Variable magnetic circuit switched reluctance motor, system and control method thereof
By changing the energization direction of the excitation winding and reducing the number of power devices, the shortcomings of the switching reluctance motor in torque density and speed regulation range are solved, and efficient and economical motor performance improvement is achieved.
Patent Information
- Application Number
- CN202510111366.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-01-23
- Publication Date
- 2025-04-25
AI Technical Summary
While increasing the torque density, existing switching reluctance motors are difficult to expand the speed regulation range, and the traditional power converter topology has problems such as large size, high cost and insufficient reliability.
The motor magnetic circuit is changed by changing the direction of power-on activation of part of the excitation windings, and two working modes are realized, and a variable magnetic circuit switching reluctance motor power converter topology is proposed to reduce the number of power devices.
The switching reluctance motor has the advantages of high torque density and wide speed regulation range, reducing system volume and cost and improving reliability.
Smart Images
Figure CN119891595A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to a variable magnetic circuit switched reluctance motor, a system and a control method thereof, and belongs to the technical field of new motors. Background Art
[0002] The switched reluctance motor has the advantages of simple structure, strong body, high reliability and low cost, but due to the electromagnetic torque characteristics of its own reluctance, the torque density needs to be improved. In order to improve the torque density of the switched reluctance motor, new structures such as dual stator type, hybrid flux type and axial flux type have appeared one after another. However, during the design process, the above-mentioned new structure motors often have a large phase inductance or inductance change rate, so the motor speed regulation range is not wide, the constant power operation range needs to be expanded, and it is difficult to achieve high torque density and wide speed range characteristics at the same time. The traditional switched reluctance motor has a fixed magnetic circuit and a single mode, which limits the current practical application of the switched reluctance motor system with both high torque density and wide speed regulation range. The existing technology has achieved the adjustable magnetic flux of the motor by setting two sets of winding coils of the armature winding and the excitation winding at the same time, in order to expand the motor speed regulation range while ensuring the torque output capacity at low speed. However, this scheme has the disadvantages of high winding slot full rate, serious electromagnetic coupling, and complex decoupling control, which restricts the promotion of this type of motor. Summary of the invention
[0003] In view of the shortcomings of the prior art, the present invention provides a novel variable magnetic circuit switched reluctance motor that changes the motor magnetic circuit by changing the energizing direction of part of the excitation winding, and does not require the provision of an additional armature winding. At the same time, since the first stator excitation winding is unipolarly energized and the second stator excitation winding is bipolarly energized, if the traditional asymmetric half-bridge and full-bridge power converter topologies are used respectively, the volume is large and the cost is high. In order to reduce the converter volume and system cost, the present invention also proposes a variable magnetic circuit switched reluctance motor power converter topology and a control method thereof that reduces the number of power devices.
[0004] The present invention is implemented according to the following technical solutions: In a first aspect, the present invention provides a variable magnetic circuit switched reluctance motor, comprising: The first stator is composed of a non-magnetic stator sleeve I and a plurality of segmented stators I, wherein the plurality of segmented stators I are uniformly and alternately embedded in the stator sleeve I along the circumferential direction; each segmented stator I is provided with at least one tooth pole I; The second stator is composed of a non-magnetic stator sleeve II and a plurality of segmented stators II, wherein the plurality of segmented stators II are uniformly and alternately embedded in the stator sleeve II along the circumferential direction; each segmented stator II is provided with at least one tooth pole II; the first and second stators have the same number, and one segmented stator II faces one segmented stator I; The rotor is composed of a non-magnetic rotor sleeve and a plurality of segmented rotors, wherein the plurality of segmented rotors are uniformly and alternately embedded in the rotor sleeve along the circumferential direction; the rotor is located in the middle of the first and second stators to form an inner and outer double stator and an intermediate rotor structure; the tooth poles I and II are both arranged toward the rotor; A first stator excitation winding is installed on each tooth pole of the first stator, the first stator excitation winding is unipolarly energized, and the winding energization direction is fixed; The second stator excitation winding is installed on each tooth pole of the second stator. The second stator excitation winding is bipolarly energized, and the winding energization direction can be changed, thereby changing the motor magnetic flux path.
[0005] In some embodiments, when the first stator excitation winding and the second stator excitation winding are energized in the same direction, the magnetic flux flows along an adjacent group of tooth poles I of block stator I, the block rotor, and tooth poles II of block stator II to form a circular closed loop, constituting a longer magnetic flux path, which is the first working mode of the motor; when the first stator excitation winding and the second stator excitation winding are energized in different directions, the magnetic flux flows along an adjacent group of tooth poles I of block stator I and tooth poles II of block stator II and then cancel each other out in the block rotor to form a closed loop, constituting a shorter magnetic flux path, which is the second working mode of the motor.
[0006] In some embodiments, in the first working mode of the motor, when the segmented rotor is aligned with the segmented stator I and the segmented stator II, the magnetic flux flows along the tooth pole I of the segmented stator I, the gap between two adjacent segmented rotors, and the tooth pole II of the segmented stator II to form a circular closed loop, and is now located at the maximum inductance position of the first working mode of the motor; in the first working mode of the motor, when the segmented rotor is not aligned with the segmented stator I and the segmented stator II, the magnetic flux flows along the tooth pole I of the segmented stator I, the gap between two adjacent segmented rotors, and the tooth pole II of the segmented stator II to form a circular closed loop, and is now located at the minimum inductance position of the first working mode of the motor; in the second working mode of the motor, When the segmented rotor is aligned with segmented stator I and segmented stator II, the magnetic flux flows along tooth pole I of segmented stator I, the gap between two adjacent segmented rotors, and tooth pole II of segmented stator II, and then cancels each other out in the segmented rotor to form a closed loop. At this time, it is located at the maximum inductance position of the second working mode of the motor; in the second working mode of the motor, when the segmented rotor is not aligned with segmented stator I and segmented stator II, the magnetic flux starts from one segmented rotor of the two adjacent segmented rotors and flows along tooth pole I and tooth pole II respectively, and then cancels each other out in the other segmented rotor of the two adjacent segmented rotors to form a closed loop. At this time, it is located at the minimum inductance position of the second working mode of the motor.
[0007] In some embodiments, the segmented stator I and the segmented stator II are U-shaped or E-shaped.
[0008] In a second aspect, the present invention provides a variable magnetic circuit switched reluctance motor system, comprising: The variable magnetic circuit switched reluctance motor mentioned above; A power converter electrically connected to the variable magnetic circuit switched reluctance motor, comprising a DC power supply module, a power switch tube, and a power diode, for realizing the positive voltage excitation and negative voltage demagnetization states corresponding to the variable magnetic circuit switched reluctance motor in the first working mode and the positive voltage excitation and negative voltage demagnetization states corresponding to the second working mode; A controller electrically connected to the variable magnetic circuit switched reluctance motor controls the operation of the variable magnetic circuit switched reluctance motor by controlling the on and off states of the power switch tube.
[0009] In some embodiments, the variable magnetic circuit switched reluctance motor includes phase A, phase B, phase C and six stator excitation windings A1, B1, C1, A2, B2, C2; wherein the stator excitation windings A1, B1, C1 constitute the first stator excitation winding, and the stator excitation windings A2, B2, C2 constitute the second stator excitation winding; the power converter is mainly composed of a DC power supply U dc , a capacitor C1, fifteen power switching tubes S1, S2, S3, S4, S5, S6, S7, S8, S9, S10, S11, S12, S13, S14, S15, and three power diodes D1, D2, D3.
[0010] In some embodiments, the DC power supply U dc Connected in parallel with capacitor C1 to form a first circuit; The power diode D1, the power switch tubes S1, S2, S3, S4, S5, and the stator excitation windings A1 and A2 are connected in series and in parallel to form a second circuit; The power diode D2, the power switch tubes S6, S7, S8, S9, S10, and the stator excitation windings B1 and B2 are connected in series and in parallel to form a third circuit; The power diode D3, the power switch tubes S11, S12, S13, S14, S15, and the stator excitation windings C1 and C2 are connected in series and in parallel to form a fourth circuit; The second circuit, the third circuit and the fourth circuit are respectively connected in parallel with the first circuit.
[0011] In some embodiments, the second line, the third line, and the fourth line are connected in the same manner: When the second circuit is used: the drain of the power switch tube S1 is connected to the DC power supply U dc The positive electrode of the stator excitation winding A1 and the cathode of the power diode D1 are connected, and the anode of the power diode D1 is connected to the DC power supply.U dc The negative electrode of the stator excitation winding A1 is connected to the source of the power switch tube S2, the drain of the power switch tube S3 is connected to the positive electrode of the stator excitation winding A2, the drain of the power switch tube S2 is connected to the drain of the power switch tube S1 and the drain of the power switch tube S3, the source of the power switch tube S3 is connected to the anode of the power diode D1 and the source of the power switch tube S5, and the negative electrode of the stator excitation winding A2 is connected to the source of the power switch tube S4 and the drain of the power switch tube S5.
[0012] In a third aspect, the present invention provides a control system for a variable magnetic circuit switched reluctance motor, comprising: A position detector is used to obtain the rotor position of the variable magnetic circuit switched reluctance motor and obtain the actual speed of the motor through a speed calculation module; A current detector is used to obtain the phase current of the variable magnetic circuit switched reluctance motor and obtain the actual torque of the motor through the torque calculation module; An online mode selector is used to determine the working mode of the variable magnetic circuit switched reluctance motor according to the actual motor speed, reference speed, actual torque and reference torque; In the above-mentioned variable magnetic circuit switched reluctance motor system, the controller is divided into a first mode control subsystem and a second mode control subsystem; the first mode control subsystem controls the on and off states of the power switch tube by obtaining the parameters of the rotor position and the phase current, so that the excitation direction of the first stator excitation winding is the same as that of the second stator excitation winding, and the motor operates in the first working mode; the second mode control subsystem controls the on and off states of the power switch tube by obtaining the parameters of the rotor position and the phase current, so that the excitation direction of the first stator excitation winding is different from that of the second stator excitation winding, and the motor operates in the second working mode.
[0013] In a fourth aspect, the present invention provides a control method based on the above variable magnetic circuit switched reluctance motor system, comprising: Obtain the rotor position of the variable magnetic circuit switched reluctance motor, and obtain the actual motor speed through the speed calculation module; Obtain the phase current of the variable magnetic circuit switched reluctance motor, and obtain the actual torque of the motor through the torque calculation module; Determine the working mode of the variable magnetic circuit switched reluctance motor according to the actual motor speed, reference speed, actual torque and reference torque; When the motor needs to work in the first working mode, the excitation direction of the second stator excitation winding is the same as that of the first stator excitation winding by controlling the on-off of the power switch tube; When the motor needs to work in the second working mode, the excitation directions of the second stator excitation winding and the first stator excitation winding are different by controlling the on-off of the power switch tube.
[0014] Compared with the prior art, the present invention has the following beneficial effects: 1. Due to the electromagnetic torque characteristics of the magnetic resistance properties of the switched reluctance motor, in order to improve the torque density of the motor, it is often designed with a larger inductance and inductance change rate, which limits the expansion of the constant torque and constant power operating range of the motor, resulting in the switch reluctance motor usually being difficult to have both high torque density and wide speed regulation characteristics at the same time; the variable magnetic circuit switched reluctance motor proposed in the present invention can form different magnetic flux paths by flexibly changing the winding energization direction online, and select different magnetic flux paths for different working conditions, so that the switch reluctance motor can have the advantages of high torque density and wide speed regulation range.
[0015] 2. In a variable magnetic circuit switched reluctance motor, different ways of energizing the stator windings are required, wherein the first stator excitation winding is unipolarly energized, while the second stator excitation winding is bipolarly energized; if traditional asymmetric half-bridge power converters and full-bridge power converters are used to power the first and second stator excitation windings respectively, the number of power devices is large, the power converter is large in size, high in cost, and insufficient in reliability; the variable magnetic circuit switched reluctance motor power converter topology proposed in the present invention reduces the number of required power devices, reduces the system size and cost, improves the system reliability, and has good engineering application value.
[0016] 3. The variable magnetic circuit switch reluctance of the present invention adopts a modular stator and a segmented rotor structure, which reduces the motor mass and reduces the core loss. In addition, during the rotation and commutation process of the motor, there is no magnetic flux reversal and no negative torque is generated, thereby improving the output efficiency of the motor.
[0017] 4. The number of phases, the number of stator pole teeth, and the number of rotor pole teeth of the variable magnetic circuit switched reluctance motor described in the present invention are flexible to select, have a wide range of applications, and have a high degree of design freedom. BRIEF DESCRIPTION OF THE DRAWINGS
[0018] The accompanying drawings are part of the present invention and are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention, but do not constitute an improper limitation of the present invention. Obviously, the accompanying drawings described below are only some embodiments. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without creative work.
[0019] In the attached picture: Figure 1 It is a schematic diagram of a transverse cross-sectional structure of a preferred embodiment of the variable magnetic circuit switched reluctance motor of the present invention.
[0020] Figure 2(a) is a schematic diagram of the excitation direction of the motor winding when the first stator excitation winding and the second stator excitation winding are energized in the same direction according to an embodiment of the present invention; Figure 2 (b) is a schematic diagram of the excitation direction of the motor winding when the first stator excitation winding and the second stator excitation winding provided in an embodiment of the present invention have different energization directions.
[0021] Figure 3 (a) is a schematic diagram of the magnetic flux path of the rotor alignment position in the first working mode of the motor provided by an embodiment of the present invention; Figure 3 (b) is a schematic diagram of the magnetic flux path of the rotor misaligned position in the first working mode of the motor provided by an embodiment of the present invention.
[0022] Figure 4 (a) is a schematic diagram of the magnetic flux path of the rotor alignment position in the second working mode of the motor provided by an embodiment of the present invention; Figure 4 (b) is a schematic diagram of the magnetic flux path of the rotor misaligned position in the second working mode of the motor provided by an embodiment of the present invention.
[0023] Figure 5 A circuit diagram of a power converter provided in an embodiment of the present invention.
[0024] Figure 6 (a) is a schematic diagram of the on / off switching of power devices and the current flow direction of a motor provided by an embodiment of the present invention when the motor is operating in a first working mode and in a positive voltage excitation state; Figure 6 (b) is a schematic diagram of the on / off of power devices and current flow when the motor provided by an embodiment of the present invention is running in the first working mode and in a negative voltage demagnetization state.
[0025] Figure 7 (a) is a schematic diagram of the on / off switching of power devices and the current flow direction of a motor provided by an embodiment of the present invention when the motor is operating in a second working mode and in a positive voltage excitation state; Figure 7 (b) is a schematic diagram of the on / off of power devices and current flow when the motor provided by an embodiment of the present invention is running in the second working mode and in a negative voltage demagnetization state.
[0026] Figure 8 A block diagram of a motor control system provided by an embodiment of the present invention.
[0027] It should be noted that these drawings and textual descriptions are not intended to limit the conceptual scope of the present invention in any way, but are intended to illustrate the concept of the present invention for those skilled in the art by referring to specific embodiments. DETAILED DESCRIPTION
[0028] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. The following embodiments are used to illustrate the present invention but are not used to limit the scope of the present invention.
[0029] In the description of the present invention, it should be noted that the directions or positional relationships indicated by terms such as “upper”, “lower”, “front”, “back”, “left”, “right”, “vertical”, “inside” and “outside” are based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as a limitation on the present invention.
[0030] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.
[0031] The present invention provides a variable magnetic circuit switched reluctance motor, comprising a first stator, a second stator, a rotor, a first stator excitation winding and a second stator excitation winding; the first stator is composed of a non-magnetic stator sleeve I and a plurality of block stators I, the plurality of block stators I are uniformly and alternately embedded in the stator sleeve I along the circumferential direction; each block stator I is provided with at least one tooth pole I; the second stator is composed of a non-magnetic stator sleeve II and a plurality of block stators II, the plurality of block stators II are uniformly and alternately embedded in the stator sleeve II along the circumferential direction; each block stator II is provided with at least one tooth pole II; the number of the first and second stators is the same, and a block stator Stator II is directly opposite to a segmented stator I; the rotor is composed of a non-magnetic rotor sleeve and a plurality of segmented rotors, and the plurality of segmented rotors are evenly and alternately embedded in the rotor sleeve along the circumferential direction; the rotor is located in the middle position of the first and second stators to form an inner and outer double stator and an intermediate rotor structure; tooth poles I and tooth poles II are both arranged toward the rotor; the first stator excitation winding is installed on each tooth pole of the first stator, the first stator excitation winding is unipolarly energized, and the winding energization direction is fixed; the second stator excitation winding is installed on each tooth pole of the second stator, the second stator excitation winding is bipolarly energized, and the winding energization direction can be changed, thereby changing the motor flux path.
[0032] The variable magnetic circuit switched reluctance motor provided by the present invention can change the motor magnetic flux path by changing the energizing direction of the second stator excitation winding, thereby realizing two different working modes; the motor has different operating characteristics in the two working modes, which are respectively suitable for different working conditions; the two working modes cooperate with each other, and can take into account the high torque density and wide speed regulation range of the motor. The motor working mode of the present invention is flexible to select, the speed regulation range is wide, and the power density is high, and it can be applied to electric vehicles, aerospace, new energy and other fields.
[0033] In a further solution, the variable magnetic circuit switched reluctance motor adopts a radial magnetic field rotating motor structure, an axial magnetic field rotating motor structure, a transverse magnetic field rotating motor structure or a linear motor structure.
[0034] In a further embodiment, the number of phases of the variable magnetic circuit switched reluctance motor can be two-phase, three-phase, four-phase, five-phase, six-phase or more phases.
[0035] In a further solution, the block stator I and the block stator II are U-shaped or E-shaped.
[0036] Figure 1 A schematic diagram of a transverse cross-sectional structure of a preferred embodiment of the variable magnetic circuit switched reluctance motor of the present invention is given. In this embodiment, the variable magnetic circuit switched reluctance motor is a radial magnetic field rotating motor, an inner and outer double stator and an intermediate rotor structure. The specific structure is: the first stator 1 includes six U-shaped block outer stators and twelve tooth poles, the second stator 2 includes six U-shaped block inner stators and twelve tooth poles, and the rotor 3 includes ten block rotors; the excitation winding is three-phase and contains twenty-four excitation winding coils. The ten block rotors are located in the middle position of the six U-shaped block outer stators and the six U-shaped block inner stators to form an inner and outer double stator and an intermediate rotor structure. The U-shaped block outer stator, the U-shaped block inner stator and the block rotor are all made of silicon steel stampings.
[0037] Further references Figure 1 It can be seen that the first stator excitation winding 4 is installed on each tooth pole of the first stator 1, including twelve excitation winding coils: namely, the excitation winding coil 4A1, the excitation winding coil 4A2, the excitation winding coil 4A3 and the excitation winding coil 4A4, which are connected in series, in parallel, or in series and parallel to form the armature winding 4A phase; the excitation winding coil 4B1, the excitation winding coil 4B2, the excitation winding coil 4B3 and the excitation winding coil 4B4, which are connected in series, in parallel, or in series and parallel to form the armature winding 4B phase; the excitation winding coil 4C1, the excitation winding coil 4C2, the excitation winding coil 4C3 and the excitation winding coil 4C4, which are connected in series, in parallel, or in series and parallel to form the armature winding 4C phase; the first stator excitation winding 4 is unipolarly energized, and the winding energization direction is fixed.
[0038] The second stator excitation winding 5 is installed on each tooth pole of the second stator 2, and includes twelve excitation winding coils: namely, the excitation winding coil 5A1, the excitation winding coil 5A2, the excitation winding coil 5A3 and the excitation winding coil 5A4, which are connected in series, in parallel, or in series-parallel mixed to form the armature winding 5A phase; the excitation winding coil 5B1, the excitation winding coil 5B2, the excitation winding coil 5B3 and the excitation winding coil 5B4, which are connected in series, in parallel, or in series-parallel mixed to form the armature winding 5B phase; the excitation winding coil 5C1, the excitation winding coil 5C2, the excitation winding coil 5C3 and the excitation winding coil 5C4, which are connected in series, in parallel, or in series-parallel mixed to form the armature winding 5C phase. The three-phase armature windings are arranged symmetrically and spaced apart in pairs, that is, each two adjacent excitation winding coils belong to the same phase; the second stator excitation winding 5 is bipolarly energized, and the winding energization direction can be changed.
[0039] Figure 2 (a) shows a schematic diagram of the excitation direction of the motor winding when the first stator excitation winding and the second stator excitation winding provided by an embodiment of the present invention are energized in the same direction; Figure 2 (b) is a schematic diagram of the excitation direction of the motor winding when the first stator excitation winding and the second stator excitation winding provided by an embodiment of the present invention are energized in different directions.
[0040] like Figure 3 As shown, the first stator excitation winding 4 and the second stator excitation winding 5 have the same winding current-carrying direction, and the magnetic flux forms a closed loop along the adjacent tooth poles I of the segmented stator I, the segmented rotor, and the tooth poles II of the segmented stator II, forming a longer magnetic flux path, which is the first working mode of the motor. Figure 3 (a) shows the schematic diagram of the magnetic flux path of the rotor alignment position in the first working mode of the motor. The magnetic flux flows along the tooth pole I of the block stator I, the gap between the two adjacent block rotors, and the tooth pole II of the block stator II to form a circular closed loop. The motor is located at the maximum inductance position of the first working mode. 3(b) shows the schematic diagram of the magnetic flux path of the rotor misalignment position in the first working mode of the motor. The magnetic flux flows along the tooth pole I of the block stator I, the gap between the two adjacent block rotors, and the tooth pole II of the block stator II to form a circular closed loop. The motor is located at the minimum inductance position of the first working mode.
[0041] like Figure 4 As shown, the first stator excitation winding 4 and the second stator excitation winding 5 are energized in opposite directions, and the magnetic flux flows along an adjacent group of tooth poles Ⅰ of the block stator Ⅰ and tooth poles Ⅱ of the block stator Ⅱ, and then cancels each other out in the block rotor to form a closed loop, forming a shorter magnetic flux path, which is the second working mode of the motor.
[0042] Figure 4(a) shows a schematic diagram of the magnetic flux path at the rotor alignment position in the second working mode of the motor. When the segmented rotor is aligned with the segmented stators I and II, the magnetic flux flows along the tooth pole I of the segmented stator I, the gap between two adjacent segmented rotors, and the tooth pole II of the segmented stator II, and then cancels each other out in the segmented rotor to form a closed loop. The motor is located at the maximum inductance position in the second working mode. Figure 4 (b) shows a schematic diagram of the magnetic flux path at the rotor misalignment position in the second working mode of the motor. When the segmented rotor is misaligned with segmented stators I and II, the magnetic flux starts from one of the two adjacent segmented rotors and flows along tooth poles I and II respectively, and then cancels each other out in the other segmented rotor of the two adjacent segmented rotors to form a closed loop. The motor is located at the minimum inductance position in the second working mode.
[0043] Combination Figure 2 , Figure 3 , Figure 4 It can be concluded that the magnetic flux path of the motor can be changed by changing the excitation direction of the second stator excitation winding.
[0044] The present invention also provides a variable magnetic circuit switched reluctance motor system, comprising the above-mentioned variable magnetic circuit switched reluctance motor, a power converter and a controller electrically connected to the variable magnetic circuit switched reluctance motor respectively; the power converter comprises a DC power supply module, a power switch tube, and a power diode, which are used to realize the positive voltage excitation and negative voltage demagnetization states corresponding to the variable magnetic circuit switched reluctance motor in the first working mode and the positive voltage excitation and negative voltage demagnetization states corresponding to the second working mode; the controller controls the operation of the variable magnetic circuit switched reluctance motor by controlling the on and off states of the power switch tube.
[0045] Figure 5 The power converter circuit topology diagram is given, which mainly consists of a DC power supply U dc , a capacitor C1, fifteen power switch tubes S1, S2, S3, S4, S5, S6, S7, S8, S9, S10, S11, S12, S13, S14, S15, and three power diodes D1, D2, D3. The variable magnetic circuit switched reluctance motor includes phase A, phase B, phase C and six stator excitation windings A1, B1, C1, A2, B2, C2; wherein the stator excitation windings A1, B1, C1 constitute the first stator excitation winding, and the stator excitation windings A2, B2, C2 constitute the second stator excitation winding.
[0046] DC power supply U dcThe first circuit is formed by connecting the power diode D1, the power switch tubes S1, S2, S3, S4, S5, and the stator excitation windings A1 and A2 in series and parallel to form the second circuit; the power diode D2, the power switch tubes S6, S7, S8, S9, S10, and the stator excitation windings B1 and B2 in series and parallel to form the third circuit; the power diode D3, the power switch tubes S11, S12, S13, S14, S15, and the stator excitation windings C1 and C2 in series and parallel to form the fourth circuit; the second circuit, the third circuit, and the fourth circuit are respectively connected in parallel with the first circuit.
[0047] It should be noted that the power switch tubes S1, S2, S3, S4, S5, S6, S7, S8, S9, S10, S11, S12, S13, S14, and S15 used in the power converter are fully controlled devices MOSFET or IGBT.
[0048] Further solutions, such as Figure 5 As shown, the drain (collector) of the power switch tube S1 is connected to the power supply U dc The positive electrode of the capacitor C1 is connected to the drain (collector) of the power switch tube S2, the source (emitter) of the power switch tube S1 is connected to the positive electrode of the winding A1 and the cathode of the power diode D1, and the anode of the power diode D1 is connected to the power supply U dc The negative electrode of winding A1, the negative electrode of capacitor C1 and the source (emitter) of power switch tube S3 are connected, the negative electrode of winding A1 is connected to the source (emitter) of power switch tube S2, the drain (collector) of power switch tube S3 and the positive electrode of winding A2, the drain (collector) of power switch tube S2 is connected to the drain (collector) of power switch tube S1 and the drain (collector) of power switch tube S3, the source (emitter) of power switch tube S3 is connected to the anode of power diode D1 and the source (emitter) of power switch tube S5, and the negative electrode of winding A2 is connected to the source (emitter) of power switch tube S4 and the drain (collector) of power switch tube S5.
[0049] The drain (collector) of the power switch tube S6 is connected to the drain (collector) of the power switch tube S7, the source (emitter) of the power switch tube S6 is connected to the positive electrode of the winding B1 and the cathode of the power diode D2, the anode of the power diode D2 is connected to the source (emitter) of the power switch tube S8, the negative electrode of the winding B1 is connected to the source (emitter) of the power switch tube S7, the drain (collector) of the power switch tube S8 and the positive electrode of the winding B2, the drain (collector) of the power switch tube S7 is connected to the drain (collector) of the power switch tube S6 and the drain (collector) of the power switch tube S8, the source (emitter) of the power switch tube S8 is connected to the anode of the power diode D2 and the source (emitter) of the power switch tube S10, and the negative electrode of the winding B2 is connected to the source (emitter) of the power switch tube S9 and the drain (collector) of the power switch tube S10.
[0050] The drain (collector) of the power switch tube S11 is connected to the drain (collector) of the power switch tube S12, the source (emitter) of the power switch tube S11 is connected to the positive electrode of the winding C1 and the cathode of the power diode D3, the anode of the power diode D3 is connected to the source (emitter) of the power switch tube S13, the negative electrode of the winding C1 is connected to the source (emitter) of the power switch tube S12, the drain (collector) of the power switch tube S13 and the positive electrode of the winding C2, the drain (collector) of the power switch tube S12 is connected to the drain (collector) of the power switch tube S11 and the drain (collector) of the power switch tube S13, the source (emitter) of the power switch tube S13 is connected to the anode of the power diode D3 and the source (emitter) of the power switch tube S15, and the negative electrode of the winding C2 is connected to the source (emitter) of the power switch tube S14 and the drain (collector) of the power switch tube S15.
[0051] Figure 6 The diagram is a schematic diagram of the on / off of power devices and the current flow direction when the motor is running in two different working states in the first working mode; the two states are respectively the positive voltage excitation state of the first working mode and the negative voltage demagnetization state of the first working mode.
[0052] Specifically, Figure 6 (a) is a schematic diagram of the power device conduction and shutdown and current flow when the motor is operating in the first working mode and positive voltage excitation state.
[0053] It can be seen that when the motor operates in the positive voltage excitation state of the first working mode, the power switch tube S1, the power switch tube S5, the power switch tube S6, the power switch tube S10, the power switch tube S11, and the power switch tube S15 are turned on, and the power switch tube S2, the power switch tube S3, the power switch tube S4, the power switch tube S7, the power switch tube S8, the power switch tube S9, the power switch tube S12, the power switch tube S13, and the power switch tube S14 are turned off.
[0054] Taking the A phase winding as an example, the electrical energy is from the power supply U dc A loop is formed along the power switch tube S1, the stator excitation winding A1, the stator excitation winding A2 and the power switch tube S5 to supply power to the stator excitation winding A1 and the stator excitation winding A2; at this time, the first stator excitation winding and the second stator excitation winding are both forward excited, and the first stator excitation winding and the second stator excitation winding have the same energization direction.
[0055] Figure 6 (b) is a schematic diagram of the power device conduction and shutdown and current flow when the motor is operating in the first working mode and negative voltage demagnetization state.
[0056] It can be seen that when the motor is running in the first working mode, negative voltage demagnetization state, taking the A phase winding as an example, the electric energy goes along the power diode D1, passes through the stator excitation winding A1, the stator excitation winding A2, and then along the power switch tube S4 to form a loop back to the power supply. U dc At this time, the first stator excitation winding and the second stator excitation winding are both positively demagnetized, and the first stator excitation winding and the second stator excitation winding are energized in the same direction.
[0057] Figure 7 It is a schematic diagram of the on-off and current flow of power devices when the motor is running in two different states in the second working mode; the two states are the positive voltage excitation state of the second working mode and the negative voltage demagnetization state of the second working mode.
[0058] Specifically, Figure 7 (a) is a schematic diagram of the on / off of power devices and current flow when the motor is operating in the second working mode, in the positive voltage excitation state; It can be seen that when the motor operates in the positive voltage excitation state of the first working mode, the power switch tube S1, the power switch tube S3, the power switch tube S4, the power switch tube S6, the power switch tube S8, the power switch tube S9, the power switch tube S11, the power switch tube S13, and the power switch tube S14 are turned on, and the power switch tube S2, the power switch tube S5, the power switch tube S7, the power switch tube S10, the power switch tube S12, and the power switch tube S15 are turned off; Taking the A phase winding as an example, the electrical energy is from the power supply U dc Starting from the stator, the first stator excitation winding is positively excited, and the second stator excitation winding is reversely excited, and the first stator excitation winding and the second stator excitation winding are energized in opposite directions.
[0059] Figure 7 (b) is a schematic diagram of the power device conduction and shutdown and current flow when the motor operates in the second working mode, the negative voltage demagnetization state.
[0060] It can be seen that when the motor is running in the second working mode, negative voltage demagnetization state, taking the A phase winding as an example, the electric energy flows along the power diode D1 and the power switch tube S5, passes through the stator excitation winding A1 and the stator excitation winding A2, and then returns to the power supply along the power switch tube S2. U dc At this time, the first stator excitation winding is demagnetized in the forward direction, the second stator excitation winding is demagnetized in the reverse direction, and the first stator excitation winding and the second stator excitation winding are energized in opposite directions.
[0061] Figure 8 The control system schematic diagram of the variable magnetic circuit switched reluctance motor is given, including a position detector, a current detector, an online mode selector and the above-mentioned variable magnetic circuit switched reluctance motor system; the position detector is used to obtain the rotor position of the variable magnetic circuit switched reluctance motor θ The actual motor speed is obtained through the speed calculation module n ; The current detector is used to obtain the phase current of the variable magnetic circuit switched reluctance motor I ph The actual torque of the motor is obtained through the torque calculation module T ; The online mode selector is used to adjust the actual motor speed n , reference speed n ref , actual torque T , reference torque T ref To determine the working mode of the variable magnetic circuit switched reluctance motor; the controller is divided into a first mode control subsystem and a second mode control subsystem; the first mode control subsystem obtains the rotor position θ and phase current I ph The parameters of the power switch tube are controlled to be on and off, so that the excitation direction of the first stator excitation winding is the same as that of the second stator excitation winding, and the motor operates in the first working mode; the second mode control subsystem obtains the rotor position θ and phase current I ph The parameters control the on and off states of the power switch tube, so that the excitation directions of the first stator excitation winding and the second stator excitation winding are different, and the motor operates in the second working mode.
[0062] In a further solution, the first mode control subsystem controls the on and off states of the power switch tubes by acquiring parameters such as the rotor position and the phase current; when the power switch tubes S1, S5, S6, S10, S11, and S15 are turned on and the power switch tubes S2, S3, S4, S7, S8, S9, S12, S13, and S14 are turned off, the first stator excitation winding and the second stator excitation winding are both forward excited, and the motor operates in the first working mode; the second mode control subsystem controls the on and off states of the power switch tubes by acquiring parameters such as the rotor position and the phase current; when the power switch tubes S1, S3, S4, S6, S8, S9, S11, S13, and S14 are turned on and the power switch tubes S2, S5, S7, S10, S12, and S15 are turned off, the first stator excitation winding is forward excited, the second stator excitation winding is reversely excited, and the motor operates in the second working mode.
[0063] The present invention also provides a control method based on the above variable magnetic circuit switched reluctance motor system, comprising: Obtain the rotor position of the variable magnetic circuit switched reluctance motor, and obtain the actual motor speed through the speed calculation module; Obtain the phase current of the variable magnetic circuit switched reluctance motor, and obtain the actual torque of the motor through the torque calculation module; Determine the working mode of the variable magnetic circuit switched reluctance motor according to the actual motor speed, reference speed, actual torque and reference torque; When the motor needs to work in the first working mode, the excitation direction of the second stator excitation winding is the same as that of the first stator excitation winding by controlling the on-off of the power switch tube; When the motor needs to work in the second working mode, the excitation directions of the second stator excitation winding and the first stator excitation winding are different by controlling the on-off of the power switch tube.
[0064] A further solution is that when the motor operates in the first working mode, the motor is controlled by the first mode control subsystem; when the motor operates in the second working mode, the motor is controlled by the second mode control subsystem; the first mode control subsystem controls the on and off states of the power switch tube by obtaining parameters such as the rotor position and the phase current; when the power switch tubes S1, S5, S6, S10, S11, and S15 are turned on and the power switch tubes S2, S3, S4, S7, S8, S9, S12, S13, and S14 are turned off, the first mode control subsystem controls the on and off states of the power switch tube A stator excitation winding and a second stator excitation winding are both energized in the forward direction, and the motor operates in the first working mode; the second mode control subsystem controls the on and off states of the power switch tubes by obtaining parameters such as the rotor position and the phase current; when the power switch tubes S1, S3, S4, S6, S8, S9, S11, S13, and S14 are turned on, and the power switch tubes S2, S5, S7, S10, S12, and S15 are turned off, the first stator excitation winding is energized in the forward direction and the second stator excitation winding is energized in the reverse direction, and the motor operates in the second working mode.
[0065] In summary, the present invention provides a variable magnetic circuit switched reluctance motor, system and control method thereof having the following advantages and beneficial effects: 1. Due to the electromagnetic torque characteristics of the magnetic resistance properties of the switched reluctance motor, in order to improve the torque density of the motor, it is often designed with a larger inductance and inductance change rate, which limits the expansion of the constant torque and constant power operating range of the motor, resulting in the switch reluctance motor usually being difficult to have both high torque density and wide speed regulation characteristics at the same time; the variable magnetic circuit switched reluctance motor proposed in the present invention can form different magnetic flux paths by flexibly changing the winding energization direction online, and select different magnetic flux paths for different working conditions, so that the switch reluctance motor can have the advantages of high torque density and wide speed regulation range.
[0066] 2. In a variable magnetic circuit switched reluctance motor, different ways of energizing the stator windings are required, wherein the first stator excitation winding is unipolarly energized, while the second stator excitation winding is bipolarly energized; if traditional asymmetric half-bridge power converters and full-bridge power converters are used to power the first and second stator excitation windings respectively, the number of power devices is large, the power converter is large in size, high in cost, and insufficient in reliability; the variable magnetic circuit switched reluctance motor power converter topology proposed in the present invention reduces the number of required power devices, reduces the system size and cost, improves the system reliability, and has good engineering application value.
[0067] 3. The variable magnetic circuit switch reluctance of the present invention adopts a modular stator and a segmented rotor structure, which reduces the motor mass and reduces the core loss. In addition, during the rotation and commutation process of the motor, there is no magnetic flux reversal and no negative torque is generated, thereby improving the output efficiency of the motor.
[0068] 4. The number of phases, the number of stator pole teeth, and the number of rotor pole teeth of the variable magnetic circuit switched reluctance motor described in the present invention are flexible to select, have a wide range of applications, and have a high degree of design freedom.
[0069] In the description provided herein, a large number of specific details are described. However, it is understood that embodiments of the present invention can be practiced without these specific details. In some instances, well-known methods, structures and techniques are not shown in detail so as not to obscure the understanding of this description.
[0070] In addition, those skilled in the art will understand that, although some embodiments described herein include certain features included in other embodiments but not other features, the combination of features of different embodiments also means being within the scope of protection of the present invention and forming different embodiments. For example, in the above embodiments, those skilled in the art can use them in combination according to the known technical solutions and the technical problems to be solved by this application.
[0071] The above is only a preferred embodiment of the present invention, and does not limit the present invention in any form. Although the present invention has been disclosed as a preferred embodiment as above, it is not used to limit the present invention. Any technician familiar with this patent can make some changes or modify the technical contents suggested above into equivalent embodiments without departing from the scope of the technical solution of the present invention. However, any simple modification, equivalent change and modification made to the above embodiments according to the technical essence of the present invention without departing from the content of the technical solution of the present invention still fall within the scope of the solution of the present invention.
Claims
1. A variable magnetic circuit switched reluctance motor, characterized in that: include: The first stator is composed of a non-magnetic stator sleeve I and a plurality of segmented stators I, wherein the plurality of segmented stators I are uniformly and alternately embedded in the stator sleeve I along the circumferential direction; each segmented stator I is provided with at least one tooth pole I; The second stator is composed of a non-magnetic stator sleeve II and a plurality of segmented stators II, wherein the plurality of segmented stators II are uniformly and alternately embedded in the stator sleeve II along the circumferential direction; Each block stator II is provided with at least one tooth pole II; the number of the first and second stators is the same, and one block stator II faces one block stator I; The rotor is composed of a non-magnetic rotor sleeve and a plurality of segmented rotors, wherein the plurality of segmented rotors are uniformly and alternately embedded in the rotor sleeve along the circumferential direction; the rotor is located in the middle of the first and second stators to form an inner and outer double stator and an intermediate rotor structure; the tooth poles I and II are both arranged toward the rotor; A first stator excitation winding is installed on each tooth pole of the first stator, the first stator excitation winding is unipolarly energized, and the winding energization direction is fixed; The second stator excitation winding is installed on each tooth pole of the second stator. The second stator excitation winding is bipolarly energized, and the winding energization direction can be changed, thereby changing the motor magnetic flux path.
2. The variable magnetic circuit switched reluctance motor according to claim 1, characterized in that: When the first stator excitation winding and the second stator excitation winding are energized in the same direction, the magnetic flux flows along the tooth poles I of the adjacent group of block stators I, the block rotor, and the tooth poles II of the block stators II to form a circular closed loop, forming a relatively long magnetic flux path, which is the first working mode of the motor; When the first stator excitation winding and the second stator excitation winding are energized in different directions, the magnetic flux flows along an adjacent group of tooth poles I of the block stator I and tooth poles II of the block stator II and then cancels each other out in the block rotor to form a closed loop, forming a shorter magnetic flux path, which is the second working mode of the motor.
3. A variable magnetic circuit switched reluctance motor according to claim 2, characterized in that: In the first working mode of the motor, when the segmented rotor is aligned with the segmented stator I and the segmented stator II, the magnetic flux flows along the tooth pole I of the segmented stator I, the gap between two adjacent segmented rotors, and the tooth pole II of the segmented stator II to form a circular closed loop, which is at the maximum inductance position of the first working mode of the motor. In the first working mode of the motor, when the segmented rotor is not aligned with the segmented stator I and the segmented stator II, the magnetic flux flows along the tooth pole I of the segmented stator I, the two adjacent segmented rotors, and the tooth pole II of the segmented stator II to form a circular closed loop, which is at the minimum inductance position of the first working mode of the motor. In the second working mode of the motor, when the segmented rotor is aligned with the segmented stator I and the segmented stator II, the magnetic flux flows along the tooth pole I of the segmented stator I, the gap between two adjacent segmented rotors, and the tooth pole II of the segmented stator II, and then cancels each other out in the segmented rotor to form a closed loop. At this time, it is at the maximum inductance position of the second working mode of the motor. In the second working mode of the motor, when the segmented rotor is not aligned with the segmented stator I and the segmented stator II, the magnetic flux starts from one of the two adjacent segmented rotors and flows along the tooth pole I and the tooth pole II respectively, and then cancels each other out in the other segmented rotor of the two adjacent segmented rotors to form a closed loop. At this time, it is at the minimum inductance position of the second working mode of the motor.
4. The variable magnetic circuit switched reluctance motor according to claim 1, characterized in that: The block stator I and the block stator II are in a U-shape or an E-shape.
5. A variable magnetic circuit switched reluctance motor system, characterized in that: include: The variable magnetic circuit switched reluctance motor according to any one of claims 1 to 4; A power converter electrically connected to the variable magnetic circuit switched reluctance motor, comprising a DC power supply module, a power switch tube, and a power diode, for realizing the positive voltage excitation and negative voltage demagnetization states corresponding to the variable magnetic circuit switched reluctance motor in the first working mode and the positive voltage excitation and negative voltage demagnetization states corresponding to the second working mode; A controller electrically connected to the variable magnetic circuit switched reluctance motor controls the operation of the variable magnetic circuit switched reluctance motor by controlling the on and off states of the power switch tube.
6. A variable magnetic circuit switched reluctance motor system according to claim 5, characterized in that: The variable magnetic circuit switched reluctance motor comprises an A phase, a B phase, a C phase and six stator excitation windings A1, B1, C1, A2, B2, and C2; wherein the stator excitation windings A1, B1, and C1 constitute a first stator excitation winding, and the stator excitation windings A2, B2, and C2 constitute a second stator excitation winding; The power converter is mainly composed of a DC power supply U dc , a capacitor C1, fifteen power switching tubes S1, S2, S3, S4, S5, S6, S7, S8, S9, S10, S11, S12, S13, S14, S15, and three power diodes D1, D2, D3.
7. The variable magnetic circuit switched reluctance motor system according to claim 6, characterized in that: DC power supply U dc Connected in parallel with capacitor C1 to form a first circuit; The power diode D1, the power switch tubes S1, S2, S3, S4, S5, and the stator excitation windings A1 and A2 are connected in series and in parallel to form a second circuit; The power diode D2, the power switch tubes S6, S7, S8, S9, S10, and the stator excitation windings B1 and B2 are connected in series and in parallel to form a third circuit; The power diode D3, the power switch tubes S11, S12, S13, S14, S15, and the stator excitation windings C1 and C2 are connected in series and in parallel to form a fourth circuit; The second circuit, the third circuit and the fourth circuit are respectively connected in parallel with the first circuit.
8. The variable magnetic circuit switched reluctance motor system according to claim 7, characterized in that: The connection method of the second, third and fourth lines is the same: When the second circuit is used: the drain of the power switch tube S1 is connected to the DC power supply U dc The positive electrode of the stator excitation winding A1 and the cathode of the power diode D1 are connected, and the anode of the power diode D1 is connected to the DC power supply. U dc The negative electrode of the stator excitation winding A1 is connected to the source of the power switch tube S2, the drain of the power switch tube S3 is connected to the positive electrode of the stator excitation winding A2, the drain of the power switch tube S2 is connected to the drain of the power switch tube S1 and the drain of the power switch tube S3, the source of the power switch tube S3 is connected to the anode of the power diode D1 and the source of the power switch tube S5, and the negative electrode of the stator excitation winding A2 is connected to the source of the power switch tube S4 and the drain of the power switch tube S5.
9. A control system for a variable magnetic circuit switched reluctance motor, characterized in that: include: A position detector is used to obtain the rotor position of the variable magnetic circuit switched reluctance motor and obtain the actual speed of the motor through a speed calculation module; A current detector is used to obtain the phase current of the variable magnetic circuit switched reluctance motor and obtain the actual torque of the motor through the torque calculation module; An online mode selector is used to determine the working mode of the variable magnetic circuit switched reluctance motor according to the actual motor speed, reference speed, actual torque and reference torque; The variable magnetic circuit switched reluctance motor system described in any one of claims 5 to 8, wherein the controller is divided into a first mode control subsystem and a second mode control subsystem; the first mode control subsystem controls the on and off states of the power switch tube by obtaining the parameters of the rotor position and the phase current, so that the excitation direction of the first stator excitation winding is the same as that of the second stator excitation winding, and the motor operates in the first working mode; the second mode control subsystem controls the on and off states of the power switch tube by obtaining the parameters of the rotor position and the phase current, so that the excitation direction of the first stator excitation winding is different from that of the second stator excitation winding, and the motor operates in the second working mode.
10. A control method for a variable magnetic circuit switched reluctance motor system according to any one of claims 5 to 8, characterized in that: Obtain the rotor position of the variable magnetic circuit switched reluctance motor, and obtain the actual motor speed through the speed calculation module; Obtain the phase current of the variable magnetic circuit switched reluctance motor, and obtain the actual torque of the motor through the torque calculation module; Determine the working mode of the variable magnetic circuit switched reluctance motor according to the actual motor speed, reference speed, actual torque and reference torque; When the motor needs to work in the first working mode, the excitation direction of the second stator excitation winding is the same as that of the first stator excitation winding by controlling the on-off of the power switch tube; When the motor needs to work in the second working mode, the excitation directions of the second stator excitation winding and the first stator excitation winding are different by controlling the on-off of the power switch tube.