Multi-motor vector control signal modulation method, apparatus and equipment and control system

Abstract

This invention discloses a multi-motor vector control signal modulation method, apparatus, device, and control system, belonging to the field of motor control. First, the effective vector duty cycle of the PWM wave acting on each phase of the motor is obtained. Then, based on the effective vector duty cycles of all motors, the three effective vector duty cycles of each motor are modulated into two target vector duty cycles and one common duty cycle. Since the common vector duty cycle acts on one phase of all motors, the original 3n control signals required for n motors are reduced to 2n+1 control signals. Thus, the control system using this modulation method requires fewer inverter bridges and fewer components, resulting in advantages such as low cost and small size.

Description

Technical Field

[0001] This invention relates to the field of motor control, and in particular to a method, apparatus, device, and control system for multi-motor vector control signal modulation. Background Technology

[0002] With the development of control theory, computer technology, and motor manufacturing technology, multi-motor variable frequency speed control systems have been widely used in home appliances, transportation, aerospace and other fields in recent years due to their advantages such as high energy density, suitability for fault-tolerant operation, and high energy efficiency.

[0003] Traditional control structure inverters require three control signals (duty cycles) to drive one motor. To drive multiple motors simultaneously, multiple inverter bridges are needed, along with numerous switching devices, resulting in higher costs and larger size. Summary of the Invention

[0004] To overcome the shortcomings of the prior art, the present invention provides a multi-motor vector control signal modulation method, apparatus, device and control system to solve the problems of having a drive system topology, needing to drive multiple motors simultaneously, requiring multiple inverter bridges, numerous switching devices, high cost and large size.

[0005] The technical solution adopted by this invention to solve its technical problem is:

[0006] Firstly, a method for modulating multi-motor vector control signals is provided, comprising the following steps:

[0007] Obtain the effective vector duty cycle of the PWM wave acting on each phase of the motor;

[0008] Based on the effective vector duty cycle of all motors, the three effective vector duty cycles used to control each motor are modulated to obtain two target vector duty cycles and a common vector duty cycle, which applies to one phase of all motors.

[0009] Further, the step of modulating the three effective vector duty cycles used to control each motor to obtain two target vector duty cycles based on the effective vector duty cycles of all motors includes:

[0010] The zero-sequence signal is obtained based on the effective vector duty cycle of all motors, and the three initial bridge arm voltage reference values ​​of the motor are obtained based on the three effective vector duty cycles of each motor.

[0011] The zero-sequence signal is added to any two initial bridge arm voltage reference values ​​to obtain the duty cycles of the two target vectors.

[0012] Further, obtaining the zero-sequence signal based on the effective vector duty cycle of all motors includes:

[0013] Obtain the maximum and minimum values ​​of the initial voltage reference values ​​used to calculate the target vector duty cycle from all motors;

[0014] The zero-sequence signal is obtained by taking the negative of half the sum of the maximum and minimum values.

[0015] Further, obtaining the three initial bridge arm voltage reference values ​​of the motor based on the three effective vector duty cycles of each motor includes:

[0016] The first initial bridge arm voltage value is obtained by adding the first effective vector duty cycles of all motors. The first effective vector duty cycle is the effective vector duty cycle of any phase. The first initial bridge arm voltage value is used to calculate the common vector duty cycle.

[0017] The initial bridge arm voltage reference values ​​are obtained by adding the first effective vector duty cycle of each motor to the other two effective vector duty cycles, and then subtracting the first effective vector duty cycle of the motor.

[0018] Further, the step of modulating the three effective vector duty cycles used to control each motor to obtain a common vector duty cycle based on the effective vector duty cycles of all motors includes:

[0019] The first initial bridge arm voltage reference value of all motors is used as the common vector duty cycle.

[0020] Furthermore, it also includes:

[0021] Determine whether the duty cycle value of the common vector is greater than 1; if it is, set the duty cycle value of the common vector to 1.

[0022] And / or, determine whether there exists a target vector duty cycle value greater than 1; if so, set the target vector duty cycle value greater than 1 to 1.

[0023] Further, obtaining the effective vector duty cycle of the PWM wave acting on each phase of the motor includes:

[0024] Obtain the voltage component of the motor;

[0025] Calculate the duration of the non-zero voltage vector in the three-phase PWM wave corresponding to the motor within one control cycle;

[0026] The ratio of the action time to the control cycle is used as the effective vector duty cycle.

[0027] Secondly, a multi-motor vector control signal modulation device is provided, comprising:

[0028] The duty cycle acquisition module is used to acquire the effective vector duty cycle of the PWM wave acting on each phase of the motor;

[0029] The duty cycle modulation module is used to modulate the three effective vector duty cycles used to control each motor to obtain two target vector duty cycles and a common vector duty cycle based on the effective vector duty cycles of all motors. The common vector duty cycle applies to one phase of all motors.

[0030] Thirdly, a multi-motor vector control signal modulation device is provided, comprising:

[0031] processor;

[0032] Memory used to store the processor's executable instructions;

[0033] The processor is configured to perform the method described in any one of the first aspect technical solutions.

[0034] Fourthly, a multi-motor vector control system is provided, comprising: at least two three-phase motors, a zero-sequence component modulation module, and a multi-arm inverter;

[0035] The zero-sequence component modulation module is used to execute the method described in any one of the first aspects of the technical solution to obtain two target vector duty cycles and a common vector duty cycle for controlling each motor;

[0036] The zero-sequence component modulation module is connected to the multi-arm inverter. The common vector duty cycle is connected to one phase of all motors through one arm of the multi-arm inverter. The two target vector duty cycles of each motor are respectively connected to the other two phases of the motor through one arm of the multi-arm inverter.

[0037] Beneficial effects:

[0038] This application provides a multi-motor vector control signal modulation method, apparatus, device, and control system. First, the effective vector duty cycle of the PWM wave acting on each phase of the motor is obtained. Then, based on the effective vector duty cycles of all motors, the three effective vector duty cycles of each motor are modulated into two target vector duty cycles and one common duty cycle. Since the common vector duty cycle acts on one phase of all motors, the original 3n control signals required for n motors are reduced to 2n+1 control signals. This modulation method reduces the number of inverter bridges required in the control system, lowers the required components, and offers advantages such as low cost and small size. Attached Figure Description

[0039] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0040] Figure 1 This is a flowchart of a multi-motor vector control signal modulation method provided in an embodiment of the present invention;

[0041] Figure 2 This is a schematic diagram of an effective vector duty cycle modulation process for two motors provided in an embodiment of the present invention;

[0042] Figure 3 This is a schematic diagram of a multi-motor vector control signal modulation device provided in an embodiment of the present invention;

[0043] Figure 4 This is a schematic diagram of a multi-motor vector control system provided in an embodiment of the present invention;

[0044] Figure 5 This is an overall structural diagram of a two-motor vector control system for a five-bridge inverter provided in an embodiment of the present invention;

[0045] Figure 6 This is a main circuit structure diagram of a five-bridge inverter two-motor drive system provided in an embodiment of the present invention. Detailed Implementation

[0046] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions of the present invention will be described in detail below with reference to the accompanying drawings and embodiments. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments in this application, all other implementation methods obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0047] The first embodiment, referred to Figure 1 This invention provides a method for modulating multi-motor vector control signals, comprising the following steps:

[0048] S11: Obtain the effective vector duty cycle of the PWM wave acting on each phase of the motor;

[0049] S12: Based on the effective vector duty cycle of all motors, the three effective vector duty cycles used to control each motor are modulated to obtain two target vector duty cycles and a common vector duty cycle. The common vector duty cycle is applied to one phase of all motors.

[0050] The multi-motor vector control signal modulation method provided in this invention first obtains the effective vector duty cycle of the PWM wave acting on each phase of the motor. Then, based on the effective vector duty cycles of all motors, the three effective vector duty cycles of each motor are modulated into two target vector duty cycles and one common duty cycle. Since the common vector duty cycle acts on one phase of all motors, the original 3n control signals required for n motors are reduced to 2n+1 control signals. Thus, the control system using this modulation method requires fewer inverter bridges and fewer components, resulting in advantages such as low cost and small size.

[0051] In a second embodiment, as an explanation of the first embodiment, the present invention provides a specific multi-motor vector control signal modulation method, comprising the following steps:

[0052] To more clearly illustrate the technical solution of the embodiments of the present invention, the number of motors in the embodiments of the present invention is 2.

[0053] The signal adjustment process is as follows:

[0054] Obtain the effective vector duty cycle of the PWM wave acting on each phase of the motor; specifically as follows: Obtain the voltage components Ua1, Ub1, Uc1 and Ua2, Ub2, Uc2 of the motor; calculate the duration of the non-zero voltage vector in the three-phase PWM wave corresponding to the motor within one control cycle; and use the ratio of the duration to the control cycle as the effective vector duty cycle. and

[0055] Based on the effective vector duty cycles of all motors, the three effective vector duty cycles used to control each motor are modulated to obtain two target vector duty cycles and one common vector duty cycle. The common vector duty cycle applies to one phase of all motors. Specifically: a zero-sequence signal is obtained based on the effective vector duty cycles of all motors, and three initial bridge arm voltage reference values ​​are obtained based on the three effective vector duty cycles of each motor; the zero-sequence signal is added to any two initial bridge arm voltage reference values ​​to obtain the two target vector duty cycles. The specific calculation formula is as follows:

[0056]

[0057]

[0058]

[0059]

[0060] Where i = a, b, c, δ zs This represents a zero-sequence signal, while Let δ1a be the duty cycle of the target vector (i = a, b; n = 1, 2). ** δ2a ** δ1b ** and δ2b ** This is the initial bridge arm voltage reference value.

[0061] The zero-sequence signal is obtained based on the effective vector duty cycle of all motors, including:

[0062] Obtain the maximum and minimum values ​​of the initial voltage reference values ​​used to calculate the target vector duty cycle from all motors; take the negative of half the sum of the maximum and minimum values ​​to obtain the zero-sequence signal. The specific calculation formula is as follows:

[0063]

[0064] The three initial bridge arm voltage reference values ​​for each motor are obtained based on the three effective vector duty cycles of each motor. This includes: summing the first effective vector duty cycles of all motors to obtain the first initial bridge arm voltage value, where the first effective vector duty cycle is the effective vector duty cycle of any phase, and this first initial bridge arm voltage value is used to calculate the common vector duty cycle; and adding the initial bridge arm voltage value to the other two effective vector duty cycles (excluding the first effective vector duty cycle) of each motor, and then subtracting the first effective vector duty cycle of the motor, to obtain the other two initial bridge arm voltage reference values. The specific calculation formula is as follows:

[0065]

[0066]

[0067]

[0068]

[0069]

[0070] Among them, the first initial bridge arm voltage reference value of all motors is used as the common vector duty cycle.

[0071] Since the maximum duty cycle is 1, the function also includes: determining whether the duty cycle of the common vector is greater than 1; if it is, setting the duty cycle of the common vector to 1.

[0072] And determine whether there is a target vector with a duty cycle greater than 1; if so, set the target vector with a duty cycle greater than 1 to 1.

[0073] The specific multi-motor vector control signal modulation method provided in this embodiment modulates the 6 control signals required by two motors into 5 control signals, saving 1 signal control channel and reducing the cost of use.

[0074] In a third embodiment, the present invention provides a multi-motor vector control signal modulation device, such as... Figure 3 As shown, it includes:

[0075] The duty cycle acquisition module 31 is used to acquire the effective vector duty cycle of the PWM wave acting on each phase of the motor. Specifically, the duty cycle acquisition module 31 acquires the voltage component of the motor; calculates the duration of the non-zero voltage vector in the three-phase PWM wave corresponding to the motor within one control cycle; and uses the ratio of the duration to the control cycle as the effective vector duty cycle.

[0076] The duty cycle modulation module 32 is used to modulate the three effective vector duty cycles used to control each motor to obtain two target vector duty cycles and a common vector duty cycle based on the effective vector duty cycles of all motors. The common vector duty cycle applies to one phase of all motors. Specifically, the duty cycle modulation module 32 obtains a zero-sequence signal based on the effective vector duty cycles of all motors, and obtains three initial bridge arm voltage reference values ​​for each motor based on the three effective vector duty cycles of each motor; the zero-sequence signal is added to any two initial bridge arm voltage reference values ​​to obtain the two target vector duty cycles.

[0077] The process of obtaining the zero-sequence signal based on the effective vector duty cycle of all motors includes: obtaining the maximum and minimum values ​​of the initial voltage reference values ​​used to calculate the target vector duty cycle among all motors; and taking the negative of half of the sum of the maximum and minimum values ​​to obtain the zero-sequence signal.

[0078] In addition, three initial bridge arm voltage reference values ​​for each motor are obtained based on the three effective vector duty cycles of each motor, including: adding the first effective vector duty cycles of all motors to obtain the first initial bridge arm voltage value, where the first effective vector duty cycle is the effective vector duty cycle of any phase, and the first initial bridge arm voltage value is used to calculate the common vector duty cycle; and adding the initial bridge arm voltage value to the other two effective vector duty cycles of each motor (excluding the first effective vector duty cycle) and subtracting the first effective vector duty cycle of the motor to obtain the other two initial bridge arm voltage reference values.

[0079] Furthermore, the first initial bridge arm voltage reference value of all motors is used as the common vector duty cycle.

[0080] Since the maximum duty cycle value is 1 in the actual process, the duty cycle modulation module 32 determines whether the value of the common vector duty cycle is greater than 1; if it is greater, the common vector duty cycle value is set to 1; and / or, determines whether there is a target vector duty cycle value greater than 1; if it exists, the target vector duty cycle value greater than 1 is set to 1.

[0081] The multi-motor vector control signal modulation device provided in this embodiment of the invention includes a duty cycle acquisition module that acquires the effective vector duty cycle of the PWM wave acting on each phase of the motor; and a duty cycle modulation module that modulates the three effective vector duty cycles used to control each motor to obtain two target vector duty cycles and one common vector duty cycle based on the effective vector duty cycles of all motors. Since the common vector duty cycle acts on one phase of all motors, the original 3n control signals required for n motors are reduced to 2n+1 control signals. This reduces the number of inverter bridges required in the control system using this modulation device, lowers the number of components needed, and offers advantages such as low cost and small size.

[0082] Fourth embodiment: The present invention provides a multi-motor vector control signal modulation device, comprising:

[0083] processor;

[0084] Memory used to store processor-executable instructions;

[0085] The processor is configured to execute the multi-motor vector control signal modulation method provided in the first or second embodiment.

[0086] The adjustment device provided in this embodiment of the invention stores executable instructions of the processor in a memory. When the processor executes the executable instructions, it can obtain the effective vector duty cycle of the PWM wave acting on each phase of the motor. Then, based on the effective vector duty cycle of all motors, it modulates the three effective vector duty cycles of each motor into two target vector duty cycles and one common duty cycle. Since the common vector duty cycle acts on one phase of all motors, the original 3n control signals required for n motors are reduced to 2n+1 control signals. Thus, the control system using this adjustment device requires fewer inverter bridges and fewer components, resulting in advantages such as low cost and small size.

[0087] Fifth embodiment, such as Figure 4 As shown, the present invention provides a multi-motor vector control system, including: at least two three-phase motors 41, a zero-sequence component modulation module 42, and a multi-bridge inverter 43;

[0088] The zero-sequence component modulation module 42 is used to execute the multi-motor vector control signal modulation method provided in the first embodiment or the second embodiment to obtain two target vector duty cycles and a common vector duty cycle for controlling each motor 41;

[0089] The zero-sequence component modulation module 42 is connected to the multi-arm inverter 43. The common vector duty cycle is connected to one phase of all motors 41 through one arm of the multi-arm inverter 43. The two target vector duty cycles of each motor 41 are respectively connected to the other two phases of the motor 41 through one arm of the multi-arm inverter 43.

[0090] To further illustrate the implementation of this embodiment of the invention, two motors are used as an example, and the overall structure diagram of the control system is as follows: Figure 5 As shown. First, obtain the three parameters of each motor's three phases. Since these parameters are in a three-phase stationary coordinate system, while PI regulation needs to be performed in a two-phase rotating coordinate system, it is necessary to convert the parameters from the three-phase stationary coordinate system to parameters in the two-phase stationary coordinate system. Figure 5 The parameters of the two-phase stationary coordinate system are then converted to the parameters of the two-phase rotating coordinate system, i.e., αβ / dq in the figure. The converted parameters are then adjusted by a PI controller to obtain the adjustment values, as shown in u1d and u1q, and u2d and u2q in the figure. Finally, after conversion by dq / αβ, u is obtained. 1α and u 1β and u 2α and u 2β Then u 1α and u 1β and u 2α and u 2β The inputs are respectively fed into the zero-sequence component modulation module for modulation. It should be noted that... Figure 2 The modulation is performed using parameters in a three-phase stationary coordinate system. Figure 5 The parameters in the two-phase stationary coordinate system are modulated. Those skilled in the art can convert them as needed. After modulation by the zero-sequence component modulation module, the input obtains the five control signals required by the two motors. Then, the five control signals are respectively input to the motors through one arm of the five-arm inverter, so as to control the two motors with five control signals.

[0091] Based on the stator voltage component u of the motor in the two-phase stationary αβ coordinate system 1α u 1β u 2α u 2β The effective time of the non-zero voltage vector in the three-phase PWM wave corresponding to each motor is calculated to obtain two new three-phase PWM waves. That is, by using two independent space vector pulse width modulation methods, the effective vector duty cycle of the inverter upper bridge arm PWM wave acting on motor 1 is obtained within one control cycle. and the effective vector duty cycle of the PWM wave acting on the upper bridge arm of the inverter for motor 2 and

[0092] In order to improve voltage utilization, the duty cycles of the two three-phase PWM waves output by the mean zero-sequence component modulation are transformed into five-phase PWM waves that simultaneously satisfy the duty cycles of the two motors. The duty cycles of each phase are calculated as follows: The specific modulation method has been explained in the second embodiment and will not be repeated here.

[0093] The current loop and speed loop of each motor employ a PI controller, with outputs u1d and u1q, and u2d and u2q, respectively. After r / s conversion, these are input to the zero-sequence component modulation module. This module appropriately processes the duty cycle to generate the PWM drive waveform required by the five-arm inverter, which is then input to the five-arm inverter to achieve independent speed control of the two motors. The structural diagram of the five-arm inverter is shown below. Figure 6 As shown.

[0094] It is understood that the same or similar parts in the above embodiments can be referred to each other, and the contents not described in detail in some embodiments can be referred to the same or similar contents in other embodiments.

[0095] It should be noted that in the description of this application, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance. Furthermore, in the description of this application, unless otherwise stated, "a plurality of" means at least two.

[0096] Any process or method described in the flowchart or otherwise herein can be understood as representing a module, segment, or portion of code comprising one or more executable instructions for implementing a particular logical function or process, and the scope of the preferred embodiments of this application includes additional implementations in which functions may be performed not in the order shown or discussed, including substantially simultaneously or in reverse order depending on the function involved, as will be understood by those skilled in the art to which embodiments of this application pertain.

[0097] It should be understood that various parts of this application can be implemented using hardware, software, firmware, or a combination thereof. In the above embodiments, multiple steps or methods can be implemented using software or firmware stored in memory and executed by a suitable instruction execution system. For example, if implemented in hardware, as in another embodiment, it can be implemented using any one or a combination of the following techniques known in the art: discrete logic circuits having logic gates for implementing logical functions on data signals, application-specific integrated circuits (ASICs) having suitable combinational logic gates, programmable gate arrays (PGAs), field-programmable gate arrays (FPGAs), etc.

[0098] Those skilled in the art will understand that all or part of the steps of the methods in the above embodiments can be implemented by a program instructing related hardware. The program can be stored in a computer-readable storage medium, and when executed, the program includes one or a combination of the steps of the method embodiments.

[0099] Furthermore, the functional units in the various embodiments of this application can be integrated into a processing module, or each unit can exist physically separately, or two or more units can be integrated into a module. The integrated module can be implemented in hardware or as a software functional module. If the integrated module is implemented as a software functional module and sold or used as an independent product, it can also be stored in a computer-readable storage medium.

[0100] The storage media mentioned above can be read-only memory, disk, or optical disk, etc.

[0101] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0102] Although embodiments of this application have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting this application. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of this application.

Claims

1. A method for modulating multi-motor vector control signals, characterized in that, Includes the following steps: Obtain the effective vector duty cycle of the PWM wave acting on each phase of the motor; Based on the effective vector duty cycles of all motors, the three effective vector duty cycles used to control each motor are modulated to obtain two target vector duty cycles and a common vector duty cycle, wherein the common vector duty cycle applies to one phase of all motors; wherein, the step of obtaining two target vector duty cycles by modulating the three effective vector duty cycles used to control each motor based on the effective vector duty cycles of all motors includes: The zero-sequence signal is obtained based on the effective vector duty cycle of all motors, and the three initial bridge arm voltage reference values ​​of the motor are obtained based on the three effective vector duty cycles of each motor; wherein, obtaining the three initial bridge arm voltage reference values ​​of the motor based on the three effective vector duty cycles of each motor includes: adding the first effective vector duty cycles of all motors to obtain a first initial bridge arm voltage reference value, wherein the first effective vector duty cycle is the effective vector duty cycle of any phase, and the first initial bridge arm voltage reference value is used to calculate the common vector duty cycle; adding the first effective vector duty cycle of the motor to the two effective vector duty cycles of each motor (excluding the first effective vector duty cycle) and subtracting the first effective vector duty cycle of the motor to obtain the other two initial bridge arm voltage reference values; The zero-sequence signal is added to any two initial bridge arm voltage reference values ​​to obtain the duty cycles of the two target vectors.

2. The method according to claim 1, characterized in that: The process of obtaining the zero-sequence signal based on the effective vector duty cycle of all motors includes: Obtain the maximum and minimum values ​​of the initial voltage reference values ​​used to calculate the target vector duty cycle from all motors; The zero-sequence signal is obtained by taking the negative of half the sum of the maximum and minimum values.

3. The method according to claim 1, characterized in that: The step of modulating the three effective vector duty cycles used to control each motor to obtain a common vector duty cycle based on the effective vector duty cycles of all motors includes: The first initial bridge arm voltage reference value of all motors is used as the common vector duty cycle.

4. The method according to claim 1, characterized in that, Also includes: Determine whether the duty cycle value of the common vector is greater than 1; if it is, set the duty cycle value of the common vector to 1. And / or, determine whether there exists a target vector duty cycle value greater than 1; if so, set the target vector duty cycle value greater than 1 to 1.

5. The method according to claim 1, characterized in that: The acquisition of the effective vector duty cycle of the PWM wave acting on each phase of the motor includes: Obtain the voltage component of the motor; Calculate the duration of the non-zero voltage vector in the three-phase PWM wave corresponding to the motor within one control cycle; The ratio of the action time to the control cycle is used as the effective vector duty cycle.

6. A multi-motor vector control signal modulation device, characterized in that, include: The duty cycle acquisition module is used to acquire the effective vector duty cycle of the PWM wave acting on each phase of the motor; The duty cycle modulation module is used to modulate the three effective vector duty cycles used to control each motor to obtain two target vector duty cycles and a common vector duty cycle based on the effective vector duty cycles of all motors. The common vector duty cycle applies to one phase of all motors. Specifically, it is used to obtain the zero-sequence signal based on the effective vector duty cycle of all motors, and to add the first effective vector duty cycles of all motors to obtain the first initial bridge arm voltage reference value. The first effective vector duty cycle is the effective vector duty cycle of any phase, and the first initial bridge arm voltage reference value is used to calculate the common vector duty cycle. The two effective vector duty cycles of each motor (excluding the first effective vector duty cycle) are added to the initial bridge arm voltage reference value and then subtracted from the first effective vector duty cycle of the motor to obtain the other two initial bridge arm voltage reference values; the zero-sequence signal is added to any two initial bridge arm voltage reference values ​​to obtain two target vector duty cycles.

7. A multi-motor vector control signal modulation device, characterized in that, include: processor; Memory used to store the processor's executable instructions; The processor is configured to perform the method according to any one of claims 1-5.

8. A multi-motor vector control system, characterized in that, include: At least two three-phase motors, a zero-sequence component modulation module, and a multi-arm inverter; The zero-sequence component modulation module is used to execute the method according to any one of claims 1-5 to obtain two target vector duty cycles and a common vector duty cycle for controlling each motor; The zero-sequence component modulation module is connected to the multi-arm inverter, and the common vector duty cycle is connected to one phase of all motors through one arm of the multi-arm inverter. The two target vector duty cycles of each motor are connected to the other two phases of the motor through one arm of the multi-arm inverter.

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