Permanent magnet synchronous motor field weakening control method, system and device and readable storage medium
By determining the target bus voltage based on the preset saturation voltage and real-time voltage under the weak magnetic condition of the motor, and adjusting the current using the mapping relationship table, the problem that the motor output torque cannot be kept constant under the magnetic flux attenuation is solved, and the stable output of torque is achieved.
Patent Information
- Application Number
- CN202510117865.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-01-24
- Publication Date
- 2025-05-02
AI Technical Summary
In the case of magnetic flux attenuation, it is difficult for the prior art to keep the voltage synthetic vector amplitude Udq constant while ensuring the motor output torque is constant.
In the motor weak magnetic condition, the target bus voltage is determined based on the preset saturation voltage, real-time voltage synthesis vector amplitude and real-time bus voltage, and the target current is determined based on the mapping relationship table between the target bus voltage and the preset different bus voltages and currents, and the real-time current reaches the target current to achieve constant torque.
Under different bus voltages, by accurately adjusting the current, the motor output torque is achieved, and torque fluctuations caused by magnetic fluctuations are avoided.
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Figure CN119921605A_ABST
Abstract
Description
Technical Field
[0001] The present application relates to the technical field of electric vehicle motor control, and in particular to a permanent magnet synchronous motor weak magnetic field control method, system, device and readable storage medium. Background Art
[0002] With the rapid popularization of electric vehicles in my country, the demand for efficient and reliable motor control strategies in electric vehicle drive systems is increasing. Among the existing electric vehicle drive motors, permanent magnet synchronous motors have become the most common choice due to their high efficiency and high reliability.
[0003] The weak magnetic control in the prior art is to adjust the current Id by the difference between the voltage synthesis vector amplitude Udq and the saturation voltage on the direct axis, so as to keep Udq constant. Then, according to the formula Iq = (Is 2 -Id 2 ) 1 / 2 The quadrature axis current Iq is calculated, where Is is the current synthesis vector amplitude. However, this strategy has certain problems: although Udq can be kept constant, it will cause the motor flux to decay, and the formula for calculating Iq is based on the assumption that the flux remains unchanged, so the output torque of the motor will not be able to remain constant when the flux decays.
[0004] Therefore, when the flux is attenuated, how to ensure that the motor output torque is constant while ensuring that Udq is constant is an urgent problem that needs to be solved. Summary of the invention
[0005] The present application provides a permanent magnet synchronous motor weak magnetic control method, system, device and readable storage medium, which can solve the technical problem in the prior art that the output torque of the motor cannot be maintained constant when the magnetic flux is attenuated.
[0006] In a first aspect, an embodiment of the present application provides a permanent magnet synchronous motor weakening magnetic field control method, the permanent magnet synchronous motor weakening magnetic field control method comprising:
[0007] Under the weak magnetic condition of the motor, the target bus voltage is determined based on the preset saturation voltage, the real-time voltage synthesis vector amplitude and the real-time bus voltage;
[0008] The target current is determined based on the target bus voltage and a preset mapping relationship table between different bus voltages and currents, and the real-time current is controlled to reach the target current to achieve constant torque.
[0009] In combination with the first aspect, in an implementation manner, before the step of determining the target current based on the target bus voltage and a preset mapping relationship table between different bus voltages and currents, the method further includes:
[0010] Dividing the bus voltage within a preset range based on a preset voltage step to obtain a plurality of bus voltages;
[0011] The torque corresponding to each bus voltage and the current corresponding to the torque are obtained to construct a mapping relationship table between different bus voltages and currents.
[0012] In combination with the first aspect, in one implementation, determining the target current based on the target bus voltage and a preset mapping relationship table between different bus voltages and currents includes:
[0013] Searching for two bus voltages adjacent to the target bus voltage from the mapping relationship table, and searching for a first current and a second current corresponding to the two bus voltages;
[0014] The first current and the second current are linearly interpolated to obtain a target current.
[0015] In combination with the first aspect, in one implementation, determining the target bus voltage based on the preset saturation voltage, the real-time voltage synthesis vector amplitude and the real-time bus voltage includes:
[0016] Determining whether there is a bus voltage offset value based on a preset saturation voltage and a real-time voltage synthesis vector amplitude;
[0017] If yes, determining the target bus voltage based on the bus voltage offset value and the real-time bus voltage;
[0018] If not, the real-time bus voltage is used as the target bus voltage.
[0019] In combination with the first aspect, in one implementation, judging whether there is a bus voltage offset value based on the preset saturation voltage and the real-time voltage synthesis vector amplitude includes:
[0020] If the ratio of the preset saturation voltage to the real-time voltage synthesis vector amplitude is greater than 1, it is determined that there is a bus voltage offset value and the ratio is used as the bus voltage offset value;
[0021] If the ratio of the preset saturation voltage to the real-time voltage synthesis vector amplitude is less than or equal to 1, it is determined that there is no bus voltage offset value.
[0022] In combination with the first aspect, in one implementation, determining the target bus voltage based on the bus voltage offset value and the real-time bus voltage includes:
[0023] The bus voltage offset value and the real-time bus voltage are multiplied to obtain a target bus voltage.
[0024] In a second aspect, an embodiment of the present application provides a permanent magnet synchronous motor weak magnetic field control system, and the permanent magnet synchronous motor weak magnetic field control system includes:
[0025] A first processing module, which is used to determine a target bus voltage based on a preset saturation voltage, a real-time voltage synthesis vector amplitude and a real-time bus voltage under a motor weak magnetic condition;
[0026] The second processing module is used to determine the target current based on the target bus voltage and a preset mapping relationship table between different bus voltages and currents, and control the real-time current to reach the target current to achieve constant torque.
[0027] In conjunction with the second aspect, in one implementation, the second processing module is specifically configured to:
[0028] Dividing the bus voltage within a preset range based on a preset voltage step to obtain a plurality of bus voltages;
[0029] The torque corresponding to each bus voltage and the current corresponding to the torque are obtained to construct a mapping relationship table between different bus voltages and currents.
[0030] In the third aspect, an embodiment of the present application provides a permanent magnet synchronous motor weak magnetic field control device, which includes a processor, a memory, and a permanent magnet synchronous motor weak magnetic field control program stored in the memory and executable by the processor, wherein when the permanent magnet synchronous motor weak magnetic field control program is executed by the processor, the steps of the permanent magnet synchronous motor weak magnetic field control method as described in any of the above items are implemented.
[0031] In a fourth aspect, an embodiment of the present application provides a computer-readable storage medium, on which a permanent magnet synchronous motor weak magnetic field control program is stored. When the permanent magnet synchronous motor weak magnetic field control program is executed by a processor, the steps of the permanent magnet synchronous motor weak magnetic field control method as described in any of the foregoing items are implemented.
[0032] The beneficial effects brought by the technical solution provided in the embodiments of the present application include:
[0033] Under the weak magnetic condition of the motor, the target bus voltage is determined based on the preset saturation voltage, the real-time voltage synthesis vector amplitude and the real-time bus voltage; the target current is determined based on the target bus voltage and a preset mapping relationship table between different bus voltages and currents, and the real-time current is controlled to reach the target current. By accurately searching the mapping relationship table, the current can be accurately adjusted under the working conditions of different bus voltages to achieve constant torque output. BRIEF DESCRIPTION OF THE DRAWINGS
[0034] Figure 1 This is a flow chart of an embodiment of a method for weakening magnetic field of a permanent magnet synchronous motor of the present application;
[0035] Figure 2A schematic diagram of the construction process of a mapping relationship table between different bus voltages and currents in an embodiment of a permanent magnet synchronous motor weak magnetic field control method of the present application;
[0036] Figure 3 For this application Figure 1 A detailed flow chart of step S10;
[0037] Figure 4 This is a schematic diagram of the hardware structure of the permanent magnet synchronous motor weak magnetic control device involved in the embodiment of the present application. DETAILED DESCRIPTION
[0038] In order to enable those skilled in the art to better understand the solution of the present application, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.
[0039] In order to make the objectives, technical solutions and advantages of the present application clearer, the implementation methods of the present application will be further described in detail below with reference to the accompanying drawings.
[0040] In a first aspect, an embodiment of the present application provides a method for weakening magnetic field of a permanent magnet synchronous motor.
[0041] In one embodiment, referring to Figure 1 , Figure 1 This is a flow chart of an embodiment of the permanent magnet synchronous motor weak magnetic control method of the present application. Figure 1 As shown, the permanent magnet synchronous motor weak magnetic control method includes:
[0042] Step S10: Under the weak magnetic condition of the motor, the target bus voltage is determined based on the preset saturation voltage, the real-time voltage synthesis vector amplitude and the real-time bus voltage.
[0043] Under the weak magnetic condition of the motor, when the motor temperature increases, the flux decreases. In order to maintain the real-time voltage synthesis vector amplitude U dq The direct-axis current I needs to be reduced d Although the value of I d Can keep U dq constant, but it will cause the motor flux to decay, then based on formula I q =(I s 2 -I d 2 ) 1 / 2 To calculate the quadrature axis current I qThis will cause the motor's output torque to be unable to remain constant. In order to maintain U dq The present application proposes a table lookup method to perform magnetic field weakening control on a permanent magnet synchronous motor.
[0044] Exemplarily, in the embodiment of the present application, the bus voltage refers to the voltage on the DC bus of the motor drive system, which determines the maximum voltage amplitude that the motor driver can provide. The real-time bus voltage refers to the bus voltage monitored in real time by the motor control system during the operation of the motor. When the motor works in the weak magnetic field area, the magnetic field of the motor will weaken and the induced voltage of the motor will drop. In order to maintain the normal operation of the motor, the system will set a voltage upper limit (i.e., preset saturation voltage) in advance, which is used to prevent the motor from being damaged due to excessive voltage and ensure that the motor operates within a safe voltage range. The calculation formula of the saturation voltage is: Where, U is the saturation voltage, U dc is the real-time bus voltage, λ is the preset saturation coefficient, wherein the specific value of the preset saturation coefficient can be determined according to actual needs and is not limited here; the real-time voltage synthesis vector amplitude is determined based on the real-time direct-axis voltage and the real-time quadrature-axis voltage, which can accurately control the voltage output of the motor under weak magnetic conditions. The calculation formula of the real-time voltage synthesis vector amplitude is as follows: Where U d is the real-time direct-axis voltage, U q is the real-time quadrature axis voltage, U dq It is the real-time voltage synthesis vector magnitude; the target bus voltage is the reference voltage of the motor drive system, which represents the desired voltage level of the system.
[0045] Specifically, under the weak magnetic condition of the motor, the system adjusts the voltage synthesis vector amplitude in real time according to the load changes and operating status of the motor, and the preset saturation voltage and real-time bus voltage provide the system with the operating voltage boundary. Then, the target bus voltage is determined by combining the preset saturation voltage, the real-time voltage synthesis vector amplitude and the real-time bus voltage to ensure that the motor can maintain the best operating efficiency under various operating conditions and avoid faults caused by excessively high or low voltage.
[0046] Step S20: Determine the target current based on the target bus voltage and a preset mapping relationship table between different bus voltages and currents, and control the real-time current to reach the target current to achieve constant torque.
[0047] Exemplarily, in an embodiment of the present application, the current includes a direct-axis current and a quadrature-axis current, and the preset mapping relationship table between different bus voltages and currents can be determined through experimental calibration, which is not limited here; for example, when the bus voltage is X1, the corresponding direct-axis current is Y1 and the quadrature-axis current is Z1, when the bus voltage is X2, the corresponding direct-axis current is Y2 and the quadrature-axis current is Z2, and when the bus voltage is X3, the corresponding direct-axis current is Y3 and the quadrature-axis current is Z3.
[0048] Specifically, a connection is established between the bus voltage and current of the motor through a mapping relationship table, and the mapping relationship table is searched according to the target bus voltage to obtain the target direct-axis current and the target quadrature-axis current; for example, assuming that the calculated target bus voltage is X2, then the target direct-axis current corresponding to the target bus voltage X2 is Y2, and the target quadrature-axis current is Z2, and then real-time feedback control is used to ensure that the real-time current I of the motor is consistent with the target direct-axis current Y2 and the quadrature-axis current Z2. In other words, the motor always maintains the required current output under different working conditions, ensuring that the motor outputs stable torque.
[0049] The present application determines the target bus voltage based on the preset saturation voltage, the real-time voltage synthesis vector amplitude and the real-time bus voltage under the weak magnetic condition of the motor; determines the target current based on the target bus voltage and a preset mapping relationship table between different bus voltages and currents, and controls the real-time current to reach the target current. By accurately searching the mapping relationship table, the current can be accurately adjusted under working conditions of different bus voltages to achieve constant torque output.
[0050] Further, in one embodiment, referring to Figure 2 As shown, before the step of determining the target current based on the target bus voltage and the preset mapping relationship table between different bus voltages and currents, it also includes:
[0051] Step P10: dividing the bus voltage within the preset range based on the preset voltage step size to obtain a plurality of bus voltages;
[0052] Step P20: Obtain the torque corresponding to each bus voltage and the current corresponding to the torque to construct a mapping relationship table between different bus voltages and currents.
[0053] For example, in the embodiment of the present application, the preset voltage step and the preset range can be determined according to actual needs and are not limited here. For example, the preset voltage step is the system rated voltage U dc_rate 5% of the preset range is [0.7*U dc_rate , 1.3*U dc_rate ], that is, the voltage minimum value U dc_min =0.7*U dc_rate , voltage maximum value U dc_maz=1.3*U dc_rate , where the system rated voltage U dc_rate It is the standard voltage value designed for electrical equipment or systems when they are working normally.
[0054] Specifically, 0.05*U dc_rate is the voltage step, from 0.7*U dc_rate Start to gradually increase the bus voltage to 1.3*U dc_rate In order to realize the division of bus voltage, multiple bus voltages are obtained; then the working condition of each bus is calibrated, and the torque corresponding to each bus voltage and the current corresponding to each torque are recorded. After obtaining the torque and current values under multiple different voltages, a mapping relationship table between bus voltage and current is constructed based on these data, which shows how different bus voltages affect the current and torque of the motor and based on what current control can achieve constant torque output; it can be understood that the above mapping table contains the mapping relationship between different bus voltages and torques and the mapping relationship between different torques and currents, that is, the mapping relationship between bus voltage and current is obtained.
[0055] Further, in one embodiment, the target current is determined based on the target bus voltage and a preset mapping relationship table between different bus voltages and currents, including:
[0056] Searching for two bus voltages adjacent to the target bus voltage from the mapping relationship table, and searching for a first current and a second current corresponding to the two bus voltages;
[0057] The first current and the second current are linearly interpolated to obtain a target current.
[0058] Exemplarily, in the embodiment of the present application, the target bus voltage U is searched from the mapping relationship table. dx_k The higher bus voltage U dc_k+1 and the target bus voltage U dc_k The lower bus voltage U dc_k-1 And find the dc_k+1 The corresponding current I d_k+1 and I q_k+1 (i.e. the first straight-axis current and the first quadrature-axis current), and U dc_k-1 The corresponding current I d_k-1 and I q_k-1 (ie, the second direct-axis current and the second quadrature-axis current).
[0059] Specifically, in U dc_k-1 , U dc_k+1 The target bus voltage U dc_k As increment, use linear interpolation to calculate the target direct axis current I d_k and the target quadrature axis current Iq_k , where the calculation formulas for the two are as follows:
[0060]
[0061] In the formula, I q_k is the target quadrature-axis current; I d_k is the target direct-axis current.
[0062] Further, in one embodiment, referring to Figure 3 As shown, the target bus voltage is determined based on the preset saturation voltage, the real-time voltage synthesis vector amplitude and the real-time bus voltage, including:
[0063] Step S101: judging whether there is a bus voltage offset value based on a preset saturation voltage and a real-time voltage synthesis vector amplitude;
[0064] Step S102: If yes, determining the target bus voltage based on the bus voltage offset value and the real-time bus voltage;
[0065] Step S103: If not, the real-time bus voltage is used as the target bus voltage.
[0066] Exemplarily, in the embodiment of the present application, the preset saturation voltage and real-time voltage synthesis vector amplitude U dq A quotient is made, and whether there is a bus voltage offset value is determined based on the size relationship between the result after the quotient is made and 1; if there is, it means that the real-time bus voltage needs to be adjusted to make the current bus voltage reach the target bus voltage, and the target bus voltage is determined based on the bus voltage offset value and the real-time bus voltage; if there is no such value, it means that the real-time bus voltage has met the expected target and no adjustment is required, and the real-time bus voltage is directly used as the target bus voltage.
[0067] Further, in one embodiment, judging whether there is a bus voltage offset value based on the preset saturation voltage and the real-time voltage synthesis vector amplitude includes:
[0068] If the ratio of the preset saturation voltage to the real-time voltage synthesis vector amplitude is greater than 1, it is determined that there is a bus voltage offset value and the ratio is used as the bus voltage offset value;
[0069] If the ratio of the preset saturation voltage to the real-time voltage synthesis vector amplitude is less than or equal to 1, it is determined that there is no bus voltage offset value.
[0070] Exemplarily, in the embodiment of the present application, the preset saturation voltage can be compared and real-time voltage synthesis vector amplitude U dqto understand the current bus voltage status. If the ratio is >1, it means there is an overvoltage phenomenon, that is, there is a bus voltage offset value, and the ratio is used as the bus voltage offset value; if the ratio is ≤1, it means there is no overvoltage phenomenon, that is, there is no bus voltage offset value.
[0071] Further, in one embodiment, determining the target bus voltage based on the bus voltage offset value and the real-time bus voltage includes:
[0072] The bus voltage offset value and the real-time bus voltage are multiplied to obtain a target bus voltage.
[0073] Exemplarily, in the embodiment of the present application, the bus voltage offset value and the real-time bus voltage are substituted into the following formula to obtain the target bus voltage, and the calculation formula is as follows:
[0074] U dc_k =U dc *K
[0075] Where U dc_k is the target bus voltage; U dc is the real-time bus voltage; K is the bus voltage offset value. It should be understood that the peak torque output capacity of the motor will decrease as the temperature increases during the operation of the motor. Therefore, the control system needs to adjust the output torque command according to the current motor state to avoid command overload. Specifically, under weak magnetic conditions, the maximum output torque of the motor is limited by voltage. Therefore, the maximum torque that the motor can provide under a certain target bus voltage can be determined to ensure that the system operates within a safe and executable range; for example, the maximum torque corresponding to the bus voltage adjacent to a certain target bus voltage can be found in the mapping table. When the target torque given by the controller is higher than the maximum torque, the system determines that the torque command does not meet the actual executable conditions and does not execute the command. At this time, the system will take a protection mechanism to prevent the motor from being damaged or overloaded.
[0076] In a second aspect, an embodiment of the present application further provides a permanent magnet synchronous motor weak magnetic field control system, the permanent magnet synchronous motor weak magnetic field control system comprising:
[0077] A first processing module, which is used to determine a target bus voltage based on a preset saturation voltage, a real-time voltage synthesis vector amplitude and a real-time bus voltage under a motor weak magnetic condition;
[0078] The second processing module is used to determine the target current based on the target bus voltage and a preset mapping relationship table between different bus voltages and currents, and control the real-time current to reach the target current to achieve constant torque.
[0079] Furthermore, in one embodiment, the second processing module is specifically configured to:
[0080] Dividing the bus voltage within a preset range based on a preset voltage step to obtain a plurality of bus voltages;
[0081] The torque corresponding to each bus voltage and the current corresponding to the torque are obtained to construct a mapping relationship table between different bus voltages and currents.
[0082] Furthermore, in one embodiment, the second processing module is further configured to:
[0083] Searching for two bus voltages adjacent to the target bus voltage from the mapping relationship table, and searching for a first current and a second current corresponding to the two bus voltages;
[0084] The first current and the second current are linearly interpolated to obtain a target current.
[0085] Furthermore, in one embodiment, the first processing module is specifically configured to:
[0086] Determining whether there is a bus voltage offset value based on a preset saturation voltage and a real-time voltage synthesis vector amplitude;
[0087] If yes, determining the target bus voltage based on the bus voltage offset value and the real-time bus voltage;
[0088] If not, the real-time bus voltage is used as the target bus voltage.
[0089] Furthermore, in one embodiment, the first processing module is further configured to:
[0090] If the ratio of the preset saturation voltage to the real-time voltage synthesis vector amplitude is greater than 1, it is determined that there is a bus voltage offset value and the ratio is used as the bus voltage offset value;
[0091] If the ratio of the preset saturation voltage to the real-time voltage synthesis vector amplitude is less than or equal to 1, it is determined that there is no bus voltage offset value.
[0092] Furthermore, in one embodiment, the first processing module is further configured to:
[0093] Determining a target bus voltage based on the bus voltage offset value and the real-time bus voltage includes:
[0094] The bus voltage offset value and the real-time bus voltage are multiplied to obtain a target bus voltage.
[0095] The present application determines the target bus voltage based on the preset saturation voltage, the real-time voltage synthesis vector amplitude and the real-time bus voltage under the weak magnetic condition of the motor; determines the target current based on the target bus voltage and a preset mapping relationship table between different bus voltages and currents, and controls the real-time current to reach the target current. By accurately searching the mapping relationship table, the current can be accurately adjusted under working conditions of different bus voltages to achieve constant torque output.
[0096] Among them, the functional implementation of each module in the above-mentioned permanent magnet synchronous motor weak magnetic control system corresponds to the various steps in the above-mentioned permanent magnet synchronous motor weak magnetic control method embodiment, and its functions and implementation processes are no longer repeated here one by one.
[0097] In a third aspect, an embodiment of the present application provides a permanent magnet synchronous motor weak magnetic field control device, which may be a personal computer (PC), a laptop computer, a server, or other device with data processing capabilities.
[0098] Reference Figure 4 , Figure 4 Schematic diagram of the hardware structure of the permanent magnet synchronous motor weak magnetic control device involved in the embodiment of the present application. In the embodiment of the present application, the permanent magnet synchronous motor weak magnetic control device may include a processor, a memory, a communication interface and a communication bus.
[0099] The communication bus may be of any type and is used to interconnect the processor, the memory, and the communication interface.
[0100] The communication interface includes input / output (I / O) interface, physical interface and logical interface, etc., which are used to realize the interconnection of devices inside the permanent magnet synchronous motor weak magnetic field control device, and the interface used to realize the interconnection between the permanent magnet synchronous motor weak magnetic field control device and other devices (such as other computing devices or user devices). The physical interface can be an Ethernet interface, a fiber optic interface, an ATM interface, etc.; the user device can be a display (Display), a keyboard (Keyboard), etc.
[0101] The memory can be various types of storage media, such as random access memory (RAM), read-only memory (ROM), non-volatile RAM (NVRAM), flash memory, optical storage, hard disk, programmable ROM (PROM), erasable PROM (EPROM), electrically erasable PROM (EEPROM), etc.
[0102] The processor may be a general-purpose processor, and the general-purpose processor may call the permanent magnet synchronous motor weak magnetic field control program stored in the memory, and execute the permanent magnet synchronous motor weak magnetic field control method provided in the embodiment of the present application. For example, the general-purpose processor may be a central processing unit (CPU). Among them, the method executed when the permanent magnet synchronous motor weak magnetic field control program is called may refer to the various embodiments of the permanent magnet synchronous motor weak magnetic field control method of the present application, and will not be repeated here.
[0103] Those skilled in the art will understand that Figure 4 The hardware structure shown in the figure does not constitute a limitation on the present application, and may include more or less components than shown in the figure, or combine certain components, or arrange the components differently.
[0104] In a fourth aspect, an embodiment of the present application also provides a readable storage medium.
[0105] The readable storage medium of the present application stores a permanent magnet synchronous motor weak magnetic field control program, wherein when the permanent magnet synchronous motor weak magnetic field control program is executed by a processor, the steps of the permanent magnet synchronous motor weak magnetic field control method as described above are implemented.
[0106] Among them, the method implemented when the permanent magnet synchronous motor weak magnetic field control program is executed can refer to the various embodiments of the permanent magnet synchronous motor weak magnetic field control method of the present application, and will not be repeated here.
[0107] The terms "including" and "having" and any variations thereof in the specification and claims of this application and the above-mentioned drawings are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device that includes a series of steps or units is not limited to the listed steps or units, but optionally includes steps or units that are not listed, or optionally includes other steps or units inherent to these processes, methods, products or devices. The terms "first", "second" and "third" are used to distinguish different objects, etc., and do not represent a sequence, nor do they limit "first", "second" and "third" to different types.
[0108] In the description of the embodiments of the present application, "exemplary", "for example" or "for example" are used to indicate examples, illustrations or descriptions. Any embodiment or design described as "exemplary", "for example" or "for example" in the embodiments of the present application should not be interpreted as being more preferred or more advantageous than other embodiments or designs. Specifically, the use of words such as "exemplary", "for example" or "for example" is intended to present related concepts in a specific way.
[0109] In the description of the embodiments of the present application, unless otherwise specified, “ / ” means or, for example, A / B can mean A or B; the “and / or” in the text is merely a description of the association relationship of associated objects, indicating that three relationships may exist, for example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone. In addition, in the description of the embodiments of the present application, “multiple” refers to two or more than two.
[0110] In some processes described in the embodiments of the present application, multiple operations or steps that appear in a specific order are included, but it should be understood that these operations or steps may not be executed in the order in which they appear in the embodiments of the present application or in parallel, and the sequence number of the operation is only used to distinguish the different operations, and the sequence number itself does not represent any execution order. In addition, these processes may include more or fewer operations, and these operations or steps may be executed in sequence or in parallel, and these operations or steps may be combined.
[0111] It should be noted that the serial numbers of the above-mentioned embodiments of the present application are only for description and do not represent the advantages or disadvantages of the embodiments.
[0112] Through the description of the above implementation methods, those skilled in the art can clearly understand that the above-mentioned embodiment methods can be implemented by means of software plus a necessary general hardware platform, and of course by hardware, but in many cases the former is a better implementation method. Based on such an understanding, the technical solution of the present application is essentially or the part that contributes to the prior art can be embodied in the form of a software product, which is stored in a storage medium (such as ROM / RAM, disk, CD) as described above, and includes a number of instructions for a terminal device to execute the methods described in each embodiment of the present application.
[0113] The above are only preferred embodiments of the present application, and are not intended to limit the patent scope of the present application. Any equivalent structure or equivalent process transformation made using the contents of the present application specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present application.
Claims
1. A permanent magnet synchronous motor weak magnetic control method, characterized in that: The permanent magnet synchronous motor weak magnetic control method comprises: Under the weak magnetic condition of the motor, the target bus voltage is determined based on the preset saturation voltage, the real-time voltage synthesis vector amplitude and the real-time bus voltage; The target current is determined based on the target bus voltage and a preset mapping relationship table between different bus voltages and currents, and the real-time current is controlled to reach the target current to achieve constant torque.
2. The permanent magnet synchronous motor weak magnetic field control method according to claim 1, characterized in that: Before the step of determining the target current based on the target bus voltage and a preset mapping relationship table between different bus voltages and currents, the method further includes: Dividing the bus voltage within a preset range based on a preset voltage step to obtain a plurality of bus voltages; The torque corresponding to each bus voltage and the current corresponding to the torque are obtained to construct a mapping relationship table between different bus voltages and currents.
3. The permanent magnet synchronous motor weak magnetic field control method according to claim 2, characterized in that: The determining the target current based on the target bus voltage and a preset mapping relationship table between different bus voltages and currents includes: Searching for two bus voltages adjacent to the target bus voltage from the mapping relationship table, and searching for a first current and a second current corresponding to the two bus voltages; The first current and the second current are linearly interpolated to obtain a target current.
4. The permanent magnet synchronous motor weak magnetic field control method according to claim 1, characterized in that: The method of determining the target bus voltage based on the preset saturation voltage, the real-time voltage synthesis vector amplitude and the real-time bus voltage includes: Determining whether there is a bus voltage offset value based on a preset saturation voltage and a real-time voltage synthesis vector amplitude; If yes, determining the target bus voltage based on the bus voltage offset value and the real-time bus voltage; If not, the real-time bus voltage is used as the target bus voltage.
5. The permanent magnet synchronous motor weakening control method according to claim 4, characterized in that: The determining whether there is a bus voltage offset value based on the preset saturation voltage and the real-time voltage synthesis vector amplitude includes: If the ratio of the preset saturation voltage to the real-time voltage synthesis vector amplitude is greater than 1, it is determined that there is a bus voltage offset value and the ratio is used as the bus voltage offset value; If the ratio of the preset saturation voltage to the real-time voltage synthesis vector amplitude is less than or equal to 1, it is determined that there is no bus voltage offset value.
6. The permanent magnet synchronous motor weak magnetic field control method according to claim 4, characterized in that: The determining of the target bus voltage based on the bus voltage offset value and the real-time bus voltage comprises: The bus voltage offset value and the real-time bus voltage are multiplied to obtain a target bus voltage.
7. A permanent magnet synchronous motor weak magnetic control system, characterized in that: The permanent magnet synchronous motor weak magnetic control system comprises: A first processing module, which is used to determine a target bus voltage based on a preset saturation voltage, a real-time voltage synthesis vector amplitude and a real-time bus voltage under a motor weak magnetic condition; The second processing module is used to determine the target current based on the target bus voltage and a preset mapping relationship table between different bus voltages and currents, and control the real-time current to reach the target current to achieve constant torque.
8. The permanent magnet synchronous motor weak magnetic field control system according to claim 7, characterized in that: The second processing module is specifically used for: Dividing the bus voltage within a preset range based on a preset voltage step to obtain a plurality of bus voltages; The torque corresponding to each bus voltage and the current corresponding to the torque are obtained to construct a mapping relationship table between different bus voltages and currents.
9. A permanent magnet synchronous motor weak magnetic control device, characterized in that: The permanent magnet synchronous motor weakening control device includes a processor, a memory, and a permanent magnet synchronous motor weakening control program stored in the memory and executable by the processor, wherein when the permanent magnet synchronous motor weakening control program is executed by the processor, the steps of the permanent magnet synchronous motor weakening control method as described in any one of claims 1 to 6 are implemented.
10. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores a permanent magnet synchronous motor weakening control program, wherein when the permanent magnet synchronous motor weakening control program is executed by the processor, the steps of the permanent magnet synchronous motor weakening control method according to any one of claims 1 to 6 are implemented.