A single current sensor control method for a tail topology switched reluctance motor

Abstract

The present application relates to the technical field of switched reluctance motor control, and specifically relates to a single current sensor control method for a tail topology switched reluctance motor, which comprises the following steps: step one: building a tail topology switched reluctance motor drive system; the system comprises a switched reluctance motor, a direct current power supply, a direct current bus, a single bridge arm, a current sensor, and a three-phase full-bridge inverter; step two: during system operation, the system is controlled as follows: an SVPWM module generates a PWM drive signal for the three-phase full-bridge inverter, and a controller generates a PWM drive signal for the single bridge arm, thereby achieving SVPWM control of the switched reluctance motor; during SVPWM control, the actual three-phase winding current value and the actual neutral point current value are reconstructed according to the direct current bus current value collected by the current sensor. The present application solves the problems of high hardware cost, high wiring complexity, and poor work reliability of the existing tail topology switched reluctance motor SVPWM control method, and is suitable for new energy vehicles, industrial drives, and other fields.

Description

Technical Field

[0001] This invention relates to the field of switched reluctance motor control technology, specifically a single current sensor control method for a tail-type topology switched reluctance motor. Background Technology

[0002] Switched reluctance motors (SRMs) are widely used in new energy vehicles and industrial drives due to their advantages such as being free of rare-earth elements, having a simple structure, high reliability, and a wide speed range. Traditional SRMs employ an asymmetric half-bridge (AHB) drive topology, which suffers from large torque ripple and high noise. Tail-type topology SRMs, a novel type of SRM, utilize a tail-type topology. By bringing out the neutral point of the star-connected three-phase windings and connecting it to an additional single bridge arm, a unique "tail-type" structure is formed. SVPWM control of this type of SRM can effectively reduce torque ripple and noise. Therefore, SVPWM control of tail-type topology SRMs has become an important development direction for SRM control technology.

[0003] However, in practical applications, existing SVPWM control methods for tail-type topology switched reluctance motors, due to their inherent limitations, require a current sensor in each of the a-phase winding, b-phase winding, c-phase winding, and neutral point lead (a total of four current sensors) to achieve closed-loop current control. This results in a large number of sensors, leading to high hardware costs, complex wiring, and poor reliability. Therefore, it is necessary to invent a single-current-sensor control method for tail-type topology switched reluctance motors to address the problems of high hardware costs, complex wiring, and poor reliability associated with existing SVPWM control methods for tail-type topology switched reluctance motors. Summary of the Invention

[0004] To address the problems of high hardware cost, high wiring complexity, and poor reliability in existing tail-type topology switched reluctance motor (SVPWM) control methods, this invention provides a single current sensor control method for tail-type topology switched reluctance motors.

[0005] This invention is achieved using the following technical solution:

[0006] A single current sensor control method for a tail-type topology switched reluctance motor, the method comprising the following steps:

[0007] Step 1: Build a tail-type topology switched reluctance motor drive system;

[0008] The system includes a switched reluctance motor, a DC power supply, a DC bus, a single bridge arm, a current sensor, and a three-phase full-bridge inverter. The switched reluctance motor's windings are three-phase windings connected in a star configuration. The midpoint of the single bridge arm is connected to the neutral point of the three-phase windings. The positive input terminal of the single bridge arm is connected to the positive terminal of the DC power supply via the positive line of the DC bus. The negative input terminal of the single bridge arm is connected to the negative terminal of the DC power supply via the negative line of the DC bus. The three-phase output terminals of the three-phase full-bridge inverter are connected to the three leads of the three-phase windings, respectively. The positive input terminal of the three-phase full-bridge inverter is connected to the positive terminal of the DC power supply sequentially via the current sensor and the positive line of the DC bus. The negative input terminal of the three-phase full-bridge inverter is connected to the negative terminal of the DC power supply via the negative line of the DC bus.

[0009] Step Two: During system operation, the following controls are performed on the system:

[0010] The SVPWM module generates the PWM drive signal for the three-phase full-bridge inverter, and the controller generates the PWM drive signal for a single bridge arm, thereby realizing the SVPWM control of the switched reluctance motor.

[0011] During SVPWM control, the actual values ​​of the three-phase winding current and the actual value of the neutral point current are reconstructed based on the DC bus current value collected by the current sensor.

[0012] The PWM drive signal of the three-phase full-bridge inverter is adjusted by feedback based on the actual value of the three-phase winding current, thereby realizing closed-loop control of the three-phase winding current.

[0013] The PWM drive signal of a single bridge arm is adjusted by feedback based on the actual value of the neutral point current, thereby realizing closed-loop control of the neutral point current.

[0014] Furthermore, in step two, the specific steps for the SVPWM module to generate the PWM drive signal for the three-phase full-bridge inverter are as follows:

[0015] Set a reference speed value; acquire the rotor angle, and the speed calculation module calculates the actual speed value based on the rotor angle; subtract the actual speed value from the reference speed value to obtain the speed deviation; the speed PI controller generates a q-axis current reference value based on the speed deviation; subtract the actual q-axis current value from the reference q-axis current value to obtain the q-axis current deviation; the q-axis current PI controller generates a q-axis voltage reference value based on the q-axis current deviation; perform an inverse Park transform based on the rotor angle on the q-axis voltage reference value to obtain the α-axis voltage reference value.

[0016] Set the d-axis current reference value to 0; calculate the difference between the actual d-axis current value and the d-axis current reference value to obtain the d-axis current deviation; the d-axis current PI regulator generates the d-axis voltage reference value based on the d-axis current deviation; and perform a Park inverse transformation based on the rotor angle on the d-axis voltage reference value to obtain the β-axis voltage reference value.

[0017] The α-axis voltage reference value and the β-axis voltage reference value are combined into a reference voltage vector; the SVPWM module generates the PWM drive signal for the three-phase full-bridge inverter based on the reference voltage vector.

[0018] Furthermore, in step two, the specific steps for the controller to generate the PWM drive signal for a single bridge arm are as follows:

[0019] The q-axis current reference value is sequentially subjected to Park inverse transformation and Clark inverse transformation to obtain the neutral point current reference value; the neutral point current deviation is obtained by subtracting the actual neutral point current value from the neutral point current reference value; the neutral point current PI regulator generates a control signal based on the neutral point current deviation; the controller generates a PWM drive signal for the single bridge arm based on the control signal.

[0020] Furthermore, in step two, the specific steps for reconstructing the actual values ​​of the three-phase winding current and the neutral point current based on the DC bus current value collected by the current sensor are as follows:

[0021] During SVPWM control, the three-phase full-bridge inverter outputs six active voltage vectors and two zero-voltage vectors. The six active voltage vectors are: active voltage vector V100, active voltage vector V110, active voltage vector V010, active voltage vector V011, active voltage vector V001, and active voltage vector V101. The two zero-voltage vectors are: zero-voltage vector V111 and zero-voltage vector V000. The six active voltage vectors divide the voltage vector plane into six sectors.

[0022] During one switching cycle of the SVPWM module, the current sensor acquires the DC bus current value under the action of 6 active voltage vectors and zero voltage vector V111.

[0023] The current reconstruction module first determines the sector where the reference voltage vector is located based on the PWM drive signal of the three-phase full-bridge inverter. Then, it substitutes the DC bus current value into the current reconstruction formula corresponding to that sector to reconstruct the actual values ​​of the three-phase winding current and the neutral point current.

[0024] Furthermore, after reconstructing the actual values ​​of the three-phase winding currents, the actual values ​​of the three-phase winding currents are subjected to Clark transformation to obtain the actual values ​​of the α-axis current and β-axis current; the actual values ​​of the α-axis current and β-axis current are subjected to Park transformation to obtain the actual values ​​of the q-axis current and d-axis current.

[0025] Furthermore, the six sectors and the six active voltage vectors satisfy the following correspondence:

[0026] When the sector number is 1, the first active voltage vector corresponding to this sector is V100, and the second active voltage vector corresponding to this sector is V110.

[0027] When the sector number is 2, the first active voltage vector corresponding to this sector is V110, and the second active voltage vector corresponding to this sector is V010.

[0028] When the sector number is 3, the first active voltage vector corresponding to this sector is V010, and the second active voltage vector corresponding to this sector is V011.

[0029] When the sector number is 4, the first active voltage vector corresponding to this sector is V011, and the second active voltage vector corresponding to this sector is V001.

[0030] When the sector number is 5, the first active voltage vector corresponding to this sector is V001, and the second active voltage vector corresponding to this sector is V101.

[0031] When the sector number is 6, the first active voltage vector corresponding to this sector is V101, and the second active voltage vector corresponding to this sector is V100.

[0032] Furthermore, the current reconstruction formula specifically includes:

[0033] When the sector number is 1, the current reconstruction formula for that sector is:

[0034] ;

[0035] ;

[0036] ;

[0037] ;

[0038] In the formula: , , These represent the actual values ​​of the current in phase a winding, phase b winding, and phase c winding, respectively. This represents the actual value of the neutral point current; This represents the DC bus current value under the action of the first active voltage vector corresponding to this sector; This represents the DC bus current value under the action of the second active voltage vector corresponding to this sector; This represents the DC bus current value under the action of the zero voltage vector V111;

[0039] When the sector number is 2, the current reconstruction formula for that sector is:

[0040] ;

[0041] ;

[0042] ;

[0043] ;

[0044] In the formula: , , These represent the actual values ​​of the current in phase a winding, phase b winding, and phase c winding, respectively. This represents the actual value of the neutral point current; This represents the DC bus current value under the action of the first active voltage vector corresponding to this sector; This represents the DC bus current value under the action of the second active voltage vector corresponding to this sector; This represents the DC bus current value under the action of the zero voltage vector V111;

[0045] When the sector number is 3, the current reconstruction formula for that sector is:

[0046] ;

[0047] ;

[0048] ;

[0049] ;

[0050] In the formula: , , These represent the actual values ​​of the current in phase a winding, phase b winding, and phase c winding, respectively. This represents the actual value of the neutral point current; This represents the DC bus current value under the action of the first active voltage vector corresponding to this sector; This represents the DC bus current value under the action of the second active voltage vector corresponding to this sector; This represents the DC bus current value under the action of the zero voltage vector V111;

[0051] When the sector number is 4, the current reconstruction formula for that sector is:

[0052] ;

[0053] ;

[0054] ;

[0055] ;

[0056] In the formula: , , These represent the actual values ​​of the current in phase a winding, phase b winding, and phase c winding, respectively. This represents the actual value of the neutral point current; This represents the DC bus current value under the action of the first active voltage vector corresponding to this sector; This represents the DC bus current value under the action of the second active voltage vector corresponding to this sector; This represents the DC bus current value under the action of the zero voltage vector V111;

[0057] When the sector number is 5, the current reconstruction formula for that sector is:

[0058] ;

[0059] ;

[0060] ;

[0061] ;

[0062] In the formula: , , These represent the actual values ​​of the current in phase a winding, phase b winding, and phase c winding, respectively. This represents the actual value of the neutral point current; This represents the DC bus current value under the action of the first active voltage vector corresponding to this sector; This represents the DC bus current value under the action of the second active voltage vector corresponding to this sector; This represents the DC bus current value under the action of the zero voltage vector V111;

[0063] When the sector number is 6, the current reconstruction formula for that sector is:

[0064] ;

[0065] ;

[0066] ;

[0067] ;

[0068] In the formula: , , These represent the actual values ​​of the current in phase a winding, phase b winding, and phase c winding, respectively. This represents the actual value of the neutral point current; This represents the DC bus current value under the action of the first active voltage vector corresponding to this sector; This represents the DC bus current value under the action of the second active voltage vector corresponding to this sector; This represents the DC bus current value under the action of the zero voltage vector V111.

[0069] Compared with the existing SVPWM control method for tail-type topology switched reluctance motors, this invention, by designing a dedicated reconfiguration algorithm adapted to the characteristics of tail-type topology, enables current closed-loop control with only one current sensor on the DC bus. This effectively reduces the number of sensors, thereby reducing hardware costs, wiring complexity, and operational reliability.

[0070] This invention effectively solves the problems of high hardware cost, high wiring complexity, and poor reliability of existing tail-type topology switched reluctance motor SVPWM control methods, and is applicable to fields such as new energy vehicles and industrial drives. Attached Figure Description

[0071] Figure 1 This is a schematic diagram of the tail-type topology switched reluctance motor drive system in this invention.

[0072] Figure 2 This is a schematic diagram of how the voltage vector plane is divided into 6 sectors by 6 active voltage vectors in this invention.

[0073] Figure 3 This is a control block diagram of the present invention.

[0074] Figure 4 The waveforms of the three-phase winding current and neutral point current are shown without the present invention.

[0075] Figure 5 The waveforms of the three-phase winding current and neutral point current after adopting this invention are shown.

[0076] In the picture: , , These represent the currents of phase a winding, phase b winding, and phase c winding, respectively. Indicates the neutral point current; This represents the DC bus current. Detailed Implementation

[0077] A single current sensor control method for a tail-type topology switched reluctance motor, the method comprising the following steps:

[0078] Step 1: Build a tail-type topology switched reluctance motor drive system;

[0079] The system includes a switched reluctance motor, a DC power supply, a DC bus, a single bridge arm, a current sensor, and a three-phase full-bridge inverter. The switched reluctance motor's windings are three-phase windings connected in a star configuration. The midpoint of the single bridge arm is connected to the neutral point of the three-phase windings. The positive input terminal of the single bridge arm is connected to the positive terminal of the DC power supply via the positive line of the DC bus. The negative input terminal of the single bridge arm is connected to the negative terminal of the DC power supply via the negative line of the DC bus. The three-phase output terminals of the three-phase full-bridge inverter are connected to the three leads of the three-phase windings, respectively. The positive input terminal of the three-phase full-bridge inverter is connected to the positive terminal of the DC power supply sequentially via the current sensor and the positive line of the DC bus. The negative input terminal of the three-phase full-bridge inverter is connected to the negative terminal of the DC power supply via the negative line of the DC bus.

[0080] Step Two: During system operation, the following controls are performed on the system:

[0081] The SVPWM module generates the PWM drive signal for the three-phase full-bridge inverter, and the controller generates the PWM drive signal for a single bridge arm, thereby realizing the SVPWM control of the switched reluctance motor.

[0082] During SVPWM control, the actual values ​​of the three-phase winding current and the actual value of the neutral point current are reconstructed based on the DC bus current value collected by the current sensor.

[0083] The PWM drive signal of the three-phase full-bridge inverter is adjusted by feedback based on the actual value of the three-phase winding current, thereby realizing closed-loop control of the three-phase winding current.

[0084] The PWM drive signal of a single bridge arm is adjusted by feedback based on the actual value of the neutral point current, thereby realizing closed-loop control of the neutral point current.

[0085] In step two, the specific steps for the SVPWM module to generate the PWM drive signal for the three-phase full-bridge inverter are as follows:

[0086] Set a reference speed value; acquire the rotor angle, and the speed calculation module calculates the actual speed value based on the rotor angle; subtract the actual speed value from the reference speed value to obtain the speed deviation; the speed PI controller generates a q-axis current reference value based on the speed deviation; subtract the actual q-axis current value from the reference q-axis current value to obtain the q-axis current deviation; the q-axis current PI controller generates a q-axis voltage reference value based on the q-axis current deviation; perform an inverse Park transform based on the rotor angle on the q-axis voltage reference value to obtain the α-axis voltage reference value.

[0087] Set the d-axis current reference value to 0; calculate the difference between the actual d-axis current value and the d-axis current reference value to obtain the d-axis current deviation; the d-axis current PI regulator generates the d-axis voltage reference value based on the d-axis current deviation; and perform a Park inverse transformation based on the rotor angle on the d-axis voltage reference value to obtain the β-axis voltage reference value.

[0088] The α-axis voltage reference value and the β-axis voltage reference value are combined into a reference voltage vector; the SVPWM module generates the PWM drive signal for the three-phase full-bridge inverter based on the reference voltage vector.

[0089] In step two, the specific steps for the controller to generate the PWM drive signal for a single bridge arm are as follows:

[0090] The q-axis current reference value is sequentially subjected to Park inverse transformation and Clark inverse transformation to obtain the neutral point current reference value; the neutral point current deviation is obtained by subtracting the actual neutral point current value from the neutral point current reference value; the neutral point current PI regulator generates a control signal based on the neutral point current deviation; the controller generates a PWM drive signal for the single bridge arm based on the control signal.

[0091] In step two, the specific steps for reconstructing the actual values ​​of the three-phase winding current and the neutral point current based on the DC bus current value collected by the current sensor are as follows:

[0092] During SVPWM control, the three-phase full-bridge inverter outputs six active voltage vectors and two zero-voltage vectors. The six active voltage vectors are: active voltage vector V100, active voltage vector V110, active voltage vector V010, active voltage vector V011, active voltage vector V001, and active voltage vector V101. The two zero-voltage vectors are: zero-voltage vector V111 and zero-voltage vector V000. The six active voltage vectors divide the voltage vector plane into six sectors.

[0093] During one switching cycle of the SVPWM module, the current sensor acquires the DC bus current value under the action of 6 active voltage vectors and zero voltage vector V111.

[0094] The current reconstruction module first determines the sector where the reference voltage vector is located based on the PWM drive signal of the three-phase full-bridge inverter. Then, it substitutes the DC bus current value into the current reconstruction formula corresponding to that sector to reconstruct the actual values ​​of the three-phase winding current and the neutral point current.

[0095] After reconstructing the actual values ​​of the three-phase winding currents, the actual values ​​of the three-phase winding currents are subjected to Clark transformation to obtain the actual values ​​of the α-axis current and β-axis current; the actual values ​​of the α-axis current and β-axis current are subjected to Park transformation to obtain the actual values ​​of the q-axis current and d-axis current.

[0096] The six sectors and the six active voltage vectors satisfy the following correspondence:

[0097] When the sector number is 1, the first active voltage vector corresponding to this sector is V100, and the second active voltage vector corresponding to this sector is V110.

[0098] When the sector number is 2, the first active voltage vector corresponding to this sector is V110, and the second active voltage vector corresponding to this sector is V010.

[0099] When the sector number is 3, the first active voltage vector corresponding to this sector is V010, and the second active voltage vector corresponding to this sector is V011.

[0100] When the sector number is 4, the first active voltage vector corresponding to this sector is V011, and the second active voltage vector corresponding to this sector is V001.

[0101] When the sector number is 5, the first active voltage vector corresponding to this sector is V001, and the second active voltage vector corresponding to this sector is V101.

[0102] When the sector number is 6, the first active voltage vector corresponding to this sector is V101, and the second active voltage vector corresponding to this sector is V100.

[0103] The current reconstruction formula specifically includes:

[0104] When the sector number is 1, the current reconstruction formula for that sector is:

[0105] ;

[0106] ;

[0107] ;

[0108] ;

[0109] In the formula: , , These represent the actual values ​​of the current in phase a winding, phase b winding, and phase c winding, respectively. This represents the actual value of the neutral point current; This represents the DC bus current value under the action of the first active voltage vector corresponding to this sector; This represents the DC bus current value under the action of the second active voltage vector corresponding to this sector; This represents the DC bus current value under the action of the zero voltage vector V111;

[0110] When the sector number is 2, the current reconstruction formula for that sector is:

[0111] ;

[0112] ;

[0113] ;

[0114] ;

[0115] In the formula: , , These represent the actual values ​​of the current in phase a winding, phase b winding, and phase c winding, respectively. This represents the actual value of the neutral point current; This represents the DC bus current value under the action of the first active voltage vector corresponding to this sector; This represents the DC bus current value under the action of the second active voltage vector corresponding to this sector; This represents the DC bus current value under the action of the zero voltage vector V111;

[0116] When the sector number is 3, the current reconstruction formula for that sector is:

[0117] ;

[0118] ;

[0119] ;

[0120] ;

[0121] In the formula: , , These represent the actual values ​​of the current in phase a winding, phase b winding, and phase c winding, respectively. This represents the actual value of the neutral point current; This represents the DC bus current value under the action of the first active voltage vector corresponding to this sector; This represents the DC bus current value under the action of the second active voltage vector corresponding to this sector; This represents the DC bus current value under the action of the zero voltage vector V111;

[0122] When the sector number is 4, the current reconstruction formula for that sector is:

[0123] ;

[0124] ;

[0125] ;

[0126] ;

[0127] In the formula: , , These represent the actual values ​​of the current in phase a winding, phase b winding, and phase c winding, respectively. This represents the actual value of the neutral point current; This represents the DC bus current value under the action of the first active voltage vector corresponding to this sector; This represents the DC bus current value under the action of the second active voltage vector corresponding to this sector; This represents the DC bus current value under the action of the zero voltage vector V111;

[0128] When the sector number is 5, the current reconstruction formula for that sector is:

[0129] ;

[0130] ;

[0131] ;

[0132] ;

[0133] In the formula: , , These represent the actual values ​​of the current in phase a winding, phase b winding, and phase c winding, respectively. This represents the actual value of the neutral point current; This represents the DC bus current value under the action of the first active voltage vector corresponding to this sector; This represents the DC bus current value under the action of the second active voltage vector corresponding to this sector; This represents the DC bus current value under the action of the zero voltage vector V111;

[0134] When the sector number is 6, the current reconstruction formula for that sector is:

[0135] ;

[0136] ;

[0137] ;

[0138] ;

[0139] In the formula: , , These represent the actual values ​​of the current in phase a winding, phase b winding, and phase c winding, respectively. This represents the actual value of the neutral point current; This represents the DC bus current value under the action of the first active voltage vector corresponding to this sector; This represents the DC bus current value under the action of the second active voltage vector corresponding to this sector; This represents the DC bus current value under the action of the zero voltage vector V111.

[0140] While specific embodiments of the present invention have been described above, those skilled in the art should understand that these are merely illustrative examples, and the scope of protection of the present invention is defined by the appended claims. Those skilled in the art can make various changes or modifications to these embodiments without departing from the principles and essence of the present invention, but all such changes and modifications fall within the scope of protection of the present invention.

Claims

1. A single current sensor control method for a tail-type topology switched reluctance motor, characterized in that: The method includes the following steps: Step 1: Build a tail-type topology switched reluctance motor drive system; The system includes a switched reluctance motor, a DC power supply, a DC bus, a single bridge arm, a current sensor, and a three-phase full-bridge inverter. The switched reluctance motor's windings are three-phase windings connected in a star configuration. The midpoint of the single bridge arm is connected to the neutral point of the three-phase windings. The positive input terminal of the single bridge arm is connected to the positive terminal of the DC power supply via the positive line of the DC bus. The negative input terminal of the single bridge arm is connected to the negative terminal of the DC power supply via the negative line of the DC bus. The three-phase output terminals of the three-phase full-bridge inverter are connected to the three leads of the three-phase windings, respectively. The positive input terminal of the three-phase full-bridge inverter is connected to the positive terminal of the DC power supply sequentially via the current sensor and the positive line of the DC bus. The negative input terminal of the three-phase full-bridge inverter is connected to the negative terminal of the DC power supply via the negative line of the DC bus. Step Two: During system operation, the following controls are performed on the system: The SVPWM module generates the PWM drive signal for the three-phase full-bridge inverter, and the controller generates the PWM drive signal for a single bridge arm, thereby realizing the SVPWM control of the switched reluctance motor. During SVPWM control, the actual values ​​of the three-phase winding current and the actual value of the neutral point current are reconstructed based on the DC bus current value collected by the current sensor. The PWM drive signal of the three-phase full-bridge inverter is adjusted by feedback based on the actual value of the three-phase winding current, thereby realizing closed-loop control of the three-phase winding current. The PWM drive signal of a single bridge arm is adjusted by feedback based on the actual value of the neutral point current, thereby realizing closed-loop control of the neutral point current.

2. The single current sensor control method for a tail-type topology switched reluctance motor according to claim 1, characterized in that: In step two, the specific steps for the SVPWM module to generate the PWM drive signal for the three-phase full-bridge inverter are as follows: Set a reference speed value; collect the rotor angle, and the speed calculation module calculates the actual speed value based on the rotor angle; the difference between the actual speed value and the speed reference value is used to obtain the speed deviation; the speed PI regulator generates a q-axis current reference value based on the speed deviation; The q-axis current deviation is obtained by subtracting the actual q-axis current value from the q-axis current reference value; the q-axis current PI regulator generates the q-axis voltage reference value based on the q-axis current deviation; the α-axis voltage reference value is obtained by performing a Park inverse transformation based on the rotor angle on the q-axis voltage reference value. Set the d-axis current reference value to 0; calculate the difference between the actual d-axis current value and the d-axis current reference value to obtain the d-axis current deviation; the d-axis current PI regulator generates the d-axis voltage reference value based on the d-axis current deviation; and perform a Park inverse transformation based on the rotor angle on the d-axis voltage reference value to obtain the β-axis voltage reference value. The α-axis voltage reference value and the β-axis voltage reference value are combined into a reference voltage vector; The SVPWM module generates the PWM drive signal for the three-phase full-bridge inverter based on the reference voltage vector.

3. The single current sensor control method for a tail-type topology switched reluctance motor according to claim 2, characterized in that: In step two, the specific steps for the controller to generate the PWM drive signal for a single bridge arm are as follows: The q-axis current reference value is sequentially subjected to Park inverse transformation and Clark inverse transformation to obtain the neutral point current reference value; the difference between the actual neutral point current value and the neutral point current reference value is obtained to obtain the neutral point current deviation; the neutral point current PI regulator generates a control signal based on the neutral point current deviation. The controller generates a PWM drive signal for a single bridge arm based on the control signal.

4. A single current sensor control method for a tail-type topology switched reluctance motor according to claim 3, characterized in that: In step two, the specific steps for reconstructing the actual values ​​of the three-phase winding current and the neutral point current based on the DC bus current value collected by the current sensor are as follows: During SVPWM control, the three-phase full-bridge inverter outputs six active voltage vectors and two zero-voltage vectors. The six active voltage vectors are: active voltage vector V100, active voltage vector V110, active voltage vector V010, active voltage vector V011, active voltage vector V001, and active voltage vector V101. The two zero-voltage vectors are: zero-voltage vector V111 and zero-voltage vector V000. The six active voltage vectors divide the voltage vector plane into six sectors. During one switching cycle of the SVPWM module, the current sensor acquires the DC bus current value under the action of 6 active voltage vectors and zero voltage vector V111. The current reconstruction module first determines the sector where the reference voltage vector is located based on the PWM drive signal of the three-phase full-bridge inverter. Then, it substitutes the DC bus current value into the current reconstruction formula corresponding to that sector to reconstruct the actual values ​​of the three-phase winding current and the neutral point current.

5. A single current sensor control method for a tail-type topology switched reluctance motor according to claim 4, characterized in that: After reconstructing the actual values ​​of the three-phase winding currents, the actual values ​​of the three-phase winding currents are subjected to Clark transformation to obtain the actual values ​​of the α-axis current and β-axis current; the actual values ​​of the α-axis current and β-axis current are subjected to Park transformation to obtain the actual values ​​of the q-axis current and d-axis current.

6. A single current sensor control method for a tail-type topology switched reluctance motor according to claim 5, characterized in that: The six sectors and the six active voltage vectors satisfy the following correspondence: When the sector number is 1, the first active voltage vector corresponding to this sector is V100, and the second active voltage vector corresponding to this sector is V110. When the sector number is 2, the first active voltage vector corresponding to this sector is V110, and the second active voltage vector corresponding to this sector is V010. When the sector number is 3, the first active voltage vector corresponding to this sector is V010, and the second active voltage vector corresponding to this sector is V011. When the sector number is 4, the first active voltage vector corresponding to this sector is V011, and the second active voltage vector corresponding to this sector is V001. When the sector number is 5, the first active voltage vector corresponding to this sector is V001, and the second active voltage vector corresponding to this sector is V101. When the sector number is 6, the first active voltage vector corresponding to this sector is V101, and the second active voltage vector corresponding to this sector is V100.

7. A single current sensor control method for a tail-type topology switched reluctance motor according to claim 6, characterized in that: The current reconstruction formula specifically includes: When the sector number is 1, the current reconstruction formula for that sector is: ； ； ； ； In the formula: , , These represent the actual values ​​of the current in phase a winding, phase b winding, and phase c winding, respectively. This represents the actual value of the neutral point current; This represents the DC bus current value under the action of the first active voltage vector corresponding to this sector; This represents the DC bus current value under the action of the second active voltage vector corresponding to this sector; This represents the DC bus current value under the action of the zero voltage vector V111; When the sector number is 2, the current reconstruction formula for that sector is: ； ； ； ； In the formula: , , These represent the actual values ​​of the current in phase a winding, phase b winding, and phase c winding, respectively. This represents the actual value of the neutral point current; This represents the DC bus current value under the action of the first active voltage vector corresponding to this sector; This represents the DC bus current value under the action of the second active voltage vector corresponding to this sector; This represents the DC bus current value under the action of the zero voltage vector V111; When the sector number is 3, the current reconstruction formula for that sector is: ； ； ； ； In the formula: , , These represent the actual values ​​of the current in phase a winding, phase b winding, and phase c winding, respectively. This represents the actual value of the neutral point current; This represents the DC bus current value under the action of the first active voltage vector corresponding to this sector; This represents the DC bus current value under the action of the second active voltage vector corresponding to this sector; This represents the DC bus current value under the action of the zero voltage vector V111; When the sector number is 4, the current reconstruction formula for that sector is: ； ； ； ； In the formula: , , These represent the actual values ​​of the current in phase a winding, phase b winding, and phase c winding, respectively. This represents the actual value of the neutral point current; This represents the DC bus current value under the action of the first active voltage vector corresponding to this sector; This represents the DC bus current value under the action of the second active voltage vector corresponding to this sector; This represents the DC bus current value under the action of the zero voltage vector V111; When the sector number is 5, the current reconstruction formula for that sector is: ； ； ； ； In the formula: , , These represent the actual values ​​of the current in phase a winding, phase b winding, and phase c winding, respectively. This represents the actual value of the neutral point current; This represents the DC bus current value under the action of the first active voltage vector corresponding to this sector; This represents the DC bus current value under the action of the second active voltage vector corresponding to this sector; This represents the DC bus current value under the action of the zero voltage vector V111; When the sector number is 6, the current reconstruction formula for that sector is: ； ； ； ； In the formula: , , These represent the actual values ​​of the current in phase a winding, phase b winding, and phase c winding, respectively. This represents the actual value of the neutral point current; This represents the DC bus current value under the action of the first active voltage vector corresponding to this sector; This represents the DC bus current value under the action of the second active voltage vector corresponding to this sector; This represents the DC bus current value under the action of the zero voltage vector V111.

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