A method for direct control of torque and axial force of a linear rotary switched reluctance motor

Abstract

This invention discloses a direct control method for torque and axial force of a linear rotary switched reluctance motor. First, the sector containing the flux linkage vector is determined through calculation. Based on the flux linkage hysteresis signal and the torque hysteresis signal, the voltage vector required for control is determined. Then, the axial force is controlled within the control range of (-15°, 15°) where the rotor position is selected. The corresponding axial force voltage vector is selected based on the axial force hysteresis signal. Finally, the operating mode of each power converter switch is determined based on the signs of all voltage vectors. This invention significantly reduces torque and axial force pulsation by directly controlling the motor's torque and axial force, resulting in a faster system response. Operating modes for the torque winding and axial force winding are established separately for torque and axial force, respectively, leading to more reasonable vector selection. Furthermore, no model calculation is performed during the control process, so the control accuracy does not depend on the analytical model, improving the system response speed and simplifying the control strategy.

Description

Technical Field

[0001] This invention relates to the field of linear rotary switched reluctance motor control technology, and mainly to a method for direct control of torque and axial force of a linear rotary switched reluctance motor. Background Technology

[0002] Linear rotary switched reluctance motors (LRSRMs) are a new type of motor developed by incorporating magnetic levitation technology into traditional switched reluctance motors. This motor can achieve not only circumferential rotational motion but also axial linear motion. On the one hand, by integrating linear and rotary motion into a single unit, the size of the transmission device is significantly reduced, and power density is increased. On the other hand, switched reluctance motors possess advantages such as simple structure, low cost, high temperature resistance, and high fault tolerance. Therefore, linear rotary switched reluctance motors are suitable for applications in aerospace, robot joints, probe positioning, CNC machine tools, and other fields.

[0003] The motor has two sets of windings on the stator teeth. One set of windings is wound laterally on the two stator teeth to generate the main magnetic field, which is used to generate torque. The other set of windings is wound in the same direction on one stator tooth and in the opposite direction on the other stator tooth to generate unbalanced magnetic pull. By adjusting the current in these two sets of windings, the rotation and linear motion of the linear rotary switched reluctance motor can be realized.

[0004] Due to the structural characteristics of linear rotary switched reluctance motors, there is coupling between torque and axial force. Current control methods for linear rotary switched reluctance motors involve calculating the current in each pole winding using a mathematical model of torque and axial force, then distributing it to the corresponding winding conduction intervals for hysteresis control. However, this method is highly dependent on model accuracy and suffers from drawbacks such as large torque and axial force pulsations, slow linear motion response, and complex control. Summary of the Invention

[0005] Purpose of the invention: To address the problems existing in the above-mentioned background technology, the present invention provides a direct control method for torque and axial force of a linear rotary switched reluctance motor. This method no longer performs current calculation on the motor model, but directly controls the torque and axial force of the motor, resulting in smaller torque and axial force pulsations. Furthermore, without the use of a calculation step, the system response is faster.

[0006] Technical solution: To achieve the above objectives, the technical solution adopted by this invention is as follows:

[0007] A method for direct control of torque and axial force of a linear rotary switched reluctance motor includes the following steps:

[0008] Step S1: Calculate and determine the sector containing the flux linkage vector by controlling the equivalent total magnetic flux of the two windings of the linear rotary switched reluctance motor LRSRM; control the torque winding current it and the axial force current i by switching the power circuit transistors on and off. f Then calculate the torque T. total The torque T total The difference is compared with a preset threshold and used as the torque hysteresis signal; the flux linkage signal ψ is calculated. s The difference is compared with a preset threshold and used as the flux linkage hysteresis signal. Based on the calculated flux linkage hysteresis signal and torque hysteresis signal, the required voltage vector is determined. Specifically, when the flux linkage hysteresis signal requires an increase in flux linkage, a voltage vector with an angle less than 90° to the current flux linkage is selected; when the flux linkage hysteresis signal requires a decrease in flux linkage, a voltage vector with an angle greater than 90° to the current flux linkage is selected. When the torque hysteresis signal requires an increase in torque, a voltage vector with a leading flux linkage is selected; when the torque hysteresis signal requires a decrease in torque, a voltage vector with a lagging flux linkage is selected.

[0009] Step S2: Select the rotor position within the control range of (-15°, 15°) to control the axial force, and sequentially conduct the three-phase windings by 30°; control the torque winding current i by switching the power circuit switching transistors on and off. t With axial force current i f Then calculate the axial force F. total , axial force F total The difference is compared with a preset threshold and used as a torque hysteresis signal. When the axial force hysteresis signal requires an increase in axial force, the two switches of the corresponding phase axial force winding are turned on. When the axial force hysteresis signal requires a decrease in axial force, the two switches of the corresponding phase axial force winding are turned off. When the rotor position is not within the control range, the control winding does not work.

[0010] Step S3: According to the three-phase winding voltage vector table, based on different rotor angle positions, within the (-15°, 15°) range, control the torque winding voltage and axial force winding voltage respectively according to the hysteresis signals of torque and axial force. Specifically, when torque needs to be increased, the torque hysteresis signal is "1", requiring a "+" torque winding voltage vector; when torque needs to be decreased, the torque hysteresis signal is "-1", requiring a "-" torque winding voltage vector; when torque is within the loop width, the torque hysteresis signal is "0", requiring a "0" torque winding voltage vector; the axial force voltage vector can be obtained similarly. After each phase stator tooth winding is assigned the corresponding torque and axial force voltage vectors, the basic voltage vector for the corresponding range is selected to achieve control of the torque and axial force of the linear rotary switched reluctance motor.

[0011] Furthermore, in step S1, a radial dual-winding LRSRM is used, and controlling the equivalent total magnetic flux of the two windings of the LRSRM specifically includes:

[0012] The torque winding spans two stator teeth, and the axial force winding is connected in reverse series on the two stator teeth. Therefore, the magnetic flux linkages of the two windings at stator 1 end are in the same direction and superimposed. Here, Ψ1 is the total magnetic flux linkage under stator 1, and Ψ2 is the total magnetic flux linkage under stator 2. t Ψ is the flux linkage generated by the torque winding. f The flux linkage generated by the axial force winding is represented as follows:

[0013] ψ1=ψ t +ψ f

[0014] The magnetic flux linkages of the two sets of windings at the two ends of the stator are in opposite directions, and the magnetic flux linkages weaken each other, as shown below:

[0015] ψ2=ψ t -ψ f

[0016] Therefore, the average flux linkage generated by the A-phase winding of the LRSRM is:

[0017] ψ A =ψ1+ψ2=2ψ t

[0018] The average flux linkage generated by the B and C phase windings is determined using the same method. By controlling the flux of the three-phase torque windings, the total flux Ψ of the LRSRM is controlled. s This allows for further control of the flux hysteresis signal, determining the required voltage vector.

[0019] Furthermore, in step S1, the torque T total The calculation method is as follows:

[0020]

[0021] Among them, K ta K tb K tc It is a coefficient related to the rotor angle, N T N f It refers to the number of turns in the torque winding and the number of turns in the axial force winding, i at i bt i ct The currents of the torque windings in phases A, B, and C are, in order, i af i bf and i cf The axial force winding currents of phases A, B, and C are, in order.

[0022] The sector containing the flux linkage vector is calculated and determined as follows:

[0023]

[0024] Where, ψ A ψ B ψ C For the three-phase magnetic flux linkages A, B, and C, δ α Let δ be the magnetic flux linkage vector angle; define δ α Sector I is defined as the region within the range (0°, 60°). α Sector II is defined as the region within the range of (60°, 120°). α Sector III is defined as the region within the (120°, 180°) interval, and δ is defined as follows. α Sector IV is defined as being located within the range of (-180°, -120°), and δ is defined as follows. α Sector V is defined as the region within the range of (-120°, -60°). α Sector VI is located within the range of (0°, 60°).

[0025] Furthermore, determining the required three-phase voltage vector in step S1 specifically includes:

[0026] Within each inductance cycle, when the motor operates in sector I, the three-phase voltage vector is v3(-1,1,0) when torque needs to increase and flux linkage needs to decrease, and v2(0,1,-1) when torque and flux linkage need to increase; v5(0,-1,1) when torque and flux linkage need to decrease, and v6(1,-1,0) when torque and flux linkage need to increase. When the motor operates in sector II, the three-phase voltage vector is v4(-1,0,1) when torque needs to increase and flux linkage needs to decrease, and v3(-1,1,0) when torque and flux linkage need to increase. When the torque and flux linkage need to be reduced, the three-phase voltage vector is v6(1,-1,0); when the torque and flux linkage need to be increased, the three-phase voltage vector is v1(1,0,-1); when the motor runs to sector III, when the torque and flux linkage need to be increased, the three-phase voltage vector is v5(0,-1,1); when the torque and flux linkage need to be increased, the three-phase voltage vector is v4(-1,0,1); when the torque and flux linkage need to be reduced, the three-phase voltage vector is v1(1,0,-1); when the torque and flux linkage need to be increased, the three-phase voltage vector is v2(0,1,-1); when the motor runs to sector IV, when the torque and flux linkage need to be reduced, the three-phase voltage vector is v5(0,-1,1); when the torque and flux linkage need to be increased, the three-phase voltage vector is v4(-1,0,1); when the torque and flux linkage need to be reduced, the three-phase voltage vector is v1(1,0,-1); when the torque and flux linkage need to be increased, the three-phase voltage vector is v2(0,1,-1); when the motor runs to sector IV, when the torque and flux linkage need to be increased, the three-phase voltage vector is v5(0,-1,1); ... When torque needs to be increased and flux linkage needs to be decreased, the three-phase voltage vector is v6(1,-1,0); when torque needs to be increased and flux linkage needs to be increased, the three-phase voltage vector is v5(0,-1,1); when torque needs to be decreased and flux linkage needs to be decreased, the three-phase voltage vector is v2(0,1,-1); when torque needs to be decreased and flux linkage needs to be increased, the three-phase voltage vector is v3(-1,1,0); when the motor runs to sector V, when torque needs to be increased and flux linkage needs to be decreased, the three-phase voltage vector is v1(1,0,-1); when torque needs to be increased and flux linkage needs to be increased, the three-phase voltage vector is v6(1,-1,0); when torque needs to be decreased ...1(1,0,-1); when torque needs to be increased and flux linkage needs to be increased, the three-phase voltage vector is v1(1,0,-1); when torque needs to be decreased and flux linkage needs to be decreased, the three-phase voltage vector is v1(1,0,-1); when torque needs to be increased and flux linkage needs to be increased, the three-phase voltage vector is v1(1,-1,-1); when torque needs to be decreased and flux linkage needs to be decreased, the three-phase voltage vector is v1(1,-1,-1); when torque needs to be The quantity is v2(0,1,-1). When the torque needs to be reduced and the flux linkage needs to be increased, the three-phase voltage vector is v3(-1,1,0). When the motor runs to sector VI, when the torque needs to be increased, the three-phase voltage vector is v2(1,1,-1), and when the torque needs to be reduced, the three-phase voltage vector is v4(-1,1,1). Here, "-1" represents that both switches of the corresponding phase torque winding power circuit are turned off, "0" represents that one switch of the corresponding phase torque winding power circuit is turned on and the other is turned off, and "1" represents that both switches of the corresponding phase torque winding power circuit are turned on. Each bit in the three-phase voltage vector v represents the control state of the switch of the corresponding phase power circuit.

[0027] Furthermore, in step S2, the axial force F total The calculation method is as follows:

[0028]

[0029] Among them, K ta K tb K tc It is a coefficient related to the rotor angle, N T N f These are the number of turns in the torque winding and the number of turns in the axial force winding.

[0030] Furthermore, the voltage vector table for one phase winding in step S3 is shown below:

[0031]

[0032]

[0033] Based on the voltage vector table above, the torque voltage symbol can be determined based on the selected voltage vector symbol, and the axial force voltage symbol can be determined based on the axial force hysteresis signal. By selecting the basic voltage vector of the corresponding interval, the torque and axial force of the linear rotary switched reluctance motor can be controlled. The other two-phase voltage vector tables can be obtained in the same way.

[0034] Beneficial effects:

[0035] The present invention provides a direct control method for torque and axial force of a linear rotary switched reluctance motor, which directly controls the motor's torque and axial force, greatly reducing torque and axial force pulsation and making the system response faster. It establishes working modes for torque windings and axial force windings respectively, and establishes torque voltage vectors and axial force voltage vectors, allowing for more reasonable vector selection. Furthermore, no model calculation is performed during the control process, so the control accuracy does not depend on the analytical model, improving the system response speed and simplifying the control strategy. Attached Figure Description

[0036] Figure 1 This is a system control block diagram of the direct control method for torque and axial force of a linear rotary switched reluctance motor provided by the present invention;

[0037] Figure 2 This is a schematic diagram of the structure of a 6 / 4 pole double winding linear rotary switched reluctance motor in an embodiment of the present invention;

[0038] Figure 3 This is a diagram showing the winding connection method of a 6 / 4 pole double-winding linear rotary switched reluctance motor in an embodiment of the present invention;

[0039] Figure 4 This is a three-phase basic voltage vector diagram in an embodiment of the present invention;

[0040] Figure 5 This is a diagram of the three-phase inductance curves in an embodiment of the present invention.

[0041] Figure 6 This is a working mode diagram of the three-phase torque winding power circuit in an embodiment of the present invention.

[0042] Figure 7 This is a working mode diagram of the three-phase axial force winding power circuit in an embodiment of the present invention. Detailed Implementation

[0043] The present invention will be further described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0044] like Figure 1 The diagram shows a block diagram of the direct control system for torque and axial force of a linear rotary switched reluctance motor according to the present invention. This control system directly controls the motor's torque, flux linkage, and axial force. First, sector calculation is performed using flux linkage. Then, based on the sector, flux linkage, and torque hysteresis signals, the required torque voltage vector is determined to control the operating mode of the torque winding power circuit. Based on the axial force hysteresis signal, the rotor's location is determined to select the axial force voltage vector, thereby controlling the operating mode of the axial force winding power circuit.

[0045] The torque winding current i is controlled by switching the power circuit transistor on and off. t With axial force current i f This controls the torque and axial force. The torque calculation formula is as follows:

[0046]

[0047] Axial force calculation formula:

[0048]

[0049] Among them, K ta K tb K tc It is a coefficient related to the rotor angle, N T N f i represents the number of turns in the torque winding and the number of turns in the axial force winding, respectively. at It is the torque winding current of phase A, i af It is the axial force winding current of phase A, i bt i ct i bf i cf Similarly.

[0050] This embodiment uses a 6 / 4 pole linear rotary switched reluctance motor as the controlled object, and the specific structure is as follows: Figure 2As shown, it consists of two stators and one rotor. The stators have six stator teeth, and the rotor has four rotor teeth, divided into three phases. Each phase has two sets of windings: a torque winding and an axial force winding. The torque winding spans two stator teeth to generate the main magnetic flux. The axial force winding is first wound in phase with the torque winding at stator end 1, and then wound in the opposite phase at stator end 2, as shown. Figure 3 As shown. Due to the unique structure and control method of the linear rotary switched reluctance motor, direct torque and direct axial force control performs hysteresis control on torque and axial force without requiring model calculations, thereby accelerating the system response speed and reducing torque and axial force pulsation. Specific control methods are provided below.

[0051] Step S1: First, control the equivalent total magnetic flux Ψ of the two windings of the linear rotary switched reluctance motor LRSRM. s The sector containing the flux linkage vector is determined by calculation.

[0052] The torque winding spans two stator teeth, and the axial force winding is connected in reverse series on the two stator teeth. Therefore, the magnetic flux linkages of the two windings at stator 1 end are in the same direction and superimposed. Here, Ψ1 is the total magnetic flux linkage under stator 1, and Ψ2 is the total magnetic flux linkage under stator 2. t Ψ is the flux linkage generated by the torque winding. f The flux linkage generated by the axial force winding is represented as follows:

[0053] ψ1=ψ t +ψ f

[0054] The magnetic flux linkages of the two sets of windings at the two ends of the stator are in opposite directions, and the magnetic flux linkages weaken each other, as shown below:

[0055] ψ2=ψ t -ψ f

[0056] Therefore, the average flux linkage generated by the A-phase winding of the LRSRM is:

[0057] ψ A =ψ1+ψ2=2ψ t

[0058] The average flux linkage generated by the B and C phase windings is determined using the same method. By controlling the flux of the three-phase torque windings, the total flux Ψ of the LRSRM is controlled. s This allows for further control of the flux hysteresis signal, determining the required voltage vector.

[0059] The sector containing the flux linkage vector is calculated and determined as follows:

[0060]

[0061] Where, ψA ψ B ψ C For the three-phase magnetic flux linkages A, B, and C, δ α Let δ be the magnetic flux linkage vector angle; define δ α Sector I is defined as the region within the range (0°, 60°). α Sector II is defined as the region within the range of (60°, 120°). α Sector III is defined as the region within the (120°, 180°) interval, and δ is defined as follows. α Sector IV is defined as being located within the range of (-180°, -120°), and δ is defined as follows. α Sector V is defined as the region within the range of (-120°, -60°). α Sector VI is located within the range of (0°, 60°).

[0062] Then, by switching the power circuit transistor on and off, the torque winding current i is controlled respectively. t With axial force current i f Then calculate the torque T. total The torque T total The difference is compared with a preset threshold and used as the torque hysteresis signal; the flux linkage signal ψ is calculated. s It is then compared with a preset threshold, and the difference is used as the flux hysteresis signal;

[0063] Where the torque T total The calculation method is as follows:

[0064]

[0065] Among them, K ta K tb K tc It is a coefficient related to the rotor angle, N T N f It refers to the number of turns in the torque winding and the number of turns in the axial force winding, i at It is the torque winding current of phase A, i af It is the axial force winding current of phase A, i bt i ct i bf i cf Similarly.

[0066] Based on the calculated flux linkage hysteresis signal and torque hysteresis signal, the required three-phase voltage vector is determined, and the required voltage vector is selected according to the sector. Figure 4The three-phase voltage vector diagram of this invention selects six voltage vectors as basic voltage vectors based on the operating state of the switched reluctance motor. Each inductance cycle of the motor operation can be divided into six sectors, N1 to N6, with one basic voltage vector in each sector. According to the direct torque control principle, when the flux hysteresis signal requires an increase in flux, a three-phase voltage vector with an angle less than 90° to the current flux is selected; when the flux hysteresis signal requires a decrease in flux, a three-phase voltage vector with an angle greater than 90° to the current flux is selected. When the torque hysteresis signal requires an increase in torque, a voltage vector with leading flux is selected; when the torque hysteresis signal requires a decrease in torque, a voltage vector with lagging flux is selected. The specific selection principles are shown in Table 1 below:

[0067] Table 1. Principles for selecting voltage vectors

[0068]

[0069] Here, "1" indicates that the torque or flux linkage needs to be increased, and "-1" indicates that the torque or flux linkage needs to be decreased. If the current flux linkage is in region k, and the flux linkage needs to be increased, then the voltage vector v is selected. k+1 or v k-1 If the flux linkage needs to be reduced, then the voltage vector v is selected. k+2 or v k-2 If the torque needs to be increased, then select the voltage vector v. k+1 If the torque needs to be reduced, then select the voltage vector v. k-1 .

[0070] Once determined, the required three-phase voltage vectors for the motor are selected as follows:

[0071] Within each inductor cycle, when the motor operates in sector I, the three-phase voltage vector is v3(-1,1,0) when torque needs to increase and flux linkage needs to decrease, and v2(0,1,-1) when torque and flux linkage need to increase; v5(0,-1,1) when torque and flux linkage need to decrease, and v6(1,-1,0) when torque and flux linkage need to increase. When the motor operates in sector II, the three-phase voltage vector is v4(-1,0,1) when torque needs to increase and flux linkage needs to decrease, and v3(-1,1) when torque and flux linkage need to increase. When the torque and flux linkage need to be reduced, the three-phase voltage vector is v6(1,-1,0); when the torque and flux linkage need to be increased, the three-phase voltage vector is v1(1,0,-1); when the motor runs to sector III, when the torque and flux linkage need to be increased, the three-phase voltage vector is v5(0,-1,1); when the torque and flux linkage need to be increased, the three-phase voltage vector is v4(-1,0,1); when the torque and flux linkage need to be reduced, the three-phase voltage vector is v1(1,0,-1); when the torque and flux linkage need to be increased, the three-phase voltage vector is v2(0,1,-1); when the motor runs to sector IV. When the torque needs to increase and the flux linkage needs to decrease, the three-phase voltage vector is v6(1,-1,0); when the torque needs to increase and the flux linkage needs to increase, the three-phase voltage vector is v5(0,-1,1); when the torque needs to decrease and the flux linkage needs to decrease, the three-phase voltage vector is v2(0,1,-1); when the torque needs to decrease and the flux linkage needs to increase, the three-phase voltage vector is v3(-1,1,0). When the motor runs to sector V, when the torque needs to increase and the flux linkage needs to decrease, the three-phase voltage vector is v1(1,0,-1); when the torque needs to increase and the flux linkage needs to increase, the three-phase voltage vector is v6(1,-1,0); when the torque needs to decrease and the flux linkage needs to decrease... When the torque needs to be reduced and the flux linkage needs to be increased, the three-phase voltage vector is v2(0,1,-1). When the motor runs to sector VI, when the torque needs to be increased, the three-phase voltage vector is v2(1,1,-1). When the torque needs to be reduced, the three-phase voltage vector is v4(-1,1,1). Here, "-1" means that both switches of the corresponding phase torque winding are turned off, "0" means that one switch of the corresponding phase torque winding is turned on and the other is turned off, and "1" means that both switches of the corresponding phase torque winding are turned on. Each bit in the three-phase voltage vector v represents the control state of the switch of the power circuit of that phase winding.

[0072] Step S2: For axial force control, since the axial force winding current needs to flow bidirectionally, the voltage vector of the power unit needs to be redefined. Define the operating mode "+1" when the voltage across the axial force winding is positive, define the operating mode "0" when the voltage across the axial force winding is 0, and define the operating mode "-1" when the voltage across the axial force winding is negative. Select the rotor position within the control range of (-15°, 15°) to control the axial force, and sequentially turn on the three-phase windings by 30°; when the axial force hysteresis signal needs to increase the axial force and the rotor position is in the (-15°, 15°) range, turn on the two switches of the corresponding phase axial force winding; when the axial force hysteresis signal needs to decrease the axial force and the rotor position is in the (-15°, 15°) range, simultaneously turn off the two switches of the corresponding phase axial force winding; when the rotor position is not within the control range, the control winding does not work.

[0073] The specific axial force calculation is as follows:

[0074]

[0075] Among them, K ta K tb K tc It is a coefficient related to the rotor angle, N T N f It refers to the number of turns in the torque winding and the number of turns in the axial force winding, i at It is the torque winding current of phase A, i af It is the axial force winding current of phase A, i bt i ct i bf i cf Similarly.

[0076] Step S3: Based on the three-phase winding voltage vector table, and according to different rotor angle positions within the (-15°, 15°) range, control the torque winding voltage and axial force winding voltage respectively based on the hysteresis signals of torque and axial force. Specifically, if the torque needs to be increased, the torque hysteresis signal is "1", and a "+" torque winding voltage vector needs to be given; if the torque needs to be decreased, the torque hysteresis signal is "-1", and a "-" torque winding voltage vector needs to be given; if the torque is within the loop width, the torque hysteresis signal is "0", and a "0" torque winding voltage vector is given. The axial force voltage vector is similarly determined. After each phase stator tooth winding is assigned the corresponding torque and axial force voltage vectors, the basic voltage vector for the corresponding range is selected to achieve control of the torque and axial force of the linear rotary switched reluctance motor. The selection table for one phase winding voltage vector is shown in Table 2 below; the voltage vector tables for the other two phases can be obtained similarly.

[0077] Table 2 Selection Table for Voltage Vector of One-Phase Winding

[0078]

[0079] Based on the voltage vector table above, the torque voltage symbol can be determined based on the selected voltage vector symbol, and the axial force voltage symbol can be determined based on the axial force hysteresis signal. By selecting the basic voltage vector for the corresponding interval, the torque and axial force of the linear rotary switched reluctance motor can be controlled. By reasonably selecting the torque voltage vector and the axial force voltage vector, the optimal working state of the torque winding and the axial force winding under each tooth pole can be obtained, thereby achieving the suppression and precise control of the pulsation of the torque and axial force of the linear rotary switched reluctance motor.

[0080] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method for direct control of torque and axial force of a linear rotary switched reluctance motor, characterized in that, Includes the following steps: Step S1: Calculate and determine the sector containing the flux linkage vector by controlling the equivalent total magnetic flux of the two windings of the linear rotary switched reluctance motor LRSRM; control the torque winding current by switching the power circuit transistors on and off. With axial force current Then calculate the torque. , to torque The difference is compared with a preset torque threshold and used as the torque hysteresis signal; the flux linkage signal is then calculated. The difference is compared with a preset threshold and used as the flux linkage hysteresis signal. Based on the calculated flux linkage hysteresis signal and torque hysteresis signal, the required voltage vector is determined. Specifically, when the flux linkage hysteresis signal requires an increase in flux linkage, a voltage vector with an angle less than 90° to the current flux linkage is selected; when the flux linkage hysteresis signal requires a decrease in flux linkage, a voltage vector with an angle greater than 90° to the current flux linkage is selected. When the torque hysteresis signal requires an increase in torque, a voltage vector with a leading flux linkage is selected; when the torque hysteresis signal requires a decrease in torque, a voltage vector with a lagging flux linkage is selected. Step S2: Select the rotor position within the control range of (-15°, 15°) to control the axial force, and sequentially conduct the three-phase windings by 30°; control the torque winding current by switching the power circuit switching transistors on and off. With axial force current Then calculate the axial force. , axial force The difference between the axial force and the preset axial force threshold is used as the axial force hysteresis signal. When the axial force hysteresis signal requires an increase in axial force, the two switching transistors of the corresponding phase axial force winding are turned on. When the axial force hysteresis signal requires a decrease in axial force, the two switching transistors of the corresponding phase axial force winding are turned off. When the rotor position is not within the control range, the control winding does not work. Step S3: According to the three-phase winding voltage vector table, based on different rotor angle positions, within the (-15°, 15°) range, control the torque winding voltage and axial force winding voltage respectively according to the hysteresis signals of torque and axial force. Specifically, when torque needs to be increased, the torque hysteresis signal is "1", requiring a "+" torque winding voltage vector; when torque needs to be decreased, the torque hysteresis signal is "-1", requiring a "-" torque winding voltage vector; when torque is within the loop width, the torque hysteresis signal is "0", requiring a "0" torque winding voltage vector; the axial force voltage vector can be obtained similarly. After each phase stator tooth winding is assigned the corresponding torque and axial force voltage vectors, the basic voltage vector for the corresponding range is selected to achieve control of the torque and axial force of the linear rotary switched reluctance motor.

2. The method for direct control of torque and axial force of a linear rotary switched reluctance motor according to claim 1, characterized in that, In step S1, the radial dual-winding LRSRM is used, and controlling the equivalent total magnetic flux of the two sets of windings of the LRSRM specifically includes: The torque winding spans two stator teeth, and the axial force windings are connected in reverse series on the two stator teeth. Therefore, the magnetic flux linkages of the two sets of windings at the first stator end are in the same direction and superimposed. The total flux linkage under the first stator. The total flux linkage under the second stator. For the magnetic flux generated by the torque winding, The flux linkage generated by the axial force winding is represented as follows: ； The magnetic flux linkages of the two sets of windings at the second stator end are in opposite directions, and the magnetic flux linkages weaken each other, as shown below: ； Therefore, the average flux linkage generated by the A-phase winding of the LRSRM is: ； The average flux linkage generated by the B and C phase windings is determined using the same method. By controlling the flux of the three-phase torque windings, the total flux of the LRSRM is controlled. This allows for further control of the flux hysteresis signal, thereby determining the required voltage vector.

3. The method for direct control of torque and axial force of a linear rotary switched reluctance motor according to claim 2, characterized in that, Torque in step S1 The calculation method is as follows: ； in, , , It is a coefficient related to the rotor angle. , It refers to the number of turns in the torque winding and the number of turns in the axial force winding. , , The actual currents of the torque windings in phases A, B, and C are shown in sequence. , and The actual currents of the axial force windings in phases A, B, and C are shown in sequence. The sector containing the flux linkage vector is calculated and determined as follows: ； in, , , For three-phase magnetic flux linkages A, B, and C, Let the magnetic flux linkage vector angle be defined. Sector I is defined as being located within the range of (0°, 60°). Sector II is defined as being located within the (60°, 120°) interval. Sector III is defined as being located within the (120°, 180°) range. Sector IV is defined as being located within the range of (-180°, -120°). Sector V is defined as being located within the range of (-120°, -60°). Sector VI is located within the range of (0°, 60°).

4. The method for direct control of torque and axial force of a linear rotary switched reluctance motor according to claim 3, characterized in that, Determining the required three-phase voltage vector in step S1 specifically includes: Within each inductance cycle, when the motor operates in sector I, the three-phase voltage vector is v3 (-1,1,0) when torque needs to increase and flux linkage needs to decrease, and v2 (0,1,-1) when torque and flux linkage need to increase; v5 (0,-1,1) when torque and flux linkage need to decrease, and v6 (1,-1,0) when torque and flux linkage need to increase. When the motor operates in sector II, the three-phase voltage vector is v4 (-1,0,1) when torque needs to increase and flux linkage needs to decrease, v3 (-1,1,0) when torque and flux linkage need to increase; v6 (1,-1,0) when torque and flux linkage need to decrease; and v1 (v2,-1,-1) when torque and flux linkage need to decrease. (1,0,-1); When the motor is running in sector III, when the torque needs to increase and the flux linkage needs to decrease, the three-phase voltage vector is v5 (0,-1,1); when the torque needs to increase and the flux linkage needs to increase, the three-phase voltage vector is v4 (-1,0,1); when the torque needs to decrease and the flux linkage needs to decrease, the three-phase voltage vector is v1 (1,0,-1); when the torque needs to decrease and the flux linkage needs to increase, the three-phase voltage vector is v2 (0,1,-1); When the motor is running in sector IV, when the torque needs to increase and the flux linkage needs to decrease, the three-phase voltage vector is v6 (1,-1,0); when the torque needs to increase and the flux linkage needs to increase, the three-phase voltage vector is v5 (0,-1,1); when the torque needs to decrease and the flux linkage needs to decrease, the three-phase voltage vector is v2 (0,1,-1); when the torque needs to decrease and the flux linkage needs to increase, the three-phase voltage vector is v3. (-1,1,0); When the motor is running in sector V, when the torque needs to increase and the flux linkage needs to decrease, the three-phase voltage vector is v1 (1,0,-1); when the torque needs to increase and the flux linkage needs to increase, the three-phase voltage vector is v6 (1,-1,0); when the torque needs to decrease and the flux linkage needs to decrease, the three-phase voltage vector is v2 (0,1,-1); when the torque needs to decrease and the flux linkage needs to increase, the three-phase voltage vector is v3 (-1,1,0); When the motor is running in sector VI, when the torque needs to increase, the three-phase voltage vector is v2(1,1,-1); when the torque needs to decrease, the three-phase voltage vector is v4. (-1,1,1); where "-1" represents that both switches of the corresponding phase torque winding power circuit are turned off, "0" represents that one switch of the corresponding phase torque winding power circuit is turned on and the other is turned off, and "1" represents that both switches of the corresponding phase torque winding power circuit are turned on. Each bit in the three-phase voltage vector v represents the control state of the switch of the corresponding phase power circuit.

5. The method for direct control of torque and axial force of a linear rotary switched reluctance motor according to claim 1, characterized in that, The axial force in step S2 The calculation method is as follows: ； in, , These are the number of turns in the torque winding and the number of turns in the axial force winding; The currents of the torque windings in phases A, B, and C are, in order. and The currents of the axial force windings are, in order, phase A, phase B, and phase C.

6. The method for direct control of torque and axial force of a linear rotary switched reluctance motor according to claim 1, characterized in that, The voltage vector table for one phase winding in step S3 is shown below: ； Based on the voltage vector table above, the torque voltage symbol can be determined based on the selected voltage vector symbol, and the axial force voltage symbol can be determined based on the axial force hysteresis signal. By selecting the basic voltage vector of the corresponding interval, the torque and axial force of the linear rotary switched reluctance motor can be controlled. The other two-phase voltage vector tables can be obtained in the same way.

Images