Method and device for determining motor mechanical loss, electronic equipment and storage medium
By replacing the rotor permanent magnet with a non-magnetized magnet in the motor and combining it with a high-precision speed sensor and an electromagnetic clutch, the problems of low accuracy and high cost in the measurement of motor mechanical losses are solved, and high-precision non-destructive measurement across the entire speed range is achieved.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- CHINA FAW CO LTD
- Filing Date
- 2026-02-26
- Publication Date
- 2026-06-09
AI Technical Summary
Existing methods for measuring the mechanical losses of motors are difficult to effectively eliminate AC copper losses in the stator windings and eddy current losses generated by the rotor permanent magnets, resulting in low accuracy in separating mechanical losses and high costs.
By controlling the motor under test to enter a preset free-speed reduction state, replacing the rotor permanent magnet with a non-magnetized magnet, and combining a high-precision speed sensor and an electromagnetic clutch, speed-time data pairs are obtained, the instantaneous dissipation power of rotational kinetic energy is calculated, and the mechanical loss power is determined.
It achieves non-destructive, rapid, and high-precision measurement of the mechanical losses of motors across the entire speed range, avoiding the use of high-cost, high-precision torque sensors.
Smart Images
Figure CN122171078A_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of motor performance testing technology, and in particular to a method, apparatus, electronic device and storage medium for determining motor mechanical losses. Background Technology
[0002] As a core power device in the industrial field, the performance and efficiency of electric motors directly affect the energy consumption and economy of the entire system. Permanent magnet synchronous motors, with their high power density, high efficiency, and excellent reliability, have become the preferred power source for electric vehicles, industrial servos, and high-end equipment. To continuously optimize system energy efficiency, accurate measurement and analysis of various motor losses (including stator copper losses, rotor iron losses, permanent magnet eddy current losses, and mechanical losses) are crucial.
[0003] In related technologies, the mainstream methods for measuring the mechanical losses of motors mainly include the no-load test method and the loss separation method. The no-load test method involves driving the motor under test to a stable speed using a drive motor, measuring the no-load torque using a high-precision torque sensor, and calculating the no-load loss by combining this with the speed measurement. The mechanical losses are then separated through numerical analysis. The loss separation method typically uses a drive motor, measuring its input power under two operating conditions: with and without the motor under test (or its dummy rotor). The difference between the two measurements is taken as the mechanical loss of the motor under test.
[0004] However, the above methods are difficult to effectively eliminate the AC copper loss of the stator winding and the eddy current loss generated by the rotor permanent magnet when the motor is running under no-load conditions. This results in low mechanical loss separation accuracy and relies on expensive high-precision torque sensors, which is costly and urgently needs to be solved. Summary of the Invention
[0005] This application provides a method, apparatus, electronic device, and storage medium for determining the mechanical losses of an electric motor, in order to solve the problems of complex, costly, and limited accuracy of mechanical loss measurement caused by the need to separate copper loss, iron loss, and eddy current loss in related technologies. It achieves non-destructive, rapid, and high-precision measurement of the mechanical losses of an electric motor across its entire speed range.
[0006] To achieve the above objectives, the first aspect of this application proposes a method for determining the mechanical losses of an electric motor, comprising the following steps:
[0007] The motor under test is controlled to enter a preset free deceleration state, wherein the rotor permanent magnet of the motor under test is a non-magnetized magnet; The test motor acquires multiple speed values and the acquisition time corresponding to each speed value under the preset free-speed-decline state, and generates speed-time data pairs of the test motor based on each speed value and each acquisition time. Based on the speed-time data pair, the instantaneous power dissipation of the rotational kinetic energy of the tested motor is calculated, and the mechanical loss power of the tested motor at different speed values is determined according to the instantaneous power dissipation.
[0008] According to one embodiment of this application, calculating the instantaneous power dissipation of the rotational kinetic energy of the tested motor based on the speed-time data pair includes: Based on the speed-time data pair, calculate the rotational kinetic energy-time data pair of the tested motor; Based on the rotational kinetic energy-time data pair, the instantaneous power dissipation of the rotational kinetic energy is obtained.
[0009] According to one embodiment of this application, the step of calculating the rotational kinetic energy-time data pair of the tested motor based on the speed-time data pair includes: Based on the speed-time data pair, the rotational kinetic energy value of the motor under test at each acquisition moment is calculated; The rotational kinetic energy-time data pair is obtained based on each acquisition time and each rotational kinetic energy value.
[0010] According to one embodiment of this application, obtaining the instantaneous power dissipation of the rotational kinetic energy based on the rotational kinetic energy-time data pair includes: Polynomial fitting is performed on the rotational kinetic energy-time data pairs to generate a rotational kinetic energy-time relationship function; The instantaneous power dissipation of the rotational kinetic energy is obtained by taking the first derivative of the rotational kinetic energy-time relationship function.
[0011] According to one embodiment of this application, before controlling the tested motor to enter the preset free-fall state, the method further includes: The test motor is driven by a drive motor to run continuously at the target speed for a preset time.
[0012] According to the method for determining the mechanical losses of a motor proposed in this application, the motor under test is controlled to enter a preset free-fall state. Multiple speed values of the motor under test in the preset free-fall state and the corresponding acquisition time for each speed value are obtained. Based on each speed value and each acquisition time, a speed-time data pair of the motor under test is generated. Based on the speed-time data pair, the instantaneous dissipation power of the rotational kinetic energy of the motor under test is calculated, and the mechanical loss power of the motor under test at different speed values is determined based on the instantaneous dissipation power. This solves the problems of complex, costly, and limited accuracy in mechanical loss measurement caused by the need to separate copper loss, iron loss, and eddy current loss in related technologies, and achieves non-destructive, rapid, and high-precision measurement of the mechanical losses of a motor across its entire speed range.
[0013] To achieve the above objectives, a second aspect of this application provides a device for determining the mechanical losses of an electric motor, comprising: The control module is used to control the motor under test to enter a preset free deceleration state, wherein the rotor permanent magnet of the motor under test is a non-magnetized magnet. The generation module is used to acquire multiple speed values of the motor under test in the preset free-speed-decline state and the acquisition time corresponding to each speed value, and generate speed-time data pairs of the motor under test based on each speed value and each acquisition time. The determination module is used to calculate the instantaneous dissipation power of the rotational kinetic energy of the tested motor based on the speed-time data pair, and to determine the mechanical loss power of the tested motor at different speed values based on the instantaneous dissipation power.
[0014] According to one embodiment of this application, the determining module includes: The calculation unit is used to calculate the rotational kinetic energy-time data pair of the tested motor based on the speed-time data pair; The acquisition unit is used to obtain the instantaneous dissipation power of the rotational kinetic energy based on the rotational kinetic energy-time data pair.
[0015] According to one embodiment of this application, the computing unit is specifically used for: Based on the speed-time data pair, the rotational kinetic energy value of the motor under test at each acquisition moment is calculated; The rotational kinetic energy-time data pair is obtained based on each acquisition time and each rotational kinetic energy value.
[0016] According to one embodiment of this application, the obtaining unit is specifically used for: Polynomial fitting is performed on the rotational kinetic energy-time data pairs to generate a rotational kinetic energy-time relationship function; The instantaneous power dissipation of the rotational kinetic energy is obtained by taking the first derivative of the rotational kinetic energy-time relationship function.
[0017] According to one embodiment of this application, before controlling the tested motor to enter the preset free-fall state, the control module is further configured to: The test motor is driven by a drive motor to run continuously at the target speed for a preset time.
[0018] The device for determining the mechanical losses of a motor according to the embodiments of this application controls the motor under test to enter a preset free-fall state, acquires multiple speed values of the motor under test in the preset free-fall state and the acquisition time corresponding to each speed value, and generates speed-time data pairs of the motor under test based on each speed value and each acquisition time; based on the speed-time data pairs, the instantaneous dissipation power of the rotational kinetic energy of the motor under test is calculated, and the mechanical loss power of the motor under test at different speed values is determined according to the instantaneous dissipation power. This solves the problems of complex, costly, and limited accuracy in mechanical loss measurement caused by the need to separate copper loss, iron loss, and eddy current loss in related technologies, and achieves non-destructive, rapid, and high-precision measurement of the mechanical losses of a motor across the entire speed range.
[0019] To achieve the above objectives, a third aspect of this application 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 method for determining motor mechanical losses as described in the above embodiments.
[0020] To achieve the above objectives, a fourth aspect of this application provides a computer-readable storage medium having a computer program stored thereon, which is executed by a processor to implement the method for determining the mechanical losses of an electric motor as described in the above embodiments.
[0021] Additional aspects and advantages of this application 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 this application. Attached Figure Description
[0022] The above and / or additional aspects and advantages of this application will become apparent and readily understood from the following description of the embodiments taken in conjunction with the accompanying drawings, wherein: Figure 1 This is a flowchart illustrating a method for determining the mechanical losses of an electric motor according to an embodiment of this application. Figure 2 This is a block diagram of a mechanical wear test bench according to an embodiment of the present application; Figure 3 This is a schematic diagram of an electromagnetic clutch system according to an embodiment of this application; Figure 4 This is a schematic diagram illustrating the modification of a motor under test according to an embodiment of this application; Figure 5 This is a schematic diagram illustrating the change of motor speed over time during a free-fall process according to an embodiment of this application; Figure 6 This is a block diagram of a device for determining the mechanical losses of an electric motor according to an embodiment of this application; Figure 7 This is a schematic diagram of the structure of an electronic device provided according to an embodiment of this application. Detailed Implementation
[0023] The embodiments of this application are described in detail below. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain this application, and should not be construed as limiting this application.
[0024] The following describes, with reference to the accompanying drawings, a method, apparatus, electronic device, and storage medium for determining motor mechanical losses according to embodiments of this application. First, the method for determining motor mechanical losses according to embodiments of this application will be described with reference to the accompanying drawings.
[0025] Figure 1 This is a flowchart of a method for determining the mechanical losses of an electric motor according to an embodiment of this application.
[0026] Before introducing the method for determining motor mechanical losses proposed in the embodiments of this application, the mechanical loss test bench involved in this method will be explained first. For example... Figure 2 As shown, the mechanical loss test bench consists of a motor controller, a servo drive motor, the motor under test, an electromagnetic clutch, and a speed sensor. To eliminate electromagnetic interference in the mechanical loss measurement, this embodiment replaces the permanent magnet of the motor rotor with an equivalent magnet of the same mass but without magnetization. This completely eliminates the rotor magnetic field while ensuring the motor's moment of inertia remains constant, effectively avoiding interference from reluctance torque during the free-fall process and eliminating the influence of stator winding AC copper loss and permanent magnet eddy current loss on the mechanical loss measurement results. The electromagnetic clutch and its control system are as follows... Figure 3 As shown, the core of this system includes a switching power supply module, a photoelectric switch, and an electromagnetic clutch body. The switching power supply module converts externally input 220V AC power into stable 24V DC power, providing a reliable operating voltage for the electromagnetic clutch. The photoelectric switch, as a control signal receiving and execution unit, can accurately and quickly connect or disconnect the power supply circuit to the electromagnetic clutch according to instructions from the host computer or controller. The input end of the electromagnetic clutch is connected to the output shaft of the drive motor, while the output end is connected to the input shaft of the motor under test. When the clutch is energized and engaged, the drive motor can drive the motor under test to rotate synchronously; when the clutch is de-energized and disengaged, the motor under test is disengaged from the drive end and enters a pure free-deceleration state. The design of this system enables remote, rapid, and reliable control of the clutch action, which is a key hardware guarantee for ensuring accurate triggering and execution of the free-deceleration experiment.
[0027] For example, such as Figure 1As shown, the method for determining the mechanical losses of this motor includes the following steps: In step S101, the motor under test is controlled to enter a preset free-speed reduction state, wherein the rotor permanent magnet of the motor under test is an unmagnetized magnet.
[0028] Specifically, in Figure 2 The mechanical loss test bench shown is used to perform mechanical loss tests on the motor under test. To ensure the purity and accuracy of the mechanical loss measurement, the electromagnetic clutch is quickly disengaged, completely disconnecting it from the drive source (servo drive motor). This allows the motor under test to enter a pure free deceleration process (i.e., the preset free deceleration state) under ideal conditions of no external power input and no electromagnetic braking interference, where it is only constrained by its own mechanical friction and wind resistance. Before this state is triggered, the key preparatory work is to replace the permanent magnets of the rotor of the motor under test with non-magnetized equivalent magnets of identical mass and shape, such as... Figure 4 As shown. This replacement operation completely eliminates the magnetic field of the permanent magnet while maintaining the rotor system's rotational inertia strictly constant, thereby fundamentally avoiding various electromagnetic losses introduced by reluctance torque, stator winding induced current (AC copper loss), and eddy currents inside the permanent magnet.
[0029] In step S102, multiple speed values of the motor under test under a preset free-speed decrease state and the acquisition time corresponding to each speed value are obtained, and a speed-time data pair of the motor under test is generated based on each speed value and each acquisition time.
[0030] Specifically, after the motor under test enters the preset free-fall state, a high-precision speed sensor (such as a rotary transformer or photoelectric encoder) will immediately activate, continuously acquiring the real-time speed signal (i.e., speed value) of the motor's rotor at a fixed sampling frequency (e.g., 10kHz). The data acquisition system can synchronously bind each speed value to its precisely recorded timestamp (i.e., acquisition time), thereby forming a series of discrete data points arranged in chronological order with a strict correspondence, i.e., speed-time data pairs. n i , t i ),like Figure 5 As shown. This process ensures that each speed value... n i Each uniquely corresponds to a single data acquisition time. t i This constitutes the original time-domain sequence necessary for subsequent kinetic energy calculations and loss analysis.
[0031] In step S103, based on the speed-time data pair, the instantaneous dissipation power of the rotational kinetic energy of the motor under test is calculated, and the mechanical loss power of the motor under test at different speed values is determined according to the instantaneous dissipation power.
[0032] Specifically, based on the speed-time data pairs, the instantaneous rate of change of the rotational kinetic energy of the tested motor at each sampling moment can be calculated. The absolute value of this rate of change characterizes the instantaneous power dissipation (i.e., the instantaneous power dissipation of rotational kinetic energy) caused by mechanical friction and wind resistance at that moment. Subsequently, a mapping relationship between the instantaneous power dissipation and the corresponding speed value is established: P m =f ( n ),in, P m For instantaneous power dissipation, n By taking the rotational speed value, the precise mechanical loss power of the tested motor at different speed points can be determined directly, thereby obtaining a continuous curve reflecting its mechanical loss characteristics across the entire speed range.
[0033] As one possible implementation, in some embodiments, the instantaneous power dissipation of the rotational kinetic energy of the motor under test is calculated based on the speed-time data pair, including: calculating the rotational kinetic energy-time data pair of the motor under test based on the speed-time data pair; and obtaining the instantaneous power dissipation of the rotational kinetic energy based on the rotational kinetic energy-time data pair.
[0034] Specifically, based on the speed-time data pair, the relationship between the rotational kinetic energy of the tested motor and time can be calculated (i.e., the rotational kinetic energy-time data pair). Subsequently, based on the rotational kinetic energy-time data pair, the instantaneous power dissipation of the rotational kinetic energy can be calculated.
[0035] Optionally, in some embodiments, the rotational kinetic energy-time data pair of the motor under test is calculated based on the speed-time data pair, including: calculating the rotational kinetic energy value of the motor under test at each acquisition time based on the speed-time data pair; and obtaining the rotational kinetic energy-time data pair based on each acquisition time and each rotational kinetic energy value.
[0036] Specifically, based on the rotational speed-time data pair, the rotational speed value corresponding to each acquisition moment can be converted into a rotational kinetic energy value, that is:
[0037]
[0038]
[0039] in, The rotational kinetic energy value corresponding to each acquisition moment. Let be the moment of inertia of the motor being tested. The angular velocity of the motor rotor being measured is... The electrical frequency of the motor being tested. The number of pole pairs of the motor being tested.
[0040] Understandably, a high-precision speed sensor (such as a rotary transformer or photoelectric encoder) can be used to first measure the position signal of the rotor of the motor under test. Then, through hardware circuits or software algorithms (such as software processing methods using microprocessors such as DSPs (Digital Signal Processors)), the rotor position signal can be converted into an electrical frequency. Finally, based on the electrical frequency and known pole pairs Calculate the rotational speed of the motor being tested.
[0041] Then, each data collection moment t i Its corresponding rotational kinetic energy E P,i The calculation results were recombined to form a new set of rotational kinetic energy-time data pairs arranged strictly in chronological order. E P,i , t i This data sequence fully characterizes the physical process of the tested motor's rotational kinetic energy continuously decaying over time during free deceleration.
[0042] Optionally, in some embodiments, obtaining the instantaneous dissipation power of rotational kinetic energy based on rotational kinetic energy-time data pairs includes: performing polynomial fitting on the rotational kinetic energy-time data pairs to generate a rotational kinetic energy-time relationship function; and taking the first derivative of the rotational kinetic energy-time relationship function to obtain the instantaneous dissipation power of rotational kinetic energy.
[0043] Specifically, by using a polynomial fitting method on discrete rotational kinetic energy-time data pairs, with time as the independent variable and rotational kinetic energy as the dependent variable, a continuous and smooth polynomial function curve was constructed. This function optimally represents the overall trend of rotational kinetic energy changing with time in a statistical sense.
[0044] Right now:
[0045] in, , , , These are the coefficients obtained by fitting experimental data.
[0046] Subsequently, the first derivative of the fitted function with respect to time is calculated to obtain its derivative function. The physical meaning of this derivative value at any acquisition moment is the instantaneous rate of change of rotational kinetic energy at that acquisition moment. Since there is no energy input to the system during free deceleration, according to the law of conservation of energy, the reduction of the rotational kinetic energy of the tested motor during free deceleration is entirely converted into mechanical loss energy. The absolute value of this instantaneous rate of change directly corresponds to the instantaneous power dissipation of the tested motor at that moment due to mechanical friction and wind resistance, i.e., the instantaneous mechanical loss power. P m :
[0047] Therefore, without relying on a high-precision torque sensor, the mechanical loss characteristic curve of the tested motor can be obtained through only a limited number of free-speed reduction experiments.
[0048] Furthermore, in some embodiments, before controlling the motor under test to enter a preset free-speed deceleration state, the method further includes: driving the motor under test to run continuously at the target speed for a preset time by a drive motor.
[0049] Specifically, before controlling the motor under test to enter the preset free-fall speed state, there is also a preliminary dragging and stabilization process, that is, using... Figure 2 The servo drive motor in the mechanical loss test bench shown accelerates and stabilizes the motor under test at the target speed, and maintains this state for a preset period of time to ensure that the rotor of the motor under test reaches a state of thermal stability and mechanical balance, eliminating the influence of transient processes on subsequent free-fall speed data, thus laying the foundation for obtaining a clean and repeatable free-fall speed kinetic energy decay curve.
[0050] According to the method for determining the mechanical losses of a motor proposed in this application, the motor under test is controlled to enter a preset free-fall state. Multiple speed values of the motor under test in the preset free-fall state and the corresponding acquisition time for each speed value are obtained. Based on each speed value and each acquisition time, a speed-time data pair of the motor under test is generated. Based on the speed-time data pair, the instantaneous dissipation power of the rotational kinetic energy of the motor under test is calculated, and the mechanical loss power of the motor under test at different speed values is determined based on the instantaneous dissipation power. This solves the problems of complex, costly, and limited accuracy in mechanical loss measurement caused by the need to separate copper loss, iron loss, and eddy current loss in related technologies, and achieves non-destructive, rapid, and high-precision measurement of the mechanical losses of a motor across its entire speed range.
[0051] Next, the apparatus for determining the mechanical losses of an electric motor according to an embodiment of this application is described with reference to the accompanying drawings.
[0052] Figure 6This is a block diagram of a device for determining the mechanical losses of an electric motor according to an embodiment of this application.
[0053] like Figure 6 As shown, the device 10 for determining the mechanical loss of the motor includes: a control module 100, a generation module 200, and a determination module 300.
[0054] The control module 100 is used to control the motor under test to enter a preset free-speed reduction state, wherein the rotor permanent magnet of the motor under test is a non-magnetized magnet. The generation module 200 is used to acquire multiple speed values of the motor under test in a preset free-speed-reduction state and the acquisition time corresponding to each speed value, and generate speed-time data pairs of the motor under test based on each speed value and each acquisition time. The determination module 300 is used to calculate the instantaneous dissipation power of the rotational kinetic energy of the motor under test based on the speed-time data pair, and to determine the mechanical loss power of the motor under test at different speed values based on the instantaneous dissipation power.
[0055] Optionally, in some embodiments, the determining module 300 includes: The calculation unit is used to calculate the rotational kinetic energy-time data pair of the motor under test based on the speed-time data pair; The acquisition unit is used to obtain the instantaneous dissipation power of rotational kinetic energy based on rotational kinetic energy-time data pairs.
[0056] Optionally, in some embodiments, the computing unit is specifically used for: Based on the speed-time data pair, the rotational kinetic energy value of the motor under test at each acquisition moment is calculated; Based on each acquisition time and each rotational kinetic energy value, rotational kinetic energy-time data pairs are obtained.
[0057] Optionally, in some embodiments, the obtaining unit is specifically used for: Polynomial fitting is performed on the rotational kinetic energy-time data pairs to generate a rotational kinetic energy-time relationship function; By taking the first derivative of the rotational kinetic energy-time relationship function, the instantaneous power dissipation of rotational kinetic energy is obtained.
[0058] Optionally, in some embodiments, before controlling the motor under test to enter a preset free-fall state, the control module 100 is further configured to: The test motor is driven by a drive motor to run continuously at the target speed for a preset time.
[0059] It should be noted that the explanation of the aforementioned method for determining motor mechanical losses also applies to the device for determining motor mechanical losses in this embodiment, and will not be repeated here.
[0060] The device for determining the mechanical losses of a motor according to the embodiments of this application controls the motor under test to enter a preset free-fall state, acquires multiple speed values of the motor under test in the preset free-fall state and the acquisition time corresponding to each speed value, and generates speed-time data pairs of the motor under test based on each speed value and each acquisition time; based on the speed-time data pairs, the instantaneous dissipation power of the rotational kinetic energy of the motor under test is calculated, and the mechanical loss power of the motor under test at different speed values is determined according to the instantaneous dissipation power. This solves the problems of complex, costly, and limited accuracy in mechanical loss measurement caused by the need to separate copper loss, iron loss, and eddy current loss in related technologies, and achieves non-destructive, rapid, and high-precision measurement of the mechanical losses of a motor across the entire speed range.
[0061] Figure 7 A schematic diagram of the structure of an electronic device provided in an embodiment of this application. The electronic device may include: The memory 701, the processor 702, and the computer program stored on the memory 701 and executable on the processor 702.
[0062] When the processor 702 executes the program, it implements the method for determining the mechanical loss of the motor provided in the above embodiments.
[0063] Furthermore, electronic devices also include: Communication interface 703 is used for communication between memory 701 and processor 702.
[0064] The memory 701 is used to store computer programs that can run on the processor 702.
[0065] The memory 701 may include high-speed RAM (Random Access Memory) memory, and may also include non-volatile memory, such as at least one disk storage.
[0066] If the memory 701, processor 702, and communication interface 703 are implemented independently, then the communication interface 703, memory 701, and processor 702 can be interconnected via a bus to complete communication between them. The bus can be an ISA (Industry Standard Architecture) bus, a PCI (Peripheral Component Interconnect) bus, or an EISA (Extended Industry Standard Architecture) bus, etc. The bus can be divided into address bus, data bus, control bus, etc. For ease of representation, Figure 7The bus is represented by a single thick line, but this does not mean that there is only one bus or one type of bus.
[0067] Optionally, in a specific implementation, if the memory 701, processor 702, and communication interface 703 are integrated on a single chip, then the memory 701, processor 702, and communication interface 703 can communicate with each other through an internal interface.
[0068] The processor 702 may be a CPU (Central Processing Unit), an ASIC (Application Specific Integrated Circuit), or one or more integrated circuits configured to implement the embodiments of this application.
[0069] This application also provides a computer-readable storage medium storing a computer program thereon, which, when executed by a processor, implements the above-described method for determining motor mechanical losses.
[0070] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.
[0071] 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 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. 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.
[0072] 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 determining the mechanical losses of an electric motor, characterized in that, Includes the following steps: The motor under test is controlled to enter a preset free deceleration state, wherein the rotor permanent magnet of the motor under test is a non-magnetized magnet; The test motor acquires multiple speed values and the acquisition time corresponding to each speed value under the preset free-speed-decline state, and generates speed-time data pairs of the test motor based on each speed value and each acquisition time. Based on the speed-time data pair, the instantaneous power dissipation of the rotational kinetic energy of the tested motor is calculated, and the mechanical loss power of the tested motor at different speed values is determined according to the instantaneous power dissipation.
2. The method according to claim 1, characterized in that, The calculation of the instantaneous power dissipation of the rotational kinetic energy of the tested motor based on the speed-time data pair includes: Based on the speed-time data pair, calculate the rotational kinetic energy-time data pair of the tested motor; Based on the rotational kinetic energy-time data pair, the instantaneous power dissipation of the rotational kinetic energy is obtained.
3. The method according to claim 2, characterized in that, The calculation of the rotational kinetic energy-time data pair of the tested motor based on the speed-time data pair includes: Based on the speed-time data pair, the rotational kinetic energy value of the motor under test at each acquisition moment is calculated; The rotational kinetic energy-time data pair is obtained based on each acquisition time and each rotational kinetic energy value.
4. The method according to claim 2, characterized in that, The step of obtaining the instantaneous power dissipation of the rotational kinetic energy based on the rotational kinetic energy-time data pair includes: Polynomial fitting is performed on the rotational kinetic energy-time data pairs to generate a rotational kinetic energy-time relationship function; The instantaneous power dissipation of the rotational kinetic energy is obtained by taking the first derivative of the rotational kinetic energy-time relationship function.
5. The method according to claim 1 or 4, characterized in that, Before controlling the tested motor to enter the preset free-fall state, the method further includes: The test motor is driven by a drive motor to run continuously at the target speed for a preset time.
6. A device for determining the mechanical losses of an electric motor, characterized in that, include: The control module is used to control the motor under test to enter a preset free deceleration state, wherein the rotor permanent magnet of the motor under test is a non-magnetized magnet. The generation module is used to acquire multiple speed values of the motor under test in the preset free-speed-decline state and the acquisition time corresponding to each speed value, and generate speed-time data pairs of the motor under test based on each speed value and each acquisition time. The determination module is used to calculate the instantaneous dissipation power of the rotational kinetic energy of the tested motor based on the speed-time data pair, and to determine the mechanical loss power of the tested motor at different speed values based on the instantaneous dissipation power.
7. The apparatus according to claim 6, characterized in that, The determining module includes: The calculation unit is used to calculate the rotational kinetic energy-time data pair of the tested motor based on the speed-time data pair; The acquisition unit is used to obtain the instantaneous dissipation power of the rotational kinetic energy based on the rotational kinetic energy-time data pair.
8. The apparatus according to claim 7, characterized in that, The computing unit is specifically used for: Based on the speed-time data pair, the rotational kinetic energy value of the motor under test at each acquisition moment is calculated; The rotational kinetic energy-time data pair is obtained based on each acquisition time and each rotational kinetic energy value.
9. An electronic device, characterized in that, include: A memory, a processor, and a computer program stored in the memory and executable on the processor, the processor executing the program to implement the method for determining the mechanical losses of an electric motor as described in any one of claims 1-5.
10. A computer-readable storage medium having a computer program stored thereon, characterized in that, The program is executed by the processor to implement the method for determining the mechanical losses of an electric motor as described in any one of claims 1-5.