Fault-tolerant control method, system and equipment for zero-sequence flux-adjusting memory motor, storage medium and program product

Abstract

The invention discloses a fault-tolerant control method, system and device for a zero-sequence magnetic modulation memory motor, a storage medium and a program product. The method comprises the following steps: when an open-circuit fault occurs in a certain bridge arm, topology reconstruction is carried out; establishing a relational expression between the three-phase voltage and the five bridge arm voltages according to the reconstructed topology, converting the relational expression into an alpha beta 0 axis coordinate system, and calculating 32 space voltage vectors of the reconstructed control topology according to different switch combinations of the five bridge arms; according to the position distribution of 32 space voltage vectors in the space, a target voltage vector and a target zero-sequence voltage vector of an alpha-beta plane are synthesized, the action time of each selected voltage vector is calculated, a PWM wave is generated, and the dq0-axis current and the rotating speed of the zero-sequence memory motor are controlled in combination with dq0 decoupling of the motor and a PI controller. According to the method, the fault-tolerant control performance of the zero-sequence flux-adjusting memory motor is improved in a fault-tolerant mode, and the output capability of the reconstructed topology zero-sequence voltage is fully exerted.

Description

Technical Field

[0001] The present invention belongs to the field of motors, and particularly relates to a fault-tolerant control method, system, device, storage medium and program product for a zero-sequence field-regulating memory motor. Background Art

[0002] Compared with traditional permanent magnet motors, memory motors can significantly broaden the speed regulation range and improve the overall operating efficiency of the motor due to the adjustable permanent magnet flux linkage. As a type of memory motor, the zero-sequence field-regulating memory motor not only inherits the advantage of the DC field-regulating memory motor being convenient for online field regulation control, but also integrates the armature winding and the DC field-regulating winding into one body, eliminating the additional field regulation circuit and greatly improving the torque density of the motor. The zero-sequence field-regulating memory motor drive system usually adopts an open-winding topology structure, which has high voltage utilization and excellent fault-tolerant performance. However, in the existing fault-tolerant control strategies based on the fault system, since the open-bridge arm part is still operating, the zero-sequence loop cannot be effectively utilized, resulting in low voltage utilization and large torque ripple of the motor. In addition, in the fault-tolerant mode, if the zero-sequence field-regulating memory motor is not field-regulated, no additional zero-sequence interference can be generated. Therefore, how to improve the control performance of the zero-sequence field-regulating memory motor in the fault-tolerant mode is still an important problem to be solved urgently. Summary of the Invention

[0003] Object of the Invention: The object of the present invention is to provide a fault-tolerant control method for a zero-sequence field-regulating memory motor, so that the zero-sequence field-regulating memory motor can operate stably in the fault-tolerant mode.

[0004] Technical Solution: The control method of the present invention includes the following steps:

[0005] An auxiliary circuit is formed by connecting three thyristors in parallel at both ends of the open winding of the motor. When an open-circuit fault occurs in a certain bridge arm, the corresponding thyristor is controlled to turn on, and the topology of the remaining five bridge arms is reconstructed;

[0006] According to the reconstructed topology, the relationship between the three-phase voltage and the five-bridge-arm voltage is established, and at the same time, the relationship is transformed to the αβ0-axis coordinate system through the Clack transformation. According to different switching combinations of the five bridge arms, 32 space voltage vectors of the reconstructed control topology are calculated;

[0007] According to the position distribution of 32 space voltage vectors in space, select 2 voltage zero vectors and 6 voltage vectors that do not contain zero sequence components and are not equal to synthesize the target voltage vector in the αβ plane, and calculate the action time of each selected voltage vector; select 4 voltage vectors to synthesize the target zero sequence voltage vector, with 2 voltage vectors in a group. One group is used to synthesize the positive target zero sequence voltage vector, and the other group is used to synthesize the negative target zero sequence voltage vector. The common feature of the two groups of voltage vectors is that the components in the αβ plane cancel each other out, and the voltage vector synthesized by the zero axis components is the largest, and calculate the action time of each selected voltage vector;

[0008] Generate PWM waves according to the action time of the selected different voltage vectors, and combine the dq0 decoupling plus PI controller of the motor to realize the control of the dq0 axis current and speed of the zero sequence memory motor.

[0009] Furthermore, the topology reconstruction is specifically as follows: when an open circuit fault occurs in the first bridge arm or the fourth bridge arm, control the first thyristor SCR1 to turn on; when an open circuit fault occurs in the second bridge arm or the sixth bridge arm, control the second thyristor SCR2 to turn on; when an open circuit fault occurs in the third bridge arm or the fifth bridge arm, control the third thyristor SCR3 to turn on.

[0010] Furthermore, the relational expressions of the three-phase voltage and the five bridge arm voltages are:

[0011]

[0012] Among them, u1, u2, u3, u4, and u5 are the bridge arm voltages of the first bridge arm, the second bridge arm, the third bridge arm, the fourth bridge arm, and the fifth bridge arm respectively, and u a is the voltage of phase A, u b is the voltage of phase B, u c is the voltage of phase C, U dc is the bus voltage, and S1, S2, S3, S4, and S5 are the switching states of the first bridge arm, the second bridge arm, the third bridge arm, the fourth bridge arm, and the fifth bridge arm respectively. Among them, S i =1 indicates that the upper tube of the bridge arm is turned on, and S i =0 indicates that the lower tube of the bridge arm is turned on, where i = 1, 2…, 5.

[0013] Furthermore, the voltage relational expressions in the αβ0 coordinate system are:

[0014]

[0015] Among them, u α is the α-axis voltage, u β is the β-axis voltage, u0 is the 0-axis voltage, and S1, S2, S3, S4, and S5 are the switching states of the first bridge arm, the second bridge arm, the third bridge arm, the fourth bridge arm, and the fifth bridge arm respectively. Among them, S i= 1 indicates the upper switch of the bridge arm is turned on, S i = 0 indicates the lower switch of the bridge arm is turned on, i = 1, 2…, 5, U dc is the bus voltage;

[0016] According to the above formula and different switching combinations of the five bridge arms, 32 space voltage vectors of the reconstructed topology are calculated.

[0017] Furthermore, the calculation method of the action time of the 8 voltage vectors for synthesizing the target voltage vector in the αβ plane includes: intermediate variable calculation, sector judgment, and calculation of the action time of the selected voltage vector:

[0018] Use three intermediate variables u ref1 , u ref2 , u ref3 to identify the sector on the αβ plane;

[0019]

[0020] Define intermediate variables A1, B1, C1. If u ref1 is greater than zero, then A1 is 1, otherwise 0; if u ref2 is greater than zero, then B1 is 1, otherwise 0; if u ref3 is greater than zero, then C1 is 1, otherwise 0;

[0021] Define N as:

[0022] N = 4C1 + 2B1 + A1

[0023] Then the relationship between N and the sector of the αβ plane is:

[0024] Table 1 Sector correspondence

[0025]

[0026] The formula for the action time of the basic voltage vector is:

[0027]

[0028] Among them, u xi and u yi are the projection amounts of the selected voltage vector on the α and β axes, i = α, β; T x and T y are the action times of the selected voltage vector; T s is the PWM switching period.

[0029] Furthermore, the action time T z of the 4 voltage vectors in the synthesized target zero-sequence voltage vector is:

[0030]

[0031] Among them, T s is the PWM switching period, u0 is the zero-sequence voltage, and u dc is the DC bus voltage.

[0032] The control system of the present invention includes:

[0033] A topology reconstruction unit, which is used to form an auxiliary circuit by incorporating three thyristors at both ends of the open winding of the motor. When an open-circuit fault occurs in a certain bridge arm, the corresponding thyristor is controlled to turn on, and the remaining five-bridge-arm structure is topologically reconstructed;

[0034] A space voltage vector calculation unit, which is used to establish a relationship between the three-phase voltage and the five-bridge-arm voltage according to the reconstructed topology, and at the same time transform the relationship to the αβ0-axis coordinate system through Clack transformation, and calculate 32 space voltage vectors of the reconstructed control topology according to different switching combinations of the five bridge arms;

[0035] A target voltage vector synthesis unit, which is used to select 2 voltage zero vectors and 6 voltage vectors that do not contain zero-sequence components and are not equal according to the position distribution of the 32 space voltage vectors in space to synthesize the target voltage vector in the αβ plane, and calculate the action time of each selected voltage vector; select 4 voltage vectors to synthesize the target zero-sequence voltage vector, where 2 voltage vectors are in a group. One group is used to synthesize the positive target zero-sequence voltage vector, and the other group is used to synthesize the negative target zero-sequence voltage vector. The common feature of the two groups of voltage vectors is that the components in the αβ plane cancel each other out, and the voltage vector synthesized by the zero-axis components is the largest, and calculate the action time of each selected voltage vector;

[0036] A fault-tolerant control unit, which is used to generate a PWM wave according to the action time of the selected different voltage vectors, and combine the dq0 decoupling plus PI controller of the motor to realize the control of the dq0-axis current and speed of the zero-sequence memory motor.

[0037] The electronic device of the present invention includes a memory, a processor, and a computer program / instructions stored on the memory and executable on the processor. When the computer program / instructions are executed by the processor, the steps of the fault-tolerant control method for the zero-sequence field-weakening memory motor are implemented.

[0038] The computer-readable storage medium of the present invention stores computer instructions. When the computer instructions are called, the steps of the fault-tolerant control method for the zero-sequence field-weakening memory motor are executed.

[0039] The computer program product of the present invention includes computer program / instructions. When the computer program / instructions are executed by the processor, the steps of the fault-tolerant control method for the zero-sequence field-weakening memory motor are implemented.

[0040] Beneficial effects: Compared with the prior art, the remarkable technical effects of the present invention are as follows: in the case of an open - circuit fault occurring in a certain leg of the inverter, the topological structure is reconstructed through an auxiliary circuit, the voltage vectors of the reconstructed topology are analyzed, and through the vector selection of the synthesized target zero - sequence voltage vector, the zero - sequence voltage output ability of the reconstructed topology is fully exerted, enabling the zero - sequence flux - modulating memory motor to operate stably in the fault - tolerant mode. Description of the Drawings

[0041] Figure 1 is the overall block diagram in the control method of the present invention.

[0042] Figure 2 is the spatial voltage vector distribution diagram of the reconstructed topology in the control method of the present invention;

[0043] Figure 3 is the comparison diagram between the method of the present invention and the traditional fault - tolerant control when the rated speed is 450 prm and the torque is 4.0 Nm, where (a) is the schematic diagram of the zero - sequence pulse current of the method of the present invention, and (b) is the schematic diagram of the zero - sequence pulse current of the traditional fault - tolerant control strategy;

[0044] Figure 4 is the comparison diagram of the three - dimensional linear modulation region, where (a) is the schematic diagram of the three - dimensional linear modulation region of the method of the present invention, and (b) is the schematic diagram of the three - dimensional linear modulation region of the traditional fault - tolerant control strategy;

[0045] Figure 5 is the comparison diagram of the two - dimensional linear modulation region between the method of the present invention and the traditional fault - tolerant control strategy. Detailed Embodiment

[0046] The following further describes the present invention in detail with reference to the drawings.

[0047] The fault - tolerant control strategy for inverter reconstruction enables the zero - sequence flux - modulating memory motor drive system to still have a controllable zero - sequence loop in the fault - tolerant mode, and the flux and electromagnetic torque can be adjusted through the zero - sequence current. In addition, the higher the utilization rate of the DC bus voltage, the stronger the zero - sequence voltage modulation ability, the larger the flux regulation range of the zero - sequence flux - modulating memory motor in the inverter fault mode, and the stronger the overload capacity. Therefore, it is necessary to study a fault - tolerant control strategy for the zero - sequence flux - modulating memory motor that can fully exert the zero - sequence voltage output ability of the reconstructed topology.

[0048] As Figure 1 shown, the fault - tolerant control system of the zero - sequence flux - modulating memory motor includes: a 0 - axis current control module, a dq - axis current control module, a space vector modulation module, an inverter module, a zero - sequence flux - modulating memory motor module, and a Clack - Park transformation module. Among them, the 0 - axis current control module inputs the zero - axis current i0 and the desired zero - axis current i0 according to the selection of the magnetization state * , and outputs the desired zero - axis voltage u0 after PI control* ; dq-axis current control module, which inputs the actual speed n r and the desired speed n r * and obtains the desired q-axis current i q * through PI control, i q * and then compares it with the actual q-axis current i q to obtain the desired q-axis voltage u q * , the desired d-axis current i d * and the actual d-axis current i d to output the desired d-axis voltage u d * , and then u q * and u d * are transformed through the inverse Park transformation (i.e., from dq0 to αβ0) to obtain the desired β-axis voltage u β * and the desired α-axis voltage u α * ; The space vector modulation module calculates and outputs the PWM waves of the 5 arms in the fault-tolerant control by inputting the u β * , u α * and u0 * ; The inverter module includes the first arm 1, the second arm 2, the third arm 3, the fourth arm 4, the fifth arm 5, the sixth arm 6, the first thyristor SCR1, the second thyristor SCR2 and the third thyristor SCR3. The first thyristor SCR1, the second thyristor SCR2 and the third thyristor SCR3 are respectively connected to both ends of the open windings of the A-phase, B-phase and C-phase of the motor, and the first thyristor SCR1 is connected in series between the midpoints of the first arm and the fourth arm, the second thyristor SCR2 is connected in series between the midpoints of the second arm and the sixth arm, and the third thyristor SCR3 is connected in series between the midpoints of the third arm and the fifth arm; when an open-circuit fault occurs in a certain arm, by controlling the corresponding thyristor to turn on, the remaining five-arm structure can be reconstructed into a new topology to control the motor; The zero-sequence flux memory motor module is the controlled object, and the data collected by the sensor includes the a-phase current i a , the b-phase current i b , the c-phase current i c , the electrical angle θ and the actual speed n r ; The Clack-Park transformation module calculates i d , i q , i0 by inputting the a, b, and c-phase currents.

[0049] This fault-tolerant method only corresponds to the open-circuit fault of a single bridge arm and does not include the cases of multi-bridge arm faults and short-circuit faults.

[0050] Combined with Figures 1 to 4 , a fault-tolerant control method for a zero-sequence field-weakening memory motor is as follows:

[0051] Step 1: Control the corresponding thyristors to turn on according to the open-circuit faults of different bridge arms, and reconstruct the topological structure; as Figure 1 shown, when an open-circuit fault occurs in a certain bridge arm, the corresponding thyristor is turned on. When a fault occurs in the first bridge arm 1 or the fourth bridge arm 4, control SCR1 to turn on; when a fault occurs in the second bridge arm 2 or the sixth bridge arm 6, control SCR2 to turn on; when a fault occurs in the third bridge arm 3 or the fifth bridge arm 5, control SCR2 to turn on.

[0052] In this embodiment, it is assumed that the sixth bridge arm 6 fails and SCR2 is turned on. The sixth bridge arm 6 has been virtualized, and only single-bridge arm open-circuit faults are considered, as Figure 1 shown in the lower right corner. When an open-circuit fault occurs in the sixth bridge arm 6, turn on the second thyristor SCR2 for topological reconstruction.

[0053] Step 2: Establish the relationship between the three-phase voltage and the voltages of the remaining five bridge arms, and at the same time, transform the relationship to the αβ0 coordinate system through the Clack transformation to obtain 32 space voltage vectors; specifically as follows:

[0054] According to the bridge arm voltage and the on-off states of the upper and lower switches of the bridge arm, the three-phase voltages u a , u b and u c can be calculated.

[0055] The relationship between the three-phase voltage and the voltages of the five bridge arms is:

[0056]

[0057] Among them, u1, u2, u3, u4, and u5 are the bridge arm voltages of the first bridge arm, the second bridge arm, the third bridge arm, the fourth bridge arm, and the fifth bridge arm respectively, u a is the A-phase voltage, u b is the B-phase voltage, u c is the C-phase voltage, U dc is the bus voltage, and S1, S2, S3, S4, and S5 are the switch states of the first bridge arm, the second bridge arm, the third bridge arm, the fourth bridge arm, and the fifth bridge arm respectively. Among them, S i = 1 indicates that the upper switch of the bridge arm is turned on, and S i = 0 indicates that the lower switch of the bridge arm is turned on, where i = 1, 2…, 5.

[0058] The voltage u in the αβ0 coordinate system is obtained through the Clack transformationα , u β , the voltage relationship formula in the u0.αβ0 coordinate system is:

[0059]

[0060] Among them, u α is the α-axis voltage, u β is the β-axis voltage, and u0 is the 0-axis voltage.

[0061] According to the above calculation formula and different switching combinations of the upper and lower tubes of the five bridge arms, 32 space voltage vectors of the reconstructed topology can be calculated. Different switching combinations result in different voltage vectors. The voltage vectors are named by converting binary to decimal. For example, when S1 = 1, S2 = 0, S3 = 0, S4 = 0, S5 = 0, the combination is 10000, and the obtained voltage vector is v 16 . Through the above formula (2) plus two switching combinations for each of the five bridge arms, that is, 2 to the 5th power, 32 voltage vectors can be calculated, which are respectively expressed as: v 14 , v 26 , v 10 , v 12 , v 15 , v8, v 11 , v 24 , v 27 , v9, v 25 , v 13 , v1, v 29 , v 17 , v5, v 21 , v 16 , v 19 , v 20 , v 23 , v4, v7, v 22 , v6, v 18 , v2 and v 30 ; The position distribution of the voltage vectors is as Figure 2 shown.

[0062] Step 3: According to the position distribution of the 32 voltage vectors calculated in Step 2 in space, select two voltage zero vectors and 6 voltage vectors that do not contain zero-sequence components and are not equal to synthesize the target voltage vector in the αβ plane. Among them, the voltage zero vector refers to the Figure 2 origin position in

[0063] Use three intermediate variables u ref1 , u ref2 , u ref3 to identify the sectors on the αβ plane.

[0064]

[0065] Define intermediate variables A1, B1, and C1. For the above three intermediate variables u ref1 If it is greater than zero, then A1 is 1; otherwise, it is 0; u ref2 If it is greater than zero, then B1 is 1; otherwise, it is 0; u ref3 If it is greater than zero, then C1 is 1; otherwise, it is 0.

[0066] Define N as:

[0067] N = 4C1 + 2B1 + A1 (4)

[0068] Then the relationship between N and the αβ plane sector (equivalent to dividing the αβ plane into 6 pieces, i.e., 6 sectors, with 0 being Figure 2 the vertical axis in the middle) is:

[0069] Table 1 Sector correspondence

[0070]

[0071] The formula for the action time of the basic voltage vector is:

[0072]

[0073] where u xi and u yi are the projection amounts of the selected basic voltage vector on the α and β axes, i = α, β; T x and T y are the action times of the selected basic voltage vector; T s is the PWM switching period.

[0074] The action times of the selected voltage vectors in different sectors can be obtained as:

[0075] Table 2 Action times of the selected voltage vectors in different sectors

[0076]

[0077] In Table 2, v x is the voltage vector with an action time of T x ; v y is the voltage vector with an action time of T y ; v 20 , v 17 , v 25 , v8, v 14 , v6, v 20 are the voltage vectors selected in Figure 2 .

[0078] Step 4: According to the position distribution of the 32 voltage vectors calculated in Step 2 in space, select 4 voltage vectors to synthesize the target zero-sequence voltage vector. Among them, two voltage vectors form a group. One group is used to synthesize the positive target zero-sequence voltage vector, and the other group is used to synthesize the negative target zero-sequence voltage vector. The common feature of the two groups of voltage vectors is that the components in the αβ plane cancel each other out, and the voltage vector synthesized by the zero-axis components is the largest. The zero-axis synthesis of one group is -U dc / 2, and the other group is U dc / 2.

[0079] According to the principle of synthesizing the maximum of zero-axis vectors, select vector v Figure 2 and v 16 to synthesize the positive target zero-sequence voltage vector; select vector v 26 and v5 to synthesize the negative target zero-sequence voltage vector; the action time T 15 of each group of two vectors is: z

[0080]

[0081] Step 5: Calculate the PWM wave by calculating the action time of the selected voltage vectors in Step 3 and Step 4, and combine the dq0 decoupling plus PI controller of the motor to realize the control of the dq0-axis current and speed of the zero-sequence memory motor (first collect the three-phase current and position signals of the motor, convert the three-phase current into dqo-axis current through Clack and Park transformations for decoupling control, and then realize the control of the dq0-axis current and speed of the zero-sequence memory motor through PI control), and jointly control the zero-sequence memory motor to realize the full zero-sequence output ability of the inverter in the fault-tolerant mode.

[0082] The present invention mainly improves the zero-sequence voltage output ability of the reconstructed topology by selecting appropriate voltage vectors to synthesize the target zero-sequence voltage vector.

[0083] Embodiment: To verify the effectiveness and superiority of the fault-tolerant control strategy of the zero-sequence flux memory motor of the present invention, select the zero-sequence flux memory motor parameters in Table 3 below. Simulate the case where the sixth bridge arm 6 has an open-circuit fault. Through the auxiliary circuit to reconstruct the topology, compare the fault-tolerant control strategy of the zero-sequence flux memory motor with the traditional fault-tolerant control strategy to generate the size of the zero-sequence flux pulse under the same conditions, so as to verify the superiority of the fault-tolerant control strategy of the zero-sequence flux memory motor in improving the zero-sequence voltage output ability in the fault-tolerant mode.

[0084] Table 3 Motor parameters

[0085]

[0086] ​The reference speed of the zero-sequence memory motor control system is set to 450 rpm, the sampling frequency and the inverter switching frequency are both set to 10 kHz, the load torque is 4.0 Nm, and the maximum zero-sequence pulse current generated under the same conditions is compared. Figure 3 In (a), the fault-tolerant control strategy of the zero-sequence field-weakening memory motor generates a maximum pulse current of 20.81 A. Figure 3 In (b), the traditional fault-tolerant control strategy generates a maximum pulse current of 14.63 A. It can be seen that compared with the traditional fault-tolerant control strategy, the present invention has a stronger zero-sequence output ability. A stronger zero-sequence output ability represents a greater flux regulation ability for the zero-sequence field-weakening memory motor.

[0087] The specific output ability gap is caused by Figure 4 in (a) and (b) and Figure 5 It can be seen that compared with the traditional fault-tolerant control strategy, the zero-sequence voltage output ability of the present invention can be increased by up to 50%. The vertical axis represents the zero-sequence voltage output ability, and the horizontal axis represents the voltage output ability in the αβ plane.

Claims

1. A fault-tolerant control method for a zero-sequence magnetic memory motor, characterized in that: The following steps are involved: An auxiliary circuit is formed by connecting three thyristors at both ends of the motor open winding. When an open circuit fault occurs in a bridge arm, the corresponding thyristor is controlled to open, and the topology of the remaining five bridge arms is reconstructed. According to the reconstructed topology, the relationship between the three-phase voltage and the five bridge arm voltages is established, and the relationship is converted to the αβ0 axis coordinate system through Clack transformation. According to the different switch combinations of the five bridge arms, the 32 space voltage vectors of the reconstructed control topology are calculated; According to the position distribution of 32 spatial voltage vectors in space, 2 voltage zero vectors and 6 unequal voltage vectors without zero-sequence components are selected to synthesize the target voltage vector in the αβ plane, and the action time of each selected voltage vector is calculated; 4 voltage vectors are selected to synthesize the target zero-sequence voltage vector, of which 2 voltage vectors are in a group, one group is used to synthesize the positive target zero-sequence voltage vector, and the other group is used to synthesize the negative target zero-sequence voltage vector. The common feature of the two groups of voltage vectors is that the components in the αβ plane cancel each other, and the voltage vector synthesized by the zero-axis component is the largest, and the action time of the selected voltage vector is calculated; The PWM wave is generated according to the action time of the selected different voltage vectors, and the dq0 axis current and speed control of the zero-sequence memory motor are realized by combining the dq0 decoupling of the motor and the PI controller.

2. A fault-tolerant control method for a zero-sequence magnetic memory motor according to claim 1, characterized in that: The topology reconstruction is specifically as follows: 1) when an open circuit fault occurs in the first bridge arm or the fourth bridge arm, the first thyristor SCR1 is controlled to open; 2) when an open circuit fault occurs in the second bridge arm or the sixth bridge arm, the second thyristor SCR2 is controlled to open; 3) when an open circuit fault occurs in the third bridge arm or the fifth bridge arm, the third thyristor SCR3 is controlled to open.

3. A fault-tolerant control method for a zero-sequence magnetic memory motor according to claim 1, characterized in that: The relationship between the three-phase voltage and the five bridge arm voltages is: Among them, u1, u2, u3, u4, and u5 are the bridge arm voltages of the first bridge arm, the second bridge arm, the third bridge arm, the fourth bridge arm, and the fifth bridge arm, respectively. a is the voltage of phase A, u b is the voltage of phase B, u c is the C phase voltage, U dc is the bus voltage, S1, S2, S3, S4, S5 are the switch states of the first bridge arm, the second bridge arm, the third bridge arm, the fourth bridge arm, and the fifth bridge arm, respectively. i =1 means the upper pipe of the bridge arm is open, S i =0 means the lower pipe of the bridge arm is open, i=1,2…,5.

4. A fault-tolerant control method for a zero-sequence magnetic memory motor according to claim 1, characterized in that: The voltage relationship in the αβ0 coordinate system is: Among them, u α is the α-axis voltage, u β is the β-axis voltage, u0 is the 0-axis voltage, S1, S2, S3, S4, S5 are the switch states of the first bridge arm, the second bridge arm, the third bridge arm, the fourth bridge arm and the fifth bridge arm respectively, where S i =1 means the upper pipe of the bridge arm is open, S i =0 means the lower pipe of the bridge arm is open, i=1,2…,5, U dc is the bus voltage; According to the above formula and different switch combinations of the five bridge arms, 32 spatial voltage vectors of the reconstructed topology are calculated.

5. The fault-tolerant control method for a zero-sequence magnetic memory motor according to claim 1, characterized in that: The method for calculating the action time of the eight voltage vectors of the target voltage vector of the synthetic αβ plane includes: intermediate variable calculation, sector judgment, and action time calculation of the selected voltage vector: Use three intermediate variables u ref1 、u ref2 、u ref3 Identify sectors on the αβ plane; Define intermediate variables A1, B1, C1, if u ref1 A1 is 1 if it is greater than zero, otherwise it is 0; if u ref2 If u is greater than zero, B1 is 1, otherwise it is 0; ref3 If it is greater than zero, C1 is 1, otherwise it is 0; Define N as: N=4C1+2B1+A1 Then the relationship between N and the αβ plane sector is: Table 1 Sector correspondence The basic voltage vector action time formula is: Among them, u xi and u yi is the projection of the selected voltage vector on the α and β axes, i = α, β; T x and T y is the action time of the selected voltage vector; T s is the PWM switching period.

6. A fault-tolerant control method for a zero-sequence magnetic memory motor according to claim 1, characterized in that: The action time T of the four voltage vectors in the synthetic target zero-sequence voltage vector z for: Among them, T s is the PWM switching period, u0 is the zero-sequence voltage, u dc is the DC bus voltage.

7. A fault-tolerant control system for a zero-sequence magnetic memory motor, characterized in that: include: The topology reconstruction unit is used to form an auxiliary circuit by connecting three thyristors at both ends of the motor open winding. When an open circuit fault occurs in a bridge arm, the corresponding thyristor is controlled to open and the remaining five bridge arm structures are topologically reconstructed; A space voltage vector calculation unit is used to establish a relationship between the three-phase voltage and the voltage of the five bridge arms according to the reconstructed topology, and at the same time, convert the relationship to the αβ0 axis coordinate system through Clack transformation, and calculate 32 space voltage vectors of the reconstructed control topology according to different switch combinations of the five bridge arms; The target voltage vector synthesis unit is used to select 2 voltage zero vectors and 6 unequal voltage vectors without zero-sequence components to synthesize the target voltage vectors in the αβ plane according to the position distribution of the 32 spatial voltage vectors in space, and calculate the action time of each selected voltage vector; select 4 voltage vectors to synthesize the target zero-sequence voltage vector, wherein 2 voltage vectors are in a group, one of which is used to synthesize the positive target zero-sequence voltage vector, and the other is used to synthesize the negative target zero-sequence voltage vector, the common feature of the two groups of voltage vectors is that the components in the αβ plane cancel each other, the voltage vector synthesized by the zero-axis component is the largest, and calculate the action time of the selected voltage vectors; The fault-tolerant control unit is used to generate PWM waves according to the action time of different selected voltage vectors, and to control the dq0 axis current and speed of the zero-sequence memory motor in combination with the dq0 decoupling and PI controller of the motor.

8. An electronic device, characterized in that: It comprises a memory, a processor and a computer program / instruction stored in the memory and executable on the processor, wherein when the computer program / instruction is executed by the processor, the steps of the fault-tolerant control method for a zero-sequence magnetic memory motor according to any one of claims 1 to 6 are implemented.

9. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores computer instructions, and when the computer instructions are called, they are used to execute the steps of the fault-tolerant control method for a zero-sequence magnetic memory motor as described in any one of claims 1-6.

10. A computer program product comprising a computer program / instructions, characterized in that When the computer program / instructions are executed by the processor, the steps of the fault-tolerant control method for a zero-sequence magnetic memory motor according to any one of claims 1 to 6 are implemented.

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