Sector real-time optimization torque ripple suppression method of switched reluctance motor

Abstract

The invention discloses a switched reluctance motor sector real-time optimization torque ripple suppression method based on a three-phase asymmetric half-bridge power converter. An original electric cycle is recombined and optimized in real time, a self-adaptive method is adopted for a sector which is switched on and switched off in advance, the size of a variable sector is obtained online in real time, generation of negative torque of the motor is reduced to the maximum extent, and the optimized sector can reflect the real working state of the motor. In addition, the selection rule of the voltage vector is also redefined, the selection of the voltage vector is not limited to the generation of positive torque and negative torque any more, the selection of the auxiliary voltage vector is more accurate, and the control precision is improved. The fuzzy controller is adopted to replace a traditional torque hysteresis controller at the same time, the fuzzy controller can analyze the running state of the motor and output different torque demand signals, voltage vectors with different torque generation capacities are adopted through the given signals, torque tracking can be better achieved, and torque pulsation is effectively reduced.

Description

Technical Field

[0001] The present invention relates to a method for suppressing torque ripple by real-time optimizing sectors of a switched reluctance motor based on a three-phase asymmetric half-bridge power converter, which is used for a switched reluctance motor control system. Background Art

[0002] Since the 1840s, the extensive exploitation and use of energy sources such as coal, oil and natural gas have promoted the rapid development of the global economy and the improvement of the quality of life. At the same time, serious problems such as climate change and energy shortage are also faced. Countries around the world have proposed corresponding policy measures and actions, and actively developed new energy sources such as wind power, hydropower, nuclear power and solar energy. The switched reluctance motor (SRM) has been recognized by the market due to its advantages such as simple structure, low cost, high efficiency and good speed regulation, and has been successfully applied in many fields such as electric vehicles, household appliances, wind power generation and aerospace.

[0003] In the switched reluctance motor control system, common power converters are full-bridge, symmetric half-bridge and asymmetric half-bridge, etc. The full-bridge power converter can use an intelligent power module, and its topological structure can achieve good current control, but its hardware is relatively complex and the cost is relatively high. The symmetric half-bridge power converter has a simple structure, but its current control accuracy and loss optimization are limited in some operating modes. Compared with other power converters, the three-phase asymmetric half-bridge power converter has independent phase currents, has no limitation on the number of winding phases, and can also be simplified or improved according to specific application situations and actual needs to achieve the actual required control strategy, which simplifies the hardware design of the system and is widely used in high-efficiency and low-cost switched reluctance motor systems.

[0004] The direct torque control method has a simple logic, directly performs hysteresis control on the output torque, has a fast torque response and good torque ripple suppression performance. However, when the hysteresis control is applied to the switched reluctance motor, it will cause the actually generated torque to exceed the given torque too much or too little, resulting in an increase in torque ripple. Summary of the Invention

[0005] Object of the Invention: Aiming at the problems and deficiencies in the prior art, the present invention provides a method for suppressing torque ripple by real-time optimizing sectors of a switched reluctance motor based on a three-phase asymmetric half-bridge power converter. This method reorganizes the division of the electrical space of the switched reluctance motor, expands it to 15 sectors on the original basis, at this time 3 early conduction sectors and 3 early turn-off sectors are generated, and the voltage vectors also increase to 15. At the same time, the proposed method adopts an adaptive method to online real-time optimize the widths of the early conduction and turn-off sectors, uses a fuzzy controller to replace the traditional torque hysteresis controller, the given signal adopts voltage vectors with different torque generation capabilities, and uses an improved flux linkage model and phase torque equation, effectively reducing the torque ripple and improving the control accuracy.

[0006] Technical solution: A method for suppressing torque ripple in real time and optimizing sectors of a switched reluctance motor based on a three-phase asymmetric half-bridge power converter, including the following content:

[0007] Reorganize and divide the electrical space of the switched reluctance motor, and expand it to 15 sectors on the original basis. Add an early conduction sector and an early turn-off sector to each phase. At this time, 3 early conduction sectors and 3 early turn-off sectors are generated, and the voltage vectors also increase to 15, minimizing the generation of instantaneous negative torque to the greatest extent.

[0008] And adaptively adjust the size of the sectors according to different motor speeds and load conditions, reducing the torque ripple of the motor and improving the efficiency of the motor. The present invention adopts an adaptive adjustment method for sectors at different speeds, and online real-time optimizes the widths of the early conduction and turn-off sectors, so as to better suppress torque ripple under different load and speed conditions.

[0009] Use a fuzzy controller to replace the traditional torque hysteresis controller. The given signal adopts voltage vectors with different torque generation capabilities, which can better achieve torque tracking and improve the control accuracy. That is: analyze according to the motor operating state and output different torque demand signals. By using voltage vectors with different torque generation capabilities through these given signals, torque tracking can be better achieved, thereby effectively reducing torque ripple.

[0010] Select an improved flux linkage model and the calculation equation of phase torque. The proposed improved flux linkage model has a better curve fitting effect than the Fourier decomposition method, the torque rate is faster when the motor is running, and the torque calculated by the phase torque equation at this time is closer to the actual torque.

[0011] The switched reluctance motor drive system includes a 12 / 8 switched reluctance motor and a three-phase asymmetric half-bridge power converter.

[0012] The improved flux linkage model is In the formula, Ψ i,θ is the phase flux linkage of the motor, ε θ is the coupling coefficient at different position angles, i is the phase current, a is a given value, and the accurate a value is obtained by curve fitting the measured flux linkage curve according to different motors; e is the exponential function.

[0013] The calculation equation of the phase torque is For calculating the torque closer to the actual torque value. In the formula, Ψ θ , T ek and i k are the flux linkage, torque and current of the k phase respectively, θ is the rotor position, and θ1, θ2 are two adjacent rotor positions. k ∈ {A, B, C}

[0014] Replace the original PI controller of the system with a fuzzy controller, characterized in that: based on its characteristics of rapid response, excellent anti-interference performance and non-overshoot output, the fuzzy controller can significantly improve the dynamic performance and robustness of the control system.

[0015] A computer device, which includes a memory, a processor, and a computer program stored on the memory and executable on the processor. When the processor executes the above computer program, it implements the steps of the method for suppressing torque ripple by real-time optimizing the sectors of the switched reluctance motor as described above.

[0016] A computer-readable storage medium stores a computer program for executing the method for suppressing torque ripple by real-time optimizing the sectors of the switched reluctance motor as described above.

[0017] Advantageous effects: Compared with the prior art solutions, the present invention has the following advantages:

[0018] The original electrical cycle is reorganized and real-time optimized. An adaptive method is adopted for the sectors with early conduction and turn-off, and the variable sector size is obtained online in real time, minimizing the generation of negative torque of the motor to the greatest extent, so that the optimized sectors can reflect the true working state of the motor. The selection rule of the voltage vector is also redefined. The selection of the voltage vector is no longer limited to generating positive torque and negative torque, and the selection of the auxiliary voltage vector is also more accurate, improving the control accuracy. The present invention also uses a fuzzy controller to replace the traditional torque hysteresis controller. The fuzzy controller can analyze the operating state of the motor and output different torque demand signals. By using voltage vectors with different torque generation capabilities through these given signals, better torque tracking can be achieved, effectively reducing torque ripple. Brief Description of the Drawings

[0019] Figure 1 It is the sector optimization diagram of the switched reluctance motor of the present invention. Detailed Embodiments

[0020] The following further clarifies the present invention in conjunction with specific embodiments. It should be understood that these embodiments are only used to illustrate the present invention and not to limit the scope of the present invention. After reading the present invention, various equivalent modifications of the present invention by those skilled in the art all fall within the scope defined by the appended claims of this application.

[0021] A torque pulsation suppression method based on real-time optimization of the switched reluctance motor sector of a three-phase asymmetric half-bridge power converter is proposed. The method adopted adds an early turn-on sector to each phase, establishes sufficient current for the input phase when the inductance change rate is low, and avoids insufficient input phase torque tracking. The proposed method also adds an early turn-off sector to each phase to avoid the generation of negative torque in each phase. In order to accurately obtain the size of the early turn-on sector and the early turn-off sector, the proposed method adopts an adaptive method to obtain the size of the variable sector online, so that the proposed control strategy can be applied to different torque and load requirements, and effectively improve the operating performance of direct torque control.

[0022] Firstly, the division of the electrical space of the switched reluctance motor is reorganized and expanded to 15 sectors on the original basis. At this time, 3 early turn-on sectors and 3 early turn-off sectors are generated, and the voltage vectors are also increased to 15.

[0023] The motor is 12 / 8, one electrical cycle is 45 degrees, and one electrical cycle is divided into 15 sectors, such as Figure 1 As shown in Table 1, sector division facilitates control.

[0024] Taking phase A as an example, when the rotor position θ rotates from the misaligned position to the aligned position, the inductance of phase A shows an upward trend, and phase A generates positive torque. When the rotor position θ rotates from the misaligned position to the aligned position, the inductance of phase A shows a downward trend, and phase A generates negative torque. In sector N8, the inductance of phase A is the largest, and the inductance change rate drops to 0. Therefore, in order to avoid generating negative torque as much as possible, the current of this phase should be positive when the phase is between the misaligned position and the aligned position, and the current of this phase should drop to 0 when it is between the aligned position and the misaligned position.

[0025] Three early conduction and variable sectors:

[0026] Sector N15 is the advance conduction of phase A and is a variable sector. The sector is optimized in real time. Under different speed and load conditions, an adaptive adjustment method is used to obtain the size of variable sector N15 online, suppress torque pulsation, and open phase A in advance. At this time, the main torque is generated by phase C, and phase A generates auxiliary torque. The negative torque generated when the motor enters sector N1 is minimal.

[0027] Sector N5 is the early conduction of phase B and is a variable sector. The sector is optimized in real time. Under different speed and load conditions, an adaptive adjustment method is used to obtain the size of variable sector N5 online, suppress torque pulsation, and open phase B in advance. At this time, the main torque is generated by phase A, and phase B generates auxiliary torque. The negative torque generated when the motor enters sector N6 is minimal.

[0028] Sector N10 is the early conduction of phase C and is a variable sector. The sector is optimized in real time. Under different rotational speeds and load conditions, an adaptive adjustment method is used to obtain the size of the variable sector N10 online, suppress torque ripple, and turn on phase C in advance. At this time, the main torque is generated by phase B, and phase C generates an auxiliary torque. The negative torque generated when the motor enters sector N11 is the smallest. Three early turn-off and variable sectors:

[0029] Sector N3 is the early turn-off of phase C and is a variable sector. The sector is optimized in real time. Under different rotational speeds and load conditions, an adaptive adjustment method is used to obtain the size of the variable sector N3 online, suppress torque ripple, and turn off phase C in advance. At this time, the main torque is generated by phase A, and phase C generates an auxiliary torque. The negative torque generated when the motor enters sector N4 is the smallest.

[0030] Sector N8 is the early turn-off of phase A and is a variable sector. The sector is optimized in real time. Under different rotational speeds and load conditions, an adaptive adjustment method is used to obtain the size of the variable sector N8 online, suppress torque ripple, and turn off phase A in advance. At this time, the main torque is generated by phase B, and phase A generates an auxiliary torque. The negative torque generated when the motor enters sector N9 is the smallest.

[0031] Sector N13 is the early turn-off of phase B and is a variable sector. The sector is optimized in real time. Under different rotational speeds and load conditions, an adaptive adjustment method is used to obtain the size of the variable sector N13 online, suppress torque ripple, and turn off phase B in advance. At this time, the main torque is generated by phase C, and phase B generates an auxiliary torque. The negative torque generated when the motor enters sector N14 is the smallest. Three single-phase conduction sectors:

[0032] In sector N4, only phase A conducts.

[0033] In sector N9, only phase B conducts.

[0034] In sector N14, only phase C conducts.

[0035] In sector N1, phases A and C conduct simultaneously. Since the inductance of phase A is less than the rate of change of the inductance of phase C, the torque generated by phase A is less than that of phase C. Thus, it can be seen that the main torque is generated by phase C, and phase A generates an auxiliary torque.

[0036] In sector N2, phases A and C conduct simultaneously. Since the inductance of phase A is greater than the rate of change of the inductance of phase C, phase A generates a higher torque than phase C. Thus, it can be seen that the main torque is generated by phase A, and phase C generates an auxiliary torque.

[0037] In sector N6, phases B and A conduct simultaneously. Since the inductance of phase B is less than the rate of change of the inductance of phase A, the torque generated by phase B is less than that of phase A. Thus, it can be seen that the main torque is generated by phase A, and phase B generates an auxiliary torque.

[0038] In sector N7, phase B and phase A are conducting simultaneously. Since the inductance of phase B is greater than the rate of change of the inductance of phase A, phase B generates a higher torque than phase A. Thus, it can be seen that the main torque is generated by phase B, while phase A generates an auxiliary torque.

[0039] In sector N11, phase C and phase B are conducting simultaneously. Since the inductance of phase C is less than the rate of change of the inductance of phase B, the torque generated by phase C is less than that generated by phase B. Thus, it can be seen that the main torque is generated by phase B, while phase C generates an auxiliary torque.

[0040] In sector N12, phase C and phase B are conducting simultaneously. Since the inductance of phase C is greater than the rate of change of the inductance of phase B, phase C generates a higher torque than phase B. Thus, it can be seen that the main torque is generated by phase C, while phase B generates an auxiliary torque.

[0041] Table 1

[0042] sector main torque auxiliary torque sector main torque auxiliary torque N1 C A N9 B B N2 A C N10 B C N3 A C N11 B C N4 A A N12 C B N5 A B N13 C B N6 A B N14 C C N7 B A N15 C A N8 B A

[0043] For different rotational speeds of the sectors, an adaptive adjustment method is adopted to optimize the widths of the sectors for early conduction and early turn-off online in real time, so as to better suppress torque ripple under different load and rotational speed conditions.

[0044] Secondly, a fuzzy controller is used to replace the traditional torque hysteresis controller, and the given signal adopts voltage vectors with different torque generation capabilities.

[0045] Finally, an improved flux linkage model and the calculation equation of the phase torque are selected. The proposed improved flux linkage model has a better curve fitting effect than the Fourier decomposition method, and the torque calculated by the phase torque equation is closest to the actual torque at this time.

[0046] The present invention reorganizes the division of the electrical space of the switched reluctance motor, expands it to 15 sectors on the original basis. At this time, 3 sectors for early conduction and 3 sectors for early turn-off are generated, and the voltage vectors also increase to 15. The selection of the voltage vectors is no longer limited to generating positive and negative torques, and the generation of instantaneous negative torque is minimized to the greatest extent. Using a fuzzy controller to replace the traditional hysteresis controller can effectively reduce torque ripple.

[0047] The switched reluctance motor drive system of the present invention uses a power converter. Due to the repeatability of the control method, for the sake of simplicity of description, only phase A is taken as an example. The flux linkage and phase torque of the motor can be obtained by the following formulas:

[0048]

[0049]

[0050] Where Ψ θ, T ek and i k are the flux linkage, torque, and current of phase A respectively, and θ is the rotor position.

[0051] At different speeds, the sector is adaptively adjusted. To reduce the generation of negative torque in the early conduction sector, the phase current in the early conduction sector should be limited to half of the rated current. To reduce the generation of negative torque in the early turn-off sector, the phase current should be 0 before the inductor drops. If the phase current is increased to a higher region (for example, at different speeds, dropping to 0 at 22.5 degrees is not a higher region, otherwise it is a higher region), it will cause the current to drop untimely and increase the torque ripple. Therefore, to avoid insufficient torque tracking and reduce the generation of negative torque in the sector, taking phase A as an example: before sector N15 reaches 0 degrees, the phase A current reaches half of the rated current. If it exceeds half of the rated current, the size of the sector needs to be widened. If it is lower than half of the rated current, the size of the sector needs to be reduced. When sector N8 reaches the turn-off angle of 22.5 degrees, the phase A current is 0. If the current is greater than 0 at this time, the size of the sector needs to be widened. If the current is less than 0, the size of the sector needs to be reduced, so as to reduce the generation of negative torque. Establish the phase current in advance. If the current does not reach half of the rated current at 0 degrees, increase sector N15 by 0.5 degrees per electrical cycle, and the initial value is set to 2 - 3 degrees.

[0052] In sector N1, since the inductance of phase A is less than the inductance change rate of phase C, the torque generated by phase A is less than that of phase C. It can be seen that in sector N1, the main torque is generated by phase C, and phase A generates auxiliary torque. When phase A and phase C conduct simultaneously, the SRM can generate the maximum torque, and the voltage vector (1, 0, 1) at this time can be defined as the Positive Large (PL) voltage vector; when only phase C conducts, the torque generated by the SRM is at a moderate level, and the corresponding voltage vector (0, 0, 1) can be regarded as the Positive Medium (PM) voltage vector. When only phase A conducts, the SRM generates a smaller torque, and the voltage vector (1, 0, 0) can be defined as the Positive Small (PS) voltage vector. Conversely, when both phase A and phase C are disconnected, the torque drop rate of the SRM is the fastest, and the voltage vector (-1, 0, -1) is defined as the Negative Large (NL) voltage vector. When only phase C is disconnected and phase A is in the zero-voltage freewheeling state, the torque drop rate of the SRM is second only to the case when both phase A and phase C are disconnected, and the corresponding voltage vector (0, 0, -1) is defined as the Negative Medium (NM) voltage vector. When only phase A is disconnected and phase C is in the zero-voltage freewheeling state, the torque drop rate of the SRM is the slowest, and the voltage vector (-1, 0, 0) is defined as the Negative Small (NS) voltage vector.

[0053] In sector N2, since the inductance change rate of phase A is greater than that of phase C, phase A generates a higher torque than phase C. At this time, (1, 0, 1) is the positive large vector, (1, 0, 0) is the positive medium vector, (0, 0, 1) is the positive small vector, (-1, 0, -1) is the negative large vector, (-1, 0, 0) is the negative medium vector, and (0, 0, -1) is the negative small vector.

[0054] In sector N3, in order to make the motor generate a smaller negative torque in sector N4, the current of phase C should be reduced to 0 in advance. At this time, in sector N3, (1, 0, 1) is the positive large vector, (1, 0, -1) is both the positive medium vector and the positive small vector, (-1, 0, -1) is the negative large vector, (-1, 0, -1) is the negative medium vector, and (0, 0, -1) is the negative small vector.

[0055] In sector N4, since the current of phase C was reduced to 0 in advance in sector N3, at this time in sector N4, only phase A of the motor generates positive rotation. When phase A is turned on, the total torque increases, and when phase A is in the off state, the total torque decreases. At this time, the (positive large, positive medium, positive small) vectors can be collectively referred to as positive vectors, denoted as (1, 0, -1), and the (negative large, negative medium, negative small) vectors can be collectively referred to as negative vectors, denoted as (-1, 0, -1).

[0056] In sector N5, turn on phase B in advance. Taking the motor used as an example, make the current of phase B reach half of the rated current, so that sufficient phase current can be established at the beginning of the inductance rising area, and thus the negative torque generated when the motor enters sector N6 can be minimized. Therefore, in sector N5, (1, 1, 0) is the positive vector (positive large, positive medium, positive small), and (-1, 1, 0) is the negative vector (negative large, negative medium, negative small). At the same time, set the current limit in this phase, and turn off phase B when the limit value is exceeded.

[0057] In sector N6, since the inductance change rate of phase A is greater than that of phase B, phase A generates a higher torque than phase B. At this time, (1, 1, 0) is the positive large vector, (1, 0, 0) is the positive medium vector, (0, 1, 0) is the positive small vector, (-1, -1, 0) is the negative large vector, (-1, 0, 0) is the negative medium vector, and (0, -1, 0) is the negative small vector.

[0058] In sector N7, since the inductance change rate of phase B is greater than that of phase A, phase B generates a higher torque than phase A. At this time, (1, 1, 0) is the positive large vector, (0, 1, 0) is the positive medium vector, (1, 0, 0) is the positive small vector, (-1, -1, 0) is the negative large vector, (0, -1, 0) is the negative medium vector, and (-1, 0, 0) is the negative small vector.

[0059] In sector N8, in order to make the motor in sector N9 generate a smaller negative torque, the current of phase A should be reduced to 0 in advance. At this time, in sector N8, (1, 1, 0) is a positive large vector, (-1, 1, 0) is a positive medium vector and also a positive small vector, (-1, -1, 0) is a negative large vector, (-1, -1, 0) is a negative medium vector, and (-1, 0, 0) is a negative small vector.

[0060] In sector N15, open phase A in advance. Taking the motor in use as an example, make the current of phase A reach half of the rated current, so that sufficient phase current can be established at the beginning of the inductance rising region, and thus the negative torque generated when the motor enters sector N1 can be minimized. Therefore, in sector N15, (1, 0, 1) is a positive vector (positive large, positive medium, positive small), and (1, 0, -1) is a negative vector (negative large, negative medium, negative small). At the same time, set the current limit in this phase, and turn off phase A when the limit value is exceeded.

[0061] After reorganizing these sectors, as Figure 1 shown.

[0062] In the previous control strategy, the input for selecting the voltage vector rule table is to subtract the actual torque from the reference torque:

[0063] ΔT e =T eref -T eactual

[0064] where T eref and T eactual are the reference torque and the actual torque respectively.

[0065] Using a fuzzy controller can output the given torque ripple under different requirements. Given ΔT e as the input, making some changes to ΔT e can divide ΔT e into six parts: (+3, +2), (+2, +1), (+1, 0), (0, -1), (-1, -2), (-2, -3).

[0066] In sectors N1 and N2, when using the positive large voltage vector, the system can generate a larger torque at this time, and set the output value e of the fuzzy controller to 3; when using the positive medium voltage vector, the system can generate a moderate torque at this time, and set e to 2; when using the positive short voltage vector, the system can generate a smaller torque at this time, and set e to 1; when using the negative large voltage vector, the system can generate a larger torque at this time, and set e to -3; when using the negative medium voltage vector, the system can generate a moderate torque at this time, and set e to -2; when using the negative small voltage vector, the system can generate a smaller torque at this time, and set e to -1.

[0067] In sector N3, in order to make the current of phase C drop to zero before the inductance drop region of phase C, phase C should be in the off state as much as possible. Therefore, in most cases in sector N3, the switching state of phase C is -1. When using the positive large vector, set e to 3; when using the positive small vector, set e to 1 or 2; when using the negative medium vector, set e to -1; when using the negative large vector, set e to -2 or -3.

[0068] In sector N4, only phase A generates positive torque. At this time, e is positive when phase A is conducting, and e is negative when phase A is off.

[0069] In sector N15, phase A should be in the conducting state as much as possible, so that the current of phase A can rise to half of the rated current in advance. Therefore, in most cases in sector N15, the switching state of phase A is 1. So when e is positive, phase C is conducting, and when e is negative, phase C is off.

[0070] Within one rotor period, the selection of voltage vectors in different sectors is based on different e - value conditions. The specific selection is shown in Table 1, and the fuzzy controller also needs to obtain the optimal voltage vector.

[0071] Table 2 Voltage Vector Selection in One Rotor Period

[0072]

[0073] Obviously, those skilled in the art should understand that each step of the method for suppressing torque ripple by real - time optimization of the sector of the switched reluctance motor in the above - mentioned embodiments of the present invention can be implemented by a general - purpose computing device. They can be concentrated on a single computing device or distributed on a network composed of multiple computing devices. Optionally, they can be implemented by program codes executable by the computing device. Thus, they can be stored in a storage device and executed by the computing device. And in some cases, the steps shown or described can be executed in a different order than here, or they can be separately fabricated into individual integrated circuit modules, or multiple modules or steps among them can be fabricated into a single integrated circuit module to be implemented. In this way, the embodiments of the present invention are not limited to any specific combination of hardware and software.

Claims

1. A real-time optimization torque ripple suppression method for switched reluctance motors based on a three-phase asymmetric half-bridge power converter, characterized in that, The electrical space of the switched reluctance motor is reorganized and divided, expanding to 15 sectors on the original basis; an early conduction sector and an early turn-off sector are added to each phase; at this time, 3 early conduction sectors and 3 early turn-off sectors are generated, and the voltage vectors also increase to 15; and the size of the sectors is adaptively adjusted according to the different motor speeds and load conditions, and the widths of the early conduction and turn-off sectors are optimized online in real time to better suppress torque ripple under different load and speed conditions; a fuzzy controller is used to replace the torque hysteresis controller, different given signals are output and voltage vectors with different torque generation capabilities are adopted, and an improved flux linkage model and a calculation equation of phase torque are selected. The proposed improved flux linkage model has a better curve fitting effect than the Fourier decomposition method, obtains the phase torque at a faster rate during motor operation, and the torque calculated by the phase torque equation at this time is closer to the actual torque.

2. The real-time optimized torque ripple suppression method for switched reluctance motors based on a three-phase asymmetric half-bridge power converter according to claim 1, characterized in that The switched reluctance motor drive system described above includes a 12 / 8 switched reluctance motor and a three-phase asymmetric half-bridge power converter.

3. The real-time optimized torque ripple suppression method for a switched reluctance motor based on a three-phase asymmetric half-bridge power converter according to claim 1, wherein The improved flux linkage model is where Ψ i,θ is the phase flux linkage of the motor, ε θ is the coupling coefficient at different position angles, i is the phase current, a is a given value, which is the value fitted from the measured flux linkage curve according to different motors; e is the exponential function.

4. The method for suppressing torque ripple in real time and optimizing sectors of a switched reluctance motor based on a three-phase asymmetric half-bridge power converter according to claim 1, wherein The calculation equation of the phase torque is so that the calculated torque is closer to the actual torque value. In the formula, Ψ θ , T ek and i k are respectively the magnetic flux linkage, torque and current of the k-phase, θ is the rotor position, and θ1, θ2 are two adjacent rotor positions.

5. The method for suppressing torque ripple by real-time optimization of sectors of a switched reluctance motor based on a three-phase asymmetric half-bridge power converter according to claim 1, wherein At different speeds, the sectors are adaptively adjusted. In the early conduction sector, the phase current should be limited to half of the rated current range. The phase current is 0 before the inductance drop region; if the phase current is increased to a higher region, it will cause the current to drop untimely and the torque ripple to increase. For phase A: Before sector N15 reaches 0 degrees, the phase A current reaches half of the rated current. If it exceeds half of the rated current value, the size of the sector needs to be widened. If it is lower than half of the rated current value, the size of the sector needs to be reduced. When sector N8 reaches the turn-off angle of 22.5 degrees, the phase A current is 0. If the current is greater than 0 at this time, the size of the sector needs to be widened. If the current is less than 0, the size of the sector needs to be reduced. In sector N1, since the inductance of phase A is less than the inductance change rate of phase C, the torque generated by phase A is less than that of phase C; in sector N1, the main torque is generated by phase C, and phase A generates an auxiliary torque. When phase A and phase C are turned on simultaneously, the SRM generates the maximum torque. At this time, the voltage vector (1, 0, 1) is defined as the positive large voltage vector; when only phase C is turned on, the torque generated by the SRM is at a moderate level, and the corresponding voltage vector (0, 0, 1) is regarded as the positive voltage vector; when only phase A is turned on, the SRM generates a smaller torque, and the voltage vector (1, 0, 0) is defined as the positive small voltage vector; conversely, when both phase A and phase C are turned off, the torque drop rate of the SRM is the fastest. At this time, the voltage vector (-1, 0, -1) is defined as the negative large voltage vector. When only phase C is turned off and phase A is in the zero-voltage freewheeling state, the torque drop rate of the SRM is second only to the case when both phase A and phase C are turned off. The corresponding voltage vector (0, 0, -1) is defined as the negative medium voltage vector; When only phase A is turned off and phase C is in the zero-voltage freewheeling state, the torque drop rate of the SRM is the slowest, and the voltage vector (-1, 0, 0) is defined as the negative small voltage vector; In sector N2, since the inductance change rate of phase A is greater than that of phase C, phase A generates a higher torque than phase C. At this time, (1, 0, 1) is the positive large vector, (1, 0, 0) is the positive medium vector, (0, 0, 1) is the positive small vector, (-1, 0, -1) is the negative large vector, (-1, 0, 0) is the negative medium vector, and (0, 0, -1) is the negative small vector; In sector N3, in order to make the motor generate a smaller negative torque in sector N4, the current of phase C should be reduced to 0 in advance. At this time, in sector N3, (1, 0, 1) is the positive large vector, (1, 0, -1) is both the positive medium vector and the positive small vector, (-1, 0, -1) is the negative large vector, (-1, 0, -1) is the negative medium vector, and (0, 0, -1) is the negative small vector; In sector N4, since the current of phase C was reduced to 0 in advance in sector N3, at this time, only phase A of the motor in sector N4 generates positive rotation. When phase A is turned on, the total torque increases, and when phase A is in the off state, the total torque decreases; at this time, (positive large, positive medium, positive small) vectors are collectively referred to as positive vectors, expressed as (1, 0, -1), and (negative large, negative medium, negative small) vectors are collectively referred to as negative vectors, expressed as (-1, 0, -1); In sector N5, phase B is turned on in advance. For the motor used, the current of phase B reaches half of the rated current, so as to establish sufficient phase current at the beginning of the inductance rising area and generate the minimum negative torque when the motor enters sector N6; therefore, in sector N5, (1, 1, 0) is the positive vector (positive large, positive medium, positive small), and (-1, 1, 0) is the negative vector (negative large, negative medium, negative small); at the same time, a current limit is set in this phase, and phase B is turned off when the limit value is exceeded; In sector N6, since the inductance change rate of phase A is greater than that of phase B, phase A generates a higher torque than phase B; at this time, (1, 1, 0) is the positive large vector, (1, 0, 0) is the positive medium vector, (0, 1, 0) is the positive small vector, (-1, -1, 0) is the negative large vector, (-1, 0, 0) is the negative medium vector, and (0, -1, 0) is the negative small vector; In sector N7, since the inductance change rate of phase B is greater than that of phase A, phase B generates a higher torque than phase A; at this time, (1, 1, 0) is the positive large vector, (0, 1, 0) is the positive medium vector, (1, 0, 0) is the positive small vector, (-1, -1, 0) is the negative large vector, (0, -1, 0) is the negative medium vector, and (-1, 0, 0) is the negative small vector; In sector N8, in order to make the motor generate a smaller negative torque in sector N9, the current of phase A should be reduced to 0 in advance. At this time, in sector N8, (1, 1, 0) is the positive large vector, (-1, 1, 0) is both the positive medium vector and the positive small vector, (-1, -1, 0) is the negative large vector, (-1, -1, 0) is the negative medium vector, and (-1, 0, 0) is the negative small vector; In sector N15, phase A is turned on in advance. For the motor in use, the current of phase A is made to reach half of the rated current, so as to establish sufficient phase current at the start of the inductance rising region, and minimize the negative torque generated when the motor enters sector N1. Therefore, in sector N15, (1, 0, 1) is the positive vector (positive large, positive medium, positive small), and (1, 0, -1) is the negative vector (negative large, negative medium, negative small). At the same time, current limiting is set in this phase, and phase A is turned off when the limit value is exceeded.

6. A computer device, characterized in that: The computer device includes a memory, a processor, and a computer program stored on the memory and executable on the processor. When the processor executes the computer program, it implements the steps of the method for suppressing torque ripple in real-time optimization of the sectors of a switched reluctance motor as described in any one of claims 1-5.

7. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores a computer program for executing the method for suppressing torque ripple in real-time optimization of the sectors of a switched reluctance motor as described in any one of claims 1-5.

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