Motor zero torque control method and related equipment

Abstract

This specification relates to the field of vehicle development and testing, and more specifically, the present invention relates to a motor zero torque control method and related equipment. The motor zero torque control method includes: obtaining the vehicle state; when the vehicle is in a gliding state, detecting the torque of the motor; when the torque of the motor is not zero, controlling the IGBT power module of the motor controller to disconnect, thereby limiting the output of three currents to the motor, so that the output torque of the motor is 0, avoiding the influence of factors such as ambient temperature, calibration accuracy and coupled reduction box on the vehicle's gliding zero torque, and in the vehicle gliding resistance test, it will not be disturbed by torque fluctuation resistance, making the test data more accurate. Compared with the existing bench calibration method, there is no need to calibrate the current value of the motor zero torque at each speed, which can save time, shorten the research and development cycle, and facilitate subsequent vehicle power and economy research.

Description

Technical Field

[0001] The present specification relates to the field of vehicle development and testing, and more specifically, the present invention relates to a motor zero torque control method and related equipment. Background Art

[0002] In the development process of new energy vehicles, the research on energy consumption, cruising range, power performance, and economic performance are all based on the premise of the sliding resistance test. In the sliding test of new energy vehicles, the time and speed during neutral sliding are collected, and the functional relationship between the vehicle's resistance and the sliding speed is further processed to obtain the vehicle's sliding resistance. The sliding resistance of the vehicle mainly includes rolling resistance and air resistance, but in the actual sliding state, due to the insufficient precision of the traditional motor zero torque control, the sliding resistance of the vehicle also includes zero torque fluctuation resistance, which leads to large fluctuations in the sliding resistance and large discreteness of the sliding damping curve, which ultimately makes it difficult to pass the sliding resistance test.

[0003] At present, the commonly used zero torque control method is to first calibrate the current value of the motor's zero torque at various speeds through a test bench and write it into the motor controller. When the motor controller receives the zero torque command sent by the VCU, it searches for and drives the motor according to the calibrated current value. However, the output torque of this method is greatly affected by the motor and ambient temperature, calibration accuracy, and the electric drive assembly on new energy vehicles is coupled with a reduction gearbox, so the actual torque output is difficult to stabilize at 0Nm.

[0004] Therefore, it is necessary to propose a motor zero torque control method to at least partially solve the problems existing in the prior art. Summary of the invention

[0005] A series of simplified concepts are introduced in the Summary of the Invention, which will be further described in detail in the Detailed Description of the Invention. The Summary of the Invention does not mean to attempt to define the key features and essential technical features of the claimed technical solution, nor does it mean to attempt to determine the scope of protection of the claimed technical solution.

[0006] In order to at least partially solve the above problems, in a first aspect, the present invention provides a motor zero torque control method, the method comprising:

[0007] Get vehicle status;

[0008] When the vehicle is in a coasting state, detecting the torque of the motor;

[0009] When the torque of the motor is not zero, the IGBT power module of the motor controller is disconnected.

[0010] Optionally, when the torque of the motor is not zero, the step of controlling the IGBT power module of the motor controller to disconnect includes:

[0011] Get the status of the high-voltage relay of the power battery;

[0012] When the high-voltage relay is in a closed state, the high-voltage relay is disconnected, and then the IGBT power module is controlled to be disconnected.

[0013] Optionally, when the high-voltage relay is closed, the step of disconnecting the high-voltage relay and then controlling the IGBT power module to disconnect comprises:

[0014] Obtaining the back electromotive force of the vehicle;

[0015] The back electromotive force is compared with the rated bus voltage, and when the back electromotive force exceeds the rated bus voltage, the high-voltage relay is disconnected.

[0016] Optionally, the step of obtaining the back electromotive force of the vehicle includes:

[0017] The rotation speed of the vehicle is obtained, and the back electromotive force is determined according to the rotation speed.

[0018] Optionally, the rotational speed is directly proportional to the back electromotive force.

[0019] In a second aspect, the present invention further proposes a computer-readable storage medium having a computer program stored thereon, and when the computer program is executed by a processor, the method for determining a target trajectory based on a mobile platform as described in any one of the above items in the first aspect is implemented.

[0020] In a third aspect, the present invention further provides a control device, comprising:

[0021] a memory storing a computer program;

[0022] A processor, for executing the above-mentioned computer program;

[0023] Wherein, when executing the above-mentioned computer program, the above-mentioned processor implements any one of the above-mentioned motor zero torque control methods.

[0024] In a fourth aspect, the present invention further provides an electric drive system, comprising:

[0025] Motor;

[0026] A power battery, the power battery is connected to the motor and is used to provide high voltage electricity to the motor;

[0027] A motor controller connected to the motor;

[0028] The above-mentioned control device controls the working states of the above-mentioned power battery and the above-mentioned motor controller based on the above-mentioned motor torque value.

[0029] Optionally, the motor controller includes:

[0030] IGBT power module, the above-mentioned IGBT power module includes multiple switch tubes, and the multiple switch tubes are respectively connected to the above-mentioned motors.

[0031] Optionally, the power battery includes a high-voltage relay electrically connected to the motor.

[0032] In summary, this solution obtains the vehicle status, detects the torque of the motor when the vehicle is in the gliding state, and controls the IGBT power module of the motor controller to disconnect when the torque of the motor is not zero, thereby limiting the output of the three currents to the motor, so that the output torque of the motor is stabilized to 0, avoiding the influence of factors such as ambient temperature, calibration accuracy and coupled reduction box on the vehicle's gliding zero torque. In the vehicle gliding resistance test, it will not be disturbed by torque fluctuation resistance, making the test data more accurate. Compared with the existing bench calibration method, there is no need to calibrate the current value of the motor's zero torque at each speed, which can save time, shorten the R&D cycle, and facilitate subsequent vehicle power and economy research.

[0033] The motor zero torque control method of the present invention, and other advantages, objectives and features of the present invention will be reflected in part through the following description, and in part will be understood by those skilled in the art through research and practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Various other advantages and benefits will become apparent to those of ordinary skill in the art by reading the detailed description of the preferred embodiments below. The accompanying drawings are only for the purpose of illustrating the preferred embodiments and are not to be considered as limiting the present specification. Also, the same reference symbols are used throughout the accompanying drawings to represent the same components. In the accompanying drawings:

[0035] Figure 1 A schematic flow chart of a motor zero torque control method provided in an embodiment of the present application;

[0036] Figure 2 A block diagram of a computer-readable storage medium provided in an embodiment of the present application;

[0037] Figure 3 A structural block diagram of a control device provided in an embodiment of the present application;

[0038] Figure 4 A schematic diagram of the structure of an electric drive system provided in an embodiment of the present application.

[0039] in, Figure 4 The corresponding relationship between the reference numerals and the component names is as follows:

[0040] 200 electric drive system, 210 motor, 220 power battery, 221 high-voltage relay, 230 motor controller, 231 switch tube. DETAILED DESCRIPTION

[0041] The embodiments of the present application provide a target trajectory determination method based on a mobile platform and related equipment, which combine the advantages of the volumetric Kalman algorithm and the interactive multi-model algorithm, can not only reduce the impact of noise on motion trajectory determination, but also accurately track targets with complex motion trajectories and strong maneuverability.

[0042] The terms "first", "second", "third", "fourth", etc. (if any) in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchangeable where appropriate, so that the embodiments described herein can be implemented in an order other than that illustrated or described herein. In addition, the terms "including" and "having" and any of their variations 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 necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices. The technical solutions 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, rather than all of the embodiments.

[0043] See also Figure 1 , is a flow chart of a motor zero torque control method provided in an embodiment of the present application, which may specifically include:

[0044] S110, obtaining vehicle status;

[0045] Specifically, the state of the vehicle is acquired according to the current gear position of the test vehicle.

[0046] S120, when the vehicle is in a coasting state, detecting the torque of the motor;

[0047] Specifically, in the coasting test of the vehicle, when the vehicle is in the N gear, i.e. the coasting state, the torque of the motor is detected. It is understandable that during the coasting process of the vehicle, the actual torque output is difficult to stabilize at 0N.m due to the influence of factors such as the motor model, working state and ambient temperature. The coasting resistance test is inevitably affected by the torque fluctuation resistance. Therefore, it is necessary to detect the current torque of the motor in order to adjust the torque later.

[0048] S130: When the torque of the motor is not zero, the IGBT (Insulated Gate Bipolar Transistor) power module of the motor controller is disconnected.

[0049] When it is detected that the current torque of the motor is not zero, the IGBT power module of the motor controller is controlled to be disconnected to stabilize the torque of the motor to 0. Specifically, the motor controller adjusts the PWM (Pulse width modulation) duty cycle through the IGBT power module to control the output of the three-phase current, thereby driving the motor. When it is detected that the current torque of the motor is not zero, the IGBT power module is controlled to be turned off, so that no three-phase current is output to the motor, and the output torque of the motor is stabilized to 0.

[0050] In summary, this method controls the torque of the motor by controlling the IGBT power module, so that the torque of the motor is 0, avoiding the influence of factors such as ambient temperature, calibration accuracy and coupled reduction box on the vehicle's coasting zero torque. In the vehicle coasting resistance test, it will not be disturbed by torque fluctuation resistance, making the test data more accurate. Compared with the existing bench calibration method, there is no need to calibrate the current value of the motor's zero torque at each speed, which can save time, shorten the R&D cycle, and facilitate subsequent vehicle power and economy research.

[0051] Exemplarily, a torque sensor may be used to detect the torque of the motor.

[0052] It is understandable that in the coasting test, by collecting the time and speed of the vehicle during the neutral coasting process, further processing is performed to obtain the functional relationship between the vehicle's resistance during the coasting process and the coasting speed, so as to further study the energy consumption, cruising range, power performance, and economic performance.

[0053] In some examples, when the torque of the motor is not zero, the step of controlling the IGBT power module of the motor controller to disconnect includes:

[0054] Obtain the state of the high-voltage relay of the power battery; when the high-voltage relay is closed, disconnect the high-voltage relay, and then control the IGBT power module to disconnect.

[0055] Specifically, when it is detected that the torque of the motor is not zero, before the IGBT power module of the motor controller is disconnected, the current state of the high-voltage relay of the power battery is obtained. When it is detected that the current state of the high-voltage relay is closed, the high-voltage relay is disconnected first, and then the above-mentioned IGBT power module is controlled to be disconnected. When it is detected that the current state of the high-voltage relay is disconnected, the above-mentioned IGBT power module is directly controlled to be disconnected. It can be understood that when the motor rotates, a back electromotive force is generated. When the back electromotive force exceeds the rated bus voltage, uncontrolled rectification will occur. Uncontrolled rectification reversely charges the power battery, and there is a risk of burning the triode of the IGBT power module, and even causing the power battery to be overcharged, causing damage to the equipment. Therefore, disconnecting the high-voltage relay first can reduce the back electromotive force so that it does not exceed the rated bus voltage, reduce the occurrence of the above-mentioned risk situations, protect the test equipment, and increase the service life.

[0056] In some examples, when the high-voltage relay is closed, the step of disconnecting the high-voltage relay and then controlling the IGBT power module to disconnect includes: obtaining the back electromotive force of the vehicle; comparing the back electromotive force with the rated bus voltage, and when the back electromotive force exceeds the rated bus voltage, disconnecting the high-voltage relay.

[0057] Specifically, after obtaining the back electromotive force of the vehicle, the back electromotive force is compared with the rated bus voltage to decide whether to disconnect the high-voltage relay. When the back electromotive force exceeds the rated bus voltage, the high-voltage relay is disconnected, and when the back electromotive force does not exceed the rated bus voltage, the high-voltage relay is kept closed. This is to avoid uncontrolled rectification and reverse charging of the power battery, so as to protect the test equipment and increase its service life.

[0058] For example, after the IGBT power module is disconnected to ensure that the torque of the motor is stable at 0, the state of the high-voltage relay is continuously detected through the BMS (Battery Management System). When the high-voltage relay is in a closed state, it is kept closed until the end of the coasting. When the high-voltage relay is in a disconnected state, it means that the back electromotive force still exceeds the rated bus voltage, and the back electromotive force needs to be further reduced until it does not exceed the rated bus voltage, and then the high-voltage relay is closed. This prevents the power battery from being in a closed state for a long time and the untimely response to emergencies, thereby improving safety.

[0059] In some examples, the step of obtaining the back electromotive force of the vehicle includes: obtaining the rotation speed of the vehicle, and determining the back electromotive force according to the rotation speed.

[0060] Specifically, the back electromotive force of the vehicle can be obtained according to the speed of the vehicle. It is only necessary to measure the current speed of the vehicle to calculate the current back electromotive force of the vehicle. It is understandable that the back electromotive force of the motor can be calibrated in advance according to different speeds, and the corresponding relationship between the speed and the back electromotive force can be determined. And the calibration data can be made into a table according to the corresponding relationship and written into the MCU (Microcontroller Unit) to facilitate subsequent test retrieval, improve test efficiency, and shorten the development cycle.

[0061] In some examples, the rotational speed is directly proportional to the back electromotive force.

[0062] It is understandable that the faster the motor speed, the greater the back EMF of the motor, and the speed and back EMF are proportional. At the beginning of the sliding resistance test, the vehicle speed is generally above 1,000 meters per hour, and the motor speed is too high. At this time, the back EMF exceeds the rated bus voltage. At this time, the high-voltage relay is disconnected to stabilize the motor zero torque while avoiding uncontrolled rectification. During the sliding process, the vehicle speed decreases, the motor speed also decreases, and then the back EMF of the motor is also degraded. When the back EMF does not exceed the rated bus voltage, the high-voltage relay can be closed to ensure that the power battery supplies power to the motor, so as to respond at any time and improve safety.

[0063] like Figure 2 As shown, according to the second aspect of the embodiment of the present application, a computer-readable storage medium 401 is proposed, and the computer-readable storage medium 401 stores a computer program 402 to implement the motor zero torque control method of any of the above technical solutions.

[0064] The computer-readable storage medium 401 provided in the embodiment of the present application obtains the state of the vehicle after the vehicle is started, detects the torque of the motor when the vehicle is in the gliding state, and controls the IGBT power module of the motor controller to disconnect when the torque of the motor is not zero, thereby limiting the output of three currents to the motor, so that the output torque of the motor is stabilized to 0, avoiding the influence of factors such as ambient temperature, calibration accuracy and coupled reduction box on the vehicle's gliding zero torque, and in the vehicle gliding resistance test, it will not be disturbed by torque fluctuation resistance, making the test data more accurate. Compared with the existing bench calibration method, there is no need to calibrate the current value of the motor's zero torque at each speed, which can save time, shorten the research and development cycle, and facilitate subsequent vehicle power and economy research.

[0065] Based on this understanding, the technical solution of the present application can be embodied in the form of a software product, which can be stored in a non-volatile storage medium (which can be a CD-ROM, a USB flash drive, a mobile hard disk, etc.), and includes a number of instructions for enabling a computer device (which can be a personal computer, a server, or a network device, etc.) to execute the methods described in each implementation scenario of the present application.

[0066] like Figure 3 As shown, according to the third aspect of an embodiment of the present application, a control device 500 is proposed, comprising: a memory 501, storing a computer program; a processor 502, executing the computer program; wherein, when the processor 502 executes the computer program, the motor zero torque control method of any of the above-mentioned technical solutions is implemented.

[0067] The control device 500 provided in the embodiment of the present application obtains the state of the vehicle after the vehicle is started, detects the torque of the motor when the vehicle is in the gliding state, and controls the IGBT power module of the motor controller to disconnect when the torque of the motor is not zero, thereby limiting the output of three currents to the motor, so that the output torque of the motor is stabilized to 0, avoiding the influence of factors such as ambient temperature, calibration accuracy and coupled reduction box on the vehicle's gliding zero torque, and in the vehicle gliding resistance test, it will not be disturbed by torque fluctuation resistance, making the test data more accurate. Compared with the existing bench calibration method, there is no need to calibrate the current value of the motor's zero torque at each speed, which can save time, shorten the research and development cycle, and facilitate subsequent vehicle power and economy research.

[0068] In some examples, the control device 500 may also include a user interface, a network interface, a camera, a radio frequency (RF) circuit, a sensor, an audio circuit, a WI-FI module, etc. The user interface may include a display, an input unit such as a keyboard, etc., and the optional user interface may also include a USB interface, a card reader interface, etc. The network interface may optionally include a standard wired interface, a wireless interface (such as a WI-FI interface), etc.

[0069] In an exemplary embodiment, the control device 500 may also include an input / output interface and a display device, wherein each functional unit may communicate with each other via a bus. The memory stores a computer program, and the processor is used to execute the program stored in the memory and execute the method in the above embodiment.

[0070] The storage medium may also include an operating system and a network communication module. The operating system is a program that manages the hardware and software resources of the physical device of the method, and supports the operation of the information processing program and other software and / or programs. The network communication module is used to realize the communication between the components inside the storage medium, and the communication with other hardware and software in the information processing physical device.

[0071] Through the description of the above implementation methods, those skilled in the art can clearly understand that the present application can be implemented by means of software plus a necessary general hardware platform, or by hardware.

[0072] like Figure 4 As shown, according to the fourth aspect of an embodiment of the present application, an electric drive system 200 is proposed, including: a motor 210; a power battery 220, the power battery 220 is connected to the motor 210, and is used to provide high voltage electricity to the motor 210; a motor controller 230, connected to the motor 210; and the above-mentioned control device, which controls the working states of the power battery 220 and the motor controller 230 based on the torque value of the motor 210.

[0073] Specifically, the electric drive system 200 is provided with a motor 210, a power battery 220 and a motor controller 230, wherein the power battery 220 is connected to the motor 210 to provide high voltage electricity to the above-mentioned motor 210; the motor controller 230 is connected to the motor 210, and the motor controller 230 can control the three-phase current input to the motor 210 by adjusting the PWM duty cycle to adjust the torque of the motor 210, thereby avoiding the torque of the motor 210 from being affected by factors such as ambient temperature, calibration accuracy and coupled reduction box, thereby ensuring that the motor 210 is stable in a zero torque state during the vehicle sliding resistance test.

[0074] It is understandable that after the control device obtains the torque value of the vehicle, when it is determined that the torque of the vehicle is not zero, the control device controls the motor controller 230 to adjust the three-phase current value of the input motor 210 so that the three-phase current value of the input motor 210 is zero, thereby making the torque of the motor 210 zero, making the vehicle sliding resistance test data more accurate, and in the test, it will not be disturbed by the torque fluctuation resistance, making the test data more accurate. Compared with the existing bench calibration method, there is no need to calibrate the current value of the zero torque of the motor 210 at each speed, which can save time, shorten the research and development cycle, and facilitate subsequent vehicle power and economy research.

[0075] like Figure 4 As shown, the motor controller 230 includes an IGBT power module. The IGBT power module includes a plurality of switch tubes 231 . The plurality of switch tubes 231 are respectively connected to the motor 210 .

[0076] Specifically, the motor controller 230 is provided with an IGBT power module, which controls the three-phase current input to the motor 210. Furthermore, the IGBT power module is provided with multiple switch tubes 231, and the multiple switch tubes 231 are respectively connected to the motor 210, and the opening and closing states of each switch tube 231 can be adjusted individually to adjust the three-phase current value input to the motor 210. When all the multiple switch tubes 231 are disconnected, the three-phase current value input to the motor 210 is zero, so that the torque of the motor 210 is zero, making the vehicle sliding resistance test data more accurate.

[0077] It can be understood that the opening and closing of the plurality of switch tubes 231 are controlled by the control device.

[0078] like Figure 4 As shown, the power battery 220 includes a high-voltage relay 221 electrically connected to the motor 210 .

[0079] Specifically, the power battery 220 is provided with a high-voltage relay 221, which is electrically connected to the motor 210 to control the power supply of the power battery 220 to the motor 210. When the high-voltage relay 221 is closed, the power battery 220 supplies power to the motor 210. When the high-voltage relay 221 is disconnected, the power battery 220 stops supplying power to the motor 210.

[0080] It is understandable that the control device determines the current back electromotive force of the vehicle based on the acquired vehicle speed. When the back electromotive force exceeds the rated bus voltage, the control device controls the high-voltage relay 221 to disconnect, and the power battery 220 stops supplying power to the motor 210. When the back electromotive force does not exceed the rated bus voltage, the control device controls the high-voltage relay 221 to close, and the power battery 220 supplies power to the motor 210.

[0081] In the description of the present invention, it is necessary to understand that the orientation or positional relationship indicated by the terms "upper", "lower", "left", "right", "front", "back", etc. is based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or unit referred to must have a specific direction, be constructed and operated in a specific orientation, and therefore, cannot be understood as a limitation on the present invention. In the description of this specification, the description of the terms "one embodiment", "some embodiments", "specific embodiments", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0082] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A motor zero torque control method, characterized in that: include: Get vehicle status; When the vehicle is in a coasting state, detecting the torque of the motor; When the torque of the motor is not zero, the IGBT power module of the motor controller is controlled to be disconnected; When the torque of the motor is not zero, the step of controlling the IGBT power module of the motor controller to disconnect comprises: Get the status of the high-voltage relay of the power battery; When the high-voltage relay is in a closed state, disconnecting the high-voltage relay, and then controlling the IGBT power module to disconnect; When the high-voltage relay is disconnected, directly controlling the IGBT power module to disconnect; Among them, when the IGBT power module is disconnected to stabilize the torque of the motor at 0, the state of the high-voltage relay continues to be detected through the BMS. When the high-voltage relay is in a closed state, the high-voltage relay remains in a closed state until the coasting ends; when the high-voltage relay is in an open state, the back electromotive force continues to be reduced until the back electromotive force is less than or equal to the rated bus voltage, and then the high-voltage relay is closed.

2. The motor zero torque control method according to claim 1, characterized in that: The step of disconnecting the high-voltage relay and then controlling the IGBT power module to disconnect when the high-voltage relay is closed comprises: obtaining a back electromotive force of the vehicle; The back electromotive force is compared with the rated bus voltage, and when the back electromotive force exceeds the rated bus voltage, the high-voltage relay is disconnected.

3. The motor zero torque control method according to claim 2, characterized in that: The step of obtaining the back electromotive force of the vehicle comprises: The rotation speed of the vehicle is acquired, and the back electromotive force is determined according to the rotation speed.

4. The motor zero torque control method according to claim 3, characterized in that: The rotation speed is directly proportional to the back electromotive force.

5. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the motor zero torque control method according to any one of claims 1 to 4 is implemented.

6. A control device, characterized in that: include: a memory storing a computer program; A processor, configured to execute the computer program; Wherein, when executing the computer program, the processor implements the motor zero torque control method as described in any one of claims 1 to 4.

7. An electric drive system, characterized in that: include: Motor; A power battery, the power battery is connected to the motor and is used to provide high voltage electricity to the motor; A motor controller connected to the motor; The control device as claimed in claim 6, wherein the control device controls the operating states of the power battery and the motor controller based on the motor torque value.

8. The electric drive system according to claim 7, characterized in that: The motor controller comprises: IGBT power module, the IGBT power module includes multiple switch tubes, and the multiple switch tubes are respectively connected to the motor.

9. The electric drive system according to claim 8, characterized in that: The power battery comprises: A high voltage relay is electrically connected to the motor.

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