阅读说明：本技术 一种基于增量式电机模型的无差拍电流预测鲁棒控制方法 (Deadbeat current prediction robust control method based on incremental motor model ) 是由 黄晓艳 胡启超 章夏荷 李赵凯 张何 于 2021-08-05 设计创作，主要内容包括：本发明公开了一种基于增量式电机模型的无差拍电流预测鲁棒控制方法。永磁同步电机伺服系统电流环的增量式无差拍电流预测鲁棒控制器以dq轴电流给定值作为输入,同时通过传感器对永磁同步电机的三相电流和转子位置角度进行采样,采样结果经数学变换后得到的dq轴电流实际值和电机电角速度作为控制器的反馈输入；控制器输出的dq轴电压给定值经空间矢量脉宽调制模块生成对应的PWM信号送往逆变器,逆变器输出电压作用于永磁同步电机进行反馈控制。本发明实现了电机参数存在误差情况下电流控制的静态无差,且不受相位延迟及逆变器非线性导致的电压误差直流分量影响,降低了方法对电感误差的敏感度,扩大系统的稳定运行范围,增强系统的鲁棒性。(The invention discloses a deadbeat current prediction robust control method based on an incremental motor model. An incremental deadbeat current prediction robust controller of a current loop of a permanent magnet synchronous motor servo system takes a dq-axis current given value as input, simultaneously samples three-phase current and a rotor position angle of the permanent magnet synchronous motor through a sensor, and takes a dq-axis current actual value and a motor electrical angular speed obtained after mathematical transformation of a sampling result as feedback input of the controller; the dq axis voltage given value output by the controller generates a corresponding PWM signal through a space vector pulse width modulation module and is transmitted to the inverter, and the output voltage of the inverter acts on the permanent magnet synchronous motor to perform feedback control. The method realizes the static state no difference of current control under the condition that the motor parameters have errors, is not influenced by the phase delay and the voltage error direct-current component caused by the nonlinearity of the inverter, reduces the sensitivity of the method to the inductance error, enlarges the stable operation range of the system and enhances the robustness of the system.)

1. A deadbeat current prediction robust control method based on an incremental motor model is characterized by comprising the following steps of:

an incremental deadbeat current prediction robust controller of a current loop of a permanent magnet synchronous motor servo system takes a dq-axis current given value as given input, simultaneously samples three-phase current and rotor position angle of a surface-mounted permanent magnet synchronous motor through a sensor, and takes a dq-axis current actual value and motor electrical angular velocity obtained after mathematical transformation of a sampling result as feedback input of the controller; the dq axis voltage given value output by the controller generates a corresponding PWM signal through a space vector pulse width modulation module and is transmitted to the inverter, and the voltage output by the inverter acts on the surface-mounted permanent magnet synchronous motor to perform feedback control, so that the robust control of the dead-beat current prediction of the surface-mounted permanent magnet synchronous motor is realized.

2. The robust control method for deadbeat current prediction based on incremental motor model as claimed in claim 1, wherein said robust control method for incremental deadbeat current prediction is set by the following control equation:

wherein, Δ i_d(k)、Δi_q(k) Incremental currents of d and q axes at the time k are respectively represented; i.e. i_d(k)、i_q(k) Actual values of currents of d and q axes at the time k are respectively represented; i.e. i_d(k-1)、i_q(k-1) represents the current actual values of d and q axes at the time of k-1, respectively;incremental current estimated values of d and q axes at the time of k +1 are respectively represented;incremental voltages respectively representing d and q axes of a k-th control period; t is_sIt is indicated that the control period is,andrespectively representing stator resistance and synchronismEstimated value of inductance, ω_e(k) Representing the electrical angular velocity of the motor at the moment k;current estimation values of d and q axes at the time of k +1 are respectively represented;incremental voltages of d and q axes respectively representing the (k +1) th control period;respectively representing the current set values of d and q axes at the moment of k-1;respectively representing the current set values of d and q axes at the moment k;voltage given values of d and q axes respectively representing a k control period;and voltage set values of d and q axes respectively representing the (k +1) th control period.

3. The incremental motor model-based deadbeat current prediction robust control method according to claim 1, wherein the voltage given value of the dq axis is subjected to a space vector pulse width modulation module to generate a corresponding PWM signal and send the PWM signal to an inverter, specifically:

the method comprises the steps of firstly carrying out coordinate transformation on a voltage given value of a dq axis to obtain a voltage given value of an alpha beta axis, then carrying out space vector pulse width modulation on the voltage given value of the alpha beta axis to generate a PWM signal with a corresponding duty ratio and sending the PWM signal to an inverter.

4. The robust control method of the deadbeat current prediction based on the incremental motor model according to claim 1, wherein a three-phase current and a rotor position angle of the surface-mounted permanent magnet synchronous motor are sampled by a sensor, and a dq-axis current actual value and a motor electrical angular velocity obtained by mathematically transforming a sampling result are used as feedback inputs of a controller, and specifically:

sampling three-phase current of the surface-mounted permanent magnet synchronous motor through a current sensor to obtain an actual value of the three-phase current, and sampling a mechanical angle of a rotor position of the surface-mounted permanent magnet synchronous motor through a position sensor to obtain a mechanical angle of the rotor position; and then, carrying out coordinate transformation from a static three-phase coordinate system to a rotating two-phase coordinate system on the three-phase current actual value to obtain a dq-axis current actual value, differentiating the rotor position mechanical angle, multiplying the differentiated rotor position mechanical angle by the number of pole pairs of the motor to obtain the electrical angular speed of the motor, and taking the dq-axis current actual value and the electrical angular speed of the motor as feedback input of the controller.

Technical Field

The invention relates to a current loop control method of a permanent magnet synchronous motor, belonging to the field of motor control, in particular to a deadbeat current prediction robust control method based on an incremental motor model.

Background

The control system of the permanent magnet synchronous servo system is generally composed of a position loop, a speed loop and a current loop, and the control on the position, the speed and the acceleration of the motor can be essentially summarized into the control on electromagnetic torque, and the electromagnetic torque is determined by current, so that the control system has important significance on researching a control method of the current loop, which is a key link of the control of the permanent magnet synchronous motor.

The dead beat current predictive control is one of the current control methods with the fastest dynamic response speed in the prior art, and is suitable for being applied to the control of the servo motor with higher requirements on the dynamic response performance. The method has the advantages of rapid dynamic response, simplicity and intuition, no need of parameter setting, small calculated amount, fixed switching frequency and the like, and becomes a hotspot of the study on the current loop control technology of the servo motor in recent years. However, the performance of the traditional deadbeat current predictive control is rather dependent on the accuracy of motor parameters in a control equation and is influenced by factors such as time delay, nonlinearity and the like in an actual system, so that the difficulty is brought to the large-scale application of the deadbeat current predictive control in the industry.

The control equation of the incremental motor model-based dead-beat current prediction control method does not contain items related to permanent magnet flux linkage, the control performance is not influenced by permanent magnet flux linkage errors, the dead-beat tracking of a current given value can be realized under the conditions that motor parameters have errors and are influenced by phase delay and voltage error direct current components caused by inverter nonlinearity, and the current ripple is small. However, the method has poor robustness, and can stably work only when the inductance estimated value is within the range of 0.8-1.25 times of the actual inductance value, so that the practical application of the method is limited.

Disclosure of Invention

In order to solve the problems in the prior art, the invention aims to provide a deadbeat current prediction robust control method based on an incremental motor model, and the incremental motor model is used to enable the method to realize current static state error-free without being influenced by a motor parameter error, phase delay and a voltage error direct-current component caused by inverter nonlinearity. The method obviously enhances the robustness of the system while retaining the advantage of current static no-difference brought by the application of the incremental motor model, so that the method has the same inductance parameter stable range as the traditional deadbeat current prediction control method, namely the inductance estimated value does not exceed twice the actual inductance value.

The technical scheme of the invention is as follows:

the invention comprises the following steps:

an incremental deadbeat current prediction robust controller of a current loop of a permanent magnet synchronous motor servo system takes a dq-axis current given value as given input, simultaneously samples three-phase current and rotor position angle of a surface-mounted permanent magnet synchronous motor through a sensor, and takes a dq-axis current actual value and motor electrical angular velocity obtained after mathematical transformation of a sampling result as feedback input of the controller; the dq axis voltage given value output by the controller generates a corresponding PWM signal through a space vector pulse width modulation module and is transmitted to the inverter, and the voltage output by the inverter acts on the surface-mounted permanent magnet synchronous motor to perform feedback control, so that the robust control of the dead-beat current prediction of the surface-mounted permanent magnet synchronous motor is realized.

The incremental deadbeat current prediction robust controller is set by the following control equation:

wherein, Δ i_d(k)、Δi_q(k) Incremental currents of d and q axes at the time k are respectively represented; i.e. i_d(k)、i_q(k) Actual values of currents of d and q axes at the time k are respectively represented; i.e. i_d(k-1)、i_q(k-1) represents the current actual values of d and q axes at the time of k-1, respectively;incremental current estimated values of d and q axes at the time of k +1 are respectively represented;incremental voltages respectively representing d and q axes of a k-th control period; t is_sIt is indicated that the control period is,andrepresenting estimated values of stator resistance and synchronous inductance, omega, respectively_e(k) Representing the electrical angular velocity of the motor at the moment k;current estimation values of d and q axes at the time of k +1 are respectively represented;incremental voltages of d and q axes respectively representing the (k +1) th control period;respectively representing the current set values of d and q axes at the moment of k-1;respectively representing the current set values of d and q axes at the moment k;voltage given values of d and q axes respectively representing a k control period;and voltage set values of d and q axes respectively representing the (k +1) th control period.

The voltage given value of the dq axis generates a corresponding PWM signal through a space vector pulse width modulation module and sends the PWM signal to an inverter, and the method specifically comprises the following steps:

the method comprises the steps of firstly carrying out coordinate transformation on a voltage given value of a dq axis to obtain a voltage given value of an alpha beta axis, then carrying out space vector pulse width modulation on the voltage given value of the alpha beta axis to generate a PWM signal with a corresponding duty ratio and sending the PWM signal to an inverter.

Three-phase current and rotor position angle of the surface-mounted permanent magnet synchronous motor are sampled through the sensors, and the dq-axis current actual value and the motor electrical angular velocity obtained after mathematical transformation of the sampling result are used as feedback input of the controller, and the method specifically comprises the following steps:

sampling three-phase current of the surface-mounted permanent magnet synchronous motor through a current sensor to obtain an actual value of the three-phase current, and sampling a mechanical angle of a rotor position of the surface-mounted permanent magnet synchronous motor through a position sensor to obtain a mechanical angle of the rotor position; and then, carrying out coordinate transformation from a static three-phase coordinate system to a rotating two-phase coordinate system on the three-phase current actual value to obtain a dq-axis current actual value, differentiating the rotor position mechanical angle, multiplying the differentiated rotor position mechanical angle by the number of pole pairs of the motor to obtain the electrical angular speed of the motor, and taking the dq-axis current actual value and the electrical angular speed of the motor as feedback input of the controller.

The invention has the beneficial effects that:

the deadbeat current prediction robust control method based on the incremental motor model has the advantages that two control periods of current delay follow given rapid dynamic response under the condition that motor parameters are accurate. Compared with the traditional deadbeat current prediction control method, the method has the advantages that permanent magnet flux linkage parameters are not needed, and static state tolerance of current can be realized under the condition that motor parameters have errors; compared with the improved deadbeat current prediction control method based on the incremental motor model, the method widens the inductance parameter error range allowed by the stable operation of the system, and has stronger robustness.

Drawings

FIG. 1 is a block diagram of the system control of the present invention.

FIG. 2 is a block diagram of a current loop transfer function under deadbeat current prediction robust control based on an incremental motor model.

FIG. 3 is a schematic diagram of the d and q axis current responses of a loaded motor under conditions where the estimated values of the inductance parameters used by the control equations are equal to the measured values.

FIG. 4 is a graph illustrating the d and q-axis current responses of a loaded motor under conditions where the estimated inductance parameter value used by the control equation is equal to 1.5 times the measured value.

FIG. 5 is a graph illustrating the d and q-axis current responses of a loaded motor under conditions where the estimated inductance parameter value used by the control equation is equal to 0.5 times the measured value.

Detailed Description

The technical scheme of the invention is applied to a surface-mounted permanent magnet synchronous motor current loop controller driven by a two-level three-phase inverter, and the specific implementation mode of the invention is further explained by combining the attached figure 1.

As shown in fig. 1, the present invention comprises the steps of:

the permanent magnet synchronous motor servo system mainly comprises an incremental deadbeat current prediction robust controller, an inverter, a surface-mounted permanent magnet synchronous motor and a space vector pulse width modulation module. The voltage set value of the dq axis output by the incremental type deadbeat current prediction robust controller sequentially passes through the space vector pulse width modulation module and the inverter and then acts on the surface-mounted permanent magnet synchronous motor, and the output of the inverter and the surface-mounted permanent magnet synchronous motor is mathematically transformed and then input into the incremental type deadbeat current prediction robust controller for feedback.

An incremental deadbeat current prediction robust controller of a current loop of a permanent magnet synchronous motor servo system takes a dq-axis current given value as given input, samples three-phase current of a surface-mounted permanent magnet synchronous motor through a current sensor to obtain a three-phase current actual value, and samples a rotor position mechanical angle of the surface-mounted permanent magnet synchronous motor through a position sensor to obtain a rotor position mechanical angle; and then, carrying out coordinate transformation from a static three-phase coordinate system to a rotating two-phase coordinate system on the three-phase current actual value to obtain a dq-axis current actual value, differentiating the rotor position mechanical angle, multiplying the differentiated rotor position mechanical angle by the number of pole pairs of the motor to obtain the electrical angular speed of the motor, and taking the dq-axis current actual value and the electrical angular speed of the motor as feedback input of the controller. The method comprises the steps of firstly carrying out coordinate transformation on a dq axis voltage given value output by a controller to obtain an alpha beta axis voltage given value, then carrying out space vector pulse width modulation on the alpha beta axis voltage given value to generate a PWM signal corresponding to a duty ratio and transmitting the PWM signal to an inverter, wherein the updating of the duty ratio of the PWM signal has a delay of a control period. The voltage output by the inverter acts on the surface-mounted permanent magnet synchronous motor to perform feedback control, and the robust control of the dead beat current prediction of the surface-mounted permanent magnet synchronous motor is realized.

The incremental deadbeat current prediction robust controller is set by the following control equation:

wherein, Δ i_d(k)、Δi_q(k) Incremental currents of d and q axes at the time k are respectively represented; i.e. i_d(k)、i_q(k) Actual values of currents of d and q axes at the time k are respectively represented; i.e. i_d(k-1)、i_q(k-1) represents the current actual values of d and q axes at the time of k-1, respectively;incremental current estimated values of d and q axes at the time of k +1 are respectively represented;incremental voltages respectively representing d and q axes of a k-th control period; t is_sIt is indicated that the control period is,andrepresenting estimated values of stator resistance and synchronous inductance, omega, respectively_e(k) Representing the electrical angular velocity of the motor at the moment k;current estimation values of d and q axes at the time of k +1 are respectively represented;incremental voltages of d and q axes respectively representing the (k +1) th control period;are respectively provided withThe current set values of d and q axes at the moment of k-1 are shown;respectively representing the current set values of d and q axes at the moment k;voltage given values of d and q axes respectively representing a k control period;and voltage set values of d and q axes respectively representing the (k +1) th control period.

Surface-mounted permanent magnet synchronous motor AC-DC axis inductor L_d＝L_q＝L。

The control equation of the incremental deadbeat current prediction robust controller is obtained by calculation through the following steps:

the method aims at the quadrature-direct axis synchronous inductor L_d＝L_qL-surface-mounted permanent magnet synchronous motor. Firstly, discretizing a stator voltage equation of the permanent magnet synchronous motor in a dq coordinate system according to a forward Euler method. Considering that the update of the PWM duty ratio has a delay of one control period, the control target is to calculate the voltage set at the (k +1) th control period in the k-th control period so that the current can reach the set value at the k-time at the k + 2-time, so that the dq-axis current at the k + 1-time needs to be predicted in the k-th control period. Assuming that the electrical angular velocity of the motor remains constant during two adjacent control periods, i.e. ω_e(k)＝ω_e(k + 1). Therefore, the current prediction and voltage given equation of the traditional deadbeat current prediction control method is derived:

wherein:current estimation values of d and q axes representing the k +1 time; i.e. i_d(k)、i_q(k) Actual values of currents of d and q axes at a time k are shown;voltage setting of d and q axes representing the k +1 th control period; t is_sIt is indicated that the control period is,andrespectively representing estimated values of stator resistance, synchronous inductance and permanent magnet flux linkage;voltage setting of d and q axes representing the k +1 th control period;and the current set values of d and q axes at the k moment are shown.

Then, the equation (6) is subtracted from the current prediction equation at the time k, and the equation (7) is subtracted from the voltage given equation at the time k, so that a control equation of the deadbeat current prediction control method based on the incremental motor model is obtained:

wherein: Δ i_d(k)、Δi_q(k) Incremental currents of d and q axes at the time k are respectively represented; i.e. i_d(k-1)、i_q(k-1) represents the current actual values of d and q axes at the time of k-1, respectively;d and q axis incremental current estimated values at the k +1 moment are shown;incremental voltages respectively representing d and q axes of a k-th control period;and d and q axis incremental voltages representing the (k +1) th control period.

By calculating the d and q axis incremental current estimated value terms in the formula (8) for the incremental voltage And replacement is carried out, so that the robustness of the system is enhanced. Respectively replacing d-axis and q-axis incremental current estimation value items at the k +1 moment in a formula (8) by using the difference between d-axis and q-axis current set values at the k-1 moment and d-axis and q-axis current actual values at the k moment to obtain a control equation of the deadbeat current prediction robust control method based on the incremental motor model:

the method reserves the advantage of current static state tolerance of the incremental motor model-based deadbeat current prediction control method under the condition that motor parameters have errors, widens the inductance error allowable range of stable operation of the system, and enhances the robustness of the system.

Examples

Firstly, collecting stator three-phase current i at the k moment by using a current sensor at the starting moment of the k control period_abc(k) Obtaining the mechanical angle theta of the rotor position of the motor at the moment k by using a rotary transformer or an encoder_m(k) In that respect To i_abc(k) Carrying out Park conversion to obtain the actual value i of the dq axis current at the k moment_dq(k) Differentiating the mechanical angle of the rotor position and multiplying the mechanical angle by the pole pair number of the motor to obtain the electrical angular velocity omega of the motor at the moment k_e(k) And input into the incremental deadbeat current prediction robust controller.

Surface-mounted permanent magnet synchronous motor adopting i_dControl 0, so d-axis current setpoint at time kQ-axis current setpoint at time kGiven by a speed ring or manually. After each parameter is input into the deadbeat controller, the incremental deadbeat current is generated according to the inventionD-axis and q-axis voltage giving of k +1 control period is calculated by current prediction and voltage giving equation of prediction robust control method

For surface-mounted permanent magnet synchronous motor, AC-DC axis synchronous inductor L_d＝L_qBy L, usingWhich represents the estimated value thereof,the stator resistance estimates are all obtained in advance by off-line measurements.

First, from equation (1), Δ i is calculated from the difference between the actual values of d-and q-axis currents at time k and time k-1_dq(k) Calculated from the previous control periodAre substituted into the formula (2) together to obtainThen, the d-axis and q-axis incremental current estimated values at the k +1 moment are added to the d-axis and q-axis current actual values at the k moment according to a formula (3)Substituting the given values of d and q axis currents at the same k moment and k-1 moment into a formula (4) to calculateFinally, according to the formula (5), the d-axis and q-axis incremental voltages of the (k +1) th control period are added with the d-axis and q-axis voltages of the (k) th control period to obtain the d-axis and q-axis voltage set of the (k +1) th control periodThe PWM duty ratio corresponding to the voltage given by the voltage calculated in the kth control period is at the beginning of the (k +1) th control periodUpdating the dq axis voltage acted on the motor by the inverter in the (k +1) th control period to be

The working principle of the invention is as follows:

using delta e when motor parameters have errors_d(k+1)、Δe_q(k +1) represents the difference between the actual value and the estimated value of the incremental current of the q-axis at the time point of k + 1:

then the difference between the given value of the dq-axis current at the moment k and the actual value of the dq-axis current at the moment k +2 is obtained according to analysis:

when the motor operates in a steady state, the current ripple and the voltage ripple are ignored, the given values of the dq axis current and the dq axis voltage can be approximately considered to be unchanged, namely the increment current of the dq axis and the increment voltage of the dq axis are both 0, so that the delta e exists_d(k+1)、Δe_d(k +2) ═ 0, and i_dq(k+2)＝i_dq(k+1)，Equation (10) can be simplified as:

according to the establishment of the formula (11), the actual current value at the moment k +2 is equal to the given current value at the moment k, so that the deadbeat current prediction robust control method based on the incremental motor model has no static difference even if motor parameters have errors, and the static difference is generated in the current under the traditional deadbeat current prediction control due to the errors of the stator resistance, the synchronous inductance and the permanent magnet flux linkage.

When considering the influence of the phase delay and the nonlinear factor of the inverter, the dq-axis voltage error caused by the phase delay is only related to the motor rotation speed, so that the dq-axis voltage error can be regarded as a constant when the control period is sufficiently short; the dq-axis voltage error caused by the inverter nonlinearity contains a dc component and a six-pulse wave component with an average value of zero.

Suppose the dq-axis voltage error due to phase delay and inverter nonlinearity is u_edqThe dq-axis voltage is givenWith the dq-axis voltage u actually applied to the motor_dqSatisfies the following conditions:

the d-axis voltage actual increment Δ u at time k_d(k) Q-axis voltage actual increment Δ u_q(k) Respectively as follows:

when the motor is in steady-state operation, u can be approximately considered without considering the six-pulse wave component of the nonlinear voltage error of the inverter_edq(k)＝u_edq(k-1). Therefore, in a steady state, the incremental deadbeat current prediction robust control method provided by the invention has the advantage that the actual voltage increment is still equal to the given voltage increment under the influence of the phase delay and the voltage error direct-current component caused by the nonlinearity of the inverter. When the actual increment of the voltage is equal to the given increment of the voltage, no static difference exists by the available current.

When the influence of motor parameter errors on system stability is analyzed, the motor parameters generally meet the requirementsThe resistance related term in the equation can be ignored. Defining d and q-axis current settings at time kThe differences between the d-axis error current i and the actual values of the d-axis and q-axis currents at the time k +1 are respectively_ed(k +1) and q-axis error current i_eq(k+1)：

From equation (4) we can obtain:

taking the term related to the back emf as a disturbance term, the discrete transfer function G of the given voltage and the error current can be obtained from equation (15)_eu(z)：

Discrete transfer function G given by combining actual current value and voltage_ui(z) as shown in equation (17), a current loop transfer function block diagram under the deadbeat current prediction robust control based on the incremental motor model can be obtained, as shown in fig. 2.

The closed loop discrete transfer function G of the current loop can be further obtained from FIG. 2_c(z)：

In order to ensure the stable operation of the system, the pole of the current loop closed loop discrete transfer function must fall within the unit circle, i.e. the inductance estimated value should satisfy 0 < L < 2L. When the inductance estimated value and the inductance actual value adopted by calculation are equal, the closed loop discrete transfer function of the current loop can be simplified into z^-2I.e. the output of the current loop is delayed by two control periodsAnd (6) tracking. As mentioned above, the improved deadbeat current prediction control method based on the incremental motor model can stably work only when the L is more than 0.8L and less than 1.25L, and the robustness of the improved method is obviously enhanced.

Experiment of

In order to verify the reliability of the method, relevant experiments are carried out, a test motor is controlled by a single current loop, a current loop controller adopts the deadbeat current prediction robust control method based on the incremental motor model, and the rotating speed of the current loop controller is provided by a load motor. The parameters of the surface-mounted permanent magnet synchronous motor used in the experiment are shown in table 1 below.

TABLE 1 Motor parameters

Fig. 3 is a dq-axis current response under the condition that the given rotation speed of the load motor is 600rpm, the given q-axis current value is suddenly increased from 1A to 1.5A at 0.15s, and is suddenly decreased from 1.5A to 0.5A at 0.25 s. At this time, the resistance and inductance parameters are substituted into the measured values. Fig. 3 (a) is a dq-axis current response waveform, and fig. 3 (b) and 3 (c) are transient current amplification waveforms at a given surge and a given surge, respectively. Therefore, the control method has the advantages that under the condition that the motor parameters basically have no errors, the current is stable and has no difference, the dynamic response is quick, and the given control period can be followed by delaying two control periods.

The operating conditions of fig. 4 are the same as those of fig. 3. And at the moment, the inductance parameter is substituted into the 1.5 times measured value, and the inductance parameter is out of the stable operation range of the actual value of the inductance parameter which is 0.8-1.25 times of the dead-beat current prediction control method based on the incremental motor model. Fig. 4 (a) is a dq-axis current response waveform, and fig. 4 (b) and 4 (c) are transient current amplification waveforms at a given surge and a given surge, respectively. It can be seen that when the estimated value of the motor parameter is approximate to 1.5 times of the actual value, the control method of the invention generates overshoot and dynamic performance reduction as the traditional deadbeat current prediction control method, but the current steady state is not poor, and the deadbeat current prediction control method based on the incremental motor model can still keep stable.

The operating conditions of fig. 5 are the same as those of fig. 3. And at the moment, the inductance parameter is substituted into the measured value of 0.5 time, and the inductance parameter is also out of the stable range of the actual value of the inductance parameter of 0.8-1.25 times based on the dead-beat current prediction control method of the incremental motor model. Fig. 5 (a) is a dq-axis current response waveform, and fig. 5 (b) and 5 (c) are transient current amplification waveforms at a given surge and a given surge, respectively. It can be seen that when the estimated value of the motor parameter is approximate to 0.5 times of the actual value, the control method of the invention keeps the current steady state and no difference even though the motor parameter is slightly overshot and the dynamic performance is reduced, and the control method of the invention can still keep stability compared with the dead-beat current prediction control method based on the incremental motor model.