A permanent magnet synchronous motor speed control method

Abstract

The invention discloses a speed control method for a permanent magnet synchronous motor. The method comprises: firstly designing an adaptively switched extended state observer of the permanent magnet synchronous motor and adding it to the speed loop control process; then inputting the speed of the permanent magnet synchronous motor and the q-axis current reference value output by the speed loop into the extended state observer, and simultaneously performing adaptive parameter switching control, outputting the observed values ​​of the speed and lumped disturbance after processing, so as to continue the speed loop control and realize the speed control of the permanent magnet synchronous motor. The method of the invention can improve the dynamic and steady-state performance of the permanent magnet synchronous motor under inertia mismatch, weaken the overshoot of the motor in the dynamic process, greatly speed up the response speed, reduce the speed fluctuation and oscillation in the adjustment process, reduce the dependence of the motor control system parameter design on the rotational inertia parameters, and at the same time enhance the estimation ability of the fast-changing lumped disturbance, and can cope with more complex lumped disturbance types.

Description

Technical Field

[0001] The invention relates to a motor control method, in particular to a permanent magnet synchronous motor speed control method. Background Art

[0002] Permanent magnet synchronous motors have been widely used in industry due to their reliable operation, high power density, and high efficiency. Typical permanent magnet synchronous motor speed control systems use field-oriented control, which is usually composed of a speed loop and a current loop. Among them, the speed loop adjusts the motor's drive output based on speed feedback and plays an important role in adjusting the motor's speed regulation performance. Common speed loop control strategies, such as proportional-integral control PI (proportional-integral), have a high dependence on the moment of inertia parameters. However, in actual applications in aerospace, industrial robots, CNC machine tools, and other fields, the total load inertia equivalent to the motor side is usually much larger than the motor's body moment of inertia, that is, inertia mismatch. If the load inertia is unknown at this time, and the speed loop controller is designed based only on the motor's moment of inertia, the dynamic and steady-state performance of the motor system will be significantly reduced, mainly including increased overshoot, longer adjustment time, oscillation, and reduced anti-disturbance performance. When the inertia mismatch is more serious, the control system may even be out of control.

[0003] In recent years, the extended state observer (ESO) has attracted widespread attention due to its superior performance. The extended state observer (ESO) can treat internal uncertainties and external disturbances including moment of inertia mismatch as lumped disturbances, and observe and feedforward compensate the lumped disturbances as the extended state of the controlled object in real time, which makes the permanent magnet synchronous motor speed control algorithm based on the extended state observer (ESO) have the advantages of strong anti-disturbance, high robustness and low model dependence. However, since the extended state observer (ESO) cannot quickly and accurately estimate the time-varying lumped disturbances including the moment of inertia, the control algorithm based on the extended state observer (ESO) is difficult to ensure that the permanent magnet synchronous motor system has good dynamic and steady-state performance when facing the inertia mismatch problem. In order to improve the convergence speed of the observer when tracking time-varying disturbances, some scholars have extended the extended state observer (ESO) to a high-order ESO containing an arbitrary-order disturbance model, which significantly improves the speed tracking performance of the permanent magnet synchronous motor when the parameter mismatch occurs. However, the convergence speed is slow, and the improvement of the dynamic performance of the motor under inertia mismatch is small.

[0004] It can be seen that under the condition of inertia mismatch, the existing speed control algorithm cannot achieve better dynamic and steady-state performance; how to design an efficient and simple motor speed control method to maintain good control performance under different inertia mismatches is still challenging. Summary of the invention

[0005] In order to solve the problems existing in the background technology, the present invention provides a permanent magnet synchronous motor speed control method. The method of the present invention can control the permanent magnet synchronous motor based on the extended state observer under the condition of system inertia mismatch, improve the dynamic control performance of the motor, the method has a simple structure, low parameter setting difficulty, and can still maintain good speed control dynamic and steady-state performance when dealing with the inertia mismatch problem.

[0006] The technical solution adopted by the present invention is:

[0007] The permanent magnet synchronous motor speed control method of the present invention comprises:

[0008] Step 1) Design an adaptively switched extended state observer (ESO) for the permanent magnet synchronous motor, and add the extended state observer (ESO) to the speed loop control process of the permanent magnet synchronous motor.

[0009] Step 2) During the control process of the permanent magnet synchronous motor, the speed of the permanent magnet synchronous motor and the q-axis current reference value output by the speed loop are input into the extended state observer ESO for processing, and at the same time, the extended state observer ESO is adaptively switched to control the parameters. After processing, the extended state observer ESO outputs the observed values ​​of the speed and the lumped disturbance, thereby continuing the speed loop control to realize the speed control of the permanent magnet synchronous motor.

[0010] In the step 1), the adaptively switched extended state observer ESO is as follows:

[0011] w m ^ =(3 pΨ f / 2 J 0) i qref + d ^

[0012] d ^ ´= d d ^ + h 1( w m ´- w m ^ ´)+ h 2( w m - w m ^ )- k 1 d ^

[0013] d d ^ ´= h 3( w m - w m ^ )- k 2 d d ^

[0014] in, w m and w m ´ are the speed and its derivative of the permanent magnet synchronous motor, w m ^ and w m ^ ´ are the speeds of the permanent magnet synchronous motors w m The observed value and its derivative, ^ It is only used as a symbolic representation to distinguish the original value from the observed value, and it is only used as a symbolic representation to distinguish the original value from the derivative value; d ^ and d ^ are the lumped disturbances of the speed loop control process of the permanent magnet synchronous motor d The observed values ​​and their derivatives, lumped disturbances d Mainly caused by inertia mismatch, friction and load torque, d d ^ and d d ^ are the lumped disturbances of the permanent magnet synchronous motor respectively. d The differential term d d Observations of and their derivatives; p is the number of pole pairs of the permanent magnet synchronous motor; P f is the permanent magnet flux of the permanent magnet synchronous motor; J 0 is the preset nominal moment of inertia of the permanent magnet synchronous motor; i qref It is the q-axis current reference value output by the speed loop of the permanent magnet synchronous motor; h 1. h 2 and h 3 are the first, second and third gain coefficients of the extended state observer ESO respectively; k 1 and k2 are the first and second parameters to be tuned of the extended state observer ESO.

[0015] In the extended state observer ESO, the first, second and third gain coefficients of the extended state observer ESO are configured according to the bandwidth configuration method, as follows:

[0016] [ h 1 h 2 h 3]=[3 w o 3 w o 2 w o 3 ]

[0017] in, w o is the bandwidth of the extended state observer ESO.

[0018] The lumped disturbance of the permanent magnet synchronous motor d as follows:

[0019] d =(3 pΨ f / 2 J -3 pΨ f / 2 J 0) i qref - Bw m / J - T L / J

[0020] in, J is the actual equivalent moment of inertia of the permanent magnet synchronous motor, including the motor moment of inertia and the load moment of inertia; B is the viscous friction coefficient; T L is the load torque of the permanent magnet synchronous motor.

[0021] The extended state observer ESO is further distinguished according to the difference between the first and second parameters to be adjusted. k 1 is greater than 0 and the second parameter to be adjusted k 2 is greater than 0, the extended state observer ESO is the dynamic observer ESO1, the purpose is to optimize the dynamic performance, speed up the dynamic response speed, and reduce overshoot; when the first parameter to be adjusted k 1 is greater than 0 and the second parameter to be adjusted kWhen 2 is equal to 0, the extended state observer ESO is the steady-state observer ESO2, the purpose of which is to optimize the steady-state performance and improve the disturbance suppression capability. The first parameters to be adjusted for the dynamic observer ESO1 and the steady-state observer ESO2 are k 1 is always equal. By designing adaptive switching control, the dynamic observer ESO1 is called in the dynamic situation, and the steady-state observer ESO2 is called in the steady-state situation, so as to obtain good dynamic and steady-state performance at the same time.

[0022] In the step 2), when the adaptive parameter switching control is performed, the first speed threshold is preset. d 1 and the preset second speed threshold d 2 Speed ​​error with permanent magnet synchronous motor e Compare and preset the first speed threshold d 1 is the boundary between the dynamic and steady states of the system, and the second speed threshold is preset d 2 is used to determine whether the steady-state error is within the system allowable range; to determine the state of the permanent magnet synchronous motor, and then perform adaptive switching control of the dynamic observer ESO1 and the steady-state observer ESO2, where: d 1> d 2, e = w mref - w m , w mref is the reference speed of the permanent magnet synchronous motor.

[0023] When the adaptive parameter switching control is performed, the first speed threshold is preset. d 1 and the preset second speed threshold d 2 Speed ​​error with permanent magnet synchronous motor e When the speed error is compared e The absolute value of | e |> d 1, the permanent magnet synchronous motor is in a dynamic process. At this time, the extended state observer ESO is switched to the dynamic observer ESO1, and the time accumulation value of the switching control process is t Set to zero; when | e |≤ d 1, the permanent magnet synchronous motor begins to enter the steady state process. At this time, when | e |≤ d 2, the speed error e Within the preset allowable speed range, there is no need to adjust the parameters, keep the current extended state observer ESO unchanged, and change the time accumulation value of the switching control process. t Set to zero when | e |> d 2, the speed error eIf the speed is not within the preset allowable speed range, the hysteresis comparison stage will be entered. Each time the hysteresis comparison stage is entered, the time accumulation value of the switching control process will be t Continue to accumulate, t = t +1, then the time accumulated value t and preset switching delay t d For comparison, t ≥ t d When , the permanent magnet synchronous motor enters the steady-state process, and the extended state observer ESO switches to the steady-state observer ESO2. t < t d When , the current extended state observer ESO is kept unchanged; the ESO type determined by the adaptive switching is used as the observer of this control cycle, and an adaptive switching control is performed in each speed control cycle of the permanent magnet synchronous motor.

[0024] In the step 2), the extended state observer ESO processes and outputs the observed values ​​of the speed and the lumped disturbance, and the observed values ​​of the speed and the lumped disturbance are further subjected to the speed loop control to control the speed of the permanent magnet synchronous motor. w m Observed value w m ^ and reference speed w mref The difference between the two is input into the linear error feedback control law in the speed loop control, and then the lumped disturbance of the speed loop control process of the permanent magnet synchronous motor is d Observed value d ^ Compensation is performed to obtain the q-axis current reference value output by the speed loop i qref ,as follows:

[0025] i qref =(2 J 0 / 3 pΨ f )×[ k p ( w mref - w m ^ )- d ^ ]

[0026] in, k p is the linear error feedback gain of the speed loop;

[0027] According to the q-axis current reference value output by the speed loop i qref Continue the adaptive parameter switching control of the next speed control cycle. In order to improve the dynamic performance of the system and enhance the dynamic and steady-state performance of the motor under the inertia mismatch condition, the speed loop controller is mainly composed of a linear error feedback control law and an adaptively switched extended state observer ESO.

[0028] The electronic device of the present invention comprises: a memory and a processor coupled to each other, wherein the memory stores program data, and the processor calls the program data to execute the method as described above.

[0029] The computer-readable storage medium of the present invention stores program data thereon, and when the program data is executed by a processor, the method described above is implemented.

[0030] The beneficial effects of the present invention are:

[0031] 1. The present invention optimizes the dynamic performance of the permanent magnet synchronous motor, has a faster dynamic response speed and a smaller overshoot, can weaken the overshoot of the motor in the dynamic process, greatly speed up the response speed, and reduce the speed fluctuation and oscillation in the adjustment process, and reduce the dependence of the motor control system parameter design on the moment of inertia parameters.

[0032] 2. The extended state observer ESO designed in the present invention adds an estimation term for the differential of the lumped disturbance, thereby enhancing the estimation capability of the extended state observer ESO for rapidly changing lumped disturbances and being able to cope with more complex lumped disturbance types.

[0033] 3. The present invention is directed to a permanent magnet synchronous motor speed control system with inertia mismatch, which can improve the dynamic and steady-state performance of the permanent magnet synchronous motor system under inertia mismatch and enhance the robustness of the system to rotational inertia parameters. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 Schematic diagram of the structure of a permanent magnet synchronous motor control system in an embodiment of the present invention;

[0035] Figure 2 It is a specific structural block diagram of the extended state observer ESO of the present invention;

[0036] Figure 3 is a flow chart of adaptive switching control of the present invention;

[0037] Figure 4 The waveform simulation comparison diagram of the permanent magnet synchronous motor using the traditional second-order extended state observer ESO and the adaptive switching extended state observer ESO proposed in the present invention when tracking the step speed reference signal, wherein: Figure 4(a) is the actual equivalent moment of inertia of the permanent magnet synchronous motor when tracking the step speed reference signal. J The preset nominal moment of inertia J 0 using the traditional second-order extended state observer ESO control waveform simulation diagram, Figure 4 (b) is the actual equivalent moment of inertia of the permanent magnet synchronous motor when tracking the step speed reference signal. J Six times the preset nominal moment of inertia J 0 using the traditional second-order extended state observer ESO control waveform simulation diagram, Figure 4 (c) is the actual equivalent moment of inertia of the permanent magnet synchronous motor when tracking the step speed reference signal. J The preset nominal moment of inertia J 0 is a waveform simulation diagram of the extended state observer ESO control using the adaptive switching proposed by the present invention, Figure 4 (d) is the actual equivalent moment of inertia of the permanent magnet synchronous motor when tracking the step speed reference signal. J Six times the preset nominal moment of inertia J 0 is a waveform simulation diagram of the extended state observer ESO control using the adaptive switching proposed by the present invention;

[0038] Figure 5 The waveform simulation comparison diagram of the permanent magnet synchronous motor using the traditional second-order extended state observer ESO and the adaptive switching extended state observer ESO proposed in the present invention when the step load torque is suddenly added, wherein: Figure 5 (a) is the actual equivalent moment of inertia of the permanent magnet synchronous motor when a step load torque is suddenly applied. J The preset nominal moment of inertia J 0 using the traditional second-order extended state observer ESO control waveform simulation diagram, Figure 5 (b) is the actual equivalent moment of inertia of the permanent magnet synchronous motor when a step load torque is suddenly applied. J Six times the preset nominal moment of inertia J 0 using the traditional second-order extended state observer ESO control waveform simulation diagram, Figure 5 (c) is the actual equivalent moment of inertia of the permanent magnet synchronous motor when a step load torque is suddenly applied. J The preset nominal moment of inertia J 0 is a waveform simulation diagram of the extended state observer ESO control using the adaptive switching proposed by the present invention, Figure 5 (d) is the actual equivalent moment of inertia of the permanent magnet synchronous motor when a step load torque is suddenly applied. J Six times the preset nominal moment of inertia J0 is a waveform simulation diagram of the extended state observer ESO control using the adaptive switching proposed in the present invention. DETAILED DESCRIPTION

[0039] In order to describe the present invention more specifically, the technical solution of the present invention is described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0040] The present invention is specifically implemented by taking a servo motor with a rated power of 3.1 kW, a rated torque of 15 Nm, and a rated speed of 2000 r / min as an example to illustrate the technical solution of the present invention. In this example, the motor's moment of inertia is 0.00272 kg m 2 , the actual equivalent moment of inertia J 0.033379 kg m 2 , by changing the preset nominal moment of inertia J 0 is used to simulate the working condition under inertia mismatch.

[0041] like Figure 1 As shown, the control system of the permanent magnet synchronous motor of the present invention adopts a control framework based on a magnetic field oriented control strategy, including a speed loop controller, a current loop controller, a coordinate transformation, a space vector pulse width modulation SVPWM (Space Vector Pulse Width Modulation), a three-phase inverter and a permanent magnet synchronous motor. Given a reference speed w mref The motor position is obtained by an incremental encoder installed on the permanent magnet synchronous motor. i and speed w m , obtain the actual current of phase a of the motor through the current sensor i A , b phase actual current i B and the actual current of phase c i C , the actual current of phase a of the motor i A , b phase actual current i B and the actual current of phase c i C The actual current value of the q axis can be obtained by Clark transformation and Park transformation in sequence. i q and the actual current value of the d-axis i d In the speed loop structure, the adaptive switching control is first used to determine whether the extended state observer ESO of the current control cycle is the dynamic observer ESO1 or the steady-state observer ESO2, and then the speed w mAnd the speed loop output q-axis reference current of the previous control cycle i qref Input the extended state observer ESO to get the speed w m Observed value w m ^ and lumped disturbance d Observed value d ^ . The speed of permanent magnet synchronous motor w m Observed value w m ^ and reference speed w mref The difference between the two is input into the linear error feedback control law in the speed loop control, and then the lumped disturbance of the speed loop control process of the permanent magnet synchronous motor is d Observed value d ^ Compensation is performed to obtain the q-axis current reference value output by the speed loop i qref The current loop controller uses proportional integral control PI control, and the d-axis reference current value is i dref 0. Set the d-axis current reference value i dref and d current actual value i d As the input of the d-axis current loop, the output is the d-axis voltage after the proportional-integral control PI controller u d . Set the q-axis current reference value i qref and the actual value of q current i q As the input of the q-axis current loop, the output is the q-axis voltage after the proportional-integral control PI controller u q . The current loop output d-axis voltage u d and q-axis voltage u q The switching signal is generated after being processed by Park inverse transform and space vector pulse width modulation algorithm SVPWM, and then the permanent magnet synchronous motor is driven to work normally through the inverter, finally realizing the closed-loop feedback control of the permanent magnet synchronous motor.

[0042] like Figure 2 As shown in FIG. 1 , the structure of the extended state observer ESO of the present invention is shown. First, the permanent magnet synchronous motor control system except the speed loop controller is simplified to a permanent magnet synchronous motor model. Its input is the q-axis current reference value iqref Lumped disturbance of the speed loop control process of permanent magnet synchronous motor d , the output is the speed w m , as follows:

[0043] w m =(3 pΨ f / 2 J 0) i qref + d

[0044] Secondly, the extended state observer (ESO) is based on the speed of the permanent magnet synchronous motor. w m , lumped disturbance d and the speed w m and lumped disturbance d The differential term d d is the observed object, and the observed result is the speed w m Observed value w m ^ , lumped disturbance d Observed value d ^ and lumped disturbance d The differential term d d Observed value d d ^ . w m and the observed value of the rotation speed w m ^ Compare, after the proportion link h 3 and low-pass filter 1 / ( s + k 2) Get the lumped disturbance of the permanent magnet synchronous motor d The differential term d d Observed value d d ^ , s is the complex frequency in the frequency domain model. w m and the observed value of the rotation speed w m ^ Compare, after the proportion link h 2 Lumped disturbance of permanent magnet synchronous motor dThe differential term d d Observed value d d ^ Add, and then pass through the low-pass filter link 1 / ( s + k 1), and obtain the lumped disturbance d Observed value d ^ . w m and the observed value of the rotation speed w m ^ Compare, after the proportion link h 2 After and lumped disturbance d Observed value d ^ , q-axis current i qref The compensation values ​​obtained through the proportional link are added together, and then the integral link 1 / s Observed value of output speed w m ^ This process is the adaptive switching extended state observer ESO of the permanent magnet synchronous motor designed by the present invention, which is specifically as follows in the time domain:

[0045] w m ^ =(3 pΨ f / 2 J 0) i qref + d ^

[0046] D ^ ´= d d ^ + h 1( w m ´- w m ^ ´)+ h 2( w m - w m ^ )- k 1 d ^

[0047] d d^ ´= h 3( w m - w m ^ )- k 2 d d ^

[0048] in, w m and w m ´ are the speed and its derivative of the permanent magnet synchronous motor, w m ^ and w m ^ ´ are the speeds of the permanent magnet synchronous motors w m The observed value and its derivative, ^ It is only used as a symbolic representation to distinguish the original value from the observed value, and it is only used as a symbolic representation to distinguish the original value from the derivative value; d ^ and d ^ are the lumped disturbances of the speed loop control process of the permanent magnet synchronous motor d The observed values ​​and their derivatives, lumped disturbances d Mainly caused by inertia mismatch, friction and load torque, d d ^ and d d ^ are the lumped disturbances of the permanent magnet synchronous motor respectively. d The differential term d d Observations of and their derivatives; p is the number of pole pairs of the permanent magnet synchronous motor; P f is the permanent magnet flux of the permanent magnet synchronous motor; J 0 is the preset nominal moment of inertia of the permanent magnet synchronous motor; i qref It is the q-axis current reference value output by the speed loop of the permanent magnet synchronous motor; h 1. h 2 and h 3 are the first, second and third gain coefficients of the extended state observer ESO respectively; k 1 and k 2 are the first and second parameters to be tuned of the extended state observer ESO.

[0049] The first, second and third gain coefficients of the extended state observer ESO are configured according to the bandwidth configuration method as follows:

[0050] [ h 1 h 2 h 3]=[3 w o 3 w o 2 w o 3 ]

[0051] in, w o is the bandwidth of the extended state observer ESO. In this example, the first gain coefficient of the extended state observer ESO is set h 1 is 15, the second gain coefficient h 2 is 75, the third gain coefficient h 3 is 125.

[0052] In the design process of the extended state observer ESO, the speed loop of the permanent magnet synchronous motor is firstly modeled according to the dynamic model of the permanent magnet synchronous motor to obtain the speed loop model. The dynamic model is as follows:

[0053] Jw m ´= T e - T L - Bw m

[0054] T e =3 pΨ f i q / 2

[0055] in, J is the actual equivalent moment of inertia of the permanent magnet synchronous motor, including the motor moment of inertia and the load moment of inertia; B is the viscous friction coefficient; T L is the load torque of the permanent magnet synchronous motor; T e is the electromagnetic torque of the permanent magnet synchronous motor, which is approximately equal to the permanent magnet torque and the reluctance torque is ignored; i q is the q-axis equivalent component of the stator current of the permanent magnet synchronous motor.

[0056] Under ideal current loop conditions, it is assumed that the current loop output can accurately track the current reference value. The speed loop model of the permanent magnet synchronous motor is the speed w m and lumped disturbance d The state equation is as follows:

[0057] w m ´= T e / J - T L / J - Bw m / J =(3 pΨ f / 2 J 0) i qref + d

[0058] d ´= d d

[0059] d =(3 pΨ f / 2 J -3 pΨ f / 2 J 0) i qref - Bw m / J - T L / J

[0060] Then, according to the established speed loop model, the structure of the extended state observer ESO is designed.

[0061] In the control process of the permanent magnet synchronous motor, the speed of the permanent magnet synchronous motor and the q-axis current reference value output by the speed loop are first input into the extended state observer ESO for processing, and at the same time, the extended state observer ESO is adaptively switched to control the parameters. The extended state observer ESO is further distinguished according to the difference between the first and second parameters to be adjusted. When the first parameter to be adjusted is k 1 is greater than 0 and the second parameter to be adjusted k 2 is greater than 0, the extended state observer ESO is the dynamic observer ESO1, the purpose is to optimize the dynamic performance, speed up the dynamic response speed, and reduce overshoot; when the first parameter to be adjusted k 1 is greater than 0 and the second parameter to be adjusted kWhen 2 is equal to 0, the extended state observer ESO is the steady-state observer ESO2, the purpose of which is to optimize the steady-state performance and improve the disturbance suppression capability. The first parameters to be adjusted for the dynamic observer ESO1 and the steady-state observer ESO2 are k 1 is always equal. By designing adaptive switching control, the dynamic observer ESO1 is called in the dynamic situation, and the steady-state observer ESO2 is called in the steady-state situation, so as to obtain good dynamic and steady-state performance at the same time. In this example, the first parameter to be tuned of the dynamic observer ESO1 is set to k 1 is 5, the second parameter to be adjusted k 2 is 0.1. Set the first parameter to be tuned for the dynamic observer ESO2 k 1 is 5, the second parameter to be adjusted k 2 is 0.

[0062] During adaptive parameter switching control, the first speed threshold is preset d 1 and the preset second speed threshold d 2 Speed ​​error with permanent magnet synchronous motor e Compare and preset the first speed threshold d 1 is the boundary between the dynamic and steady states of the system, and the second speed threshold is preset d 2 is used to determine whether the steady-state error is within the system allowable range; to determine the state of the permanent magnet synchronous motor, and then perform adaptive switching control of the dynamic observer ESO1 and the steady-state observer ESO2, where: d 1> d 2, e = w mref - w m , w mref is the reference speed of the permanent magnet synchronous motor. The adaptive parameter switching control is as follows:

[0063] like Figure 3 As shown, the first speed threshold is preset d 1 and the preset second speed threshold d 2 Speed ​​error with permanent magnet synchronous motor e When the speed error is compared e The absolute value of | e |> d 1, the permanent magnet synchronous motor is in a dynamic process. At this time, the extended state observer ESO is switched to the dynamic observer ESO1, and the time accumulation value of the switching control process is t Set to zero; when | e |≤ d 1, the permanent magnet synchronous motor begins to enter the steady state process. At this time, when | e |≤ d2, the speed error e Within the preset allowable speed range, there is no need to adjust the parameters, keep the current extended state observer ESO unchanged, and change the time accumulation value of the switching control process. t Set to zero when | e |> d 2, the speed error e If the speed is not within the preset allowable speed range, the hysteresis comparison stage will be entered. Each time the hysteresis comparison stage is entered, the time accumulation value of the switching control process will be t Continue to accumulate, t = t +1, then the accumulated time value t and preset switching delay t d For comparison, t ≥ t d When , the permanent magnet synchronous motor enters the steady-state process, and the extended state observer ESO switches to the steady-state observer ESO2. t < t d When , the current extended state observer ESO is kept unchanged; the ESO type determined by the adaptive switching is used as the observer of this control cycle, and an adaptive switching control is performed in each speed control cycle of the permanent magnet synchronous motor.

[0064] The extended state observer (ESO) outputs the observed values ​​of the speed and the lumped disturbance after processing, and the observed values ​​of the speed and the lumped disturbance are further used for speed loop control to control the speed of the permanent magnet synchronous motor. w m Observed value w m ^ and reference speed w mref The difference between them is input into the linear error feedback control law in the speed loop control, and after comparison, it passes through the proportional link k p , and then the lumped disturbance of the speed loop control process of the permanent magnet synchronous motor d Observed value d ^ Compensation is performed, and the q-axis current reference value output by the speed loop is obtained through the proportional link and limiter. i qref ,as follows:

[0065] i qref =(2 J 0 / 3 pΨ f )×[ k p (w mref - w m ^ )- d ^ ]

[0066] in, k p is the speed loop linear error feedback gain; in this example, the speed loop linear error feedback gain is set k p is 10.

[0067] According to the q-axis current reference value output by the speed loop i qref Continue to perform adaptive parameter switching control in the next speed control cycle, and finally realize the speed control of the permanent magnet synchronous motor. In order to improve the dynamic performance of the system and improve the dynamic and steady-state performance of the motor under inertia mismatch conditions, the speed loop controller is mainly composed of a linear error feedback control law and an adaptively switched extended state observer ESO.

[0068] like Figure 4 As shown in FIG. 1 , the waveforms of the conventional second-order extended state observer ESO and the adaptive switching extended state observer ESO proposed in the present invention are compared in the step response during the specific implementation of the present invention. The preset load torque is 0 Nm, and the reference speed is w mref From 0r / min to 500r / min. Figure 4 As shown in (a), when the permanent magnet synchronous motor tracks the step speed reference signal, the actual equivalent moment of inertia is J The preset nominal moment of inertia J 0, the traditional second-order extended state observer ESO control is used. At this time, the tracking has no overshoot and the adjustment time t s is 0.511s. Figure 4 As shown in (b), when the permanent magnet synchronous motor tracks the step speed reference signal, the actual equivalent moment of inertia is J Six times the preset nominal moment of inertia J 0, the traditional second-order extended state observer ESO control is used. At this time, the tracking has an overshoot of 144r / min, and the adjustment time t s is 3.43s. Figure 4 As shown in (c), when the permanent magnet synchronous motor tracks the step speed reference signal, the actual equivalent moment of inertia is J The preset nominal moment of inertia J 0, the adaptive switching extended state observer ESO control proposed by the present invention is adopted. At this time, the tracking has no overshoot and the adjustment time ts is 0.571s. Figure 4 As shown in (d), when the permanent magnet synchronous motor tracks the step speed reference signal, the actual equivalent moment of inertia is J Six times the preset nominal moment of inertia J 0, the adaptive switching extended state observer ESO control proposed by the present invention is adopted. At this time, the tracking has no overshoot and the adjustment time t s It is 0.828s.

[0069] like Figure 5 As shown in FIG. 1 , the waveforms of the conventional second-order extended state observer ESO and the adaptive switching extended state observer ESO proposed in the present invention when the load is suddenly increased. The preset motor reference speed is constant. w mref is 500r / min, and the load torque jumps from 0Nm to 3.5Nm at a specific moment. Figure 5 As shown in (a), when the permanent magnet synchronous motor is subjected to a sudden step load torque, the actual equivalent moment of inertia is J The preset nominal moment of inertia J 0 using the traditional second-order extended state observer ESO control simulation waveform, when the load is suddenly added, the speed drops by 97r / min. Figure 5 As shown in (b), when the permanent magnet synchronous motor is subjected to a sudden step load torque, the actual equivalent moment of inertia is J Six times the preset nominal moment of inertia J 0 using the traditional second-order extended state observer ESO control simulation waveform, when the load is suddenly added, the speed drops by 252r / min. Figure 5 As shown in (c), when the permanent magnet synchronous motor is subjected to a sudden step load torque, the actual equivalent moment of inertia is J The preset nominal moment of inertia J 0, the simulation waveform of the extended state observer ESO control with adaptive switching proposed by the present invention is used. When the load is suddenly added, the speed drops by 72r / min. Figure 5 As shown in (d), when the permanent magnet synchronous motor is subjected to a sudden step load torque, the actual equivalent moment of inertia is J Six times the preset nominal moment of inertia J 0, the simulation waveform of the extended state observer ESO control with adaptive switching proposed by the present invention is used. When the load is suddenly added, the speed drops by 224r / min.

[0070] From the above comparison, we can see that in the actual equivalent moment of inertia J The preset nominal moment of inertia J0, the second-order extended state observer ESO and the adaptive switching extended state observer ESO proposed in the present invention can maintain good speed dynamic and steady-state control performance and anti-disturbance ability. However, in the actual equivalent moment of inertia J Six times the preset nominal moment of inertia J At 0, the second-order extended state observer ESO tracks the speed step reference signal w mref A large overshoot will occur when the motor changes from the reference speed step to the steady state. t s The ESO of the adaptive switching proposed in the present invention is greatly extended, and certain fluctuations are generated in the dynamic process of tracking step signals and sudden loads. J Six times the preset nominal moment of inertia J At 0, track the reference mechanical acceleration w mref No overshoot will be generated, and its dynamic response speed is significantly improved compared with the second-order extended state observer ESO. At the same time, no obvious fluctuation will be generated in the dynamic process of tracking step signals and sudden load addition. Therefore, the use of the adaptive switching extended state observer ESO proposed by the present invention can significantly improve the control performance of the motor, weaken overshoot, speed up the response speed, reduce oscillation, and reduce the dependence of the motor control system parameter design on the moment of inertia parameters.

[0071] Those skilled in the art will appreciate that the embodiments of the present application may be provided as methods, systems, or computer program products. Therefore, the present application may adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Moreover, the present application may adopt the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program codes.

[0072] The above description of the embodiments is to facilitate the understanding and application of the present invention by those skilled in the art. It is obvious that those skilled in the art can easily make various modifications to the above embodiments and apply the general principles described herein to other embodiments without creative work. Therefore, the present invention is not limited to the above embodiments. Improvements and modifications made by those skilled in the art to the present invention based on the disclosure of the present invention should be within the protection scope of the present invention.

Claims

1. A permanent magnet synchronous motor speed control method, characterized in that: include: Step 1) Design an adaptively switched extended state observer ESO for the permanent magnet synchronous motor, and add the extended state observer ESO to the speed loop control process of the permanent magnet synchronous motor; Step 2) In the control process of the permanent magnet synchronous motor, the speed of the permanent magnet synchronous motor and the q-axis current reference value output by the speed loop are input into the extended state observer ESO for processing, and the extended state observer ESO is adaptively switched to control the parameters. After processing, the extended state observer ESO outputs the observed values ​​of the speed and the lumped disturbance, so as to continue the speed loop control and realize the speed control of the permanent magnet synchronous motor; In the step 1), the adaptively switched extended state observer ESO is as follows: w m ^ ´=(3 pΨ f / 2 J 0) i qref + d ^ d ^ ´= d d ^ + h 1( w m ´- w m ^ ´)+ h 2( w m - w m ^ )- k 1 d ^ d d ^ ´= h 3( w m - w m ^ )- k 2 d d ^ in, w m and w m ´ are the speed and derivative of the permanent magnet synchronous motor, w m ^ and w m ^ ´ are the speeds of the permanent magnet synchronous motors w m Observations of and their derivatives; d ^ and d ^ are the lumped disturbances of the speed loop control process of the permanent magnet synchronous motor d The observed value and its derivative, d d ^ and d d ^ are the lumped disturbances of the permanent magnet synchronous motor. d The differential term d d Observations of and their derivatives; p is the number of pole pairs of the permanent magnet synchronous motor; Ψ f is the permanent magnet flux of the permanent magnet synchronous motor; J 0 is the preset nominal moment of inertia of the permanent magnet synchronous motor; i qref It is the q-axis current reference value output by the speed loop of the permanent magnet synchronous motor; h 1. h 2 and h 3 are the first, second and third gain coefficients of the extended state observer ESO respectively; k 1 and k 2 are the first and second parameters to be tuned of the extended state observer ESO; The extended state observer ESO is further distinguished according to the difference between the first and second parameters to be adjusted. k 1 is greater than 0 and the second parameter to be adjusted k 2 is greater than 0, the extended state observer ESO is the dynamic observer ESO1; when the first parameter to be tuned k 1 is greater than 0 and the second parameter to be adjusted k When 2 is equal to 0, the extended state observer ESO is the first parameter to be tuned of the steady-state observer ESO2, the dynamic observer ESO1 and the steady-state observer ESO2 k 1 is always equal; In the step 2), when the adaptive parameter switching control is performed, the first speed threshold is preset. δ 1 and the preset second speed threshold δ 2 Speed ​​error with permanent magnet synchronous motor e By comparison, the state of the permanent magnet synchronous motor is determined, and then the adaptive switching control of the dynamic observer ESO1 and the steady-state observer ESO2 is performed, where: δ 1> δ 2, e = w mref - w m , w mref is the reference speed of the permanent magnet synchronous motor; When the adaptive parameter switching control is performed, the first speed threshold is preset. δ 1 and the preset second speed threshold δ 2 Speed ​​error with permanent magnet synchronous motor e When the speed error is compared e The absolute value of | e |> δ 1, the permanent magnet synchronous motor is in a dynamic process. At this time, the extended state observer ESO is switched to the dynamic observer ESO1, and the time accumulation value of the switching control process is t zero; when | e |≤ δ 1, the permanent magnet synchronous motor begins to enter the steady state process. At this time, when | e |≤ δ 2, the speed error e Within the preset allowable speed range, keep the current extended state observer ESO unchanged, and change the time accumulation value of the switching control process t Set to zero when | e |> δ 2, the speed error e If the speed is not within the preset allowable speed range, the hysteresis comparison stage will be entered. Each time the hysteresis comparison stage is entered, the time accumulation value of the switching control process will be t Continue to accumulate, and then add the accumulated time value t and preset switching delay t d For comparison, t ≥ t d When , the permanent magnet synchronous motor enters the steady-state process, and the extended state observer ESO switches to the steady-state observer ESO2. t < t d When , the current extended state observer ESO is kept unchanged; in each speed control cycle of the permanent magnet synchronous motor, an adaptive switching control is performed.

2. The permanent magnet synchronous motor speed control method according to claim 1, characterized in that: In the extended state observer ESO, the first, second and third gain coefficients of the extended state observer ESO are configured according to the bandwidth configuration method, as follows: [ h 1 h 2 h 3]=[3 w o 3 w o 2 w o 3 ] in, w o is the bandwidth of the extended state observer ESO.

3. The permanent magnet synchronous motor speed control method according to claim 1, characterized in that: The lumped disturbance of the permanent magnet synchronous motor d as follows: d =(3 pΨ f / 2 J -3 pΨ f / 2 J 0) i qref - B m / J - T L / J in, J is the actual equivalent moment of inertia of the permanent magnet synchronous motor; B is the viscous friction coefficient; T L is the load torque of the permanent magnet synchronous motor.

4. The permanent magnet synchronous motor speed control method according to claim 1, characterized in that: In the step 2), the extended state observer ESO processes and outputs the observed values ​​of the speed and the lumped disturbance, and the observed values ​​of the speed and the lumped disturbance are further subjected to the speed loop control to control the speed of the permanent magnet synchronous motor. w m Observed value w m ^ and reference speed w mref The difference between the two is input into the linear error feedback control law in the speed loop control, and then the lumped disturbance of the speed loop control process of the permanent magnet synchronous motor is d Observed value d ^ Compensation is performed to obtain the q-axis current reference value output by the speed loop i qref ,as follows: i qref =(2 J 0 / 3 pΨ f )×[ k p ( w mref - w m ^ )- d ^ ] in, k p is the linear error feedback gain of the speed loop; According to the q-axis current reference value output by the speed loop i qref Continue with the adaptive parameter switching control for the next speed control cycle.

5. An electronic device, characterized in that: include: A memory and a processor coupled to each other, wherein the memory stores program data, and the processor calls the program data to execute the method according to any one of claims 1 to 4.

6. A computer-readable storage medium having program data stored thereon, characterized in that: When the program data is executed by a processor, the method according to any one of claims 1 to 4 is implemented.

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