Switched reluctance motor radial force control system and method based on fuzzy current compensation

Abstract

The application discloses a switching reluctance motor radial force control system and method based on fuzzy current compensation, and the system comprises a disturbance rejection speed controller, an optimal reference current real-time lookup table module, a fuzzy current compensation module, a reference radial force generation module, a real-time radial force lookup table module, a current hysteresis control module, a radial force hysteresis control module, a switching signal logic judgment module, a rotating speed calculation module, a position sensor, a power converter and a switching reluctance motor. The application can simultaneously inhibit torque ripple and radial force ripple, and the rotating speed of the switching reluctance motor is not affected by load fluctuation. Under the premise of ensuring that the motor has stable rotating speed, torque ripple during commutation is inhibited, radial force is directly controlled, radial force fluctuation is reduced, and the purpose of reducing vibration and noise of the switching reluctance motor is achieved.

Description

Technical Field

[0001] This invention relates to the field of vibration reduction control technology for switched reluctance motors, specifically a radial force control system and method for switched reluctance motors based on fuzzy current compensation. Background Technology

[0002] Switched reluctance motors (SRMs), as a new type of motor, are distinguished from traditional motors by having salient poles in both the stator and rotor. Only the stator has concentrated windings, while the rotor, made of laminated silicon steel sheets, has neither windings nor permanent magnets on its salient poles. This robust and simple structure contributes to the high reliability and low production cost of SRMs. Because the SRM rotor has neither windings nor permanent magnets, it can be used in harsh conditions such as high speed, high temperature, and strong corrosion. These advantages have led to the widespread application of SRMs in various fields. However, their extremely high torque ripple and vibration noise limit their further promotion and application.

[0003] To address the aforementioned issues, conventional optimized control methods for switched reluctance motors, such as torque distribution function control and direct instantaneous torque control, typically focus on suppressing torque ripple. However, a major cause of vibration and noise in switched reluctance motors is the fluctuation of radial force on the motor stator. Therefore, without controlling the radial force, it is difficult to achieve a good vibration reduction effect. Furthermore, based on the torque and radial force characteristics of switched reluctance motors, controlling the radial force to reduce radial force ripple can lead to an increase in torque ripple. Therefore, to resolve the contradiction between reducing torque ripple and radial force ripple, a fuzzy current compensation technique is needed. Summary of the Invention

[0004] To address the aforementioned technical problems, this invention provides a radial force control system and method for switched reluctance motors based on fuzzy current compensation. This method overcomes the shortcomings of existing vibration reduction control for switched reluctance motors, reducing the peak radial force and lowering the vibration of the switched reluctance motor under the premise of low torque pulsation. Simultaneously, it enhances the stability and anti-interference capability of the speed loop.

[0005] The technical solution adopted in this invention is as follows:

[0006] A radial force control system for a switched reluctance motor based on fuzzy current compensation, comprising:

[0007] The system includes an active disturbance rejection speed controller, an optimal reference current real-time lookup table module, a fuzzy current compensation module, a reference radial force generation module, a real-time radial force lookup table module, a current hysteresis control module, a radial force hysteresis control module, a switch signal logic judgment module, a speed calculation module, a position sensor, and a power converter.

[0008] The input terminal of the active disturbance rejection speed controller is connected to the reference speed signal n. * The speed deviation is obtained by subtracting the output from the speed calculation module.

[0009] The output of the active disturbance rejection speed controller is connected to the input of the optimal reference current real-time lookup table module and the input of the reference radial force generation module, respectively; the output of the reference radial force generation module is connected to the input of the radial force hysteresis control module.

[0010] The input terminals of the real-time radial force lookup table module are connected to the output terminal of the position sensor and the switched reluctance motor, respectively. The input terminal of the position sensor is connected to the switched reluctance motor, and the output terminal of the real-time radial force lookup table module is connected to the input terminal of the radial force hysteresis control module.

[0011] The input terminals of the fuzzy current compensation module are connected to the output terminals of the optimal reference current real-time lookup table module and the position sensor, respectively; the output terminals of the fuzzy current compensation module and the optimal reference current real-time lookup table module are added together to obtain the compensated reference current.

[0012] The compensated reference current flows through the input terminal of the current hysteresis control module, which is connected to the switched reluctance motor.

[0013] The output terminals of the current hysteresis control module and the radial force hysteresis control module are both connected to the input terminal of the switch signal logic judgment module. The output terminal of the switch signal logic judgment module is connected to the input terminal of the power converter, and the output terminal of the power converter is connected to the switched reluctance motor.

[0014] The active disturbance rejection speed controller will use a manually given reference speed signal n * Using the actual speed n as input, active disturbance rejection control is used to adjust the speed difference to obtain the reference torque T. ref This helps maintain a stable rotational speed.

[0015] The optimal reference current real-time lookup table module will use the reference torque T output by the active disturbance rejection speed controller. ref The output n of the rotational speed calculation module is used as input, and different reference torques T are obtained in advance using a genetic algorithm. ref And the optimal reference current data i at rotational speed n ref (T ref ,n); The optimal reference current data i ref (T ref The n) is placed into the Lookup Table 2-D module to retrieve the optimal reference current i. ref .

[0016] The fuzzy current compensation module, for the reference current i ref The compensation current Δi is obtained by calculating the rotor position angle θ. comp Reference current i ref The input universes of discourse for the rotor position angle θ are [0 20] and [0 22.5], respectively. The fuzzy operation adopts Mamdani-type inference. The input fuzzy language values ​​are {NM, NS, ZE, PS, PM}, and the output fuzzy language values ​​are {ZE, PS, PM, PB}. Among them, NM, NS, ZE, PS, PM and PB represent negative middle, negative small, zero, positive small, positive middle and positive large, respectively. The fuzzy rules are set as shown in Table 1:

[0017] Table 1. Fuzzy Rules Set

[0018]

[0019]

[0020] The reference radial force generation module couples the torque characteristic T(i,θ) and radial force characteristic F(i,θ) obtained from finite element simulation to output the reference radial force F. ref .

[0021] The real-time radial force lookup module obtains the radial force characteristic F(i,θ) of the switched reluctance motor through finite element simulation, puts the radial force characteristic F(i,θ) into the Lookup Table 2-D module, takes the real-time phase current and rotor position angle output by the switched reluctance motor as input, and obtains the real-time radial force F by looking up the radial force characteristic F(i,θ).

[0022] The current hysteresis control module will compensate the reference current i nref With the actual phase current i ph The difference is calculated, and the difference is controlled by the current hysteresis loop to output the switching signal of the power converter.

[0023] The radial force hysteresis control module will reference the radial force F ref With the actual radial force F r The difference is calculated, and the difference is controlled by a radial force hysteresis loop to output the switching signal of the power converter.

[0024] The switching signal logic judgment module performs logical judgment on the output signals of the current hysteresis control module and the radial force hysteresis control module, and outputs the optimal control signal under the current operating condition.

[0025] The genetic algorithm is used to obtain the lookup data of the real-time lookup table module for the optimal reference current, and the torque ripple T is then processed. ripple The reciprocal of the function is used as the fitness function F. fit Its expression is:

[0026]

[0027] Among them, T, T ref Let τ be the actual torque and the reference torque, respectively, and τ be the simulation time. Based on the fitness function, a genetic algorithm is used to optimize the reference current under different speeds and reference torques to obtain the optimal reference current corresponding to the minimum torque ripple under different speeds and reference torques.

[0028] The fuzzy current compensation module performs current compensation on the active phase during commutation to increase the current level of the first half of the active phase, thereby compensating for the torque drop caused by the previous phase disconnection.

[0029] The radial force hysteresis control module employs dual hysteresis control, with the inner loop interval [-ΔF]. min ΔF min ], outer ring interval [-ΔF max ΔF max For the currently conducting phase in the commutation region, in the direction where the difference ΔF between the reference radial force Fref and the actual radial force Fr decreases, when ΔF is greater than zero, let the switching signal S = 1. When ΔF is in [-ΔF]... max When the interval is 0, let S = 0. When ΔF is less than -ΔF max When S = -1, in the direction of increasing ΔF, when ΔF is less than zero, let S = -1, when ΔF is in [0 ΔF max When the interval is [0, S = 0, when ΔF is greater than ΔF] max When S = 1; for the single-phase conduction region and the soon-to-conduct region of the commutation region, in the direction of decreasing ΔF, when ΔF is greater than -ΔF min When S = 1, when ΔF is less than -ΔF min When S = 0, in the direction of increasing ΔF, when ΔF is less than ΔF min When S = 0, when ΔF is greater than ΔF min At that time, let S = 1.

[0030] The switching signal logic judgment module has the following judgment logic: when the actual radial force F r Less than the reference radial force F ref When the switching signal logic judgment module outputs the switching signal from the current hysteresis control module, the radial force hysteresis control module temporarily does not participate in the control; when the actual radial force F r Greater than the reference radial force F ref At that time, the output of the switch signal logic judgment module is the signal obtained by performing an AND operation between the output signal of the current hysteresis control module and the output signal of the radial force hysteresis control module.

[0031] The radial force control method for a switched reluctance motor based on fuzzy current compensation includes the following steps:

[0032] Step 1: Calculate the speed error by subtracting the reference speed from the actual speed;

[0033] Step 2: The speed error is processed by the active disturbance rejection speed controller to obtain the reference torque T. ref ;

[0034] Step 3: Reference torque T ref After the optimal reference current real-time lookup module and the reference radial force generation module, the reference current i is generated. ref and reference radial force F ref ;

[0035] Step 4: For the reference current i ref The compensation current Δi is obtained by performing fuzzy calculations on the rotor position angle θ. comp and with reference current i ref The compensated reference current i is obtained by adding them together. nref ;

[0036] Step 5: Based on the rotor position angle θ and phase current i ph The real-time radial force F is obtained by looking up the table. r ;

[0037] Step 6: Compensated reference current i nref With phase current i ph The switching signal S is obtained through hysteresis. i Reference radial force F ref and real-time radial force F r The switching signal S is obtained through hysteresis. F ;

[0038] Step 7: Switch signal S i and switch signal S F The power converter switching signal S is obtained after logic processing;

[0039] Step 8: The power converter turns the motor on or off according to the switching signal S, controlling the operation of the switched reluctance motor;

[0040] Step 9: The position sensor calculates the rotor position angle and obtains the real-time speed of the motor through the speed calculation module.

[0041] This invention provides a radial force control system and method for a switched reluctance motor based on fuzzy current compensation, with the following technical advantages:

[0042] 1) This invention suppresses radial force fluctuations and reduces vibration noise of the switched reluctance motor while maintaining low torque pulsation of the switched reluctance motor. It also avoids the deterioration of torque pulsation caused by controlling radial force. At the same time, the principle is simple and easy to implement, and the control effect is good.

[0043] 2) This invention uses a fuzzy current compensation module to compensate for the drop in the turn-off phase current caused by radial force control. It uses the compensation of the turn-on phase current to maintain low torque pulsation, which solves the problem of the contradiction between torque pulsation and radial force pulsation optimization and achieves good vibration reduction effect.

[0044] 3) The control system of this invention adopts an active disturbance rejection controller in the speed loop to prevent the impact of external load or internal parameter changes on system stability, and has extremely strong anti-interference ability. Attached Figure Description

[0045] The present invention will be further described below with reference to the accompanying drawings and embodiments:

[0046] Figure 1 A general block diagram of the direct radial force control method for fuzzy current compensation of switched reluctance motors.

[0047] Figure 2(a) is a schematic diagram of the membership function of input 1 (reference current) of the fuzzy current compensation module of the present invention;

[0048] Figure 2(b) is a schematic diagram of the membership function of input 2 (position angle) of the fuzzy current compensation module of the present invention;

[0049] Figure 2(c) is a schematic diagram of the membership function of the output (compensation current) of the fuzzy current compensation module of the present invention.

[0050] Figure 3 The flowchart shows the steps of obtaining the optimal reference current under different operating conditions using the genetic algorithm of this invention.

[0051] Figure 4 The figure shows the torque-radial force coupling curve of the radial force generation module for reference in this invention.

[0052] Figure 5 This is a diagram illustrating the hysteresis control rules of the current hysteresis control module of the present invention.

[0053] Figure 6 This is a diagram illustrating the hysteresis control rules of the radial force hysteresis control module of the present invention.

[0054] Figure 7(a) shows the current waveform of the current chopper control when running at 800 rpm and 3 N·m.

[0055] Figure 7(b) is a current waveform diagram of the control method of the present invention.

[0056] Figure 8(a) shows the torque waveform of the current chopper control when running at 800 rpm and 3 N·m.

[0057] Figure 8(b) is a torque waveform diagram of the control method of the present invention.

[0058] Figure 9(a) shows the radial force waveform of the current chopper control when running at 800 rpm and 3 N·m.

[0059] Figure 9(b) is a radial force waveform diagram of the control method of the present invention. Detailed Implementation

[0060] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. The motor used in the example is a 7.5kW three-phase 12 / 8-pole switched reluctance motor.

[0061] like Figure 1 As shown, a direct radial force control system for fuzzy current compensation of a switched reluctance motor is constructed. The system includes:

[0062] 1. Active Disturbance Rejection Speed ​​Controller; 2. Optimal Reference Current Real-time Lookup Table Module; 3. Fuzzy Current Compensation Module; 4. Reference Radial Force Generation Module; 5. Real-time Radial Force Lookup Table Module; 6. Current Hysteresis Control Module; 7. Radial Force Hysteresis Control Module; 8. Switch Signal Logic Judgment Module; 9. Speed ​​Calculation Module; 10. Position Sensor; 11. Power Converter.

[0063] The aforementioned active disturbance rejection speed controller 1, optimal reference current real-time lookup table module 2, fuzzy current compensation module 3, reference radial force generation module 4, real-time radial force lookup table module 5, current hysteresis control module 6, radial force hysteresis control module 7, switch signal logic judgment module 8, and speed calculation module 9 are all based on simulation models built using Matlab / Simulink, and executable machine code can be generated with one click through a hardware-in-the-loop simulator; position sensor 10 is a Hall position sensor; the topology of power converter 11 is a three-phase asymmetrical half-bridge topology.

[0064] The input terminal of the active disturbance rejection speed controller 1 is connected to the reference speed signal n. * The speed deviation is obtained by subtracting the output of the speed calculation module 9 from the speed deviation.

[0065] The output of the self-disturbance rejection speed controller 1 is connected to the input of the optimal reference current real-time lookup table module 2 and the input of the reference radial force generation module 4, respectively.

[0066] The output of the radial force generation module 4 is connected to the input of the radial force hysteresis control module 7;

[0067] The input terminals of the real-time radial force lookup table module 5 are connected to the output terminals of the position sensor 10 and the switched reluctance motor 12, respectively. The input terminal of the position sensor 10 is connected to the switched reluctance motor 12, and the output terminal of the real-time radial force lookup table module 5 is connected to the input terminal of the radial force hysteresis control module 7.

[0068] The input terminal of the fuzzy current compensation module 3 is connected to the output terminal of the optimal reference current real-time lookup table module 2 and the output terminal of the position sensor 10, respectively; the output terminal of the fuzzy current compensation module 3 is added to the output terminal of the optimal reference current real-time lookup table module 2 to obtain the compensated reference current;

[0069] The compensated reference current flows through the input terminal of the current hysteresis control module 6, and the input terminal of the current hysteresis control module 6 is connected to the switched reluctance motor 12.

[0070] The output terminals of the current hysteresis control module 6 and the radial force hysteresis control module 7 are both connected to the input terminal of the switch signal logic judgment module 8. The output terminal of the switch signal logic judgment module 8 is connected to the input terminal of the power converter 11, and the output terminal of the power converter 11 is connected to the switched reluctance motor 12.

[0071] The active disturbance rejection speed controller 1 will use the manually given reference speed signal n * Using the actual speed n as input, active disturbance rejection control is used to adjust the speed difference to obtain the reference torque T. ref This helps maintain a stable rotational speed.

[0072] The optimal reference current real-time lookup table module 2 will use the reference torque T output by the active disturbance rejection speed controller 1. ref The output n of the rotational speed calculation module 9 is used as input, and different reference torques T are obtained in advance using a genetic algorithm. ref And the optimal reference current data i at rotational speed n ref (T ref The optimization process is as follows (n), Figure 3 As shown. Figure 3 In the middle, the torque pulsation T ripple The reciprocal of the value is used as the fitness function of the genetic algorithm, and the optimal reference current i is obtained through iterative selection. ref This current minimizes torque ripple in the switched reluctance motor 12 under current operating conditions. The optimal reference current data i ref (T ref The n) is placed into the Lookup Table2-D module to retrieve the optimal reference current i. ref .

[0073] The fuzzy current compensation module 3, for the reference current i ref The compensation current Δi is obtained by performing calculations with the position angle θ.comp The membership functions of the input and output of fuzzy current compensation are as follows: Figures 2(a) to 2(c) As shown. Figures 2(a) to 2(c) Triangular membership functions are used in all cases. Figure 2(a) shows the input reference current i. ref The membership function graph of the input position angle θ has a universe of discourse of [0 20] and is divided into five fuzzy language values; Figure 2(b) is the membership function graph of the input position angle θ, with a universe of discourse of [0 22.5] and is divided into five fuzzy language values; Figure 2(c) is the membership function graph of the output compensation current, with a universe of discourse of [0 4.5] and is divided into four fuzzy language values.

[0074] Reference current i ref The input domains of discourse for position angle θ are [0 20] and [0 22.5], respectively. The fuzzy operation adopts Mamdani-type inference. The input fuzzy language values ​​are {NM, NS, ZE, PS, PM}, and the output fuzzy language values ​​are {ZE, PS, PM, PB}. Among them, NM, NS, ZE, PS, PM and PB represent negative middle, negative small, zero, positive small, positive middle and positive large, respectively. The fuzzy rules are set as shown in Table 1:

[0075] The fuzzy rules set in Table 1

[0076]

[0077] The reference radial force generation module 4 couples the torque characteristic T(i,θ) and radial force characteristic F(i,θ) obtained from finite element simulation to output the reference radial force F. ref .like Figure 4 As shown, by reference torque T ref Output reference radial force F ref .

[0078] The real-time radial force lookup module 5 obtains the radial force characteristic F(i,θ) of the switched reluctance motor through finite element simulation, puts the radial force characteristic F(i,θ) into the Lookup Table 2-D module, takes the real-time phase current and rotor position angle output by the switched reluctance motor as input, and obtains the real-time radial force F by querying the radial force characteristic F(i,θ).

[0079] The current hysteresis control module 6 will compensate the reference current i nref With the actual phase current i ph The difference is calculated, and the difference is controlled by a current hysteresis loop, which outputs a switching signal to the power converter 11. The hysteresis control rule is as follows: Figure 5 As shown. By Figure 5 It can be seen that: at the reference current i nref With the actual phase current i phIn the direction where the difference decreases, the switching signal is 1, and the actual phase current i ph As the difference increases, it decreases. When the difference is less than -Δi, the switching signal becomes -1, and the actual phase current i ph The value starts to decrease, the difference starts to increase, and when the difference is greater than Δi, the switch signal becomes 1.

[0080] The radial force hysteresis control module 7 will reference the radial force F ref With the actual radial force F r The difference is calculated, and the difference is controlled by a radial force hysteresis loop, outputting a switching signal to power converter 11. The hysteresis control rule is as follows: Figure 6 As shown, by Figure 6 It can be seen that: under the reference radial force F ref With the actual radial force F r The direction in which the difference ΔF increases; when ΔF is less than 0, the current conducting phase switch signal is -1, and the actual radial force F... r The signal decreases continuously until ΔF is greater than 0. When ΔF becomes 0, the switching signal becomes 0, and the currently conducting phase is in freewheeling state, until ΔF is greater than the outer hysteresis ΔF. max At this time, the current conducting phase switch signal becomes 1, and the actual radial force F r The signal to turn on the phase switch is about to increase according to the inner hysteresis ΔF. min Enable conduction.

[0081] The switch signal logic judgment module 8 performs logical judgment on the output signals of the current hysteresis control module 6 and the radial force hysteresis control module 7, and outputs the optimal control signal under the current working condition.

[0082] The genetic algorithm is used to obtain the lookup data of the real-time reference current lookup module 2, and the torque ripple T is then processed. ripple The reciprocal of the function is used as the fitness function F. fit Its expression is:

[0083]

[0084] Among them, T, T ref Let be the actual torque and the reference torque, respectively, and τ be the simulation time. Based on the fitness function, a genetic algorithm is used to optimize the reference current under different speeds and reference torques to obtain the optimal reference current under different speeds and reference torques. The optimization steps are as follows:

[0085] Step 1: Set the current speed and load values;

[0086] Step 2: Initialize the reference current i ref The population assigns values ​​to modules in the simulation model by assigning variable values ​​to the reference current and then runs them.

[0087] Step 3: Calculate the fitness function F using the model output. fit ;

[0088] Step 4: Set the reference current i ref population crossover, mutation, merging, and generation of new reference current i ref population;

[0089] Step 5: Increase the number of population iterations;

[0090] Step 6: Determine whether the number of iterations has reached the maximum or whether the fitness function meets the criteria;

[0091] Step 7: Obtain the optimal reference current i under the current speed and load. ref Then proceed to the first step.

[0092] The fuzzy current compensation module 3 performs current compensation on the active phase during commutation to increase the current level of the first half of the active phase, thereby compensating for the torque drop caused by the previous phase disconnection.

[0093] The radial force hysteresis control module 7 adopts dual hysteresis control, with the inner loop interval [-ΔF]. min ΔF min ], outer ring interval [-ΔF max ΔF max For the currently conducting phase in the commutation region, in the direction where the difference ΔF between the reference radial force Fref and the actual radial force Fr decreases, when ΔF is greater than zero, let the switching signal S = 1. When ΔF is in [-ΔF]... max When the interval is 0, let S = 0. When ΔF is less than -ΔF max When S = -1, in the direction of increasing ΔF, when ΔF is less than zero, let S = -1, when ΔF is in [0ΔF] max When the interval is [0, S = 0, when ΔF is greater than ΔF] max When S = 1; for the single-phase conduction region and the soon-to-conduct region of the commutation region, in the direction of decreasing ΔF, when ΔF is greater than -ΔF min When S = 1, when ΔF is less than -ΔF min When S = 0, in the direction of increasing ΔF, when ΔF is less than ΔF min When S = 0, when ΔF is greater than ΔF min At that time, let S = 1.

[0094] The switching signal logic judgment module 8 has the following judgment logic: when the actual radial force F r Less than the reference radial force F ref When the switch signal logic judgment module 8 outputs the switch signal output by the current hysteresis control module 7, the radial force hysteresis control module 7 temporarily does not participate in the control; when the actual radial force Fr Greater than the reference radial force F ref At this time, the output of the switch signal logic judgment module 8 is the signal obtained by performing an AND operation between the output signal of the current hysteresis control module 6 and the output signal of the radial force hysteresis control module 7.

[0095] The radial force control method for a switched reluctance motor based on fuzzy current compensation includes the following steps:

[0096] Step 1: Calculate the speed error by subtracting the reference speed from the actual speed;

[0097] Step 2: The speed error is processed by the active disturbance rejection speed controller 1 to obtain the reference torque T. ref ;

[0098] Step 3: Reference torque T ref After the optimal reference current real-time lookup module 2 and the reference radial force generation module 4, the reference current i is generated. ref and reference radial force F ref ;

[0099] Step 4: For the reference current i ref The compensation current Δi is obtained by performing fuzzy calculations on the rotor position angle θ. comp and with reference current i ref The compensated reference current i is obtained by adding them together. nref ;

[0100] Step 5: Based on the rotor position angle θ and phase current i ph The real-time radial force F is obtained by looking up the table. r ;

[0101] Step 6: Compensated reference current i nref With phase current i ph The switching signal S is obtained through hysteresis. i Reference radial force F ref and real-time radial force F r The switching signal S is obtained through hysteresis. F ;

[0102] Step 7: Switch signal S i and switch signal S F The switching signal S of power converter 11 is obtained after logic processing;

[0103] Step 8: The power converter 11 turns on or off according to the switching signal S, controlling the operation of the switched reluctance motor 12;

[0104] Step 9: Position sensor 10 calculates the rotor position angle and obtains the real-time speed of the motor through speed calculation module 9.

[0105] This invention is based on simulation experiments on the Matlab / Simulink platform. The parameters of the switched reluctance motor 12 are as follows:

[0106] The stator has 12 poles, the rotor has 8 poles, and the DC bus voltage is 514V. The formula for calculating torque ripple is: T max T min T av These represent the maximum torque, minimum torque, and average torque, respectively. The formula for calculating radial force pulsation is as follows: F max F min F av These are the maximum radial force, minimum radial force, and average radial force, respectively.

[0107] Figure 7(a) shows the current waveform of the current chopping control when running at 800 rpm and 3 N·m; Figure 7(b) shows the current waveform of the control method of the present invention. As shown in Figure 7(a), the current of the current chopping is chopped around a certain value and fluctuates around a stable current value; as shown in Figure 7(b), the current waveform of the method of the present invention has a rapid rise in current when the phase is turned on, and then slowly falls back to around a certain current value. This waveform can compensate for the drop in torque when the phase is turned on and increase the total torque value.

[0108] As shown in Figures 8(a) and 8(b), when the switched reluctance motor is running at 800 rpm and 3 N·m, the torque waveforms of the current chopper control and the method proposed in this invention are compared. The torque ripple of the current chopper control is 60%, while the torque ripple of the method proposed in this invention is 35.6%.

[0109] As shown in Figures 9(a) and 9(b), when the switched reluctance motor is running at 800 rpm and 3 N·m, the radial force waveforms of the current chopper control and the method proposed in this invention are compared. The radial force pulsation of the current chopper control is 173.2%, while the radial force pulsation of the method proposed in this invention is 115.2%.

[0110] In summary, this invention can simultaneously suppress torque pulsation and radial force pulsation, and ensure that the speed of the switched reluctance motor is unaffected by load fluctuations. While maintaining a stable motor speed, it suppresses torque pulsation during commutation; simultaneously, it directly controls the radial force, reducing radial force fluctuations, thereby achieving the goal of reducing the vibration and noise of the switched reluctance motor.

Claims

1. A radial force control system for a switched reluctance motor based on fuzzy current compensation, characterized in that, The system includes: Self-disturbance rejection speed controller (1), optimal reference current real-time lookup table module (2), fuzzy current compensation module (3), reference radial force generation module (4), real-time radial force lookup table module (5), current hysteresis control module (6), radial force hysteresis control module (7), switch signal logic judgment module (8), speed calculation module (9), position sensor (10), power converter (11); A reference speed signal n is connected to the input of the disturbance- free speed controller (1) * and the speed deviation obtained by differencing the outputs of the speed calculation module (9); The output of the self-disturbance rejection speed controller (1) is connected to the input of the optimal reference current real-time lookup table module (2) and the input of the reference radial force generation module (4), respectively. The output of the reference radial force generation module (4) is connected to the input of the radial force hysteresis control module (7). The input of the real-time radial force lookup table module (5) is connected to the output of the position sensor (10) and the switched reluctance motor (12), respectively. The input of the position sensor (10) is connected to the switched reluctance motor (12), and the output of the real-time radial force lookup table module (5) is connected to the input of the radial force hysteresis control module (7). The input terminal of the fuzzy current compensation module (3) is connected to the output terminal of the optimal reference current real-time lookup table module (2) and the output terminal of the position sensor (10), respectively; the output terminal of the fuzzy current compensation module (3) is added to the output terminal of the optimal reference current real-time lookup table module (2) to obtain the compensated reference current; The compensated reference current flows through the input terminal of the current hysteresis control module (6), and the input terminal of the current hysteresis control module (6) is connected to the switched reluctance motor (12). The output of the current hysteresis control module (6) and the output of the radial force hysteresis control module (7) are both connected to the input of the switch signal logic judgment module (8). The output of the switch signal logic judgment module (8) is connected to the input of the power converter (11). The output of the power converter (11) is connected to the switched reluctance motor (12).

2. The radial force control system for a switched reluctance motor based on fuzzy current compensation according to claim 1, characterized in that: The active disturbance rejection speed controller (1) regulates the difference between the given reference rotational speed signal n * The active disturbance rejection speed controller (1) regulates the difference between the given reference rotational speed signal n ref .

3. The radial force control system for a switched reluctance motor based on fuzzy current compensation according to claim 1, characterized in that: The optimal reference current real-time lookup table module (2) will use the reference torque T output by the self-disruption speed controller (1) as the reference current. ref The output n of the rotational speed calculation module (9) is used as input, and different reference torques T are obtained in advance using a genetic algorithm. ref And the optimal reference current data i at rotational speed n ref (T ref ,n); The optimal reference current data i ref (T ref The n) is placed into the Lookup Table2-D module to retrieve the optimal reference current i. ref .

4. The radial force control system for a switched reluctance motor based on fuzzy current compensation according to claim 1, characterized in that: The fuzzy current compensation module (3) adjusts the reference current i ref The compensation current Δi is obtained by calculating the rotor position angle θ. comp Reference current i ref The input universes of discourse for the rotor position angle θ are [0 20] and [0 22.5], respectively. The fuzzy operation adopts Mamdani-type inference. The input fuzzy language values ​​are {NM, NS, ZE, PS, PM}, and the output fuzzy language values ​​are {ZE, PS, PM, PB}, where NM, NS, ZE, PS, PM and PB represent negative middle, negative small, zero, positive small, positive middle and positive large, respectively.

5. The radial force control system for a switched reluctance motor based on fuzzy current compensation according to claim 1, characterized in that: The reference radial force generation module (4) couples the torque characteristics T(i, θ) and the radial force characteristics F(i, θ) obtained by finite element simulation, and outputs the reference radial force F ref .

6. The radial force control system for a switched reluctance motor based on fuzzy current compensation according to claim 1, characterized in that: The real-time radial force lookup module (5) obtains the radial force characteristic F(i,θ) of the switched reluctance motor through finite element simulation, puts the radial force characteristic F(i,θ) into the Lookup Table 2-D lookup module, takes the real-time phase current and rotor position angle output by the switched reluctance motor as input, and obtains the real-time radial force F by querying the radial force characteristic F(i,θ).

7. The radial force control system for a switched reluctance motor based on fuzzy current compensation according to claim 3, characterized in that: The genetic algorithm is used to obtain the lookup data of the real-time reference current lookup module (2), and the torque ripple T is then processed. ripple The reciprocal of the fitness function F fit Its expression is: Among them, T, T ref Let τ be the actual torque and the reference torque, respectively, and τ be the simulation time. Based on the fitness function, a genetic algorithm is used to optimize the reference current under different speeds and reference torques to obtain the optimal reference current corresponding to the minimum torque ripple under different speeds and reference torques.

8. The radial force control system for a switched reluctance motor based on fuzzy current compensation according to claim 1, characterized in that: The radial force hysteresis control module (7) adopts dual hysteresis control, with the inner loop interval [-ΔF] min ΔF min ], outer ring interval [-ΔF max ΔF max For the currently conducting phase in the commutation region, in the direction where the difference ΔF between the reference radial force Fref and the actual radial force Fr decreases, when ΔF is greater than zero, let the switching signal S = 1. When ΔF is in [-ΔF]... max When the interval is 0, let S = 0. When ΔF is less than -ΔF max When S = -1, in the direction of increasing ΔF, when ΔF is less than zero, let S = -1, when ΔF is in [0ΔF] max When the interval is [0, S = 0, when ΔF is greater than ΔF] max When S = 1; for the single-phase conduction region and the soon-to-conduct region of the commutation region, in the direction of decreasing ΔF, when ΔF is greater than -ΔF min When S = 1, when ΔF is less than -ΔF min When S = 0, in the direction of increasing ΔF, when ΔF is less than ΔF min When S = 0, when ΔF is greater than ΔF min At that time, let S = 1.

9. The radial force control system for a switched reluctance motor based on fuzzy current compensation according to claim 1, characterized in that: The switching signal logic judgment module (8) has the following judgment logic: when the actual radial force F r Less than the reference radial force F ref When the switching signal logic judgment module (8) outputs the switching signal output by the current hysteresis control module (7), the radial force hysteresis control module (7) temporarily does not participate in the control; when the actual radial force F r Greater than the reference radial force F ref At that time, the output of the switch signal logic judgment module (8) is the signal after performing an AND operation between the output signal of the current hysteresis control module (6) and the output signal of the radial force hysteresis control module (7).

10. A radial force control method for a switched reluctance motor based on fuzzy current compensation, characterized in that... Includes the following steps: Step 1: Calculate the speed error by subtracting the reference speed from the actual speed; Step 2: The speed error is processed through a disturbance-observer-based speed controller (1) to obtain a reference torque T ref ; Step 3: Reference torque T ref The reference current i is generated through the optimal reference current real-time lookup table module (2) and the reference radial force generation module (4) ref and the reference radial force F ref ; Step 4: fuzzy operation on the reference current i ref and the rotor position angle θ to obtain a compensation current Δi comp , and add it to the reference current i ref to obtain the compensated reference current i nref ; Step 5: Based on the rotor position angle θ and phase current i ph The real-time radial force F is obtained by looking up the table. r ; Step 6: Compensated reference current i nref With phase current i ph The switching signal S is obtained through hysteresis. i Reference radial force F ref and real-time radial force F r The switching signal S is obtained through hysteresis. F ; Step 7: Switch signal S i and switch signal S F After logic processing, the switching signal S of the power converter (11) is obtained; Step 8: The power converter (11) turns on or off according to the switching signal S, and controls the operation of the switched reluctance motor (12); Step 9: The position sensor (10) calculates the rotor position angle and obtains the real-time speed of the motor through the speed calculation module (9).

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