Motor dynamic control method, device, equipment and vehicle

Abstract

The application provides a motor dynamic control method, device, equipment and vehicle, which can determine different induced electromotive force voltages according to different operation parameters of a target motor, determine a maximum value of the induced electromotive force voltage allowed to appear in the current relay state, and further determine the maximum allowed speed of the target motor. Since the induced electromotive force voltage is constantly changing, the maximum allowed speed is also changing. The switching of the protection mode is performed according to the maximum allowed speed, the dynamic switching is realized, the safety of the motor is ensured, the maximum allowed speed corresponds to a higher vehicle speed, and the normal driving of the vehicle is not affected by limiting the vehicle speed according to the maximum allowed speed.

Description

Motor dynamic control methods, devices, equipment and vehicles Technical Field

[0001] This application relates to the field of vehicle technology, and in particular to a method, device, equipment and vehicle for dynamic control of an electric motor. Background Technology

[0002] With the rapid development of new energy vehicles, drive motors of different power and speed ranges have been widely used. Four-wheel drive vehicles, with a rear drive motor on the rear axle and a drive source (including an engine and drive motor) on the front axle, are increasingly popular due to their powerful performance. For vehicles with two or more drive sources, if one motor fails, while another drive source can still power the vehicle, the protection strategies in the technology will limit the vehicle's movement to a lower motor speed, affecting normal vehicle operation. Directly increasing the upper limit of the speed limit could damage the motor and compromise driving safety. Summary of the Invention

[0003] In view of this, the purpose of this application is to provide a method, device, equipment and vehicle for dynamic control of motors, so as to solve the problem of motor failure affecting the normal use of vehicles.

[0004] To achieve the above objectives, the first aspect of this application provides a method for dynamic control of a motor, comprising:

[0005] Identify the faulty target motor and the power source used to drive the vehicle;

[0006] Control the power drive source to drive the vehicle, and determine the operating parameters of the target motor;

[0007] The maximum permissible speed of the target motor is determined based on the operating parameters and the preset standard margin voltage.

[0008] The vehicle speed limit and protection mode are switched according to the maximum permissible speed.

[0009] A second aspect of this application provides a motor dynamic control device, comprising:

[0010] The fault diagnosis module is configured to: determine the target motor with a fault and the power drive source used to drive the vehicle;

[0011] The status determination module is configured to: control the power drive source to drive the vehicle, and determine the operating parameters of the target motor;

[0012] The speed determination module is configured to: determine the maximum allowable speed of the target motor based on the operating parameters and a preset standard margin voltage;

[0013] The dynamic control module is configured to switch between vehicle speed limits and protection modes based on the maximum permissible speed.

[0014] 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, when executing the program, implements the method provided in the first aspect of this application.

[0015] A fourth aspect of this application provides a vehicle that includes the apparatus provided in the second aspect of this application.

[0016] As can be seen from the above, the motor dynamic control method, device, equipment, and vehicle provided in this application, after identifying the target motor with a fault and the power drive source used to drive the vehicle, control the power drive source to drive the vehicle, and determine the maximum permissible speed of the target motor based on the operating parameters of the target motor and the preset standard margin voltage; and switch between vehicle speed limiting and protection modes based on the maximum permissible speed. Since the maximum permissible speed is variable, switching the protection mode based on the maximum permissible speed achieves dynamic switching, ensuring the safety of the motor. Furthermore, since the maximum permissible speed corresponds to a relatively high vehicle speed, limiting the vehicle speed based on the maximum permissible speed will not affect the normal operation of the vehicle. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in this application or related technologies, the drawings used in the description of the embodiments or related technologies will be briefly introduced below. Obviously, the drawings described below are only embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 is a schematic diagram of the short-circuit protection mode according to an embodiment of this application;

[0019] Figure 2 is a schematic diagram of the open-circuit protection mode according to an embodiment of this application;

[0020] Figure 3 is a flowchart of the motor dynamic control method according to an embodiment of this application;

[0021] Figure 4 is a flowchart of the speed limitation in an embodiment of this application;

[0022] Figure 5 is a flowchart of the protection mode switching in an embodiment of this application;

[0023] Figure 6 is a flowchart of determining the induced electromotive force voltage in an embodiment of this application;

[0024] Figure 7 is a flowchart illustrating the determination of the maximum permissible rotational speed according to an embodiment of this application;

[0025] Figure 8 is a flowchart illustrating the determination of the target motor in an embodiment of this application;

[0026] Figure 9 is a schematic diagram of the motor dynamic control device according to an embodiment of this application;

[0027] Figure 10 is a schematic diagram of the structure of an electronic device according to an embodiment of this application. Detailed Implementation

[0028] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with specific embodiments and the accompanying drawings.

[0029] It should be noted that, unless otherwise defined, the technical or scientific terms used in the embodiments of this application should have the ordinary meaning understood by one of ordinary skill in the art to which this application pertains. The terms "first," "second," and similar terms used in the embodiments of this application do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Terms such as "comprising" or "including" mean that the element or object preceding the word encompasses the elements or objects listed after the word and their equivalents, without excluding other elements or objects. Terms such as "connected" or "linked" are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. Terms such as "upper," "lower," "left," and "right" are only used to indicate relative positional relationships; when the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0030] In this article, it is important to understand that any number of elements in the accompanying figures is for illustrative purposes and not for limitation, and any naming is for distinction only and has no limiting meaning.

[0031] Based on the above background description, the following situations also exist in the related technologies:

[0032] When the vehicle is under the following operating conditions, the drive motor system will enter the open-circuit protection mode (free wheeling, FW) or the active short circuit protection mode (ASC).

[0033] 1) When the vehicle loses control, implementing ASC can generate reverse torque, causing the vehicle to brake slowly and come to a safe stop.

[0034] 2) When the power battery fails, implementing ASC can isolate the motor, motor controller and power battery, ensuring the high voltage safety of the whole vehicle.

[0035] 3) When the drive motor speed is too high or abnormal during vehicle operation, implementing ASC can prevent excessive back EMF from damaging the power battery, bus capacitor and other high voltage devices.

[0036] 4) When a switching transistor in the inverter circuit of the motor controller fails, implementing ASC can prevent uncontrolled rectified current from damaging other devices or the power battery.

[0037] In other cases, the open circuit protection mode can be entered first.

[0038] As shown in Figure 1, the exemplary drive motor system includes a power battery, a main positive relay, a main negative relay, a capacitor, a motor, and an inverter composed of six switching transistors. The three upper switching transistors constitute the upper arm of the inverter, and the three lower switching transistors constitute the lower arm. The short-circuit protection mode operates by turning off the three upper arm switching transistors of the inverter while simultaneously turning on the three lower arm switching transistors, as shown in Figure 1; or by turning on the three upper arm switching transistors of the inverter while simultaneously turning off the three lower arm switching transistors. This constitutes the safe operating state of the active short-circuit protection mode. The short-circuit protection mode causes the motor stator windings to form a closed loop, resulting in rapid internal heating of the motor, but it does not affect the controller, and a corresponding braking torque is generated at the motor output.

[0039] As shown in Figure 2, the open-circuit protection mode shuts off all switches in the upper and lower bridge arms, putting the inverter into passive rectification mode. In this mode, if the motor back EMF is less than the bus voltage, the current will not flow into the battery through the freewheeling diode, having no impact on the system. If the back EMF is greater than the bus voltage, the current flows in the reverse direction, from the motor through the freewheeling diode into the battery, resulting in reverse current flow.

[0040] In related technologies, when a FW / ASC switching condition is required, it is generally performed based on the motor's voltage threshold. When the motor's back EMF is higher than this voltage threshold, it enters short-circuit protection mode; when it is lower, it enters open-circuit protection mode. This voltage threshold corresponds to a fixed motor speed, which in turn corresponds to a fixed vehicle speed. Therefore, the vehicle is limited from exceeding this fixed speed during operation. However, this speed is generally low, which restricts the vehicle from traveling at lower speeds and affects its normal use.

[0041] It can be seen that the relevant technology uses a constant voltage to switch between FW / ASC and limit the speed. Because the short-circuit protection mode causes the motor stator windings to form a closed loop, the continuous current generated by the back EMF may cause the motor to overheat. Overheating can lead to demagnetization of the rotor magnets and also cause the inverter to overheat, potentially damaging it. Therefore, ASC mode should not be maintained for extended periods. Thus, the voltage is limited to switch to FW to reduce current, thereby limiting the motor speed and ultimately the vehicle speed. At higher speeds, the vehicle will enter ASC mode, and prolonged high-speed driving will lead to the aforementioned dangers. Therefore, the vehicle can only travel at lower speeds, affecting its normal operation.

[0042] The motor dynamic control method, apparatus, equipment, and vehicle provided in this application, after identifying the target motor with a fault and the power drive source used to drive the vehicle, control the power drive source to drive the vehicle, and determine the maximum allowable speed of the target motor based on the operating parameters of the target motor and a preset standard margin voltage; then, perform speed limiting and protection mode switching based on the maximum allowable speed. Since the maximum allowable speed is variable, switching the protection mode based on this maximum allowable speed achieves dynamic switching, ensuring motor safety. Furthermore, the maximum allowable speed corresponds to a relatively high vehicle speed, so limiting the vehicle speed based on the maximum allowable speed does not affect the normal operation of the vehicle.

[0043] In some embodiments, as shown in FIG3, the motor dynamic control method includes:

[0044] Step 301: Identify the faulty target motor and the power source used to drive the vehicle.

[0045] In practical implementation, a multi-drive-source vehicle includes at least one motor among its multiple drive sources. Taking a vehicle with two drive sources as an example, one drive source is a motor, and the other drive source can be either a motor or an engine. One drive source is located at the front drive axle, and the other drive source is located at the rear drive axle. When the motor drive source fails, the vehicle can be driven by the other drive source. The faulty motor is identified as the target motor, and the other drive source is identified as the power drive source.

[0046] Step 302: Control the power drive source to drive the vehicle and determine the operating parameters of the target motor.

[0047] In practice, the operating parameters are the conditions for determining whether the target motor and the power battery are connected. These parameters may include the voltage values ​​of the lines at both ends of the relay (there is a voltage difference when the lines are disconnected, and there is no voltage difference or the difference is very small when the lines are connected), the current value flowing through the power battery (no current is generated or only a very small current is generated when the lines are disconnected, and a large current flows through when the lines are connected), and the relay status of the main positive relay and the main negative relay corresponding to the target motor. Any data or information that can be used to determine whether the target motor and the power battery are connected can be used as operating parameters, and no specific limitations are imposed here.

[0048] For example, the operating parameters are explained using the states of the main positive relay and the main negative relay. The main positive relay is the relay installed on the positive terminal of the power battery module. When this relay is disconnected, the power battery's external output is cut off. Therefore, this relay is designed to handle very large currents, typically above 300A. The main negative relay is the relay installed on the negative terminal of the power battery. Under normal circumstances, it is disconnected along with the main positive relay to ensure complete insulation of the high-voltage battery from the outside environment, thus protecting the power battery. Alternatively, it may be energized along with the main positive relay to ensure smooth power battery output.

[0049] Step 303: Determine the maximum allowable speed of the target motor based on the operating parameters and the preset standard margin voltage.

[0050] In some alternative embodiments, step 303 includes:

[0051] Step 3031: Determine the induced electromotive force of the target motor based on the operating parameters and the preset standard margin voltage.

[0052] In practice, the relay states include two types: both the main positive and main negative relays are simultaneously disconnected, and both the main positive and main negative relays are simultaneously engaged. When both the main positive and main negative relays are simultaneously disconnected, the power battery is completely insulated from the outside, ensuring there is no risk of reverse current flow. Therefore, at this time, only the maximum bus voltage that each electrical component (such as capacitors and switching transistors) can withstand needs to be considered (for safety reasons, the maximum bus voltage is generally higher than the maximum output voltage of the power battery). However, to ensure that no danger occurs, the maximum bus voltage needs to be limited based on the standard margin voltage. The voltage difference between the maximum bus voltage and the standard margin voltage is then determined as the induced electromotive force voltage of the target motor. Due to the existence of the standard margin voltage, even if the actual electromotive force voltage is higher than the induced electromotive force voltage during vehicle operation, no danger will occur.

[0053] When both the main positive relay and the main negative relay are engaged in the relay state, the power battery is connected to the outside, which may pose a risk of reverse current. Therefore, at this time, only the bus voltage after the power battery output needs to be considered. However, in order to ensure that no danger occurs, the bus voltage needs to be limited according to the standard margin voltage. Then, the voltage difference between the bus voltage and the standard margin voltage is determined as the induced electromotive force voltage of the target motor. Due to the existence of the standard margin voltage, even if the actual electromotive force voltage is higher than the induced electromotive force voltage during vehicle operation, there will be no risk of reverse current.

[0054] Step 3032: Determine the maximum permissible speed of the target motor based on the induced electromotive force voltage.

[0055] In practice, the relationship between the induced electromotive force voltage and the target motor speed can be determined based on the open-circuit back electromotive force table. Then, the maximum allowable speed of the target motor corresponding to the induced electromotive force voltage can be determined by looking up the table. The open-circuit back electromotive force table can be obtained by bench testing the open-circuit back electromotive force of the electric drive axle corresponding to the target motor. For example, the open-circuit back electromotive force table is shown in Table 1.

[0056] Table 1 Open-circuit back electromotive force table

[0057] Rotational speed induced electromotive force voltage [rpm][V] 0 0.05 00 16.96 1000 33.92 2000 67.85 3000 101.78 s 600 190.048 300 278.34 10800 366.72 13400 455.18 16000 543.77 surface

[0058] Step 304: Switch between vehicle speed limit and protection mode based on the maximum permissible speed.

[0059] In practice, the voltage of the power battery may change in real time, so the calculated maximum permissible speed will also change dynamically. The protection mode is switched based on this dynamically changing maximum permissible speed. When the actual speed of the target motor exceeds the maximum permissible speed, short-circuit protection mode can be entered to prevent backflow of current into the power battery or damage to electrical components due to excessive voltage. Since short-circuit protection mode is not suitable for prolonged operation, vehicle speed must be limited based on the maximum permissible speed. After entering short-circuit protection mode, the driver can be instructed to reduce speed via voice prompts or display screen alerts to lower the target motor speed. Once the speed is reduced below the maximum permissible speed, the mode is switched to open-circuit protection mode. Because the induced electromotive force voltage generated when driving at speeds below the maximum permissible speed will not pose a danger to the power battery or electrical components, the vehicle can continue to operate in open-circuit protection mode until the fault repair is completed. In short, speed limitation keeps the vehicle in open-circuit protection mode, and switching to protection mode ensures vehicle safety when the limit is exceeded.

[0060] Among them, the maximum permissible speed obtained by sensing the electromotive force voltage corresponds to the vehicle speed, which is the maximum permissible speed in open-circuit protection mode. Exceeding this speed will switch to short-circuit protection mode. Therefore, limiting the vehicle speed based on the maximum permissible speed will not limit the vehicle speed to a very small range. This relaxes the speed limit in open-circuit mode, improves the vehicle's power and drivability, reduces the impact on the user's normal driving, and allows the user to drive at the maximum speed under the speed limit until the user repairs the fault, thus improving the user's driving experience.

[0061] In summary, the motor dynamic control method provided in this application, after identifying the target motor with a fault and the power drive source used to drive the vehicle, controls the power drive source to drive the vehicle and determines the maximum allowable speed of the target motor based on the operating parameters of the target motor and the preset standard margin voltage. It then switches between speed limits and protection modes based on the maximum allowable speed. Different induced electromotive force (EMF) voltages are determined based on different operating parameters, and the maximum allowable EMF voltage under the current operating parameters is determined, thereby determining the maximum allowable speed of the target motor. Since the induced EMF voltage is constantly changing, the maximum allowable speed also changes. Switching the protection mode based on this maximum allowable speed achieves dynamic switching, ensuring motor safety. Furthermore, the maximum allowable speed corresponds to a relatively high vehicle speed, so speed limiting based on the maximum allowable speed does not restrict the vehicle speed to a very small range, improving the vehicle's dynamics and drivability, reducing the impact on normal driving, and allowing the user to drive at the maximum speed under the speed limit until the fault is repaired, thus improving the user's driving experience.

[0062] In some embodiments, as shown in FIG4, vehicle speed is limited based on the maximum permissible rotational speed, including:

[0063] Step 401: Determine the maximum permissible vehicle speed based on the maximum permissible engine speed.

[0064] In practice, there is a certain conversion relationship between the target motor speed and the vehicle speed. This conversion relationship is related to the gear position of the target motor's transmission. Therefore, firstly, the current gear position of the vehicle at the current moment can be obtained. Different gears have different conversion rates; the higher the current gear, the higher the conversion rate. Given a fixed maximum permissible speed, the corresponding maximum permissible speed is greater. If the vehicle uses a single-gear shifting mode, the conversion rate is fixed, and the maximum permissible speed can be directly determined based on this conversion rate. Then, the current maximum permissible speed is determined based on the current gear and the maximum permissible speed. This maximum permissible speed is the speed at which the user can continuously drive, ensuring safety. When the user's speed exceeds this speed, a short-circuit protection mode will be entered. Since the short-circuit mode cannot be maintained for an extended period, it is necessary to limit the time the user drives at speeds exceeding this maximum permissible speed.

[0065] Step 402: Determine the safe speed based on the maximum permissible speed and the preset margin speed.

[0066] In practice, if the speed limit is set based on the maximum permissible speed, it's impossible for a user to maintain a consistently stable speed at that speed. Since vehicle speed fluctuates, this could lead to frequent and repeated speed changes around the maximum permissible speed, requiring frequent reminders to slow down and negatively impacting the driving experience. Therefore, a safety margin speed is set to determine the safe speed. This means that when the speed exceeds the maximum permissible speed, the user is notified to reduce their speed. Once the user reduces their speed to below the safe speed, the speed reduction is considered successful, and notifications cease.

[0067] Step 403: Limit the output speed of the power drive source according to the safe vehicle speed.

[0068] In practice, when the vehicle speed exceeds the maximum permissible speed, the user is notified to reduce the speed. Once the user reduces the speed to below the safe speed, the speed reduction is confirmed as successful, and the notification stops. At this point, the vehicle speed fluctuates around the safe speed, and the speed reduction notification is not frequently triggered. The preset margin speed is generally small and will not affect the vehicle's driving speed. Then, the conversion rate between vehicle speed and engine speed is determined based on the gear of the power drive source. Based on this conversion rate, the output speed of the power drive source corresponding to the safe speed is determined. When driving, the user needs to control the output speed to be near the speed corresponding to the safe speed and not to exceed the speed corresponding to the maximum permissible speed. This achieves the limitation of the output speed of the power drive source to ensure that the vehicle speed is maintained near the safe speed, maximizing the permissible speed of the vehicle in open road mode and reducing the impact on the user's normal driving.

[0069] In practical implementation, the protection modes include open-circuit protection mode and short-circuit protection mode; as shown in Figure 5, the protection mode is switched according to the maximum permissible speed, including:

[0070] Step 501: Determine the current protection mode.

[0071] In practice, the switching of protection modes includes three scenarios: 1) Upon the immediate occurrence of a fault, it needs to enter either open-circuit or short-circuit protection mode; 2) After a period of time following the fault, it switches from open-circuit protection mode to short-circuit protection mode; 3) After a period of time following the fault, it switches from short-circuit protection mode to open-circuit protection mode. To determine the specific switching method, the current protection mode needs to be determined.

[0072] Step 502: Obtain the actual speed of the target motor.

[0073] In practice, if the front and rear drives use the same drive axle and have the same gear, the speed of the motor or engine of the power drive source can be determined as the actual speed of the target motor. Alternatively, the actual speed of the target motor can be directly detected, which is more universal. The actual speed of the target motor corresponds to the actual induced electromotive force voltage that can be generated, which is equivalent to detecting the induced electromotive force voltage of the target motor.

[0074] Step 503: Compare the actual speed with the maximum permissible speed to obtain the comparison results.

[0075] In practice, comparing the actual speed with the maximum permissible speed is equivalent to comparing the actual induced electromotive force voltage with the induced electromotive force voltage. If the actual speed is greater than or equal to the maximum permissible speed, it indicates a risk of current backflow or damage to electrical components. If the actual speed is less than the maximum permissible speed, it indicates no risk of current backflow or damage to electrical components, but there is a risk of the target motor being damaged by high temperature.

[0076] Step 504: Switch between short-circuit protection mode and open-circuit protection mode based on the comparison results and the current protection mode.

[0077] In practice, if the actual speed is greater than or equal to the maximum permissible speed, it is necessary to enter or switch to short-circuit protection mode to prevent the risk of backflow of current or damage to electrical components. If the actual speed is less than the maximum permissible speed, it indicates that there is a risk of backflow of current or damage to electrical components. In order to prevent the target motor from being damaged by high temperature, it is necessary to enter or switch to open-circuit protection mode. The switching between short-circuit protection mode and open-circuit protection mode will be dynamically switched according to the change of user vehicle speed, ensuring that there is no risk of backflow of current or damage to electrical components, nor is there a risk of motor burnout.

[0078] In practical implementation, if the current protection mode includes short-circuit protection mode, open-circuit protection mode, and no protection mode entered, then step 504 includes:

[0079] Step 5041: In response to the current protection mode not being entered and the comparison result showing that the actual speed is greater than or equal to the maximum allowable speed, enter the short circuit protection mode; or, in response to the current protection mode not being entered and the comparison result showing that the actual speed is less than the maximum allowable speed, enter the open circuit protection mode.

[0080] In practical implementation, for situations where a fault has just occurred and no protection mode has been entered yet, the current protection mode is "not in protection mode." At this point, the appropriate protection mode needs to be determined based on the comparison results. If the comparison result shows that the actual speed is greater than or equal to the maximum permissible speed, it indicates that the generated actual induced electromotive force voltage is higher than the calculated induced electromotive force voltage, potentially posing a risk of current backflow or component damage. Therefore, the short-circuit protection mode is entered, and the vehicle speed limit is activated to reduce the actual speed. If the comparison result shows that the actual speed is less than the maximum permissible speed, it indicates that the generated actual induced electromotive force voltage is lower than the calculated induced electromotive force voltage, and there is no risk of current backflow or component damage. Therefore, the open-circuit protection mode is entered, and the actual speed is monitored in real time, preparing for a switch to the appropriate protection mode.

[0081] Step 5042: In response to the current protection mode being open circuit protection mode, and the comparison result showing that the actual speed is greater than or equal to the maximum allowable speed, switch the open circuit protection mode to short circuit protection mode.

[0082] In practice, when a fault has occurred for a certain period of time and a safe state has been entered (a state of switching between open-circuit protection mode and short-circuit protection mode), if the current protection mode is open-circuit protection mode, it is necessary to determine whether to switch the protection mode based on the comparison results. If the comparison results show that the actual speed is greater than or equal to the maximum allowable speed, it means that the actual induced electromotive force voltage generated is higher than the calculated induced electromotive force voltage, which may pose a risk of current backflow or damage to electrical components. Therefore, the open-circuit mode is no longer safe and it is necessary to enter the short-circuit protection mode and activate the vehicle speed limit to reduce the actual speed.

[0083] Step 5043: In response to the current protection mode being short-circuit protection mode and the maximum allowable speed being greater than the actual speed, determine the speed difference between the maximum allowable speed and the actual speed; in response to the speed difference being greater than or equal to the preset protection speed threshold, switch the short-circuit protection mode to open-circuit protection mode.

[0084] In practice, after a certain period of time following a fault, the system has entered a safe state (a state of switching between open-circuit protection mode and short-circuit protection mode). When the current protection mode is short-circuit protection mode, switching to open-circuit protection mode requires ensuring that the maximum permissible speed is greater than the actual speed. To prevent frequent switching between open-circuit and short-circuit protection modes due to speed fluctuations, a certain margin needs to be set when exiting short-circuit mode and switching to open-circuit protection mode. This margin is the protection speed threshold. Therefore, when determining that the maximum permissible speed is greater than the actual speed, the speed difference between the maximum permissible speed and the actual speed needs to be calculated. If this speed difference is greater than the protection speed threshold, the protection mode can be switched from short-circuit protection mode to open-circuit protection mode.

[0085] In some embodiments, the operating parameters include the relay states of the main positive relay and the main negative relay corresponding to the target motor, as shown in Figure 6. Determining the induced electromotive force voltage of the target motor based on the operating parameters and a preset standard margin voltage includes:

[0086] Step 601: In response to the relay status, both the main positive relay and the main negative relay are in the energized state, determine the bus voltage of the power battery.

[0087] In practice, when both the main positive relay and the main negative relay are engaged in the relay state, the power battery is connected to the outside. Before the electrical components are damaged due to high voltage, the reverse current from the power battery will definitely occur first. This is because the maximum bus voltage that the electrical components can withstand is greater than the maximum output voltage of the power battery, so the risk of reverse current will occur first. Therefore, at this time, only the bus voltage after the power battery output needs to be considered.

[0088] Step 602: Determine the voltage difference between the bus voltage and the standard margin voltage as the induced electromotive force voltage.

[0089] In practice, to ensure that there is no risk of backflow of current, the bus voltage needs to be limited by the standard margin voltage. The voltage difference obtained by subtracting the standard margin voltage from the bus voltage is then determined as the induced electromotive force voltage of the target motor. Due to the existence of the standard margin voltage, even if the actual electromotive force voltage is higher than the induced electromotive force voltage during vehicle operation, there will be no risk of backflow of current. This ensures that when switching protection modes, there will be no backflow of current due to short-term high voltage.

[0090] Step 603: In response to the relay status being that both the main positive relay and the main negative relay are in the off state, the voltage difference between the preset maximum bus voltage and the standard margin voltage is determined as the induced electromotive force voltage.

[0091] In practice, when both the main positive relay and the main negative relay are disconnected, the power battery is completely insulated from the outside, ensuring there is no risk of reverse current flow. Therefore, only the maximum bus voltage that each electrical component can withstand needs to be considered. However, to ensure that no danger occurs, the maximum bus voltage needs to be limited based on the standard margin voltage. The voltage difference obtained by subtracting the standard margin voltage from the maximum bus voltage is then determined as the induced electromotive force voltage of the target motor. Due to the existence of the standard margin voltage, even if the actual electromotive force voltage is higher than the induced electromotive force voltage during vehicle operation, it will not cause danger to the electrical components. This ensures that the electrical components will not be damaged by short-term high voltage when switching protection modes.

[0092] In some embodiments, as shown in FIG7, determining the maximum permissible speed of the target motor based on the induced electromotive force voltage includes:

[0093] Step 701: Determine the conversion curve based on the preset open-circuit back electromotive force table.

[0094] In practice, as shown in Table 1, the induced electromotive force voltage and rotational speed in the open-circuit back electromotive force table are discrete data. Therefore, in order to accurately determine the rotational speed, it is necessary to construct a conversion curve (or a straight line) based on the discrete data in the open-circuit back electromotive force table to realize the conversion between induced electromotive force voltage and rotational speed. Here, a coordinate system can be constructed with rotational speed as the horizontal axis and induced electromotive force voltage as the vertical axis.

[0095] Step 702: Determine the maximum permissible speed based on the induced electromotive force voltage on the conversion curve.

[0096] In practice, each point on the conversion curve corresponds to a rotational speed and an induced electromotive force voltage. Therefore, the maximum permissible rotational speed can be determined on the conversion curve based on the induced electromotive force voltage.

[0097] In some embodiments, as shown in FIG8, determining the faulty target motor and the power drive source for driving the vehicle includes:

[0098] Step 801: Obtain the working status signals of multiple drive sources.

[0099] In practice, each driver source generates a corresponding working status signal during runtime to reflect the status of the driver source in real time.

[0100] Step 802: In response to the presence of a motor fault signal in the working status signal, the motor corresponding to the motor fault signal is identified as the target motor, and the drive source other than the target motor is identified as the power drive source.

[0101] In practice, when a motor fault signal is present in the working status signal, it indicates that a faulty motor has occurred. The motor corresponding to the fault signal is identified as the target motor, and the drive source other than the target motor is identified as the power drive source. At this time, the protection mode of the target motor needs to be activated, and the power drive source is used to drive the vehicle to ensure the normal operation of the vehicle.

[0102] It should be noted that the method in this embodiment can be executed by a single device, such as a computer or server. The method can also be applied in a distributed scenario, where multiple devices cooperate to complete the task. In such a distributed scenario, one of these devices may execute only one or more steps of the method in this embodiment, and the multiple devices will interact with each other to complete the method described.

[0103] It should be noted that the above description describes some embodiments of this application. Other embodiments are within the scope of the appended claims. In some cases, the actions or steps recorded in the claims can be performed in a different order than that shown in the above embodiments and still achieve the desired result. Furthermore, the processes depicted in the drawings do not necessarily require a specific or sequential order to achieve the desired result. In some embodiments, multitasking and parallel processing are also possible or may be advantageous.

[0104] Based on the same inventive concept, corresponding to the methods of any of the above embodiments, this application also provides a motor dynamic control device, wherein at least one motor is included among the plurality of drive sources.

[0105] Referring to Figure 9, the motor dynamic control device includes:

[0106] The fault diagnosis module 10 is configured to: determine the target motor with a fault and the power drive source used to drive the vehicle;

[0107] The status determination module 20 is configured to: control the power drive source to drive the vehicle and determine the operating parameters of the target motor;

[0108] The speed determination module 30 is configured to determine the maximum allowable speed of the target motor based on the operating parameters and the preset standard margin voltage.

[0109] The dynamic control module 40 is configured to switch between vehicle speed limit and protection mode based on the maximum permissible speed.

[0110] In some embodiments, the dynamic control module 40 includes:

[0111] The vehicle speed determination unit is configured to determine the maximum permissible vehicle speed based on the maximum permissible engine speed.

[0112] The safe speed unit is configured to determine the safe speed based on the maximum permissible speed and a preset margin speed.

[0113] The speed limiting unit is configured to limit the output speed of the power drive source based on a safe vehicle speed.

[0114] In some embodiments, the protection modes include an open-circuit protection mode and a short-circuit protection mode; the dynamic control module 40 further includes:

[0115] The mode detection unit is configured to: determine the current protection mode;

[0116] The speed detection unit is configured to acquire the actual speed of the target motor.

[0117] The speed comparison unit is configured to compare the actual speed with the maximum allowable speed and obtain a comparison result.

[0118] The mode switching unit is configured to switch between short-circuit protection mode and open-circuit protection mode based on the comparison results and the current protection mode.

[0119] In some embodiments, the rotational speed determining module 30 includes:

[0120] The electromotive force confirmation unit is configured to determine the induced electromotive force voltage of the target motor based on the operating parameters and the preset standard margin voltage.

[0121] The speed confirmation unit is configured to determine the maximum permissible speed of the target motor based on the induced electromotive force voltage.

[0122] For ease of description, the above devices are described in terms of function, divided into various modules. Of course, in implementing this application, the functions of each module can be implemented in one or more software and / or hardware.

[0123] The apparatus described above is used to implement the corresponding motor dynamic control method in any of the foregoing embodiments, and has the beneficial effects of the corresponding method embodiments, which will not be repeated here.

[0124] Based on the same inventive concept, corresponding to the methods of any of the above embodiments, this application also provides an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the program to implement the motor dynamic control method described in any of the above embodiments.

[0125] Figure 10 shows a more specific hardware structure diagram of an electronic device provided in this embodiment. The device may include: a processor 1010, a memory 1020, an input / output interface 1030, a communication interface 1040, and a bus 1050. The processor 1010, memory 1020, input / output interface 1030, and communication interface 1040 are interconnected internally via the bus 1050.

[0126] The processor 1010 can be implemented using a general-purpose CPU (Central Processing Unit), microprocessor, application-specific integrated circuit (ASIC), or one or more integrated circuits, and is used to execute relevant programs to implement the technical solutions provided in the embodiments of this specification.

[0127] The memory 1020 can be implemented in the form of ROM (Read Only Memory), RAM (Random Access Memory), static storage device, dynamic storage device, etc. The memory 1020 can store the operating system and other applications. When the technical solutions provided in the embodiments of this specification are implemented by software or firmware, the relevant program code is stored in the memory 1020 and is called and executed by the processor 1010.

[0128] The input / output interface 1030 is used to connect input / output modules to realize information input and output. Input / output modules can be configured as components within the device (not shown in the figure) or externally connected to the device to provide corresponding functions. Input devices may include keyboards, mice, touchscreens, microphones, various sensors, etc., while output devices may include displays, speakers, vibrators, indicator lights, etc.

[0129] The communication interface 1040 is used to connect a communication module (not shown in the figure) to enable communication between this device and other devices. The communication module can communicate via wired means (such as USB, Ethernet cable, etc.) or wireless means (such as mobile network, WIFI, Bluetooth, etc.).

[0130] Bus 1050 includes a pathway for transmitting information between various components of the device, such as processor 1010, memory 1020, input / output interface 1030, and communication interface 1040.

[0131] It should be noted that although the above-described device only shows the processor 1010, memory 1020, input / output interface 1030, communication interface 1040, and bus 1050, in specific implementations, the device may also include other components necessary for normal operation. Furthermore, those skilled in the art will understand that the above-described device may only include the components necessary for implementing the embodiments of this specification, and not necessarily all the components shown in the figures.

[0132] The electronic devices described above are used to implement the corresponding motor dynamic control methods in any of the foregoing embodiments, and have the beneficial effects of the corresponding method embodiments, which will not be repeated here.

[0133] Based on the same inventive concept, corresponding to the methods of any of the above embodiments, this application also provides a non-transitory computer-readable storage medium that stores computer instructions for causing the computer to execute the motor dynamic control method as described in any of the above embodiments.

[0134] The computer-readable medium of this embodiment includes permanent and non-permanent, removable and non-removable media, and information storage can be implemented by any method or technology. Information can be computer-readable instructions, data structures, program modules, or other data. Examples of computer storage media include, but are not limited to, phase-change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technologies, CD-ROM, digital versatile optical disc (DVD) or other optical storage, magnetic tape, magnetic magnetic disk storage or other magnetic storage devices, or any other non-transfer medium that can be used to store information accessible by a computing device.

[0135] The computer instructions stored in the storage medium of the above embodiments are used to cause the computer to execute the motor dynamic control method as described in any of the above embodiments, and have the beneficial effects of the corresponding method embodiments, which will not be repeated here.

[0136] Based on the same inventive concept, corresponding to the methods of any of the above embodiments, this application also provides a vehicle, including a motor dynamic control device, which is used to execute the motor dynamic control method as described in any of the above embodiments, and has the beneficial effects of the corresponding method embodiments, which will not be repeated here.

[0137] Those skilled in the art should understand that the discussion of any of the above embodiments is merely exemplary and is not intended to imply that the scope of this application (including the claims) is limited to these examples; within the framework of this application, the technical features of the above embodiments or different embodiments can also be combined, the steps can be implemented in any order, and there are many other variations of different aspects of the embodiments of this application as described above, which are not provided in the details for the sake of brevity.

[0138] Additionally, to simplify the description and discussion, and to avoid obscuring the embodiments of this application, the well-known power / ground connections to integrated circuit (IC) chips and other components may or may not be shown in the provided drawings. Furthermore, the apparatus may be shown in block diagram form to avoid obscuring the embodiments of this application, and this also takes into account the fact that the details of the implementation of these block diagram apparatuses are highly dependent on the platform on which the embodiments of this application will be implemented (i.e., these details should be fully understood by those skilled in the art). While specific details (e.g., circuits) have been set forth to describe exemplary embodiments of this application, it will be apparent to those skilled in the art that the embodiments of this application can be implemented without these specific details or with variations thereof. Therefore, these descriptions should be considered illustrative rather than restrictive.

[0139] Although this application has been described in conjunction with specific embodiments thereof, many substitutions, modifications, and variations of these embodiments will be apparent to those skilled in the art from the foregoing description. For example, other memory architectures (e.g., dynamic RAM (DRAM)) may be used with the embodiments discussed.

[0140] The embodiments of this application are intended to cover all such substitutions, modifications, and variations that fall within the broad scope of the appended claims. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the embodiments of this application should be included within the protection scope of this application.

Claims

1. A method for dynamic control of a motor, characterized in that, include: Identify the faulty target motor and the power source used to drive the vehicle; Control the power drive source to drive the vehicle, and determine the operating parameters of the target motor; The maximum permissible speed of the target motor is determined based on the operating parameters and a preset standard margin voltage. The operating parameters include the relay states of the main positive and main negative relays corresponding to the target motor. Determining the maximum permissible speed of the target motor based on the operating parameters and the preset standard margin voltage includes: when both the main positive and main negative relays are simultaneously engaged, determining the voltage difference between the bus voltage of the power battery and the standard margin voltage as the induced electromotive force (EMF) voltage of the target motor; when both the main positive and main negative relays are simultaneously disengaged, determining the voltage difference between the maximum bus voltage and the standard margin voltage as the induced EMF voltage of the target motor; determining the maximum permissible speed corresponding to the induced EMF voltage based on a preset open-circuit back EMF table; and switching between vehicle speed limits and protection modes based on the maximum permissible speed.

2. The method according to claim 1, characterized in that, Limiting vehicle speed based on the maximum permissible speed includes: determining the maximum permissible vehicle speed based on the maximum permissible speed; determining a safe vehicle speed based on the maximum permissible vehicle speed and a preset margin vehicle speed; and limiting the output speed of the power drive source based on the safe vehicle speed.

3. The method according to claim 1, characterized in that, The protection modes include an open-circuit protection mode and a short-circuit protection mode; the switching of protection modes based on the maximum permissible speed includes: determining the current protection mode; obtaining the actual speed of the target motor; comparing the actual speed with the maximum permissible speed to obtain a comparison result; and switching between the short-circuit protection mode and the open-circuit protection mode based on the comparison result and the current protection mode.

4. The method according to claim 3, characterized in that, The current protection mode includes the short-circuit protection mode, the open-circuit protection mode, and the non-entered protection mode. Switching between the short-circuit protection mode and the open-circuit protection mode based on the comparison result and the current protection mode includes: entering the short-circuit protection mode in response to the current protection mode being the non-entered protection mode and the comparison result indicating that the actual rotational speed is greater than or equal to the maximum permissible rotational speed; or entering the open-circuit protection mode in response to the current protection mode being the non-entered protection mode and the comparison result indicating that the actual rotational speed is less than the maximum permissible rotational speed; switching the open-circuit protection mode to the short-circuit protection mode in response to the current protection mode being the short-circuit protection mode and the maximum permissible rotational speed being greater than the actual rotational speed; and switching the short-circuit protection mode to the open-circuit protection mode in response to the current protection mode being the short-circuit protection mode and the maximum permissible rotational speed being greater than the actual rotational speed.

5. The method according to claim 1, characterized in that, The step of determining the maximum permissible speed corresponding to the induced electromotive force voltage according to a preset open-circuit back electromotive force table includes: determining a conversion curve according to the preset open-circuit back electromotive force table; and determining the maximum permissible speed on the conversion curve according to the induced electromotive force voltage.

6. A dynamic control device for a motor, characterized in that, include: The fault diagnosis module is configured to: determine the target motor with a fault and the power drive source used to drive the vehicle; The status determination module is configured to: control the power drive source to drive the vehicle, and determine the operating parameters of the target motor; The speed determination module is configured to: determine the maximum permissible speed of the target motor based on the operating parameters and a preset standard margin voltage; wherein, the operating parameters include the relay states of the main positive relay and the main negative relay corresponding to the target motor; determining the maximum permissible speed of the target motor based on the operating parameters and the preset standard margin voltage includes: when the main positive relay and the main negative relay are simultaneously engaged, determining the voltage difference between the bus voltage of the power battery and the standard margin voltage as the induced electromotive force voltage of the target motor; when the main positive relay and the main negative relay are simultaneously disengaged, determining the voltage difference between the maximum bus voltage and the standard margin voltage as the induced electromotive force voltage of the target motor; and determining the maximum permissible speed corresponding to the induced electromotive force voltage based on a preset open-circuit back electromotive force table; the dynamic control module is configured to: switch between vehicle speed limiting and protection modes based on the maximum permissible speed.

7. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the program, it implements the method as described in any one of claims 1 to 5.

8. A vehicle, characterized in that, Includes the motor dynamic control device as described in claim 6.

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