Switched reluctance motor control method based on variable-frequency and variable-duty-ratio pulse injection

Abstract

The invention discloses a switched reluctance motor control method based on variable-frequency and variable-duty-ratio pulse injection, and belongs to the technical field of switched reluctance motor control. The method is characterized by comprising the following steps: step a, determining an initial injection parameter of a pulse injection signal; injecting a pulse signal into the turn-off phase; b, performing double-threshold comparison on the pulse response current peak value; c, adjusting a frequency step length and a duty ratio step length through a step length scaling factor; step d, stopping injecting the pulse signal to the phase winding after the phase winding is conducted; e, calculating a current slope difference value or increment inductance; and f, performing position-free control on the switched reluctance motor through the current slope difference value or the incremental inductance. According to the switched reluctance motor control method based on variable-frequency and variable-duty-ratio pulse injection, real-time control over the pulse response current can be achieved, the pulse response current is limited in the given threshold interval, and the problems existing in the alignment position and the non-alignment position of the stator and the rotor of the motor in a traditional method are solved.

Description

TECHNICAL FIELD

[0001] The application discloses a switched reluctance motor control method based on variable frequency and variable duty cycle pulse injection, and belongs to the technical field of switched reluctance motor control. BACKGROUND

[0002] Switched reluctance motors (SRMs) are widely used in electric vehicles and aerospace due to their simple structure, low manufacturing cost, and strong robustness. The operation control of such motors requires the use of relative position signals between the stator and the rotor, which are often detected by optical or Hall position sensors. The presence of position sensors not only increases the installation and maintenance costs of the system, but also significantly reduces the measurement accuracy and operational reliability of the sensors in harsh working conditions such as dust pollution and strong mechanical vibration, affecting the performance of SRMs. Therefore, position sensorless control methods for SRMs are of great research value.

[0003] During the startup and low-speed operation of a switched reluctance motor, pulse injection-based methods are commonly used to achieve position sensorless control of the motor. For example, the technical solution described in Chinese Patent No. 202311527378.2, filed on November 16, 2023, and entitled "Switched Reluctance Motor Position Sensorless System Control Method", the technical solution described in Chinese Patent No. 201910532340.1, filed on June 19, 2019, and entitled "Pulse Injection Position Sensorless Switched Reluctance Motor Control Method", and the technical solution described in Chinese Patent No. 202110617061.2, filed on June 3, 2021, and entitled "Switched Reluctance Motor Rotor Positioning Method with Pulse Number Self-Adjusting Based on Speed".

[0004] However, in the pulse injection-based control methods of the prior art, including the above technical solutions, the pulse injection method has a fixed pulse injection frequency and duty cycle. Due to the nonlinear distribution of the phase inductance of the switched reluctance motor, the traditional pulse injection method has a low signal-to-noise ratio in the incremental inductance or current slope calculation process near the aligned position of the motor stator and rotor, resulting in a small pulse response current. Near the misaligned position, the pulse response current is large, which produces additional copper loss and negative torque. SUMMARY

[0005] The technical problem to be solved by the present application is to overcome the shortcomings of the prior art and provide a switched reluctance motor control method based on variable frequency and variable duty cycle pulse injection, which can realize real-time control of the pulse response current and limit the pulse response current within a given threshold range, solving the problems of traditional methods at aligned and misaligned positions.

[0006] The technical scheme adopted by the present application to solve its technical problems is: a switched reluctance motor control method based on variable frequency and variable duty cycle pulse injection, characterized by comprising the following steps:

[0007] Step a, determining initial injection parameters of the pulse signal, the initial injection parameters of the pulse signal including a frequency step of the pulse signal and a step of the pulse duty cycle; detecting a freewheeling current of the off-phase, and injecting a pulse signal into the phase winding of the off-phase after the freewheeling current is less than a freewheeling current threshold; step b, comparing a pulse response current peak value with given upper and lower threshold values, and adjusting the pulse injection frequency and the control signal duty cycle;

[0008] Step c, after the speed of the switched reluctance motor is greater than a preset base speed, introducing a step scaling factor to adjust the frequency step and the duty cycle step;

[0009] Step d, after the phase winding of the switched reluctance motor is turned on, stopping injecting the pulse signal into the phase winding of the off-phase;

[0010] Step e, real-time sampling of three-phase current of the switched reluctance motor, calculation of current slope difference or incremental inductance;

[0011] Step f, control of the switched reluctance motor by the current slope difference or incremental inductance obtained in step e.

[0012] Preferably, in step b, the adjustment rules of the pulse signal injection frequency and the pulse signal duty cycle are:

[0013]

[0014] Wherein, k is a discrete time step, I th_down and I th_up are lower and upper threshold values corresponding to the pulse response current peak value respectively, D(k) is the current stage control signal duty cycle, D(k+1) is the next stage control signal duty cycle; F(k) is the current stage pulse injection frequency, F(k+1) is the next stage pulse injection frequency, I pk is the pulse response current peak value, ΔF step and ΔD step are the step of the pulse signal frequency and the step of the pulse signal duty cycle respectively.

[0015] Preferably, the calculation formula of the step of the pulse signal duty cycle ΔD step is:

[0016]

[0017] Wherein, F max is the pulse signal injection frequency near the misalignment position, I pk_downis the lower limit of the peak value of the impulse response current, I pk_up is the upper limit of the peak value of the impulse response current, U dc is the bus voltage, K dstep is an empirical coefficient, L min is the phase inductance at the misalignment position.

[0018] the step size of the pulse signal frequency, ΔF step The calculation formula is:

[0019] ΔF step = K fstep · F init

[0020] wherein, K fstep is an adjustment coefficient, which needs to balance the adjustment speed and the steady-state ripple. If the value is too large, it will lead to oscillation, and if it is too small, the response will be slow. According to the parameters and simulation tests of the system, a value range of 0.3-0.5 can obtain better comprehensive performance. init is the initial injection frequency of the pulse signal.

[0021] Preferably, the lower limit threshold I th_down corresponding to the peak value of the impulse response current and the upper limit threshold I th_up corresponding to the peak value of the impulse response current are calculated respectively as follows:

[0022] I th_down = K snr I noisemax

[0023] I th_up = K rated I rated

[0024] wherein, K snr is a signal-to-noise ratio coefficient, I noisemax is the peak value of the equivalent current noise of the system, K rated is an upper threshold coefficient, and rated is the rated current of the switched reluctance motor.

[0025] Preferably, step c includes the following steps:

[0026] Step c-1, defining the speed change rate ω ratio ;

[0027] Step c-2, the calculation formula of the speed change rate ω ratio maps the clamped speed ω clamped to the interval [0, 1] to obtain the relative position of the corresponding speed in the interval;

[0028] Step c-3, calculating the step size amplification multiple ω current_factor of the current speed;

[0029] Step c-4, increase the step size by factor ω current_factor Applying this to the base step size yields the final adjustment step size.

[0030] Preferably, in step c-1, the rate of change of rotational speed ω ratio The calculation formula is:

[0031]

[0032] Where, ω base As the base velocity, ω max ω represents the maximum speed of the switched reluctance motor in CCC mode. clamped This refers to the clamping speed.

[0033] Preferably, in step c-3, the step size magnification factor ω current_factor The calculation formula is:

[0034] ω current_factor =1+ω ratio (step factor -1)

[0035] Among them, step factor ω is the step size scaling factor, and the selected interval is [1, 2]. ratio This represents the rate of change of rotational speed.

[0036] Preferably, in step c-4, the final formula for calculating the adjustment step size is:

[0037]

[0038] Where, ΔF dynamic and ΔD dynamic It is the pulse injection frequency step size and control signal duty cycle step size after dynamic adjustment.

[0039] Compared with the prior art, the beneficial effects of this invention are:

[0040] The switch reluctance motor control method based on variable frequency and variable duty cycle pulse injection proposed in this application can realize real-time control of the pulse response current and limit it to a given threshold range. This solves the problem of low signal-to-noise ratio caused by small pulse response current near the alignment position and the additional copper loss and negative torque caused by large pulse response current near the misalignment position, thereby reducing the switching loss near the alignment position.

[0041] After the dual-threshold pulse injection parameters are calculated, they are input into the control algorithm. The pulse injection interval is determined based on the current feedback signal. The peak signal of the pulse response current in the sampled pulse injection interval is compared with the given threshold signal to achieve variable frequency and variable duty cycle pulse injection, limiting the pulse response current within the threshold interval. At the same time, based on the speed feedback signal of the switched reluctance motor, an appropriate step size scaling factor is introduced to achieve dynamic adjustment of the frequency step size and duty cycle step size.

[0042] In the switched reluctance motor control method based on variable frequency and variable duty cycle pulse injection proposed in this application, the introduced step size scaling factor reduces the negative effect of the narrowing pulse injection interval on the injection algorithm, allowing it to be used over a wider speed range. Furthermore, the proposed method can accurately estimate the incremental inductance and current slope difference curve. When extended to existing positionless algorithms, it can accurately estimate the rotor position of the switched reluctance motor.

[0043] While ensuring accurate calculation of the motor's incremental inductance, the pulse response current is limited to a threshold range. This overcomes the low signal-to-noise ratio problem caused by the small pulse response current near the motor stator-rotor alignment position in traditional pulse injection methods, as well as the additional copper losses and negative torque caused by the large pulse response current at the misaligned position. It also reduces switching losses at the alignment position, broadens the speed range applicable to the pulse injection method, and can be extended to existing positionless control algorithms based on full-cycle incremental inductance or full-cycle current slope difference. This can significantly reduce the motor loss problem caused by traditional pulse injection methods and improve the stability of related algorithms. Attached Figure Description

[0044] Fig. 1 This is a flowchart of a control method for a switched reluctance motor based on variable frequency and variable duty cycle pulse injection.

[0045] Fig. 2 The diagram shows the control block diagram of the switch reluctance motor control method based on variable frequency and variable duty cycle pulse injection in the positionless algorithm.

[0046] Fig. 3 This is a control block diagram of a positionless control algorithm based on the current slope difference or incremental inductance of a switched reluctance motor control method using variable frequency and variable duty cycle pulse injection.

[0047] Fig. 4 This is a waveform diagram of the traditional pulse injection method.

[0048] Fig. 5 This is a schematic diagram of the pulse injection waveform for a switched reluctance motor control method based on variable frequency and variable duty cycle pulse injection. Detailed Implementation

[0049] Figs. 1-5 This is the preferred embodiment of the present invention, which is described below in conjunction with the accompanying drawings. Figs. 1-5The present invention will be further described below.

[0050] like Fig. 1 As shown, the control method for a switched reluctance motor based on variable frequency and variable duty cycle pulse injection (hereinafter referred to as this control method) includes the following steps:

[0051] Step 1: Determine the initial injection parameters of the pulse signal offline;

[0052] As is generally known in this field, the peak value of the impulse response current I pk The relationship between the duty cycle D and the pulse signal frequency F is shown in the following formula:

[0053]

[0054] Where D is the duty cycle, F is the pulse signal frequency, Δt is the phase winding conduction time, and U dc Let L(θ) be the bus voltage and L(θ) be the phase inductance. Therefore, it can be seen that the pulse response current can be controlled by adjusting the injection frequency and duty cycle of the pulse signal.

[0055] To address the low signal-to-noise ratio issue caused by the small pulse response current near the alignment position, the initial pulse response current I... pk_init Must meet:

[0056]

[0057] Among them, L max To determine the unsaturated inductance value at the alignment position, D init and F init I represents the initial duty cycle and the initial injection frequency of the pulse signal, respectively, and also the maximum duty cycle and the minimum pulse injection frequency, respectively. pk_down U is the lower limit of the peak value of the pulse response current. dc This is the bus voltage.

[0058] The definition of the pulse response current decay time is:

[0059]

[0060] Among them, D init and F init These represent the initial duty cycle and the initial injection frequency of the pulse signal, respectively.

[0061] To ensure that the pulse response current can decay normally to 0 within one cycle, T off It must be greater than or equal to the actual current decay time t f ,Right now:

[0062]

[0063] Among them, D init and F init Let L(θ) be the initial duty cycle and the initial injection frequency of the pulse signal, respectively, and let I be the phase inductance. pk U is the peak value of the pulse response current, R is the phase inductance, and U is the peak value of the pulse response current. dc This is the bus voltage.

[0064] Initial duty cycle D init The selection of D must follow the above formula to prevent large negative torque from being generated due to the accumulation of pulse response current. Typically, D... init ≤0.5.

[0065] Define the longest excitation time of pulse injection as Δt. max The initial injection frequency F of the pulse signal init The lower limit can be expressed by the following formula:

[0066]

[0067] Among them, D init Let Δt be the initial duty cycle. max The longest excitation time for pulse injection.

[0068] In practical engineering, to avoid noise problems caused by low injection frequency, F init It is usually set above 2kHz.

[0069] The initial duty cycle and initial injection frequency of the pulse signal can be determined through the above calculations.

[0070] Step 2: Detect the freewheeling current of the off-phase. If the freewheeling current is less than the freewheeling current threshold, inject a pulse signal into the phase winding of the off-phase.

[0071] The operating status of the phase windings of the switched reluctance motor is monitored in real time. When the phase winding is turned off, the freewheeling current of the phase winding of the turned-off phase is monitored. When the freewheeling current in the phase winding of the turned-off phase is less than the freewheeling current threshold, a pulse signal is injected into the phase winding of the turned-off phase.

[0072] Step 3: Compare the peak value of the pulse response current with the given upper and lower threshold values, and adjust the pulse injection frequency and the duty cycle of the control signal;

[0073] The adjustment rules for the pulse signal injection frequency and pulse signal duty cycle are as follows:

[0074]

[0075] Where k is the discrete time step, I th_down with I th_upHere, D(k) represents the lower and upper threshold values ​​corresponding to the peak value of the pulse response current, respectively; D(k) is the duty cycle of the control signal in the current stage, and D(k+1) is the duty cycle of the control signal in the next stage; F(k) is the pulse injection frequency in the current stage, and F(k+1) is the pulse injection frequency in the next stage, I... pk The peak value of the pulse response current, ΔF step and ΔD step These represent the step size of the pulse signal frequency and the step size of the pulse signal duty cycle, respectively.

[0076] Pulse response current peak I pk Sensitivity S to duty cycle D D It can be expressed by the following formula:

[0077]

[0078] Where D is the duty cycle, F is the pulse signal frequency, and U dc L(θ) is the bus voltage, and L(θ) is the phase inductance.

[0079] From this formula, we can see that at the misaligned position S D To maximize the stability of the proposed method in the pulse injection region, ΔD step The introduction of this should ensure that large impulse response current oscillations do not occur at misaligned positions. The change in response current ΔI caused by a single step size change... D It should be less than or approximately equal to the width of the threshold interval, that is:

[0080] ΔI D ≈K dstep (I pk_up -I pk_down )

[0081] Among them, K dstep This is an empirical coefficient, typically ranging from 0.1 to 0.5. The smaller the value, the more stable the system, but the slower the response speed. pk_down I is the lower limit of the peak value of the pulse response current. pk_up This is the upper limit of the peak value of the pulse response current.

[0082] The step size ΔD of the pulse signal duty cycle step The calculation formula is:

[0083]

[0084] Among them, F max Inject frequency U into the pulse signal near the misaligned position. dc For the bus voltage, K dstep This is an empirical coefficient.

[0085] Similarly, I pkThe sensitivity formula for the pulse injection frequency F is as follows:

[0086]

[0087] Wherein, the negative sign indicates that as the pulse frequency increases, the corresponding peak response current decreases, S F With F 2 Inversely proportional, when the pulse injection frequency is at its lowest, S F Highest, U dc Where θ is the bus voltage, F is the pulse signal frequency, D is the duty cycle, and L(θ) is the phase inductance.

[0088] Due to S F The nonlinear variation within the pulse injection interval leads to low robustness of conventional fixed-step frequency conversion methods. To optimize the frequency adjustment effect, a fixed-step frequency conversion method based on the initial injection frequency of the pulse signal is adopted. This method combines the frequency step size with the pulse injection frequency at the alignment position, fully utilizing the high sensitivity generated by the lowest pulse injection frequency at the alignment position. The step size ΔF of the pulse signal frequency... step The calculation formula is:

[0089] ΔF step =K fstep ·F init

[0090] Among them, K fstep This is the adjustment coefficient. The value of this coefficient needs to balance the adjustment speed and steady-state ripple. An excessively large value will lead to oscillation, while an excessively small value will result in a slow response. Based on the system parameters and simulation tests, a value between 0.3 and 0.5 yields good overall performance. init This is the initial injection frequency of the pulse signal.

[0091] The lower threshold I corresponding to the peak value of the impulse response current th_down The upper threshold I corresponding to the peak value of the impulse response current th_up The calculation formulas are as follows:

[0092] I th_down =K snr I noisemax

[0093] I th_up =K rated I rated

[0094] Among them, K snr The signal-to-noise ratio (SNR) is typically set to 5–10 to ensure that the current signal is much stronger than the noise. noisemax This represents the peak value of the system's equivalent current noise, which can be calibrated by analyzing the phase current signals of the switched reluctance motor. K ratedThe upper threshold coefficient is typically set at 5% to 15%; I rated This is the rated current of the switched reluctance motor. To prevent system oscillation, I... th_up Usually set to I th_down 1.5 to 2 times.

[0095] Step 4: After the switched reluctance motor speed exceeds the preset base speed, a step scaling factor is introduced to adjust the frequency step size and duty cycle step size.

[0096] Determine the rotational speed of the switched reluctance motor. If the current rotational speed is greater than the base speed, introduce a step scaling factor to adjust the frequency step size and duty cycle step size.

[0097] The base speed is typically one-third of the rated speed of the switched reluctance motor. As the speed of the switched reluctance motor increases, the pulse injection range gradually narrows. Continuing to use the original fixed step size for pulse injection will cause the response current to fail to stabilize within the threshold range. When this condition occurs, a step size scaling factor is introduced to dynamically adjust the frequency step size and duty cycle step size.

[0098] The calculation process for the step scaling factor is as follows:

[0099] Step 4-1, first define the rate of change of rotational speed ω ratio Rate of change of rotational speed ω ratio The calculation formula is:

[0100]

[0101] Where, ω base As the base speed, after the switched reluctance motor speed exceeds the base speed, a step scaling factor is introduced. factor ;ω max This represents the maximum speed of the switched reluctance motor in CCC mode. ω clamped For the clamping speed, at ω base and ω max between.

[0102] Step 4-2, Rate of change of rotational speed ω ratio The calculation formula will ω clamped Mapping to the [0,1] interval yields the relative position of the corresponding rotational speed within that interval.

[0103] Step 4-3: Calculate the step size amplification factor for the current rotational speed using the following formula:

[0104] ω current_factor =1+ω ratio (step factor -1)

[0105] Among them, step factorThe step size scaling factor is set to the range [1,2].

[0106] This formula is a linear interpolation formula, starting from 1 and using steps... factor As the endpoint, according to ω ratio The specific value of ω is smoothly adjusted. current_factor .

[0107] Step 4-4, ω current_factor Applying this to the base step size yields the final adjustment step size:

[0108]

[0109] Where, ΔF dynamic and ΔD dynamic It is the pulse injection frequency step size and control signal duty cycle step size after dynamic adjustment.

[0110] The step size scaling factor can automatically adapt to the narrowing of the injection region due to the increased speed of the switched reluctance motor, enabling the dual-threshold variable frequency-variable duty cycle pulse injection method to be applied to a wider speed range. This method achieves real-time control of the pulse response current, reducing the additional copper losses and negative torque caused by traditional pulse injection methods, as well as the low signal-to-noise ratio problem, while simultaneously broadening the applicable speed range of this method.

[0111] Step 5: After the phase windings of the switched reluctance motor are turned on, stop injecting pulse signals into the phase windings of the off phases;

[0112] Step 6: Sample the three-phase current of the switched reluctance motor in real time and calculate the current slope difference or incremental inductance.

[0113] Combination Fig. 2 By injecting a high-frequency pulse signal into the off-phase, a pulse response current is generated. The three-phase current signals are sampled, and the current slope difference ΔI and the incremental inductance L are calculated. inc The rotor position signal, commutation signal, and switched reluctance motor speed signal are estimated by comparing the slope difference signal of the three-phase current or by performing coordinate transformation on the three-phase incremental inductance signal. The formula for calculating the incremental inductance is shown below:

[0114]

[0115] Among them, U dc For the bus voltage, di / dt on With di / dt off These are the current rising edge slope and the current falling edge slope, respectively, and ΔI is the difference in current slope.

[0116] Step 7: Apply the obtained current slope difference or incremental inductance to the existing positionless control algorithm to realize positionless operation of the switched reluctance motor;

[0117] Combination Fig. 3 Similar to the traditional pulse injection method in the overall positionless control system, this method injects pulse signals into the off phase. However, this control method requires feedback of pulse response current signals and speed feedback signals to achieve real-time control of the pulse response current and adapt to the narrowing of the pulse injection range caused by increased speed.

[0118] Further integration Figs. 4-5 The comparison diagram between the traditional pulse injection method and this control method shows that both methods inject high-frequency pulse signals into the idle phase to generate pulse response current signals. However, due to the fixed pulse injection frequency and duty cycle, the traditional pulse injection method results in a smaller pulse response current near the stator-rotor alignment position of the switched reluctance motor. This leads to a lower signal-to-noise ratio in the calculation of the incremental inductance curve and the difference in current slope. Near the misaligned position, the pulse response current is larger, which generates additional copper losses and negative torque.

[0119] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention in any other way. Any person skilled in the art may make changes or modifications to the above-disclosed technical content to create equivalent embodiments. However, any simple modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the protection scope of the present invention.

Claims

1. A control method for switched reluctance motor based on variable frequency and variable duty cycle pulse injection, characterized in that: The method comprises the following steps: Step a, determining initial injection parameters of the pulse signal, the initial injection parameters of the pulse signal comprising a frequency step of the pulse signal and a step of a pulse duty cycle; detecting a freewheeling current of the off phase, and injecting a pulse signal into a phase winding of the off phase after the freewheeling current is less than a freewheeling current threshold value; Step b, comparing a pulse response current peak value with given upper and lower threshold values, and adjusting a pulse injection frequency and a control signal duty cycle; Step c, introducing a step scaling factor to adjust the frequency step and the duty cycle step after a switching reluctance motor speed is greater than a preset base speed; Step d, stopping injection of the pulse signal into the phase winding of the off phase after the phase winding of the switching reluctance motor is turned on; Step e, sampling three-phase currents of the switching reluctance motor in real time, and calculating a current slope difference value or an incremental inductance; Step f, controlling the switching reluctance motor by using the current slope difference value or the incremental inductance obtained in step e.

2. The variable frequency and variable duty cycle pulse injection based switched reluctance motor control method of claim 1, wherein: In step b, adjustment rules of the pulse signal injection frequency and the pulse signal duty cycle are as follows: where k is the discrete time step, I th_down and I th_up are the lower and upper threshold values corresponding to the peak value of the impulse response current, respectively, D(k) is the duty cycle of the control signal at the current stage, D(k+1) is the duty cycle of the control signal at the next stage; F(k) is the frequency of the pulse injection at the current stage, F(k+1) is the frequency of the pulse injection at the next stage, I pk is the peak value of the impulse response current, ΔF step and ΔD step are the step size of the frequency of the pulse signal and the step size of the duty cycle of the pulse signal, respectively.

3. The variable frequency and variable duty cycle pulse injection based switched reluctance motor control method of claim 2, wherein: Step size ΔD of the pulse signal duty cycle step The calculation formula is: where F max is the frequency of the pulse signal near the misalignment position, I pk_down is the lower limit of the peak value of the pulse response current, I pk_up is the upper limit of the peak value of the pulse response current, U dc is the bus voltage, K dstep is the empirical coefficient, L min is the phase inductance at the misalignment position; Step ΔF of the frequency of the pulse signal step The calculation formula is: ΔF step = K fstep · F init Wherein, K fstep is the adjustment coefficient, its value range is 0.3~0.5, F init is the initial injection frequency of the pulse signal.

4. The variable frequency and variable duty cycle pulse injection based switched reluctance motor control method of claim 2, wherein: a lower threshold value I corresponding to the peak value of the impulse response current th_down an upper threshold value I corresponding to the peak value of the impulse response current th_up The calculation formulas are respectively: I th_down = K snr I noisemax I th_up = K rated I rated wherein K snr is the signal-to-noise ratio coefficient, I noisemax is the peak value of the equivalent current noise of the system, K rated is the upper threshold coefficient, and rated is the rated current of the switched reluctance motor.

5. The variable frequency and variable duty cycle pulse injection based switched reluctance motor control method as claimed in claim 1, wherein: Step c comprises the following steps: Step c-1, defining the rate of change of rotational speed ω ratio ; Step c-2, ω ratio The calculation formula maps the clamped rotational speed ω clamped to the interval [0, 1] to obtain the relative position of the corresponding rotational speed in the interval. Step c-3, calculate the step-up factor ω for the current rotational speed current_factor ; Step c-4, scaling the step size by a factor ω current_factor Apply to the base step size to get the final adjusted step size.

6. The variable frequency and variable duty cycle pulse injection based switched reluctance motor control method as claimed in claim 5, wherein: In step c-1, the rate of change of rotational speed ω ratio The formula for calculating ω is: where ω base is the base speed, ω max is the maximum speed of the switched reluctance motor in CCC mode, and ω clamped is the clamping speed.

7. The variable frequency and variable duty cycle pulse injection based switched reluctance motor control method as claimed in claim 5, wherein: In step c-3, the step size magnification ω current_factor The calculation formula is: ω current_factor = 1 + ω ratio (step factor -1) where step factor is a step size scaling factor, selected in the interval [1, 2], ω ratio is the rate of change of speed.

8. The variable frequency and variable duty cycle pulse injection based switched reluctance motor control method as claimed in claim 5, wherein: In step c-4, a final adjustment step is calculated according to the following formula: where ΔF dynamic and ΔD dynamic are the dynamically adjusted pulse injection frequency step size and control signal duty cycle step size, respectively.

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