proportional-integral resonant controller. When the given rotating speed is 3000rpm, the rotating speed control waveforms of the proportional-integral controller and the adaptive quasi-proportional-integral resonance controller under the steady-state working condition are shown in FIG. 4. As can be seen from the figure, the fluctuation of the rotating speed of the proportional-integral controller under the influence of the periodic pulsating load in a steady state is 1rpm, while the fluctuation of the rotating speed of the adaptive quasi-proportional-integral resonant controller is only 0.4rpm, so that the periodic high-frequency fluctuation of the rotating speed can be effectively reduced.

3. The Luenberger dynamic bandwidth-based load torque observer is designed according to the formula (18), and the model is as follows

The electromagnetic torque and the mechanical angular speed of the motor are input values, the load torque estimation value is an output value, and feedforward compensation is carried out on the input of the inner loop controller so as to improve the anti-interference performance of the speed loop. The gain coefficient of the dynamic bandwidth load torque observer is constructed based on the hyperbolic tangent function, the change trend is shown in fig. 5, and it can be known that the gain is increased along with the increase of the rotation speed error, and the fast compensation of the high-amplitude non-periodic impact load is facilitated.

Assuming a 16Nm load disturbance at 9s, the estimated load torque value of the load torque observer is shown in fig. 6. Therefore, the load torque observer can quickly estimate the sudden non-periodic impact load, and the accuracy is high. The rotational speed waveforms for the start and load conditions are shown in FIG. 7. The figure shows that the starting overshoot of the self-adaptive quasi-proportional-integral resonance controller is smaller during starting, and the high-precision rotating speed tracking control of the plunger pump is facilitated. Fig. 8 is a waveform of the motor rotation speed under the influence of the non-periodic impact load. As can be seen from the figure, when the load of 16Nm is suddenly added, the combined control of the adaptive quasi proportional integral resonance controller and the Luenberger dynamic bandwidth load torque observer has a smaller rotating speed drop amplitude which is only 5rpm, and the rotating speed adjusting back speed is faster; the rotating speed falls to 7rpm under the action of the self-adaptive quasi-proportional-integral resonance controller, and the rotating speed adjusting back time is longer; the speed drop of the proportional-integral controller is larger and is 14 rpm. Therefore, the combined control of the adaptive quasi-proportional-integral resonance controller of the permanent magnet synchronous motor for driving and the Luenberger dynamic bandwidth load torque observer has the best compensation effect on periodic pulsating load and non-periodic impact load of the aviation plunger pump, and has strong stability and strong anti-interference control performance.