Asymmetric six-phase hybrid excitation synchronous motor, control algorithm and two-gear transmission thereof

Abstract

The invention discloses an asymmetric six-phase hybrid excitation synchronous motor, a control algorithm and a two-gear transmission thereof, a stator winding of the motor is composed of two sets of three-phase symmetric windings in star connection, the first set of windings and the second set of windings are respectively connected to two three-phase PWM (Pulse Width Modulation) controllers, namely a main controller and an auxiliary controller, and the main controller and the auxiliary controller are respectively connected with the three-phase PWM controllers. And the two controllers are jointly powered by a vehicle-mounted battery. According to the asymmetric six-phase hybrid excitation synchronous motor, the control algorithm and the two-gear transmission thereof, under the condition that the battery voltage is limited, the output power of the motor can be further improved, in addition, the motor rotor is powered by the excitation winding, the excitation winding of the rotor is directly regulated and controlled in real time, and the efficiency of the motor is improved. And the high speed, miniaturization and high efficiency of the vehicle-mounted synchronous motor are greatly improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of synchronous motors, and in particular relates to an asymmetric six-phase hybrid excitation synchronous motor, a control algorithm and a two-speed transmission thereof. Background Art

[0002] Currently, the powertrain motors used in new energy vehicles, including electric vehicles (EVs), hybrid electric vehicles (HEVs / PHEVs), extended-range electric vehicles (REEVs), and fuel cell vehicles (FCEVs), mostly utilize three-phase permanent magnet synchronous motors (IPMSMs). These motors are widely used due to their compact size, lightweight, and high efficiency. However, the key technologies for permanent magnet synchronous motors are trending towards higher speeds and higher power density, requiring sufficiently high voltages for onboard batteries, which increases costs.

[0003] Therefore, under the condition of the vehicle battery voltage limitation, the purpose of the present invention is to further increase the line voltage of the vehicle synchronous motor to achieve miniaturization, high speed and high efficiency of the vehicle synchronous motor. Summary of the Invention

[0004] The main purpose of the present invention is to provide an asymmetric six-phase hybrid excitation synchronous motor, a control algorithm, and a two-speed transmission thereof. These can further increase the motor's output power under battery voltage limitations. Furthermore, the motor rotor is powered by an excitation winding, which directly regulates the rotor's excitation winding in real time, significantly improving the speed, miniaturization, and efficiency of the on-board synchronous motor. This motor can be referred to as an asymmetrically six-phase hybrid excitation synchronous motor (ASPHESM).

[0005] To achieve the above objectives, the present invention provides an asymmetric six-phase hybrid excitation synchronous motor, characterized in that it is driven by a six-phase two-level controller, wherein: The stator winding of the motor consists of two sets of three-phase symmetrical windings connected in star shape. The midpoints of the two sets of windings are isolated from each other. The first set of windings is the main winding Um-Vm-Wm; the second set of windings is the auxiliary winding Us-Vs-Ws. The first set of windings and the second set of windings are connected to two three-phase PWM controllers, one for the main controller and the other for the auxiliary controller, which are powered by the vehicle battery. The motor stator winding control in both the main controller and the auxiliary controller includes six IGBTs or MOSFETs, six freewheeling diodes (FWD) power modules, thin film capacitors, and control circuits to perform real-time control of the stator three-phase current. The three-phase currents Ium, Ivm and Iwm of the main controller and the three-phase currents Ius, Ivs and Iws of the sub-controller are all obtained by current sensors, and the rotor angle signal is obtained by the selected resolver; the electrical angle phase difference between two sets of adjacent windings is 30 degrees.

[0006] As a further preferred technical solution of the above technical solution, the six-phase motor coordinate system is mapped to three orthogonal coordinate spaces, α-β and xy space and zero-sequence n1-n2 space; the α-β coordinate system is used to control the current fundamental wave and torque output; the xy coordinate system is used to control the current harmonics, and the n1-n2 coordinate space is a zero-sequence space and does not participate in energy conversion, wherein: The voltage equation of the asymmetric six-phase hybrid excitation synchronous motor based on the dq coordinate system is: ; in, The air gap magnetic field flux generated by the rotor magnet is the magnetic field generated by the magnet itself; is the air gap magnetic field flux generated by the rotor excitation winding, Through the excitation current Adjust size and direction; is the d-axis motor voltage; is the q-axis motor voltage; is the d-axis motor current, ; is the q-axis motor current, ; is the Peak value of the motor phase current, ; is the leading phase angle of the motor current starting from the q axis; is the d-axis motor inductance, is the q-axis motor inductance; is the motor rotor magnetic pole deviation angle; is the motor phase resistance; is the electrical angle of the motor rotor; The voltage equation of the asymmetric six-phase hybrid excitation synchronous motor based on the xy coordinate system is: ; in, is the x-axis motor voltage in the xy coordinate space; is the y-axis motor voltage in the xy coordinate space; is the x-axis motor current in the xy coordinate space; is the y-axis motor current in the xy coordinate space; is the leakage inductance; The electromagnetic torque of the asymmetric six-phase hybrid excitation synchronous motor is expressed by the following formula: ; in, is the number of rotor pole pairs; The formula for converting the six-phase current in the six-phase coordinate system into the dq, xy and n1-n2 coordinate systems is as follows: ; is the motor rotor angle; Ium, Ivm, and Iwm are the three-phase currents of the first set of windings; Ius, Ivs, and Iws are the three-phase currents of the second set of windings; and are the d-axis and q-axis currents in the dq coordinate system; and are the x-axis and y-axis currents in the xy coordinate system; and are the n1-axis and n2-axis currents in the xy coordinate system; The xy coordinate system is used to control current harmonics, and the current command value in the xy coordinate space is and Set to 0, through the command , and actual current , The PI feedback control is used to achieve zero harmonic content in the actual current of the six-phase motor. The setting of the current command value in the xy coordinate space is expressed as follows: .

[0007] The present invention also provides a control algorithm for an asymmetric six-phase hybrid excitation synchronous motor. The six-phase two-level controller has a total of 64 switching states. The vectors corresponding to the 64 switching states in α-β and xy space are expressed by the following formula: ; ; in, and They represent the voltage synthesis vectors corresponding to the α-β and xy spaces respectively, S represents the switching state of all bridge arms, Represents the switching state of the first set of windings, Represents the switching state of the second set of windings. 1 represents the upper bridge arm is on and the lower bridge arm is off. 0 represents the upper bridge arm is off and the lower bridge arm is on. The vector number uses a binary switching state. , Convert to octal representation; Use the space four-vector control method to obtain the time value of each voltage vector in the α-β and xy coordinate space; Calculate the rotor excitation winding voltage, , is the rotor excitation winding resistance, is the rotor excitation winding current; Calculate the magnetic field of the rotor excitation winding, , is the rotor excitation winding inductance; Calculate the current limit and voltage limit of the motor, where: For the current limit value, , is the current limit value; For voltage limit values, ; ; is the terminal voltage in steady state, is the voltage limit value; The simplified limiting equation for the motor voltage is: ; = - ,in: is the simplified circle of motor voltage, is the simplified limit circle for the motor voltage, is the phase resistance.

[0008] As a further preferred technical solution of the above technical solution, the characteristic current is expressed by the following formula: ; Maximum value of characteristic current ; When the motor operating conditions reach the voltage limit circle and the maximum motor speed and output power need to be further increased, the traditional Mtpv control curve ① is converted to Mtpv control curve ②. The conversion formula is as follows: When the motor runs to ①, it has reached the voltage limit ellipse Vam; at this time, Vam is determined by the following formula: ; is the actual voltage utilization; ; is the battery voltage; The command voltage utilization is In order to make the actual voltage utilization rate not exceed the command voltage utilization rate, the following equation is used for control: ; ; ; ; in, is the current leading phase angle The adjustment parameters, is the rotor excitation current The adjustment parameters, is the excitation current, is the command value of the current leading phase angle, is the command value of the excitation current, by adjusting the current leading phase angle and excitation current The command value is adjusted to increase the motor speed and output power.

[0009] The present invention also provides a two-speed transmission equipped with an asymmetric six-phase hybrid excitation synchronous motor, wherein the output shaft of the motor is connected to the first-stage driving gear Z of the first gear. 11 , and the first-stage driving gear Z of the two-speed gear 21 , Z 21 Connected to a wet friction plate clutch, the two gears transmit power when the wet friction plate clutch is engaged, and the two gears do not transmit power and idle when the wet friction plate clutch is disengaged; The intermediate shaft is connected to the second-stage main reducer driving gear Z 31 , 1st gear driven gear Z 12 , Z 12 Connect the one-way overrunning clutch and synchronizer, and the intermediate shaft is finally connected to the first-stage driven gear Z of the second gear. 22 ; Z 32 The driven gear Z of the 2nd stage main reducer 32 , connect the differential.

[0010] The beneficial effects of the present invention are: 1. Within the constraints of vehicle battery voltage, the line-to-line voltage of the onboard synchronous motor is further increased, achieving miniaturization, higher speed, and higher efficiency. A new electric drive system and control method for the asymmetrically six-phase hybrid excited synchronous motor (ASPHESM) has been invented, which can increase the output power of the synchronous motor within the constraints of the vehicle battery voltage.

[0011] 2. A new control algorithm for the asymmetric six-phase hybrid excitation synchronous motor ASPHESM was invented. By adjusting the excitation winding current and the leading phase angle of the current, the maximum speed of the motor can be greatly improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 1 is a block diagram of an electric drive system equipped with an asymmetric hybrid excitation synchronous motor according to the present invention.

[0013] Figure 2 It is a schematic diagram of the rotor structure and power supply method of the motor of the present invention.

[0014] Figure 3 It is a control block diagram of the electric drive system of the motor of the present invention.

[0015] Figure 4 Schematic diagram of the control algorithm of the motor of the present invention.

[0016] Figure 5 Schematic diagram of a two-speed transmission equipped with an asymmetric six-phase hybrid excitation synchronous motor according to the present invention. DETAILED DESCRIPTION

[0017] The following description is intended to disclose the present invention so that those skilled in the art can implement the present invention. The preferred embodiments described below are for illustrative purposes only, and those skilled in the art will readily appreciate other obvious variations. The basic principles of the present invention defined in the following description may be applied to other embodiments, variations, improvements, equivalents, and other technical solutions that do not depart from the spirit and scope of the present invention.

[0018] In the preferred embodiment of the present invention, those skilled in the art should note that the coordinate system and the like involved in the present invention may be regarded as prior art.

[0019] Preferred embodiment.

[0020] like Figure 1 As shown, the present invention discloses an asymmetric six-phase hybrid excitation synchronous motor, which is driven by a six-phase two-level controller, wherein: The stator winding of the motor consists of two sets of three-phase symmetrical windings connected in star shape. The midpoints of the two sets of windings are isolated from each other. The first set of windings is the main winding Um-Vm-Wm; the second set of windings is the auxiliary winding Us-Vs-Ws. The first and second sets of windings are connected to two three-phase PWM controllers, one for the master and one for the slave, respectively. Both controllers are powered by the vehicle's battery. The motor stator winding control in both the master and slave controllers includes six IGBTs or MOSFETs, six freewheeling diode (FWD) power modules, thin-film capacitors, and control circuits for real-time control of the stator's three-phase current. (The master and slave controllers have a total of 12 power modules, requiring 12 PWM signals for drive control.) The three-phase currents Ium, Ivm and Iwm of the main controller and Ius, Ivs and Iws of the sub-controller are obtained by current sensors, and the rotor angle signal is obtained by the selected resolver (Vdc is the vehicle battery voltage); the electrical angle phase difference between the two adjacent windings is 30 degrees (called a double Y-shifted 30-degree six-phase ASPHESM asymmetric hybrid excitation synchronous motor; the two-level controller has a total of 2 6 =64 switching states; the motor rotor is a hybrid excitation rotor composed of magnets and windings).

[0021] It also includes a Boost circuit, which consists of two power devices and an inductor. It can adaptively boost the battery voltage to the optimal voltage based on the output torque and output power required by the drive motor and combined with the battery voltage, further improving efficiency and reducing losses.

[0022] like Figure 2 As shown, the rotor consists of excitation coils. The motor rotor winding control section is comprised of an H-bridge control circuit. The H-bridge control circuit's ①-④ ON, ②-③ OFF positions the excitation current in the excitation winding to be positive, enabling magnetization control of the air gap magnetic flux. The ②-③ ON, ①-④ OFF positions the excitation current in the excitation winding to be negative, enabling field weakening control of the air gap magnetic flux.

[0023] Specifically, the six-phase motor coordinate system is mapped to three orthogonal coordinate spaces: α-β, xy, and zero-sequence n1-n2. The α-β coordinate system is used to control the current fundamental and torque output. The xy coordinate system is used to control the current harmonics. The n1-n2 coordinate space is a zero-sequence space and does not participate in energy conversion. It's worth noting that the dq coordinate system (also called a synchronously rotating coordinate system) is based on the synchronous rotation of the motor's rotor magnetic field. The d-axis (direct axis) and q-axis (quadrature axis) rotate synchronously with the rotor magnetic field. For example, in permanent magnet synchronous motor control, the Clark transform is used to convert the three-phase stationary coordinate system (ABC) into a two-phase stationary coordinate system (α-β). The Park transform then converts the two-phase stationary coordinate system into a dq rotating coordinate system. This allows time-varying AC quantities (such as three-phase current) to be converted into DC quantities synchronized with the rotating coordinate system, facilitating control.

[0024] The voltage equation of the asymmetric six-phase hybrid excitation synchronous motor based on the dq coordinate system is: ; in, The air gap magnetic field flux generated by the rotor magnet is the magnetic field generated by the magnet itself; is the air gap magnetic field flux generated by the rotor excitation winding, Through the excitation current Adjust size and direction; is the d-axis motor voltage; is the q-axis motor voltage; is the d-axis motor current, ; is the q-axis motor current, ; is the Peak value of the motor phase current, ; is the leading phase angle of the motor current starting from the q axis; is the d-axis motor inductance, is the q-axis motor inductance; is the motor rotor magnetic pole deviation angle ( ); is the motor phase resistance; is the electrical angle of the motor rotor; The voltage equation of the asymmetric six-phase hybrid excitation synchronous motor based on the xy coordinate system is: ; in, is the x-axis motor voltage in the xy coordinate space; is the y-axis motor voltage in the xy coordinate space; is the x-axis motor current in the xy coordinate space; is the y-axis motor current in the xy coordinate space; is the leakage inductance; The electromagnetic torque of the asymmetric six-phase hybrid excitation synchronous motor is expressed by the following formula: ; in, is the number of rotor pole pairs; The formula for converting the six-phase currents (Ium, Ivm, Iwm; Ius, Ivs, Iws) in the six-phase coordinate system (Um-Vm-Wm-Us-Vs-Ws) into the dq, xy, and n1-n2 coordinate systems is as follows: ; is the motor rotor angle; Ium, Ivm, and Iwm are the three-phase currents of the first set of windings; Ius, Ivs, and Iws are the three-phase currents of the second set of windings; and are the d-axis and q-axis currents in the dq coordinate system; and are the x-axis and y-axis currents in the xy coordinate system; and are the n1-axis and n2-axis currents in the xy coordinate system; The xy coordinate system is used to control current harmonics, and the current command value in the xy coordinate space is and Set to 0, through the command , and actual current , The PI feedback control is used to achieve zero harmonic content in the actual current of the six-phase motor. The setting of the current command value in the xy coordinate space is expressed as follows: .like Figure 3 As shown, spatial four-vector control is adopted to achieve the control purpose of reducing the harmonic content to a minimum, and the maximum speed and output power can be expanded.

[0025] The present invention also discloses a control algorithm for an asymmetric six-phase hybrid excitation synchronous motor. The six-phase two-level controller has a total of 64 switching states. The vectors corresponding to the 64 switching states in α-β and xy space are expressed by the following formula: ; ; in, and They represent the voltage synthesis vectors corresponding to the α-β and xy spaces respectively, S represents the switching state of all bridge arms, Represents the switching state of the first set of windings, Represents the switching state of the second set of windings. 1 represents the upper bridge arm is on and the lower bridge arm is off. 0 represents the upper bridge arm is off and the lower bridge arm is on. The vector number uses a binary switching state. , Convert to octal representation (for example: , ; The corresponding binary number is 110100, which is converted to octal number 64); The time value of each voltage vector in the α-β and xy coordinate space is obtained by using the space four-vector control method, specifically: Taking the first sector of the α-β xy coordinate space as an example, , , , The four largest vectors are synthesized and according to the volt-second balance principle, we can get: ; : is the voltage composite value in the α-β coordinate system; : is the voltage composite value in the x-y coordinate system; it is obtained by coordinate transformation after the PI feedback control between the six-phase currents Ium, Ivm, Iwm; Ius, Ivs, Iws in the six-phase coordinate system is converted into the formula in the dq, xy, n1-n2 coordinate system.

[0026] α-β; The time value of each voltage vector in the xy coordinate space is expressed by the following formula: ; Calculate the rotor excitation winding voltage, , is the rotor excitation winding resistance, is the rotor excitation winding current; Calculate the magnetic field of the rotor excitation winding, , is the rotor excitation winding inductance; Calculate the current limit and voltage limit of the motor, where: For the current limit value, , is the current limit value; For voltage limit values, ; ; is the terminal voltage in steady state, is the voltage limit value; The simplified limiting equation for the motor voltage is: ; = - ,in: is the simplified circle of motor voltage, is the simplified limit circle for the motor voltage, is the phase resistance ( The equation, removing Ra, is simplified to ).

[0027] Specifically, if Figure 4 As shown, the characteristic current is expressed by the following formula: ; Maximum value of characteristic current ; When the motor operating conditions reach the voltage limit circle and the maximum motor speed and output power need to be further increased, the traditional Mtpv control curve ① is converted to Mtpv control curve ②. The conversion formula is as follows ([Mtpv (Maximum Torque Per Volt)] is the abbreviation for maximum torque voltage ratio and is the second stage of permanent magnet synchronous motor field weakening control. The first stage is called Mtpa (Maximum Torque Per Ampere)): When the actual operating voltage of the motor reaches the voltage limit circle, the speed and output power need to be further increased. Assuming that the motor is in the operating state of ①, through the control of the method of the present invention, the motor operating state gradually switches from ① to ②. When the motor runs to ①, it has reached the voltage limit ellipse Vam; at this time, Vam is determined by the following formula: ; is the actual voltage utilization; ; is the battery voltage; The command voltage utilization is In order to make the actual voltage utilization rate not exceed the command voltage utilization rate, the following equation is used for control: ; ; ; ; in, is the current leading phase angle The adjustment parameters, is the rotor excitation current The adjustment parameters, is the excitation current ( ), is the command value of the current leading phase angle, is the command value of the excitation current, by adjusting the current leading phase angle and excitation current The command value is adjusted to increase the motor speed and output power.

[0028] like Figure 5 As shown, the present invention also discloses a two-speed transmission equipped with an asymmetric six-phase hybrid excitation synchronous motor, comprising an asymmetric six-phase hybrid excitation synchronous motor, the output shaft of which is connected to the first-stage driving gear Z of the first gear. 11 , and the first-stage driving gear Z of the two-speed gear 21 , Z 21Connected to a wet friction plate clutch, the two gears transmit power when the wet friction plate clutch is engaged, and the two gears do not transmit power and idle when the wet friction plate clutch is disengaged; The intermediate shaft is connected to the second-stage main reducer driving gear Z 31 , 1st gear driven gear Z 12 , Z 12 Connect the one-way overrunning clutch and synchronizer, and the intermediate shaft is finally connected to the first-stage driven gear Z of the second gear. 22 ; Z 32 The driven gear Z of the 2nd stage main reducer 32 , connect the differential.

[0029] The advantages of the present invention are: 1. Within the limits of the vehicle battery voltage, the line-to-line voltage and power density of the vehicle synchronous motor are further improved, achieving miniaturization, higher speed, and higher efficiency. The electric drive system of the newly invented asymmetrically six-phase hybrid excited synchronous motor (ASPHESM) is itself.

[0030] 2. The new control algorithm for the asymmetric six-phase hybrid excitation synchronous motor ASPHESM can significantly improve the motor's maximum speed and operating efficiency by adjusting the excitation winding current and the leading phase angle of the current, and coordinating the control with the magnetic field generated by the rotor magnets.

[0031] 3. New energy vehicles equipped with the ASPHESM motor system include electric vehicles (EVs), hybrid electric vehicles (HEVs / PHEVs), extended-range electric vehicles (REEVs), fuel cell vehicles (FCEVs), and other rear-wheel drive or four-wheel drive vehicles, as well as two-wheeled motorcycles and three-wheeled vehicles.

[0032] 4. The invention of ASPHESM six-phase motor is deeply integrated with two-speed or multi-speed gearbox, which further improves the low-speed climbing ability and maximum speed of the vehicle.

[0033] 5. The Boost circuit is composed of two power devices and an inductor. It can adaptively boost the battery voltage to the optimal voltage based on the output torque and output power required by the drive motor and the battery voltage, further improving efficiency and reducing losses.

[0034] It is worth mentioning that the technical features such as the coordinate system involved in the patent application of this invention should be regarded as prior art. The specific structure, working principle and possible control method and spatial layout method of these technical features can be selected by conventional means in the field and should not be regarded as the inventive point of the patent of this invention. The patent of this invention will not be further elaborated.

[0035] For those skilled in the art, it is still possible to modify the technical solutions described in the aforementioned embodiments, or to make equivalent replacements for some of the technical features therein. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. An asymmetric six-phase hybrid excitation synchronous motor, characterized in that: Driven by a six-phase two-level controller, where: The stator winding of the motor consists of two sets of three-phase symmetrical windings connected in star shape. The midpoints of the two sets of windings are isolated from each other. The first set of windings is the main winding Um-Vm-Wm; the second set of windings is the auxiliary winding Us-Vs-Ws. The first set of windings and the second set of windings are connected to two three-phase PWM controllers, one for the main controller and the other for the auxiliary controller, which are powered by the vehicle battery. The motor stator winding control in both the main controller and the auxiliary controller includes six IGBTs or MOSFETs, six freewheeling diodes (FWD) power modules, thin film capacitors, and control circuits to perform real-time control of the stator three-phase current. The three-phase currents Ium, Ivm and Iwm of the main controller and the three-phase currents Ius, Ivs and Iws of the sub-controller are all obtained by current sensors, and the rotor angle signal is obtained by the selected resolver; the electrical angle phase difference between two sets of adjacent windings is 30 degrees.

2. The asymmetric six-phase hybrid excitation synchronous motor according to claim 1, characterized in that: The six-phase motor coordinate system is mapped to three orthogonal coordinate spaces: α-β, xy, and zero-sequence n1-n2. The α-β coordinate system is used to control the current fundamental and torque output. The xy coordinate system is used to control current harmonics. The n1-n2 coordinate space is a zero-sequence space and does not participate in energy conversion. The voltage equation of the asymmetric six-phase hybrid excitation synchronous motor based on the dq coordinate system is: ； in, The air gap magnetic field flux generated by the rotor magnet is the magnetic field generated by the magnet itself; is the air gap magnetic field flux generated by the rotor excitation winding, Through the excitation current Adjust size and direction; is the d-axis motor voltage; is the q-axis motor voltage; is the d-axis motor current, ; is the q-axis motor current, ; is the Peak value of the motor phase current, ; is the leading phase angle of the motor current starting from the q axis; is the d-axis motor inductance, is the q-axis motor inductance; is the motor rotor magnetic pole deviation angle; is the motor phase resistance; is the electrical angle of the motor rotor; The voltage equation of the asymmetric six-phase hybrid excitation synchronous motor based on the xy coordinate system is: ； in, is the x-axis motor voltage in the xy coordinate space; is the y-axis motor voltage in the xy coordinate space; is the x-axis motor current in the xy coordinate space; is the y-axis motor current in the xy coordinate space; is the leakage inductance; The electromagnetic torque of the asymmetric six-phase hybrid excitation synchronous motor is expressed by the following formula: ； in, is the number of rotor pole pairs; The formula for converting the six-phase current in the six-phase coordinate system into the dq, xy and n1-n2 coordinate systems is as follows: ； is the motor rotor angle; Ium, Ivm, and Iwm are the three-phase currents of the first set of windings; Ius, Ivs, and Iws are the three-phase currents of the second set of windings; and are the d-axis and q-axis currents in the dq coordinate system; and are the x-axis and y-axis currents in the xy coordinate system; and are the n1-axis and n2-axis currents in the xy coordinate system; The xy coordinate system is used to control current harmonics, and the current command value in the xy coordinate space is and Set to 0, through the command , and actual current , The PI feedback control is used to achieve zero harmonic content in the actual current of the six-phase motor. The setting of the current command value in the xy coordinate space is expressed as follows: .

3. A control algorithm for an asymmetric six-phase hybrid excitation synchronous motor, applied to an asymmetric six-phase hybrid excitation synchronous motor according to any one of claims 1-2, characterized in that: The six-phase two-level controller has a total of 64 switching states. The vectors corresponding to the 64 switching states in α-β and xy space are expressed as follows: ； ； in, and They represent the voltage synthesis vectors corresponding to the α-β and xy spaces respectively, S represents the switching state of all bridge arms, Represents the switching state of the first set of windings, Represents the switching state of the second set of windings. 1 represents the upper bridge arm is on and the lower bridge arm is off. 0 represents the upper bridge arm is off and the lower bridge arm is on. The vector number uses a binary switching state. , Convert to octal representation; Use the space four-vector control method to obtain the time value of each voltage vector in the α-β and xy coordinate space; Calculate the rotor excitation winding voltage, , is the rotor excitation winding resistance, is the rotor excitation winding current; Calculate the magnetic field of the rotor excitation winding, , is the rotor excitation winding inductance; Calculate the current limit and voltage limit of the motor, where: For the current limit value, , is the current limit value; For voltage limit values, ; ； is the terminal voltage in steady state, is the voltage limit value; The simplified limiting equation for the motor voltage is: ; = - ,in: is the simplified circle of motor voltage, is the simplified limit circle for the motor voltage, is the phase resistance.

4. The control algorithm of the asymmetric six-phase hybrid excitation synchronous motor according to claim 3 is characterized in that: The characteristic current is expressed by the following formula: ; Maximum value of characteristic current ; When the motor operating conditions reach the voltage limit circle and the maximum motor speed and output power need to be further increased, the traditional Mtpv control curve ① is converted to Mtpv control curve ②. The conversion formula is as follows: When the motor runs to ①, it has reached the voltage limit ellipse Vam; at this time, Vam is determined by the following formula: ; is the actual voltage utilization; ; is the battery voltage; The command voltage utilization is In order to make the actual voltage utilization rate not exceed the command voltage utilization rate, the following equation is used for control: ； ； ； ； in, is the current leading phase angle The adjustment parameters, is the rotor excitation current The adjustment parameters, is the excitation current, is the command value of the current leading phase angle, is the command value of the excitation current, by adjusting the current leading phase angle and excitation current The command value is adjusted to increase the motor speed and output power.

5. A two-speed transmission equipped with an asymmetric six-phase hybrid excitation synchronous motor, characterized in that: The asymmetric six-phase hybrid excitation synchronous motor comprises the asymmetric six-phase hybrid excitation synchronous motor according to any one of claims 1 to 2, wherein the output shaft of the motor is connected to the first-stage driving gear Z of the first gear. 11 , and the first-stage driving gear Z of the two-speed gear 21 , Z 21 Connected to a wet friction plate clutch, the two gears transmit power when the wet friction plate clutch is engaged, and the two gears do not transmit power and idle when the wet friction plate clutch is disengaged; The intermediate shaft is connected to the second-stage main reducer driving gear Z 31 , 1st gear driven gear Z 12 , Z 12 Connect the one-way overrunning clutch and synchronizer, and the intermediate shaft is finally connected to the first-stage driven gear Z of the second gear. 22 ; Z 32 The driven gear Z of the 2nd stage main reducer 32 , connect the differential.

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