Multi-phase motor efficiency optimization method, system and equipment based on variable conduction mode

Abstract

The invention relates to the field of motor control, and provides a multi-phase motor efficiency optimization method, system and equipment based on a variable conduction mode, and the method comprises the steps: constructing a torque expression, and determining the number of conduction phases, thereby determining the maximum torque limit; constructing a total copper loss expression, calculating a phase current effective value, and calculating phase copper loss based on the total copper loss expression and the phase current effective value; constructing an odd-number-phase conduction loss expression and an even-number-phase conduction loss expression, and calculating the conduction loss of the inverter according to the odd-number-phase conduction loss expression and the even-number-phase conduction loss expression; calculating the switching loss of the inverter, obtaining the loss of the inverter through the conduction loss of the inverter and the switching loss of the inverter, and obtaining the total loss of the motor according to the loss of the inverter and the phase copper loss; and obtaining the optimal conduction phase number through the total loss of the motor under the constraint of the maximum torque limit, and adjusting the operation phase of the target motor according to the optimal conduction phase number to complete the control of the target motor.

Description

Technical Field

[0001] This invention relates to the field of motor control technology, and in particular to a method, system and device for optimizing the efficiency of multiphase motors based on variable conduction modes. Background Technology

[0002] As a core power source in modern industrial and transportation systems, electric motors play a vital role in energy utilization, automation control, and high-end equipment. With the rapid development of emerging applications such as electric vehicles, new energy power generation, aerospace, and high-performance industrial drives, the demand for efficient and reliable operation of electric motors is constantly increasing. Compared to traditional three-phase motors, multiphase motors, due to their higher power density, stronger fault tolerance, and lower torque ripple, are gradually becoming important technical equipment to meet these requirements.

[0003] Multiphase brushless DC motors have gained increasing research and application due to their advantages of simple structure, flexible control, and high reliability. In existing technologies, multiphase brushless DC motors are typically controlled using a fixed conduction mode. Under different loads and operating conditions, the loss distribution of the multiphase brushless DC motor system varies significantly. Under light loads, the proportion of switching losses in power devices increases, reducing inverter efficiency; under heavy loads, excessive phase current leads to a significant increase in winding copper losses, limiting system performance. This fixed control method makes it difficult to achieve efficient operation under all operating conditions. Summary of the Invention

[0004] This invention aims to at least solve one of the technical problems existing in related technologies. To this end, this invention provides a method, system, and device for optimizing the efficiency of multiphase motors based on variable conduction modes, thereby achieving a balance between motor copper losses and inverter losses while ensuring motor operating efficiency.

[0005] This invention provides a method, system, and device for optimizing the efficiency of multiphase motors based on variable conduction modes, including: S1: Determine the target motor, construct the torque expression and determine the number of conducting phases, and determine the maximum torque limit based on the torque expression and the number of conducting phases; S2: Calculate the average copper loss of the current, construct the total copper loss expression through the average copper loss of the current, calculate the effective value of the phase current, and calculate the phase copper loss based on the total copper loss expression and the effective value of the phase current. S3: Construct expressions for odd-phase conduction loss and even-phase conduction loss, and calculate inverter conduction loss based on these expressions. S4: Calculate the inverter switching loss. Obtain the inverter loss through the inverter conduction loss and inverter switching loss. Obtain the total motor loss based on the inverter loss and phase copper loss. S5: Under the constraint of maximum torque limit, the optimal number of conducting phases is obtained through the total motor loss. The operating phase of the target motor is adjusted according to the optimal number of conducting phases to complete the control of the target motor.

[0006] According to the multiphase motor efficiency optimization method based on variable conduction mode provided by the present invention, step S1 further includes: S11: Determine the multiphase motor as the target motor, determine the mechanical angular velocity and back EMF amplitude of the target motor, and obtain the torque expression based on the mechanical angular velocity and back EMF amplitude; S12: Determine the number of conducting phases and the maximum allowable current, and substitute the number of conducting phases and the maximum allowable current into the torque expression to obtain the maximum torque limit.

[0007] According to the multiphase motor efficiency optimization method based on variable conduction mode provided by the present invention, in step S2, the instantaneous copper loss of the current is calculated, the average copper loss of the current is obtained based on the instantaneous copper loss of the current, and the total copper loss expression is constructed through the average copper loss of the current.

[0008] According to the multiphase motor efficiency optimization method based on variable conduction mode provided by the present invention, in step S2, the effective values ​​of odd-phase phase current and even-phase phase current are constructed, and the effective values ​​of odd-phase phase current and even-phase phase current are substituted into the total copper loss expression to obtain the phase copper loss.

[0009] According to the multiphase motor efficiency optimization method based on variable conduction mode provided by the present invention, in step S3, the expression for the odd-phase conduction loss is: in, Let d be the conduction loss in the (n-2)th phase, and d be the duty cycle during conduction. For the IGBT resistor, This represents the phase current amplitude at the (n-2)th phase. This refers to the zero-current on-state voltage drop of the IGBT. The resistance of the diode, denoted as the zero-current forward voltage drop of the diode, and n is the number of phases of the target motor.

[0010] According to the multiphase motor efficiency optimization method based on variable conduction mode provided by the present invention, in step S3, the expression for the even-numbered phase conduction loss is: in, Let d be the conduction loss in the (n-1)th phase, d be the duty cycle during conduction, and n be the number of phases of the target motor. This refers to the zero-current on-state voltage drop of the IGBT. The resistance of the diode, This is the zero-current forward voltage drop of the diode. For the IGBT resistor, This represents the phase current amplitude at the (n-1)th phase.

[0011] According to the multiphase motor efficiency optimization method based on variable conduction mode provided by the present invention, in step S4, after obtaining the inverter switching loss, the inverter switching loss is added to the inverter conduction loss to obtain the inverter loss, and the inverter loss is added to the phase copper loss to obtain the total motor loss.

[0012] According to the multiphase motor efficiency optimization method based on variable conduction mode provided by the present invention, in step S5, the torque when the total motor loss between adjacent phases is equal is taken as the critical torque, and the critical torque is constrained by the maximum torque limit to obtain the optimal number of conducting phases; The hysteresis width and torque change indication value are determined, and the operating phase of the target motor is adjusted according to the optimal number of conducting phases, the torque change indication value, and the hysteresis width.

[0013] This invention also provides a multiphase motor efficiency optimization system based on variable conduction mode, comprising: Maximum torque limit module: used to determine the target motor, construct the torque expression and determine the number of conducting phases, and determine the maximum torque limit based on the torque expression and the number of conducting phases; Phase copper loss module: used to calculate the average copper loss of current, construct the total copper loss expression through the average copper loss of current, calculate the effective value of phase current, and calculate the phase copper loss based on the total copper loss expression and the effective value of phase current; Inverter conduction loss module: Constructs expressions for odd-phase conduction loss and even-phase conduction loss, and calculates inverter conduction loss based on these expressions; Motor total loss module: used to calculate inverter switching losses. Inverter losses are obtained through inverter conduction losses and inverter switching losses. The total motor loss is obtained based on inverter losses and phase copper losses. Motor control module: Used to obtain the optimal number of conducting phases by the total motor loss under the constraint of maximum torque limit, and adjust the operating phase of the target motor according to the optimal number of conducting phases to complete the control of the target motor.

[0014] The present invention also provides an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the program to implement the steps of any of the above-described methods for optimizing the efficiency of a multiphase motor based on a variable conduction mode.

[0015] The above-described one or more technical solutions in the embodiments of the present invention have at least one of the following technical effects: The present invention provides a method, system, and device for optimizing the efficiency of multiphase motors based on variable conduction modes. By calculating the total motor losses, the optimal number of conducting phases is obtained, allowing the motor to select an appropriate number of phases under different torques. This results in lower copper losses, improving the motor's operating efficiency and lifespan. The method is applicable to target motors with different phases. Furthermore, no additional hardware is required; efficiency optimization can be achieved solely through control strategies, reducing system costs and implementation complexity. This demonstrates good engineering feasibility and versatility.

[0016] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in this invention 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 some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0018] Figure 1 This is a flowchart illustrating the multiphase motor efficiency optimization method based on variable conduction mode provided by the present invention.

[0019] Figure 2 This is a circuit diagram of a nine-phase brushless DC motor based on a multiphase motor efficiency optimization method with variable conduction mode provided by the present invention.

[0020] Figure 3 This is a schematic diagram of the structure of the multiphase motor efficiency optimization system based on variable conduction mode provided by the present invention.

[0021] Figure 4 This is a schematic diagram of the structure of the multiphase motor efficiency optimization device based on variable conduction mode provided by the present invention.

[0022] Figure label: 100. Maximum torque limiting module; 200. Phase copper loss module; 300. Inverter conduction loss module; 400. Motor total loss module; 500. Motor control module; 810. Processor; 820. Communication interface; 830. Memory; 840. Communication bus. Detailed Implementation

[0023] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention. The following embodiments are used to illustrate this invention but cannot be used to limit the scope of this invention.

[0024] In the description of the embodiments of the present invention, it should be noted that the terms "first", "second" and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0025] In the description of the embodiments of the present invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "connected" and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in the embodiments of the present invention based on the specific circumstances.

[0026] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of the present invention. 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. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0027] The following is combined with Figures 1 to 4 Specific embodiments of the present invention are described below. Figure 1 This is a flowchart illustrating the multiphase motor efficiency optimization method based on variable conduction mode provided by the present invention, including: S1: Determine the target motor, construct the torque expression and determine the number of conducting phases, and determine the maximum torque limit based on the torque expression and the number of conducting phases; Furthermore, the objective of this stage is to construct a torque expression and determine the number of conducting phases, thereby determining the maximum torque limit. Specifically, step S1 further includes: S11: Determine the multiphase motor as the target motor, determine the mechanical angular velocity and back EMF amplitude of the target motor, and obtain the torque expression based on the mechanical angular velocity and back EMF amplitude; S12: Determine the number of conducting phases and the maximum allowable current, and substitute the number of conducting phases and the maximum allowable current into the torque expression to obtain the maximum torque limit.

[0028] The specific implementation method for the above steps in this embodiment is as follows: First, it is necessary to determine the multiphase motor as the target motor. In this embodiment, the target motor is a nine-phase brushless DC motor, and its circuit diagram is shown below. Figure 2 As shown. Then, based on the operating parameters of the target motor, the mechanical angular velocity ω and back EMF amplitude E of the target motor during the m-th phase are determined, thereby obtaining the torque at the m-th phase. The torque expression: in, Let m be the phase current amplitude at phase m. This is the back electromotive force coefficient.

[0029] Next, the number of conducting phases is determined. Here, the usable conducting phases for a nine-phase brushless DC motor are 2 to 8. Additionally, the maximum allowable current of the target motor needs to be determined. Then, by maximizing the phase current amplitude under different phases, the maximum allowable output torque under different conducting phases can be obtained, which is the maximum torque limit. The maximum torque limits are shown in Table 1. Table 1 Maximum torque limits for each phase

[0030] Among them T N This represents the maximum torque that the target motor can output. The maximum torque limit can be used as a limiting parameter, ensuring that the output torque in any phase does not exceed the maximum torque limit.

[0031] S2: Calculate the average copper loss of the current, construct the total copper loss expression through the average copper loss of the current, calculate the effective value of the phase current, and calculate the phase copper loss based on the total copper loss expression and the effective value of the phase current. Furthermore, the objective of this stage is to construct a total copper loss expression to calculate phase copper losses. Specifically, in step S2, the instantaneous current copper loss is calculated, the average current copper loss is obtained based on the instantaneous current copper loss, and the total copper loss expression is constructed using the average current copper loss.

[0032] In step S2, the effective values ​​of the odd-phase phase current and the even-phase phase current are constructed, and the effective values ​​of the odd-phase phase current and the even-phase phase current are substituted into the total copper loss expression to obtain the phase copper loss.

[0033] The specific implementation method for the above steps in this embodiment is as follows: During the operation of the target motor, iron loss and mechanical loss are mainly caused by changes in speed and are independent of phase. Here, we focus on phase-dependent copper loss and inverter losses. Copper loss is essentially Joule loss on the winding resistance. For any phase of the winding, the instantaneous copper loss at time t can be expressed as… : in, Let be the instantaneous current of the winding at time t. This represents the resistance of the motor stator. Furthermore, under steady-state operating conditions, averaging over one electrical cycle yields the average copper loss of the current in that phase. : in, The length of one current cycle, To perform integration over time t, This represents the effective value of the phase current within one current cycle. Since the target motor has a symmetrical winding structure, under a given conduction mode, the winding parameters of each conducting phase are consistent, and the phase copper loss in the m-th phase is... The total copper loss expression is: in, Let be the effective value of the phase current at the m-th phase within a current cycle. For a brushless DC motor, the relationship between the effective value of the phase current and the amplitude of the phase current varies depending on the conduction method, and the effective value of the current is difficult to measure directly. Here, we first construct the effective value of the phase current for odd-numbered phases. First, we need to ensure that the phase is an odd number. Let the number of phases of the target motor be n. Since the target motor in this embodiment is a nine-phase brushless DC motor, the number of phases is n-2, which is an odd number. Therefore: in, This represents the effective value of the phase current in the upper half-cycle under the (n-2)th phase. This represents the effective value of the phase current in the second half-cycle under the (n-2)th phase. This represents the amplitude of the phase current in the upper half of the (n-2)th phase. Let be the amplitude of the phase current in the lower half-cycle under the (n-2)th phase. Due to symmetry, the effective value of the current in the upper half-cycle is equal to the effective value of the current in the upper half-cycle, and the amplitude of the current in the upper half-cycle is equal to the amplitude of the current in the upper half-cycle. Therefore, the effective value of the phase current in the odd-numbered phases under the (n-2)th phase is: in, This represents the phase current amplitude at the (n-2)th phase. This represents the effective value of the phase current at the (n-2)th phase.

[0034] For the effective value of the phase current in an even-numbered phase, when the number of phases is n-1, it is an even number. In this case, the effective value of the phase current in an even-numbered phase is: in, This represents the effective value of the phase current at the (n-1)th phase. Let be the phase current amplitude at the (n-1)th phase. Due to the symmetry of the target motor, the conclusions for the (n-1)th and (n-2)th phases can be generalized to all phases. In this case, replacing the (n-2)th and (n-1)th phases with the m-th phase yields the effective value of the phase current at the m-th phase within one current cycle: in, Let be the amplitude of the phase current at phase m. Substituting the effective value of the phase current at phase m into the total copper loss expression yields the phase copper loss: Thus, the phase copper loss at phase m can be obtained by measuring the phase current amplitude, which is easy to measure. It can be seen that the motor copper loss is mainly determined by the phase current. When the number of conducting phases decreases, the phase current amplitude increases to maintain the same torque output, resulting in increased copper loss; when the number of conducting phases increases, the phase current amplitude decreases, and the copper loss decreases accordingly.

[0035] S3: Construct expressions for odd-phase conduction loss and even-phase conduction loss, and calculate inverter conduction loss based on these expressions. Furthermore, the objective of this stage is to construct expressions for the odd-phase conduction loss and the even-phase conduction loss, thereby calculating the inverter's conduction loss. Specifically, in step S3, the expression for the odd-phase conduction loss is: in, Let d be the conduction loss in the (n-2)th phase, and d be the duty cycle during conduction. For the IGBT resistor, This represents the phase current amplitude at the (n-2)th phase. This refers to the zero-current on-state voltage drop of the IGBT. The resistance of the diode, denoted as the zero-current forward voltage drop of the diode, and n is the number of phases of the target motor.

[0036] In step S3, the expression for the even-numbered phase conduction loss is: in, Let d be the conduction loss in the (n-1)th phase, d be the duty cycle during conduction, and n be the number of phases of the target motor. This refers to the zero-current on-state voltage drop of the IGBT. The resistance of the diode, This is the zero-current forward voltage drop of the diode. For the IGBT resistor, This represents the phase current amplitude at the (n-1)th phase.

[0037] The specific implementation method for the above steps in this embodiment is as follows: Inverter losses mainly consist of two parts: conduction losses and switching losses. The conduction loss at the m-th phase is... The on-resistance of the IGBT and diode involved in conduction and the current flowing through them are determined by: in, This represents the number of IGBTs (Insulated-Gate Bipolar Transistors) participating in conduction at the m-th phase. This represents the number of diodes participating in conduction during the m-th phase. For the IGBT resistor, This represents the effective value of the current flowing through the IGBT. This refers to the zero-current on-state voltage drop of the IGBT. This represents the average current flowing through the IGBT. The resistance of the diode, This represents the effective value of the current flowing through the diode. This represents the average current flowing through the diode. This is the zero-current forward voltage drop of the diode.

[0038] Then, the odd conduction loss is constructed. Here, as described in step S2, when the number of phases is n-2, it is an odd number. Therefore, the odd conduction loss can be obtained as follows: in, Let d be the conduction loss in the (n-2)th phase. Due to the symmetry of the target motor, it can be generalized to the conduction loss in the odd phase, that is, the odd conduction loss. d is the duty cycle when conducting.

[0039] As described in step S2, when the number of phases is n-1, it is an even number. Therefore, the expression for the conduction loss of the even-numbered phases is: in, The conduction loss is the (n-1)th phase. Due to the symmetry of the target motor, it can be generalized to the conduction loss under even phases, that is, the even-phase conduction loss.

[0040] Furthermore, using the torque expression Due to the symmetry of the target motor, the conclusions for the (n-1)th and (n-2)th phases can be generalized to all phases. In this case, replacing the (n-2)th and (n-1)th phases with the m-th phase, and replacing other n-related parameters with their corresponding m-related parameters, yields the inverter conduction losses for the m-th phase. for: The following relationship holds: in, For the first even-numbered loss parameter, For the second even-numbered loss parameter, For the first odd-numbered loss parameter, This is the second odd-numbered loss parameter.

[0041] S4: Calculate the inverter switching losses. The inverter losses are obtained through the inverter conduction losses and inverter switching losses. The total motor losses are then obtained based on the inverter losses and phase copper losses. Further, the purpose of this stage is to obtain the inverter losses, thereby obtaining the total motor losses. Specifically, in step S4, after obtaining the inverter switching losses, the inverter switching losses are added to the inverter conduction losses to obtain the inverter losses. The inverter losses are then added to the phase copper losses to obtain the total motor losses.

[0042] The specific implementation method for the above steps in this embodiment is as follows: First, calculate the inverter switching losses at the m-th phase. : in, This refers to the switching frequency of the inverter when the motor is running. This represents the total energy loss during turn-on and turn-off as obtained from the experiment. Then, by adding the inverter switching loss to the inverter conduction loss, the inverter loss at phase m can be obtained. : As can be seen here, the inverter's conduction losses are related to the number of conducting phases and the phase current amplitude. As the number of conducting phases increases, the number of power devices participating in conduction increases. Switching losses, on the other hand, are related to the switching frequency of the power devices and the number of bridge arms participating in conduction. When the number of conducting phases is small, the inverter losses are relatively low, while when the number of conducting phases is large, the inverter losses increase significantly. Finally, adding the inverter losses to the phase copper losses yields the total motor losses.

[0043] S5: Under the constraint of maximum torque limit, the optimal number of conducting phases is obtained through the total motor loss. The operating phase of the target motor is adjusted according to the optimal number of conducting phases to complete the control of the target motor.

[0044] Furthermore, the objective of this stage is to obtain the optimal number of conducting phases, thereby adjusting the operating phase of the target motor and completing the control of the target motor. Specifically, in step S5, the torque at which the total motor loss between adjacent phases is equal is taken as the critical torque, and the critical torque is constrained by the maximum torque limit to obtain the optimal number of conducting phases; The hysteresis width and torque change indication value are determined, and the operating phase of the target motor is adjusted according to the optimal number of conducting phases, the torque change indication value, and the hysteresis width.

[0045] The specific implementation method for the above steps in this embodiment is as follows: Here, for each pair of adjacent phases, such as phase 8 and phase 7, or phase 7 and phase 6, each pair of adjacent phases is substituted with a different torque value, ensuring that the substituted torque value meets the maximum torque limit. The critical torque is found when the total motor losses between adjacent phases are equal. For the critical torque, when the actual load torque of the target motor is less than the critical torque, using the smaller phase among the adjacent phases can reduce the operating losses of the target motor; when the actual load torque of the target motor is greater than the critical torque, using the larger phase among the adjacent phases can improve operating efficiency.

[0046] The optimal number of conducting phases can be obtained based on the critical torque. This means that within the torque range defined by the critical torque, operating at this number of phases achieves lower losses and higher efficiency. The optimal number of conducting phases in this embodiment is shown in Table 2. Table 2. Schematic diagram of the relationship between optimal number of conducting phases and torque range.

[0047] In actual operation, the optimal number of conducting phases can be found based on the torque of the target motor load, thereby adjusting the phase of the target motor.

[0048] In actual operation, if the torque of the target motor fluctuates repeatedly around the critical torque, it may cause repeated phase switching of the target motor, leading to unstable operation. Therefore, a hysteresis width needs to be set, which is essentially a manually determined torque value. Additionally, a torque change indicator value needs to be determined. Here, if the torque continuously increases over a period of time, the torque change indicator value is set to 1; if the torque continuously decreases over a period of time, the torque change indicator value is set to 0; otherwise, the torque change indicator value is set to -1. When the torque change indicator value is 1 and the torque is close to the nearest critical torque, the number of conducting phases of the target motor can be increased when the torque value reaches the nearest critical torque plus the hysteresis width. Similarly, when the torque change indicator value is 0 and the torque is close to the nearest critical torque, the number of conducting phases of the target motor can be decreased when the torque value reaches the nearest critical torque minus the hysteresis width. When the torque change indicator value is -1, the number of conducting phases remains unchanged.

[0049] To match the switching between different conduction modes, the feedback value of the current loop is also switched. In the current conduction mode, the current of all non-commutated windings is collected, and its average value is calculated as the current feedback for that conduction mode. This average value, along with the reference current, forms a closed-loop current control, used to generate the duty cycle of pulse width modulation and adjust the actual current. Since the number of phases involved in conduction differs in different conduction modes, to ensure that the current loop maintains consistent dynamic characteristics before and after mode switching, the current of all non-commutated windings needs to be collected in each conduction mode, and their average value is used as a unified current feedback signal.

[0050] Subsequently, a proportional-integral closed-loop current regulator is constructed using the average current and the reference current to generate a pulse-width modulated duty cycle, which is then applied to the inverter to quickly track the desired current command. Furthermore, using the average current as the feedback quantity effectively eliminates the differences in current sampling structure caused by conduction mode switching, ensuring that the current loop maintains consistent control characteristics under different conduction modes, avoiding sudden current changes during switching, and improving the robustness and stability of the overall control system.

[0051] The following describes the multiphase motor efficiency optimization device based on variable conduction mode provided by the present invention. The multiphase motor efficiency optimization device based on variable conduction mode described below and the multiphase motor efficiency optimization method based on variable conduction mode described above can be referred to in correspondence.

[0052] Figure 3 A schematic diagram of a multiphase motor efficiency optimization system based on variable conduction mode is shown in the example, such as... Figure 3As shown, the method for optimizing the efficiency of a multiphase motor based on variable conduction mode, as described above, includes: Maximum torque limiting module 100: used to determine the target motor, construct the torque expression and determine the number of conducting phases, and determine the maximum torque limit based on the torque expression and the number of conducting phases; Phase copper loss module 200: used to calculate the average copper loss of current, construct the total copper loss expression through the average copper loss of current, calculate the effective value of phase current, and calculate the phase copper loss based on the total copper loss expression and the effective value of phase current; Inverter conduction loss module 300: Constructs expressions for odd-phase conduction loss and even-phase conduction loss, and calculates inverter conduction loss based on these expressions; Motor total loss module 400: used to calculate inverter switching losses, obtain inverter losses through inverter conduction losses and inverter switching losses, and obtain total motor losses based on inverter losses and phase copper losses. Motor control module 500: It is used to obtain the optimal number of conducting phases by the total motor loss under the constraint of maximum torque limit, and adjust the running phase of the target motor according to the optimal number of conducting phases to complete the control of the target motor.

[0053] Figure 4 An example is a schematic diagram of the physical structure of an electronic device, such as... Figure 4 As shown, the electronic device may include: a processor 810, a communication interface 820, a memory 830, and a communication bus 840, wherein the processor 810, the communication interface 820, and the memory 830 communicate with each other via the communication bus 840. The processor 810 can call a computer program in the memory 830 to execute a multiphase motor efficiency optimization method based on variable conduction mode, the method including: S1: Determine the target motor, construct the torque expression and determine the number of conducting phases, and determine the maximum torque limit based on the torque expression and the number of conducting phases; S2: Calculate the average copper loss of the current, construct the total copper loss expression through the average copper loss of the current, calculate the effective value of the phase current, and calculate the phase copper loss based on the total copper loss expression and the effective value of the phase current. S3: Construct expressions for odd-phase conduction loss and even-phase conduction loss, and calculate inverter conduction loss based on these expressions. S4: Calculate the inverter switching loss. Obtain the inverter loss through the inverter conduction loss and inverter switching loss. Obtain the total motor loss based on the inverter loss and phase copper loss. S5: Under the constraint of maximum torque limit, the optimal number of conducting phases is obtained through the total motor loss. The operating phase of the target motor is adjusted according to the optimal number of conducting phases to complete the control of the target motor.

[0054] Furthermore, when the computer program in the aforementioned memory 830 can be implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art, or a part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of the present invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0055] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs. Those skilled in the art can understand and implement this without any creative effort.

[0056] Through the above description of the embodiments, those skilled in the art can clearly understand that each embodiment can be implemented by means of software plus necessary general-purpose hardware platforms, and of course, it can also be implemented by hardware. Based on this understanding, the above technical solutions, in essence or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, magnetic disk, optical disk, etc., and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute the methods described in the various embodiments or some parts of the embodiments.

[0057] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for optimizing the efficiency of a multiphase motor based on variable conduction mode, characterized in that, include: S1: Determine the target motor, construct the torque expression and determine the number of conducting phases, and determine the maximum torque limit based on the torque expression and the number of conducting phases; S2: Calculate the average copper loss of the current, construct the total copper loss expression through the average copper loss of the current, calculate the effective value of the phase current, and calculate the phase copper loss based on the total copper loss expression and the effective value of the phase current. S3: Construct expressions for odd-phase conduction loss and even-phase conduction loss, and calculate inverter conduction loss based on these expressions. S4: Calculate the inverter switching loss. Obtain the inverter loss through the inverter conduction loss and inverter switching loss. Obtain the total motor loss based on the inverter loss and phase copper loss. S5: Under the constraint of maximum torque limit, the optimal number of conducting phases is obtained through the total motor loss. The operating phase of the target motor is adjusted according to the optimal number of conducting phases to complete the control of the target motor.

2. The method for optimizing the efficiency of a multiphase motor based on a variable conduction mode according to claim 1, characterized in that, Step S1 further includes: S11: Determine the multiphase motor as the target motor, determine the mechanical angular velocity and back EMF amplitude of the target motor, and obtain the torque expression based on the mechanical angular velocity and back EMF amplitude; S12: Determine the number of conducting phases and the maximum allowable current, and substitute the number of conducting phases and the maximum allowable current into the torque expression to obtain the maximum torque limit.

3. The method for optimizing the efficiency of a multiphase motor based on a variable conduction mode according to claim 1, characterized in that, In step S2, the instantaneous copper loss of the current is calculated, the average copper loss of the current is obtained based on the instantaneous copper loss of the current, and the total copper loss expression is constructed through the average copper loss of the current.

4. The method for optimizing the efficiency of a multiphase motor based on a variable conduction mode according to claim 1, characterized in that, In step S2, the effective values ​​of the odd-phase phase current and the even-phase phase current are constructed, and the effective values ​​of the odd-phase phase current and the even-phase phase current are substituted into the total copper loss expression to obtain the phase copper loss.

5. The method for optimizing the efficiency of a multiphase motor based on a variable conduction mode according to claim 1, characterized in that, In step S3, the expression for the odd-numbered phase conduction loss is: in, Let d be the conduction loss in the (n-2)th phase, and d be the duty cycle during conduction. For the IGBT resistor, This represents the phase current amplitude at the (n-2)th phase. This refers to the zero-current on-state voltage drop of the IGBT. The resistance of the diode, denoted as the zero-current forward voltage drop of the diode, and n is the number of phases of the target motor.

6. The method for optimizing the efficiency of a multiphase motor based on a variable conduction mode according to claim 1, characterized in that, In step S3, the expression for the even-numbered phase conduction loss is: in, Let d be the conduction loss in the (n-1)th phase, d be the duty cycle during conduction, and n be the number of phases of the target motor. This refers to the zero-current on-state voltage drop of the IGBT. The resistance of the diode, This is the zero-current forward voltage drop of the diode. For the IGBT resistor, This represents the phase current amplitude at the (n-1)th phase.

7. The method for optimizing the efficiency of a multiphase motor based on a variable conduction mode according to claim 1, characterized in that, In step S4, after obtaining the inverter switching loss, the inverter switching loss is added to the inverter conduction loss to obtain the inverter loss, and the inverter loss is added to the phase copper loss to obtain the total motor loss.

8. The method for optimizing the efficiency of a multiphase motor based on a variable conduction mode according to claim 1, characterized in that, In step S5, the torque at which the total motor loss between adjacent phases is equal is taken as the critical torque, and the critical torque is constrained by the maximum torque limit to obtain the optimal number of conducting phases; The hysteresis width and torque change indication value are determined, and the operating phase of the target motor is adjusted according to the optimal number of conducting phases, the torque change indication value, and the hysteresis width.

9. A multiphase motor efficiency optimization system based on variable conduction mode, used to execute the multiphase motor efficiency optimization method based on variable conduction mode as described in any one of claims 1 to 8, characterized in that, include: Maximum torque limit module: used to determine the target motor, construct the torque expression and determine the number of conducting phases, and determine the maximum torque limit based on the torque expression and the number of conducting phases; Phase copper loss module: used to calculate the average copper loss of current, construct the total copper loss expression through the average copper loss of current, calculate the effective value of phase current, and calculate the phase copper loss based on the total copper loss expression and the effective value of phase current; Inverter conduction loss module: Constructs expressions for odd-phase conduction loss and even-phase conduction loss, and calculates inverter conduction loss based on these expressions; Motor total loss module: used to calculate inverter switching losses. Inverter losses are obtained through inverter conduction losses and inverter switching losses. The total motor loss is obtained based on inverter losses and phase copper losses. Motor control module: Used to obtain the optimal number of conducting phases by the total motor loss under the constraint of maximum torque limit, and adjust the operating phase of the target motor according to the optimal number of conducting phases to complete the control of the target motor.

10. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the computer program, it implements the steps of the multiphase motor efficiency optimization method based on variable conduction mode as described in any one of claims 1 to 8.

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