阅读说明：本技术 一种基于傅里叶级数模型的开关磁阻电机转矩控制方法 (Switched reluctance motor torque control method based on Fourier series model ) 是由 葛乐飞 钟继析 黄佳乐 宋受俊 于 2021-08-25 设计创作，主要内容包括：本发明公开了一种基于傅里叶级数模型开关磁阻电机转矩控制方法。该方法需要通过离线转矩平衡法测量获取开关磁阻电机的磁链特性,采用4阶傅里叶级数对磁链特性进行建模,由磁共能对位置求偏导计算转矩,由此可得到完整的磁链和转矩特性。根据当前位置、转速和电流信息,结合开关状态查表预测下一时刻的磁链和位置信息,为进行延时补偿,需再进一步磁链和位置信息,通过查表获取电流预测值,然后计算各开关状态下的转矩并带入成本函数,以成本函数值最小的运行状态为最优状态作为开关信号控制功率变换器中的开关,由此达到转矩脉动抑制的效果。仿真验证了所述方法的有效性,所述方法控制逻辑简单、转矩脉动和振动抑制效果明显且易于工程实现。(The invention discloses a switched reluctance motor torque control method based on a Fourier series model. According to the method, flux linkage characteristics of the switched reluctance motor are measured and obtained through an offline torque balance method, the flux linkage characteristics are modeled by adopting a 4-order Fourier series, and the position deviation is calculated through magnetic common energy to calculate the torque, so that complete flux linkage and torque characteristics can be obtained. And predicting the flux linkage and the position information at the next moment by combining a switch state lookup table according to the current position, the rotating speed and the current information, further obtaining a current predicted value by looking up the flux linkage and the position information for delay compensation, calculating the torque in each switch state and bringing the torque into a cost function, and controlling the switch in the power converter by taking the operation state with the minimum cost function value as an optimal state as a switching signal, thereby achieving the effect of inhibiting the torque pulsation. The effectiveness of the method is verified through simulation, the method is simple in control logic, obvious in torque ripple and vibration suppression effect and easy to realize in engineering.)

1. A switched reluctance motor torque control method based on a Fourier series model is characterized by comprising the following steps:

the method comprises the following steps:

step 1: acquiring magnetic linkage characteristics at electrical angles of 0 degrees, 60 degrees, 120 degrees and 180 degrees by using a torque balance method; according to the approximately linear relation between 60 degrees and 120 degrees, the flux linkage characteristic at the electric angle of 90 degrees can be calculated;

step 2: modeling the flux linkage characteristic by using a 4-order Fourier series model;

and step 3: the position deviation can be calculated according to the magnetic common energy to calculate the torque;

and 4, step 4: given reference torque T_refIn a closed loop system, T_refThe output of the rotating speed conversion PI regulator can be obtained; constructing a data table i (psi) from the flux linkage characteristics found in step 2_ph,θ_ph) (ii) a Wherein psi_ph、θ_phRespectively representing flux linkage and rotor position of the switched reluctance motor;

and 5: collecting rotor position theta (k) and phase current i of the motor at the moment k_ph(k) Phase winding voltage V_ph(k) And the value of the rotation speed omega (k), calculates the flux linkage at the time k and predicts the phase flux linkage psi at the time k +1_ph(k +1), rotor position θ (k +1), phase current i_ph(k+1)；

Step 6: predicting the rotor position theta (k +2) at the moment of k +2 and judging the running state of the motor; defining a switching vector s_phThe relationship with the phase voltage is as follows, where s_ph1 denotes that both switching tubes of the asymmetric half-bridge power converter are on, s_ph0 has only one switch on, representing s_ph-1 means that both switching tubes are closed; the combination principle of the switch states is as follows: in the one-way conduction area, only the switch state of the current conduction phase is calculated, and the other phases are-1; in the commutation zone, only the two-phase switching states that are being commutated are predicted

In the formula V_busRepresenting bus voltage, V_T、V_D、V_ph、s_phRespectively representing the voltage drop of a switching tube, the voltage drop of a freewheeling diode, phase voltage and state variables;

further predicting the phase flux linkage psi at the time k +2 according to the predicted switch state_ph(k +2) and phase current i_ph(k+2)；

And 7: combining the predicted phase current at the moment k +2 and the rotor position information, substituting the phase torque at the moment k +2 predicted by the torque model in the step 3, and adding the phase torques to obtain the total torque;

and 8: predicting the total torque at the moment of k +2 according to the step 7, and solving a cost function;

and step 9: the operation state with the minimum cost function value is taken as an optimal state to be used as a switching signal to control a switch in the power converter;

step 10: checking whether a termination command is given; if so, stopping the circulation; otherwise, return to step 5.

2. The switched reluctance motor torque control method based on the Fourier series model according to claim 1, characterized in that: in the step 1, flux linkage characteristics at the electrical angles of 0 degrees, 60 degrees, 120 degrees and 180 degrees of the switched reluctance motor are obtained through a torque balance method, and the flux linkage characteristics at the electrical angle of 90 degrees are calculated, wherein the calculation formula is as follows:

in the formula, #_ph(60°el,i_ph)、ψ_ph(90°el,i_ph)、ψ_ph(120°el,i_ph) Phase current represented as i_phMagnetic chains at electrical angle positions of 60 °, 90 °, 120 °.

3. The switched reluctance motor torque control method based on the Fourier series model according to claim 1, characterized in that: step 2 according to the formula

ψ_ph(θ_ph,i_ph)＝a₀(i_ph)+a₁(i_ph)cos(θ_ph)+a₂(i_ph)cos(2θ_ph)+a₃(i_ph)cos(3θ_ph)+a₄(i_ph)cos(4θ_ph)

Calculating the flux linkage of phase, wherein a₀(i_ph)、a₁(i_ph)、a₂(i_ph)、a₃(i_ph)、a₄(i_ph) Phase current represented as i_phCoefficient of time, θ_phIs the rotor position.

4. The switched reluctance motor torque control method based on the Fourier series model according to claim 1, characterized in that: step 3 according to the formula

T_ph(θ_ph,i_ph)＝T₁(i_ph)sin(θ_ph)+T₂(i_ph)sin(2θ_ph)+T₃(i_ph)sin(3θ_ph)+T₄(i_ph)sin(4θ_ph)

Calculating the phase torque, where T₁(i_ph)、T₂(i_ph)、T₃(i_ph)、T₄(i_ph) Phase current represented as i_phThe torque model coefficients of time, which may be determined fromAnd (4) calculating.

5. The switched reluctance motor torque control method based on the Fourier series model according to claim 1, characterized in that: step 5 according to the formula

θ(k+1)＝θ(k)+ω(k)T_s

Calculating the rotor position at the moment k +1, where T_sFor sampling frequency, ω (k) and θ (k) are the rotation speed and position at time k, θ (k +1) and i_ph(k +1) is the rotor position and phase current value at the moment of k +1, respectively;

according to the formula

ψ_ph(k+1)＝ψ_ph(k)+T_s(V_ph(k)-R_phi_ph(k))

Calculating the flux linkage at the time of k +1, where T_sFor sampling frequency, R_phIs the winding resistance, V_ph(k)、i_ph(k) The phase voltage and phase current measured by the sensor at the moment k.

6. The switched reluctance motor torque control method based on the Fourier series model according to claim 1, characterized in that: step 6 according to the formula

θ(k+2)＝2θ(k+1)-θ(k)

Calculating the rotor position at the moment k +2, wherein theta (k +2) is the rotor position at the moment k +2 respectively;

according to the formula

ψ_ph(k+2)＝ψ_ph(k+1)+T_s(V_ph(k+1)-R_phi_ph(k+1))

Calculating the flux linkage at the k +2 moment; in the formula T_sFor sampling frequency, R_phIs the winding resistance, V_ph(k+1)、i_phThe (k +1) values are phase voltage values and phase current values at the time k +1, respectively.

7. The switched reluctance motor torque control method based on the Fourier series model according to claim 1, characterized in that: step 7 according to the formula

Calculating the total torque at the moment k +2, wherein N_phRepresenting the number of phases, T, of a switched reluctance machine_ph(k +2) represents the phase torque at the time k + 2.

8. The switched reluctance motor torque control method based on the Fourier series model according to claim 1, characterized in that: in step 8 by formula

The value of the cost function is calculated, where η and λ are the weighting factors for the torque and current, respectively, and m is the number of phases.

9. The switched reluctance motor torque control method based on the Fourier series model according to claim 1, characterized in that: in step 9, the operation state with the minimum cost function value is taken as the optimal state to be used as the switching signal of the power converter.

Technical Field

The invention relates to a switched reluctance motor torque control method based on a Fourier series model, and belongs to the field of motor control.

Background

The switched reluctance motor has been widely applied to the fields of electric automobiles, photovoltaic water pump systems, aerospace, oil field exploitation and the like by virtue of the advantages of simple structure, low manufacturing cost, reliable operation, flexible control, wide speed regulation range and the like. However, due to the inherent doubly salient structure, the electromagnetic characteristics of the switched reluctance motor are highly nonlinear, so that the switched reluctance motor has the defect of large torque ripple, the control performance of the switched reluctance motor is seriously influenced, and the application field of the switched reluctance motor is also limited. Therefore, in order to improve the performance of the speed regulating system of the switched reluctance motor, the suppression of the torque ripple is a breakthrough for the popularization and the application of the switched reluctance motor, and has become one of the research hotspots of the switched reluctance motor.

The current common methods for reducing the torque ripple mainly comprise a torque distribution function, a phase current PI controller, direct torque control, direct instantaneous torque control, model prediction torque control and the like. The model prediction torque control intuitively and conveniently realizes multi-objective optimization by constructing a cost function, and is paid more and more attention in the control of the switched reluctance motor. By constructing a cost function of the torque and the current of the switched reluctance motor, the model predicts the torque control, not only can solve the problem of torque pulsation, but also considers the system efficiency, and has an important effect on improving the applicability and the speed regulation performance of the switched reluctance motor. The model predictive control method relies on an accurate, simple model to describe the electromagnetic properties. However, the current research on electromagnetic characteristic modeling is often over-simplified, poor in control performance or over-complicated, and industrial application of the electromagnetic characteristic modeling is hindered.

Disclosure of Invention

The invention provides a switched reluctance motor torque control method based on a Fourier series model, aiming at the technology of inhibiting the torque ripple of the switched reluctance motor. According to the method, flux linkage characteristics of the switched reluctance motor are measured and obtained through an offline torque balance method, the flux linkage characteristics are modeled by adopting a 4-order Fourier series, and the position deviation is calculated through magnetic common energy to calculate the torque, so that complete flux linkage and torque characteristics can be obtained. And predicting the flux linkage and the position information at the next moment by combining a switch state lookup table according to the current position, the rotating speed and the current information, further obtaining a current predicted value by looking up the flux linkage and the position information for delay compensation, calculating the torque in each switch state and bringing the torque into a cost function, and controlling the switch in the power converter by taking the operation state with the minimum cost function value as an optimal state as a switching signal, thereby achieving the effect of inhibiting the torque pulsation.

The technical scheme of the invention is as follows:

the switched reluctance motor torque control method based on the Fourier series model comprises the following steps:

step 1: the flux linkage characteristics at the electrical angles of 0 °, 60 °, 120 °, and 180 ° are obtained using a torque balancing method. According to the approximately linear relationship between 60 ° and 120 °, the flux linkage characteristic at 90 ° electrical angle can be calculated by the following formula:

in the formula i_phFor phase current, ψ_phIs a phase flux linkage.

Step 2: and modeling the flux linkage characteristic by using a 4-order Fourier series model. The concrete formula is as follows:

ψ_ph(θ_ph,i_ph)＝a₀(i_ph)+a₁(i_ph)cos(θ_ph)+a₂(i_ph)cos(2θ_ph)

+a₃(i_ph)cos(3θ_ph)+a₄(i_ph)cos(4θ_ph)

in the formula, a₀(i_ph)、a₁(i_ph)、a₂(i_ph)、a₃(i_ph)、a₄(i_ph) Phase current represented as i_phCoefficient of time, θ_phAre phase angles.

Substituting the magnetic linkage characteristics at the electrical angles of 0 °, 60 °, 90 °, 120 ° and 180 ° obtained in step 1 into the above formula can calculate the coefficients of a 4-order fourier series model, which are expressed by a matrix:

in the formula, #_u(i_ph)、ψ₁(i_ph)、ψ_m(i_ph)、ψ₂(i_ph)、ψ_a(i_ph) Magnetic linkage characteristics at 0 °, 60 °, 90 °, 120 ° and 180 ° electrical angles, respectively.

And step 3: the torque can be calculated by deviatorily deriving the position from the magnetic resonance. The concrete formula is as follows:

in the formula, T_phIs phase torque, W_coIs magnetic resonance.

Substituting the flux linkage model in step 2 into the above equation, the torque model can be calculated as:

T_ph(θ_ph,i_ph)＝T₁(i_ph)sin(θ_ph)+T₂(i_ph)sin(2θ_ph)

+T₃(i_ph)sin(3θ_ph)+T₄(i_ph)sin(4θ_ph)

in the formula, T₁(i_ph)、T₂(i_ph)、T₃(i_ph)、T₄(i_ph) Phase current represented as i_phThe calculation formula of the time torque model coefficient is as follows:

and 4, step 4: given reference torque T_refIn a closed loop system, T_refCan be obtained by the output of the rotating speed conversion PI regulator. Constructing a data table i (psi) from the flux linkage characteristics found in step 2_ph,θ_ph). Wherein psi_ph、θ_phRespectively representing switched reluctance motor flux linkage and rotor position.

And 5: collecting rotor position theta (k) and phase current i of the motor at the moment k_ph(k) Phase winding voltage V_ph(k) And the value of the rotation speed omega (k) is determined by the flux linkage model of step 2Calculating the flux linkage at time k and predicting the phase flux linkage psi at time k +1_ph(k +1), rotor position θ (k +1), phase current i_ph(k + 1). Mixing theta (k) and i_ph(k) And (5) substituting the magnetic linkage model in the step 2 to calculate the magnetic linkage at the moment k. Magnetic flux linkage psi_phThe specific calculation formula of (k +1) is respectively as follows:

ψ_ph(k+1)＝ψ_ph(k)+T_s(V_ph(k)-R_phi_ph(k))

in the formula, T_sTo sample time, R_phIs the phase winding resistance.

The specific calculation formula of the rotor position theta (k +1) is as follows:

θ(k+1)＝θ(k+1)+ω(k)T_s

in the formula, T_sFor the sample time, θ (k +1) is the rotor position at time k + 1.

Further by looking up the table i (θ)_ph(k+1),ψ_ph(k +1)) predicting the current i at the time of k +1_ph(k+1)。

Step 6: predicting a rotor position theta (k +2) at the moment k +2 and judging the running state of the motor, wherein the calculation formula of the rotor position theta (k +2) at the moment k +2 is as follows:

θ(k+2)＝2θ(k+1)-θ(k)

further, a switching vector s is defined_phThe relationship with the phase voltage is as follows:

in the formula V_busRepresenting bus voltage, V_T、V_D、V_ph、s_phRespectively representing the voltage drop of a switching tube, the voltage drop of a freewheeling diode, phase voltage and state variables. Wherein s is_ph1 denotes that both switching tubes of the asymmetric half-bridge power converter are on, s_phWhen 0, only one switch tube is on, s is represented_phAnd-1 means that both switching tubes are closed. The combination principle of the switch states is as follows: in the one-way conduction area, only the switch state of the current conduction phase is calculated, and the other phases are-1; in the commutation zone, only the phase being commutated is predictedTwo-phase switch state.

Further predicting the phase flux linkage psi at the time k +2 according to the predicted switch state_ph(k +2) and phase current i_ph(k +2), flux linkage psi_phThe formula for the calculation (k +2) is:

ψ_ph(k+2)＝ψ_ph(k+1)+T_s(V_ph(k+1)-R_phi_ph(k+1))

in the formula, V_ph(k +1) is the predicted phase voltage value at time k +1, T_sTo sample time, R_phIs the phase winding resistance.

Further by looking up the table i (θ)_ph(k+2),ψ_ph(k +2)) predicting the current i at time k +2_ph(k+2)。

And 7: substituting the phase torque at the moment k +2 predicted by the torque model in the step 3 by combining the phase current at the moment k +2 and the rotor position information, and adding the phase torques to obtain the total torque, wherein the total torque calculation formula is as follows:

in the formula N_phRepresenting the number of phases, T, of a switched reluctance machine_ph(k +2) represents the phase torque predicted at time k + 2.

And 8: predicting the total torque at the moment k +2 according to the step 7, wherein the solving formula of the cost function is

Where η and λ are weighting factors for torque and current, respectively, and m is the number of phases.

And step 9: and taking the operation state with the minimum cost function value as an optimal state as a switching signal to control the switch in the power converter.

Step 10: it is checked whether a termination command is given. If so, stopping the circulation; otherwise, returning to the step 5;

advantageous effects

The invention discloses a switched reluctance motor torque control method based on a Fourier series model. According to the method, flux linkage characteristics of the switched reluctance motor are measured and obtained through an offline torque balance method, the flux linkage characteristics are modeled by adopting a 4-order Fourier series, and the position deviation is calculated through magnetic common energy to calculate the torque, so that complete flux linkage and torque characteristics can be obtained. And predicting the flux linkage and the position information at the next moment by combining a switch state lookup table according to the current position, the rotating speed and the current information, further obtaining a current predicted value by looking up the flux linkage and the position information for delay compensation, calculating the torque in each switch state and bringing the torque into a cost function, and controlling the switch in the power converter by taking the operation state with the minimum cost function value as an optimal state as a switching signal, thereby achieving the effect of inhibiting the torque pulsation. The effectiveness of the method is verified through simulation and experiments, the method is simple in control logic, obvious in torque ripple suppression effect and easy to realize in engineering.

Additional aspects and advantages of the invention will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the invention.

Drawings

The above and/or additional aspects and advantages of the present invention will become apparent and readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings of which:

FIG. 1 is a comparison graph of flux linkage characteristics obtained by a torque balance method and a rotor fixing method;

FIG. 2 is a coefficient diagram of a 4-order Fourier series flux linkage model;

FIG. 3 is a coefficient plot of a torque model;

FIG. 4 is a control block diagram of a switched reluctance motor model predictive torque control method based on a Fourier series model;

FIG. 5 is a flow chart of a method for controlling the predicted torque of a switched reluctance motor model based on a Fourier series model;

FIG. 6 is a graph comparing current and torque ripple when switching from current chopping control to the method of the present invention at 500rpm operation;

fig. 7 is a graph comparing current and torque ripple when switching from current chopping control to the method proposed by the present invention at 1000rpm operation.

Detailed Description

The technical scheme of the invention is explained in detail in the following by combining the drawings and specific examples. The motor used in the example was a 1kW three-phase 12/8 pole switched reluctance motor.

Step 1: the flux linkage characteristics at the electrical angles of 0 °, 60 °, 120 °, and 180 ° are obtained using a torque balancing method. The comparison graph of the magnetic linkage characteristics of the 0 DEG, 60 DEG, 120 DEG and 180 DEG electrical angles obtained by the torque balance method and the rotor climbing method is shown in FIG. 1. According to the approximately linear relation between 60 degrees and 120 degrees, the flux linkage characteristic at the 90-degree electrical angle can be calculated, and the calculation formula is shown as the formula (1).

In the formula i_phFor phase current, ψ_phIs a phase flux linkage.

Step 2: and modeling the flux linkage characteristic by using a 4-order Fourier series model. The flux linkage calculation formula is shown as formula (2).

In the formula, a₀(i_ph)、a₁(i_ph)、a₂(i_ph)、a₃(i_ph)、a₄(i_ph) Phase current represented as i_phCoefficient of time, θ_phAre phase angles.

Substituting the magnetic linkage characteristics at the electrical angles of 0 degrees, 60 degrees, 90 degrees, 120 degrees and 180 degrees obtained in the step 1 into the formula (2) to obtain the formula (3), calculating the coefficients of the 4-order Fourier series model by solving the formula (3), and expressing the coefficients of the 4-order Fourier series magnetic linkage model by a matrix as shown in the formula (4), wherein the coefficients of the 4-order Fourier series magnetic linkage model are shown in a figure 2.

In the formula, #_u(i_ph)、ψ₁(i_ph)、ψ_m(i_ph)、ψ₂(i_ph)、ψ_a(i_ph) Magnetic linkage characteristics at 0 °, 60 °, 90 °, 120 ° and 180 ° electrical angles, respectively.

And step 3: the magnetic common energy is used for solving the position deviation to calculate the torque, and the magnetic common energy is used for solving the deviation to calculate the torque as shown in the formula (5). Further, the flux linkage molding belt in the step 2 is taken into the formula (5), and a torque calculation formula can be obtained as shown in the formula (6).

In the formula, T_phIs phase torque, W_coIs magnetic resonance.

In the formula, T₁(i_ph)、T₂(i_ph)、T₃(i_ph)、T₄(i_ph) Phase current represented as i_phThe calculation formula of the time-dependent torque model coefficient is shown in formula (7). The torque model coefficients are shown in fig. 3.

And 4, step 4: given reference torque T_refIn a closed loop system, T_refCan be obtained by the output of the rotating speed conversion PI regulator. In a closed loop system as shown in FIG. 4, T_refGiven by the system. The number of flux linkage characteristics constructed by the step 2According to table i (psi)_ph,θ_ph). Wherein psi_ph、θ_phRespectively representing switched reluctance motor flux linkage and rotor position.

And 5: collecting rotor position theta (k) and phase current i of the motor at the moment k_ph(k) Phase winding voltage V_ph(k) And the value of the rotation speed ω (k), calculating the flux linkage at the time k from the equation (2), and predicting the phase flux linkage ψ at the time k +1_ph(k +1), rotor position θ (k +1), phase current i_ph(k + 1). Mixing theta (k) and i_ph(k) And (5) substituting the magnetic linkage model in the step 2 to calculate the magnetic linkage at the moment k. k +1 time phase flux linkage psi_phThe calculation of (k +1) is shown in formula (8).

ψ_ph(k+1)＝ψ_ph(k)+T_s(V_ph(k)-R_phi_ph(k)) (8)

In the formula, T_sTo sample time, R_phIs the phase winding resistance.

The rotor position θ (k +1) is calculated as shown in equation (9).

θ(k+1)＝θ(k+1)+ω(k)T_s (9)

In the formula, T_sFor the sample time, θ (k +1) is the rotor position at time k + 1.

Further by looking up the table i (θ)_ph(k+1),ψ_ph(k +1)) predicting the current i at the time of k +1_ph(k+1)。

Step 6: and predicting the rotor position theta (k +2) at the moment k +2 and judging the running state of the motor, wherein the rotor position theta (k +2) at the moment k +2 is calculated as shown in the formula (10).

θ(k+2)＝2θ(k+1)-θ(k) (10)

Further, a switching vector s is defined_phThe relationship with the phase voltage is shown in equation (11).

In the formula V_busRepresenting bus voltage, V_T、V_D、V_ph、s_phRespectively showing the voltage drop of the switching tube, the voltage drop of the freewheeling diode and the phase currentPressure and state variables. Wherein s is_ph1 denotes that both switching tubes of the asymmetric half-bridge power converter are on, s_phWhen 0, only one switch tube is on, s is represented_phAnd-1 means that both switching tubes are closed. The combination principle of the switch states is as follows: in the one-way conduction area, only the switch state of the current conduction phase is calculated, and the other phases are-1; in the commutation zone, only the two-phase switching states that are commutation are predicted, and the table of prediction of switching states is shown in table 1.

TABLE 1 switch State

Further predicting the phase flux linkage psi at the time k +2 according to the predicted switch state_ph(k +2) and phase current i_ph(k + 2). Magnetic flux linkage psi_phThe formula (k +2) is shown in formula (12).

ψ_ph(k+2)＝ψ_ph(k+1)+T_s(V_ph(k+1)-R_phi_ph(k+1)) (12)

In the formula, V_ph(k +1) is the predicted phase voltage value at time k +1, T_sTo sample time, R_phIs the phase winding resistance.

Further by looking up the table i (θ)_ph(k+2),ψ_ph(k +2)) predicting the current i at time k +2_ph(k+2)。

And 7: and (3) substituting the phase torque at the moment k +2 predicted by the torque model in the step (3) by combining the phase current at the moment k +2 and the rotor position information, and adding the phase torques to obtain the total torque, wherein a calculation formula of the total torque is shown as a formula (13).

In the formula N_phRepresenting the number of phases, T, of a switched reluctance machine_ph(k +2) represents the phase torque predicted at time k + 2.

And 8: and (4) predicting the total torque at the moment k +2 according to the step 7, wherein a solving formula of the cost function is shown as an equation (14).

Where η and λ are weighting factors for torque and current, respectively.

And step 9: and taking the operation state with the minimum cost function value as an optimal state as a switching signal to control the switch in the power converter.

Step 10: it is checked whether a termination command is given. If so, stopping the circulation; otherwise, returning to the step 5;

fig. 5 is a flow chart of the control method proposed by the present invention, and fig. 6 and 7 are comparative graphs of the control effect when the motor is switched from the current chopping control to the control method proposed by the present invention at 500rpm and 1000rpm, respectively. At 500rpm, when the current chopping control is switched to the model prediction torque ripple suppression control method, the torque ripple is reduced from 105.05% to 38.85%. At 1000rpm, after switching the control method, the torque ripple was reduced from 77.1% to 33.03%. Therefore, the switched reluctance motor torque ripple suppression method based on the Fourier series model prediction control has obvious effect on reducing the torque ripple.

Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention, and that variations, modifications, substitutions and alterations can be made in the above embodiments by those of ordinary skill in the art without departing from the principle and spirit of the present invention.