Electric vehicle and motor drive system thereof

Abstract

The present application is applicable to the technical field of electric vehicles, and provides an electric vehicle and its motor drive system, including a battery management system, a circuit breaker, a motor driver, a motor brake device and a control system; the battery management system is connected in communication with the control system, electrically connected with the battery, obtains the input current and output voltage of the battery and sends them to the control system; the front end of the circuit breaker is electrically connected with the battery, and the rear end is electrically connected with the motor driver and the control system; the motor driver is electrically connected with the motor brake device and the motor, obtains its own input voltage and sends it to the control system; the control system is connected in communication with the motor driver and electrically connected with the motor brake device, and when the input current of the battery is greater than or equal to 0 and the difference between the input voltage of the motor driver and the output voltage of the battery is greater than a preset voltage threshold, the motor brake device is directly controlled to brake the motor. The present application can be used for emergency braking when the electric vehicle is sliding down a slope to avoid safety accidents.

Description

Technical Field

[0001] The present application belongs to the technical field of electric vehicles, and in particular, relates to an electric vehicle and a motor drive system thereof. Background Art

[0002] Electric vehicles powered by batteries are prone to sliding down a slope when the power system fails. At this time, the motor will also generate a large amount of back electromotive force energy. In addition to powering the electric vehicle, this excess energy will be absorbed by the battery when the battery input circuit is normal. In this case, the power system is unstable and easily out of control, causing safety accidents. Summary of the invention

[0003] The embodiments of the present application provide an electric vehicle and a motor drive system thereof, which are intended to solve the problem that the power system of the electric vehicle is unstable and prone to loss of control when sliding down a slope, causing safety accidents.

[0004] A first aspect of an embodiment of the present application provides a motor drive system for an electric vehicle, including a battery management system, a circuit breaker, a motor driver, a motor brake device, and a control system;

[0005] The battery management system is communicatively connected to the control system and is configured to be electrically connected to the battery to obtain the input current and output voltage of the battery and send them to the control system;

[0006] The front end of the circuit breaker is configured to be electrically connected to the battery, the rear end of the circuit breaker is electrically connected to the motor driver and the control system, and the circuit breaker is configured to be disconnected when the output current of the battery is greater than a preset current threshold;

[0007] The motor driver is electrically connected to the motor brake device, and is configured to be electrically connected to the motor to drive the motor, obtain its own input voltage and send it to the control system;

[0008] The control system is communicatively connected to the motor driver and electrically connected to the motor brake device, and is configured to directly control the motor brake device to brake the motor when the input current of the battery is greater than or equal to 0 and the difference between the input voltage of the motor driver and the output voltage of the battery is greater than a preset voltage threshold.

[0009] In one embodiment, the battery management system is communicatively connected to the control system via a first CAN bus, and the motor driver is communicatively connected to the control system via a second CAN bus.

[0010] In one embodiment, the motor braking device includes an electromagnetic brake;

[0011] The control system is configured to directly control the electromagnetic brake to cut off power to brake the motor when the input current of the battery is greater than or equal to 0 and the difference between the input voltage of the motor driver and the output voltage of the battery is greater than a preset voltage threshold.

[0012] In one embodiment, the motor drive system further includes a switch module;

[0013] The first end, the second end and the controlled end of the switch module are electrically connected to the rear end of the circuit breaker, the motor driver and the control system in a one-to-one correspondence, respectively, and are configured to be opened or closed under the control of the control system to connect or disconnect the electrical connection path between the motor driver and the battery when the circuit breaker is closed.

[0014] In one embodiment, the switch module includes a field effect tube, and the input end, the output end and the gate of the field effect tube respectively constitute the first end, the second end and the controlled end of the switch module.

[0015] In one embodiment, the battery management system is further configured to:

[0016] Obtaining the output current and temperature of the battery and sending them to the control system;

[0017] When the output current, output voltage or temperature of the battery is abnormal, corresponding alarm information is sent to the control system.

[0018] In one embodiment, the motor driver is further configured to:

[0019] Get its own output voltage and send it to the control system;

[0020] When an abnormality occurs in its input voltage or output voltage, a corresponding alarm message is sent to the control system.

[0021] In one embodiment, the motor drive system further includes an inertial measurement unit and a motor encoder;

[0022] The inertial measurement unit is in communication with the control system and is configured to obtain the inclination data of the electric vehicle and send it to the control system;

[0023] The motor encoder is communicatively connected to the motor driver and is configured to obtain operating data of the electric vehicle and send the data to the motor driver;

[0024] The motor driver is further configured to send the operating data to the control system;

[0025] The control system is also configured to:

[0026] Acquiring the inclination angle of the electric vehicle relative to the horizontal according to the inclination angle data;

[0027] Acquiring a running speed of the electric vehicle according to the running data;

[0028] The preset voltage threshold is obtained according to the inclination angle, the running speed and a preset corresponding relationship, wherein the preset corresponding relationship is a corresponding relationship between different inclination angles and different running speeds of the electric vehicle and different preset voltage thresholds.

[0029] In one embodiment, the inertial measurement unit is communicatively connected to the control system via a third CAN bus, and the motor encoder is communicatively connected to the motor driver via a fourth CAN bus.

[0030] A second aspect of an embodiment of the present application provides an electric vehicle, comprising a battery, a motor, and the motor drive system provided by the first aspect.

[0031] The motor drive system of an electric vehicle provided in the first aspect of an embodiment of the present application is configured to be electrically connected to the battery by communicating with the control system, so as to obtain the input current and output voltage of the battery and send them to the control system; the front end of the circuit breaker is configured to be electrically connected to the battery, and the rear end of the circuit breaker is electrically connected to the motor driver and the control system, and the circuit breaker is configured to disconnect when the output current of the battery is greater than a preset current threshold; the motor driver is electrically connected to the motor braking device, and is configured to be electrically connected to the motor to drive the motor, obtain its own input voltage and send it to the control system; the control system is communicated with the motor driver and electrically connected to the motor braking device, and is configured to directly control the motor braking device to brake the motor when the electric vehicle rolls down a slope, causing the input current of the battery to be greater than or equal to 0 and the difference between the input voltage of the motor driver and the output voltage of the battery is greater than the preset voltage threshold; emergency braking can be performed when the electric vehicle rolls down a slope to avoid safety accidents and improve safety performance.

[0032] It can be understood that the beneficial effects of the second aspect mentioned above can be found in the relevant description of the first aspect mentioned above, and will not be repeated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0034] Figure 1 This is a schematic diagram of the first structure of the motor drive system provided in the embodiment of the present application;

[0035] Figure 2 is a second structural schematic diagram of the motor drive system provided in an embodiment of the present application;

[0036] Figure 3 This is a third structural schematic diagram of the motor drive system provided in an embodiment of the present application. DETAILED DESCRIPTION

[0037] In the following description, specific details such as specific system structures, technologies, etc. are provided for the purpose of illustration rather than limitation, so as to provide a thorough understanding of the embodiments of the present application. However, it should be clear to those skilled in the art that the present application may also be implemented in other embodiments without these specific details. In other cases, detailed descriptions of well-known systems, devices, circuits, and methods are omitted to prevent unnecessary details from obstructing the description of the present application.

[0038] As used in the specification and appended claims of this application, the term "if" can be interpreted as "when" or "uponce" or "in response to determining" or "in response to detecting", depending on the context. Similarly, the phrase "if it is determined" or "if [described condition or event] is detected" can be interpreted as meaning "uponce it is determined" or "in response to determining" or "uponce [described condition or event] is detected" or "in response to detecting [described condition or event]", depending on the context.

[0039] In addition, in the description of the present application specification and the appended claims, the terms "first", "second", "third", etc. are only used to distinguish the descriptions and cannot be understood as indicating or implying relative importance.

[0040] References to "one embodiment" or "some embodiments" etc. described in the specification of this application mean that one or more embodiments of the present application include specific features, structures or characteristics described in conjunction with the embodiment. Therefore, the statements "in one embodiment", "in some embodiments", "in some other embodiments", "in some other embodiments", etc. that appear in different places in this specification do not necessarily refer to the same embodiment, but mean "one or more but not all embodiments", unless otherwise specifically emphasized in other ways. The terms "including", "comprising", "having" and their variations all mean "including but not limited to", unless otherwise specifically emphasized in other ways.

[0041] An embodiment of the present application provides a motor drive system for an electric vehicle, which can determine whether the electric vehicle is rolling down a slope by detecting the input current and output voltage of the battery of the electric vehicle and the input voltage of the motor driver, and perform emergency braking when the electric vehicle rolls down a slope to avoid safety accidents and improve safety performance.

[0042] In applications, the electric vehicle can be an intelligent inspection vehicle, an automated guided vehicle (AGV), an electric vehicle robot, etc., which are unmanned vehicles powered by batteries. The battery can be a large-capacity single cell or battery pack, specifically a rechargeable lithium battery pack.

[0043] like Figure 1 As shown, the motor drive system 100 provided in the embodiment of the present application includes a battery management system (BMS) 101, a circuit breaker 102, a motor driver 103, a motor brake device 104 and a control system 105;

[0044] The battery management system 101 is in communication connection with the control system 105 and is configured to be electrically connected to the battery 200 to obtain the input current and output voltage of the battery 200 and send them to the control system 105;

[0045] The front end of the circuit breaker 102 is configured to be electrically connected to the battery 200, and the rear end of the circuit breaker 102 is electrically connected to the motor driver 103 and the control system 105. The circuit breaker 102 is configured to be disconnected when the output current of the battery 200 is greater than a preset current threshold;

[0046] The motor driver 103 is electrically connected to the motor brake device 104 , and is configured to be electrically connected to the motor 300 to drive the motor 300 , obtain its own input voltage and send it to the control system 105 ;

[0047] The control system 105 is communicatively connected to the motor driver 103 and electrically connected to the motor brake device 104, and is configured to directly control the motor brake device 104 to brake the motor 300 when the input current of the battery 200 is greater than or equal to 0 and the difference between the input voltage of the motor driver 103 and the output voltage of the battery 200 is greater than a preset voltage threshold.

[0048] In the application, based on Figure 1 The structure of the motor drive system shown in the figure, the working principles of each component in the motor drive system are as follows:

[0049] 1. Battery Management System

[0050] The battery management system can communicate with the control system via the CAN bus. The battery management system can obtain the battery's input current, output current, output voltage, temperature and other data and send them to the control system, and generate corresponding alarm information and send it to the control system when any data is abnormal. The control system can also actively read the battery's input current, output current, output voltage, temperature and corresponding alarm information from the battery management system.

[0051] 2. Circuit breaker

[0052] When the circuit breaker is closed, the output current of the battery supplies power to the motor driver and control system through the circuit breaker. When the output current of the battery is too large (that is, greater than the preset current threshold) and exceeds the protection point of the circuit breaker, the circuit breaker automatically disconnects and stops supplying power to the motor driver and control system to protect the motor driver and control system.

[0053] When an electric vehicle rolls down a slope, the motor becomes a generator, converting mechanical energy into electrical energy. The energy of the back electromotive force generated by the motor is large, and this part of the energy is fed back to the DC bus of the motor driver through the UVW three-phase electrical circuit of the motor, so that the motor driver can be powered on and work normally. At this time, if the circuit breaker is closed, this part of the energy can also charge the battery and power the control system; if the circuit breaker is disconnected, this part of the energy is consumed by the motor driver and the control system. The energy of the back electromotive force generated by the motor is unstable and there are uncertain factors. When the circuit breaker is closed, it is very easy to damage the battery, motor driver and control system, and when the circuit breaker is disconnected, it is very easy to damage the motor driver and control system.

[0054] 3. Motor driver

[0055] The motor driver can be connected to the control system through the CAN bus. The motor driver is connected to the motor through the UVW three-phase electrical line to control the operation of the motor. The motor driver provides power to the motor encoder set on the motor. The motor encoder collects the operating data of the electric vehicle (for example, the position information of the motor rotor) and feeds it back to the motor driver so that the motor driver can perform servo closed-loop control on the motor. The motor driver can actively or under the control of the motion command sent by the control system to perform corresponding operations, for example, control the movement of the motor, obtain its own input voltage, output voltage, and operating data collected by the motor encoder and send it to the control system, and generate corresponding alarm information and send it to the control system when any data is abnormal. The control system can also actively read the input voltage, output voltage, operating data collected by the motor encoder and corresponding alarm information of the motor driver from the motor driver.

[0056] 4. Motor brake device

[0057] The motor braking device may include an electromagnetic brake. Both the motor driver and the control system can control the power supply of the electromagnetic brake. When the electromagnetic brake is connected to the power supply, the motor can work normally; when the electromagnetic brake is disconnected from the power supply, the motor bearing is locked to achieve motor braking.

[0058] 5. Control system

[0059] The control system can determine whether the electric vehicle is rolling down a slope based on the input current of the battery and the input voltage and output voltage of the motor drive.

[0060] When the electric vehicle is operating normally and not sliding down a slope: A. The battery is not faulty and the circuit breaker is closed.

[0061] In case A, the working principle of the motor drive system is as follows:

[0062] 1) The circuit breaker is closed, and the path of the battery output current is the electrical path 1→2, 3→10, that is, the battery output current passes through the circuit breaker to power on the motor driver and the control system respectively, so that the control system and the motor driver are powered on and initialized;

[0063] 2) The path for the control system to control the motor operation is electrical path 7→8, that is, the control system sends motion instructions to the motor driver through CAN bus 7, and the motor driver outputs UVW three-phase voltage to control the motor operation; the path for the control system to actively control the motor braking is electrical path 7→10, that is, the control system sends braking instructions to the motor driver through CAN bus 7, and the motor driver turns off the power supply of the motor braking device through electrical path 10 to achieve braking.

[0064] When the electric vehicle rolls down a slope: B. The battery has no fault and the circuit breaker is disconnected; C. The battery has a fault and there is no output and the circuit breaker is closed; D. The battery has a fault and there is no output and the circuit breaker is disconnected. At this time, the input current I of the battery is greater than or equal to 0 (that is, I≥0, the battery is discharged when I<0, the battery is charged when I>0, and the battery is in a critical state of charge and discharge or the circuit breaker is disconnected and there is no output when I=0), and the difference between the input voltage U2 of the motor driver and the output voltage U1 of the battery is greater than the preset voltage threshold ΔU (that is, U2-U1>ΔU). If the battery fails and the output voltage of the battery cannot be read from the battery management system, the last output voltage before the battery fails can be read as U1. In the three cases of B, C, and D, the working principle of the motor drive system is as follows:

[0065] 1) The electrical path of the electric energy generated by the back electromotive force of the motor is 4→5→2. The motor becomes a generator, and the generated electric energy is fed back to the DC bus of the motor driver through the UVW three-phase electrical line. The DC bus of the motor driver is connected to the rear-end line of the circuit breaker. The control system can be powered through electrical path 2. The working principle of the motor brake device is the same as in case A, which will not be repeated here.

[0066] 2) When the control system is working, it will read the battery input current I and output voltage U1 from the battery management system through the CAN bus 6, and read the input voltage U2 of the motor driver through the CAN bus 7.

[0067] In order to prevent the electric vehicle from sliding down the slope, when I≥0 and U2-U1>ΔU, the control system sends a braking command directly to the motor braking device through the electrical path 11, quickly disconnects the power supply of the electromagnetic brake of the braking device, and allows the electromagnetic brake to perform the braking action to avoid accidents.

[0068] In one embodiment, the battery management system is communicatively connected to the control system via a first CAN bus, and the motor driver is communicatively connected to the control system via a second CAN bus.

[0069] In the application, the battery management system and the motor driver are respectively connected to the control system through the CAN bus to realize the transmission of data and control instructions.

[0070] In applications, the control system may include a processor, which may be a central processing unit (CPU), other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. A general-purpose processor may be a microprocessor or any conventional processor, etc.

[0071] In one embodiment, the motor braking device includes an electromagnetic brake;

[0072] The control system is configured as:

[0073] When the input current of the battery is greater than or equal to 0 and the difference between the input voltage of the motor driver and the output voltage of the battery is greater than a preset voltage threshold, the electromagnetic brake is directly controlled to cut off power to brake the motor.

[0074] In one embodiment, the battery management system is further configured to:

[0075] Obtain the output current and temperature of the battery and send them to the control system;

[0076] When the output current, output voltage or temperature of the battery is abnormal, the corresponding alarm information is sent to the control system.

[0077] In the application, the alarm information corresponding to the abnormal conditions of the output current, output voltage and temperature of the battery is different, so that the control system can identify the corresponding abnormal conditions according to the different alarm information, and then take corresponding treatment measures, for example, control the motor braking and control the entire motor drive system to power off, or the motor drive system can also include an alarm device, and the control system controls the alarm device to send a corresponding alarm signal to remind the user. The alarm signals corresponding to the abnormal conditions of the output current, output voltage and temperature of the battery are different, so that the user can identify the corresponding abnormal conditions according to the different alarm signals, and then take corresponding treatment measures, for example, replace or repair the battery.

[0078] In one embodiment, the motor driver is further configured to:

[0079] Get its own output voltage and send it to the control system;

[0080] When its own input voltage or output voltage is abnormal, the corresponding alarm information is sent to the control system.

[0081] In the application, the alarm information corresponding to the abnormal conditions of the input voltage and output voltage of the motor driver is different, so that the control system can identify the corresponding abnormal conditions according to the different alarm information, and then take corresponding treatment measures, for example, control the motor braking and control the entire motor drive system to power off, or the motor drive system can also include an alarm device, and the control system controls the alarm device to send a corresponding alarm signal to remind the user. The alarm signals corresponding to the abnormal conditions of the input voltage and output voltage of the motor driver are different, so that the user can identify the corresponding abnormal conditions according to the different alarm signals, and then take corresponding treatment measures, for example, replace or repair the motor controller.

[0082] In applications, the alarm device may include at least one of a light alarm and a sound alarm.

[0083] like Figure 2 As shown, in one embodiment, the motor drive system 100 further includes a switch module 106;

[0084] The first end, the second end and the controlled end of the switch module 106 are electrically connected to the rear end of the circuit breaker 102, the motor driver 103 and the control system 105 respectively, and are configured to be opened or closed under the control of the control system 105 to connect or disconnect the electrical connection path between the motor driver 103 and the battery 200 when the circuit breaker 102 is closed.

[0085] In application, the control system can control the opening and closing of the switch module, so as to control the motor driver to connect or disconnect the electrical connection with the battery when the circuit breaker is closed, so as to control the motor driver to power on and start working or power off and shut down.

[0086] based on Figure 2 The structure of the motor drive system shown in Figure 1, in case A, the principle of the motor drive and control system power-on startup is as follows:

[0087] The circuit breaker is closed, and the path of the battery output current is electrical path 1→2→9→3→10, that is, the battery output current passes through the circuit breaker to power on the control system. After the control system is powered on and initialized, the switch module is controlled to open through electrical path 9 to power on the motor driver, so that the motor driver is powered on and initialized.

[0088] In the application, the switch module can be realized by any soft switch, for example, an insulated gate bipolar transistor (IGBT), a bipolar junction transistor (BJT), a field effect transistor (FET), a thyristor, etc. The insulated gate bipolar transistor is a composite fully controlled voltage-driven power semiconductor device composed of a bipolar transistor and an insulated gate field effect transistor, and has the advantages of high input impedance of the insulated gate field effect transistor and low conduction voltage drop of the bipolar transistor. The field effect transistor can specifically be a metal oxide semiconductor field effect transistor (Metal-Oxide Semiconductor FET, referred to as MOS-FET).

[0089] In one embodiment, the switch module includes a field effect tube, and the input end, the output end and the gate of the field effect tube respectively constitute the first end, the second end and the controlled end of the switch module.

[0090] like Figure 3 As shown, in one embodiment, the motor drive system 100 further includes an inertial measurement unit (IMU) 107 and a motor encoder 108;

[0091] The inertial measurement unit 107 is in communication with the control system 105 and is configured to obtain the inclination data of the electric vehicle and send it to the control system 105;

[0092] The motor encoder 108 is in communication connection with the motor driver 103 and is configured to obtain the operation data of the electric vehicle and send it to the motor driver 103;

[0093] The motor driver 103 is also configured to send operating data to the control system 105;

[0094] The control system 105 is also configured to:

[0095] Obtaining the inclination angle of the electric vehicle relative to the horizontal according to the inclination angle data;

[0096] Obtaining the running speed of the electric vehicle according to the running data;

[0097] According to the inclination angle, the running speed and the preset corresponding relationship, the preset voltage threshold is obtained, and the preset corresponding relationship is the corresponding relationship between different inclination angles and different running speeds of the electric vehicle and different preset voltage thresholds.

[0098] In the application, the preset voltage threshold ΔU is related to the initial speed of the electric vehicle when it slides down the slope and the inclination angle θ of the slope. The initial speed of the electric vehicle when it slides down the slope is the running speed of the electric vehicle when the input current of the battery is greater than or equal to 0. The difference ΔU between the input voltage U2 of the motor driver and the output voltage U1 of the battery corresponding to different initial speeds V0 and different inclination angles θ will vary. It is necessary to test under different conditions to obtain the corresponding difference ΔU. The relevant test data can be made into a data table, which is convenient for looking up the table according to the initial speed V0 and the inclination angle θ to obtain the corresponding difference ΔU. The control system can obtain the inclination θ through the inertial measurement unit, and the initial speed V0 can be calculated by the data feedback from the motor encoder. Then, according to the data table searched for different initial speeds V0 and different inclination angles θ, different difference ΔU is selected. The selection of the difference ΔU will vary according to the actual site where the electric vehicle actually slides down the slope, which improves the dynamic adaptability of controlling the motor brake device based on the size of the difference ΔU to brake the motor, and ensures that the electric vehicle can achieve emergency braking when the above situation B, C or D occurs on different slopes, avoiding safety accidents and improving safety performance.

[0099] In one embodiment, the inertial measurement unit is communicatively connected to the control system via a third CAN bus, and the motor encoder is communicatively connected to the motor driver via a fourth CAN bus.

[0100] In the application, the inertial measurement unit and the motor encoder are respectively connected to the control system through the CAN bus to realize the transmission of data and control instructions.

[0101] Figure 1-Figure 3 Solid arrows represent electrical connections, dashed arrows represent communication connections, and dotted lines represent physical connections.

[0102] The motor drive system of the electric vehicle provided in the embodiment of the present application can determine whether the electric vehicle is sliding down a slope simply by obtaining the input current and output voltage of the battery and the input voltage of the motor driver, and perform emergency braking when the electric vehicle is sliding down a slope, thereby avoiding safety accidents and improving safety performance. The logic is simple and easy to implement.

[0103] An embodiment of the present application also provides an electric vehicle, including a battery, a motor and the above-mentioned motor drive system.

[0104] In application, electric vehicles may include, but are not limited to, batteries, motors, and the above-mentioned motor drive systems. Those skilled in the art will appreciate that Figures 1 to 3 The illustration is only an example of an electric vehicle and does not constitute a limitation on the electric vehicle. The electric vehicle may include more or fewer components than shown in the illustration, or may combine certain components, or may include different components. For example, the electric vehicle may also include input and output devices, network access devices, etc. The input and output devices may include the aforementioned human-computer interaction devices, and may also include a display screen for displaying the working parameters of the electric vehicle. The network access device may include a communication module for the electric vehicle to communicate with a client.

[0105] In application, the memory may be an internal storage unit of an electric vehicle in some embodiments, such as a hard disk or memory of an electric vehicle. In other embodiments, the memory may also be an external storage device of an electric vehicle, such as a plug-in hard disk, a smart media card (SMC), a secure digital (SD) card, a flash card, etc. equipped on an electric vehicle. The memory may also include both an internal storage unit and an external storage device of an electric vehicle. The memory is used to store operating systems, applications, boot loaders, data, and other programs, such as program codes of computer programs. The memory may also be used to temporarily store data that has been output or is to be output.

[0106] In applications, the display may be a thin film transistor liquid crystal display (TFT-LCD), a liquid crystal display (LCD), an organic electroluminesence display (OLED), a quantum dot light emitting diode (QLED) display, a seven-segment or eight-segment digital tube, etc.

[0107] In the application, the communication module can be set as any device that can directly or indirectly communicate with the client over a long distance by wire or wireless communication according to actual needs, so that the user can control the running state of the electric vehicle by operating the client. The communication module can provide communication solutions including wireless local area networks (WLAN) (such as Wi-Fi networks), Bluetooth, Zigbee, mobile communication networks, global navigation satellite systems (GNSS), frequency modulation (FM), near field communication technology (NFC), infrared technology (IR), etc., which are applied to network devices. The communication module can include an antenna, which can have only one array element or an antenna array including multiple array elements. The communication module can receive electromagnetic waves through the antenna, modulate the electromagnetic wave signal and filter it, and send the processed signal to the processor. The communication module can also receive the signal to be sent from the processor, modulate the frequency and amplify it, and convert it into electromagnetic waves for radiation through the antenna.

[0108] Those skilled in the art can clearly understand that, for the convenience and simplicity of description, only the division of the above-mentioned functional components is used as an example for illustration. In actual applications, the above-mentioned functions can be assigned to different functional components as needed, that is, the internal structure of the device can be divided into different functional components to complete all or part of the functions described above. The functional components in the embodiment can be integrated into a processing component, or each component can exist physically separately, or two or more components can be integrated into one component. The above-mentioned integrated components can be implemented in the form of hardware or in the form of software functional components. In addition, the specific names of the functional components are only for the convenience of distinguishing each other, and are not used to limit the scope of protection of this application.

[0109] If the integrated module is implemented in the form of a software function module and sold or used as an independent product, it can be stored in a computer-readable storage medium. The computer-readable medium may at least include: any entity or device that can carry the computer program code to the electric vehicle, a recording medium, a computer memory, a read-only memory (ROM), a random access memory (RAM), an electric carrier signal, a telecommunication signal, and a software distribution medium. For example, a USB flash drive, a mobile hard disk, a magnetic disk, or an optical disk.

[0110] In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described or recorded in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0111] In the embodiments provided in the present application, it should be understood that the disclosed device can be implemented in other ways. For example, the device embodiments described above are only schematic, for example, the division of components is only a logical function division, and there may be other division methods in actual implementation, such as multiple components or assemblies can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or components, which can be electrical, mechanical or other forms.

[0112] The components described as separate components may or may not be physically separated, and the components displayed as components may or may not be physical components, that is, they may be located in one place or distributed on multiple network components. Some or all of the components may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0113] The embodiments described above are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, a person skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. Such modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present application, and should all be included in the protection scope of the present application.

Claims

1. A motor drive system for an electric vehicle, characterized in that: It includes a battery management system, a circuit breaker, a motor driver, a motor brake device, a control system, an inertial measurement unit and a motor encoder, wherein the motor brake device includes an electromagnetic brake; The battery management system is communicatively connected to the control system via a first CAN bus and is configured to be electrically connected to the battery to obtain the input current and output voltage of the battery and send them to the control system; The front end of the circuit breaker is configured to be electrically connected to the battery, the rear end of the circuit breaker is electrically connected to the motor driver and the control system, and the circuit breaker is configured to be disconnected when the output current of the battery is greater than a preset current threshold; The motor driver is electrically connected to the motor brake device, and is configured to be electrically connected to the motor to drive the motor, obtain its own input voltage and send it to the control system; The control system is communicatively connected to the motor driver through a second CAN bus and electrically connected to the motor brake device, and is configured to directly control the electromagnetic brake to cut off power to brake the motor when the input current of the battery is greater than or equal to 0 and the difference between the input voltage of the motor driver and the output voltage of the battery is greater than a preset voltage threshold; The inertial measurement unit is in communication with the control system and is configured to obtain the inclination data of the electric vehicle and send it to the control system; The motor encoder is communicatively connected to the motor driver and is configured to obtain operating data of the electric vehicle and send the data to the motor driver; The motor driver is further configured to send the operating data to the control system; The control system is also configured to: Acquiring the inclination angle of the electric vehicle relative to the horizontal according to the inclination angle data; Acquiring a running speed of the electric vehicle according to the running data; The preset voltage threshold is obtained according to the inclination angle, the running speed and a preset corresponding relationship, wherein the preset corresponding relationship is a corresponding relationship between different inclination angles and different running speeds of the electric vehicle and different preset voltage thresholds.

2. The motor drive system according to claim 1, characterized in that: Also included is a switch module; The first end, the second end and the controlled end of the switch module are electrically connected to the rear end of the circuit breaker, the motor driver and the control system in a one-to-one correspondence, respectively, and are configured to be opened or closed under the control of the control system to connect or disconnect the electrical connection path between the motor driver and the battery when the circuit breaker is closed.

3. The motor drive system according to claim 2, characterized in that: The switch module comprises a field effect tube, and the input end, the output end and the gate of the field effect tube respectively constitute the first end, the second end and the controlled end of the switch module.

4. The motor drive system according to claim 1, characterized in that: The battery management system is further configured to: Obtaining the output current and temperature of the battery and sending them to the control system; When the output current, output voltage or temperature of the battery is abnormal, corresponding alarm information is sent to the control system.

5. The motor drive system according to claim 1, characterized in that: The motor driver is further configured to: Get its own output voltage and send it to the control system; When an abnormality occurs in its input voltage or output voltage, a corresponding alarm message is sent to the control system.

6. The motor drive system according to claim 1, characterized in that: The inertial measurement unit is connected to the control system through a third CAN bus, and the motor encoder is connected to the motor driver through a fourth CAN bus.

7. An electric vehicle, characterized in that: The invention comprises a battery, a motor and a motor drive system as claimed in any one of claims 1 to 6.

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