Vehicle control method and device, vehicle and storage medium

Abstract

The application discloses a vehicle control method and device, a vehicle and a storage medium. The vehicle control method comprises the following steps: in an electric braking working condition, acquiring a current voltage on a bus; determining a current traction motor feedback electric power corresponding to the current voltage according to a corresponding relationship between the bus voltage and the traction motor feedback electric power; and controlling the traction motor to feedback electric power to the bus according to the current traction motor feedback electric power. According to the above scheme, the current traction motor feedback electric power corresponding to the current voltage is determined according to the current voltage on the bus, and the traction motor is controlled to feedback electric power to the bus according to the current traction motor feedback electric power. Since the corresponding electric power can be fed back to the bus according to the current voltage, the problem that the bus voltage is increased to be higher than the overvoltage protection voltage threshold of the electric appliance connected to the bus due to excessive feedback electric power, so that the corresponding electric appliance cannot work normally, can be avoided.

Description

Technical Field

[0001] This invention generally relates to the field of vehicles, and more specifically to a vehicle control method, device, vehicle, and storage medium. Background Technology

[0002] For electrically driven vehicles, the traction motor is powered by electricity, and the drive motor directly or through a reducer drives the wheels to move the vehicle. To improve braking performance and save energy, electrically driven vehicles generally use both mechanical and electric braking.

[0003] Electric braking refers to a situation where, when a vehicle brakes, the traction motor no longer draws electrical energy from the bus as a load, but instead operates in generator mode, feeding electrical energy back to the bus. This causes the voltage on the bus to rise. In some cases, excessive electrical energy feedback can cause the voltage on the bus to rise above the overvoltage protection threshold of the connected electrical appliances, resulting in the appliances malfunctioning. Summary of the Invention

[0004] This application aims to provide a vehicle control method, device, vehicle, and storage medium to at least solve the problem that the voltage on the busbar rises above the overvoltage protection voltage threshold of the electrical appliances connected to it due to the feedback of electrical energy from the traction motor, causing the electrical appliances to malfunction.

[0005] In a first aspect, the present invention provides a vehicle control method, comprising the following steps:

[0006] Under electric braking conditions, obtain the current voltage on the bus.

[0007] Based on the correspondence between bus voltage and traction motor feedback power, determine the current traction motor feedback power corresponding to the current voltage;

[0008] The current traction motor feedback power is used to control the traction motor's feedback power to the bus.

[0009] As an implementation method, the relationship between the bus voltage and the traction motor feedback power is specifically as follows:

[0010] If the bus voltage is less than the first voltage threshold, then the traction motor feedback power is the first power.

[0011] If the bus voltage is greater than or equal to the first voltage threshold and less than the second threshold voltage, then the traction motor feedback power is the second power.

[0012] If the bus voltage is greater than or equal to the second voltage threshold, then the traction motor feedback power is the third power.

[0013] The first electrical power is greater than the second electrical power, and the second electrical power is greater than the third electrical power.

[0014] As one possible implementation, the first electrical power is the rated regenerative power of the traction motor; and / or,

[0015] The second electrical power is P = P_rated - (P_rated - P1)·(Ua) / (ba); and / or,

[0016] The third electrical power is the sum of the operating power of each electrical appliance connected to the busbar under the electric braking condition;

[0017] Wherein, P is the second electric power, P_rated is the rated feedback electric power of the traction motor, P1 is the third electric power, U is the current voltage, a is the first voltage threshold, and b is the second voltage threshold.

[0018] As an implementation method, the first voltage threshold is a = bc;

[0019] The second voltage threshold is the lowest overvoltage protection voltage threshold among all electrical appliances connected to the busbar;

[0020] Where a is the first voltage threshold, b is the second voltage threshold, and c is a preset value.

[0021] In a second aspect, the present invention provides a vehicle control device, comprising:

[0022] The voltage monitoring module is used, at least under electric braking conditions, to obtain the current voltage on the bus.

[0023] The feedback power determination module is used to determine the current traction motor feedback power corresponding to the current voltage based on the correspondence between the bus voltage and the traction motor feedback power.

[0024] The control module is used to control the traction motor to feed power back to the bus based on the current traction motor feed power.

[0025] Thirdly, the present invention provides a vehicle including the vehicle control device described above.

[0026] Fourthly, the present invention provides a computer-readable storage medium having a computer program stored thereon for implementing the vehicle control method as described above.

[0027] The above scheme determines the current traction motor feedback power based on the current voltage on the busbar, and controls the traction motor's feedback power to the busbar based on the current feedback power. Since the feedback power can be adjusted according to the current voltage, it avoids the problem of the busbar voltage rising above the overvoltage protection threshold of connected appliances due to excessive feedback power, which could prevent these appliances from malfunctioning. Attached Figure Description

[0028] Other features, objects, and advantages of this application will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings:

[0029] Figure 1 A circuit architecture diagram of the vehicle control method provided in the embodiments of the present invention;

[0030] Figure 2 A flowchart of a vehicle control method provided in an embodiment of the present invention;

[0031] Figure 3 A flowchart of a vehicle control method provided in another embodiment of the present invention;

[0032] Figure 4 This is a schematic diagram of the vehicle control device provided in an embodiment of the present invention. Detailed Implementation

[0033] The present application will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, only the parts relevant to the invention are shown in the accompanying drawings.

[0034] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. This application will now be described in detail with reference to the accompanying drawings and embodiments.

[0035] Electric vehicles, such as electric locomotives and high-speed trains, obtain electrical energy from the power grid through a pantograph and then connect to various electrical appliances through a busbar connected to it. Urban rail vehicles obtain electrical energy from the power supply rail through a current collector and then connect to various electrical appliances through a busbar connected to it. Electric cars and electric buses are directly connected to the power battery through a busbar and then connected to various electrical appliances through a busbar.

[0036] In the aforementioned electrically driven vehicles, to improve braking performance and save energy, electric braking is generally used simultaneously with mechanical braking during the braking process. During electric braking, the vehicle's traction motor 4 no longer draws power from the bus as a load, but instead operates in generator mode, feeding some power back to the bus. This causes the voltage on the bus to rise. In some cases, excessive power feedback can cause the bus voltage to rise above the overvoltage protection threshold of connected electrical appliances, leading to malfunctions. To address this issue, this application obtains the current voltage on the bus during electric braking and controls the amount of power fed back from the traction motor 4 to the bus based on this voltage. This prevents excessive power feedback from causing the bus voltage to rise above the overvoltage protection threshold of connected electrical appliances, thus avoiding malfunctions. The solution presented in this application can be applied to the following circuit architecture:

[0037] like Figure 1 As shown, the circuit architecture includes a bus, which is divided into a positive bus 7 and a negative bus 6. Depending on the vehicle type, the positive bus 7 and negative bus 6 can obtain power from the aforementioned power grid, power rail, or power battery. Multiple electrical appliances are connected to the positive bus 7 and negative bus 6, such as, but not limited to, an auxiliary converter 1, an air conditioner 5, a traction inverter module 3, and other electrical appliances 2. The traction inverter module 3 is connected to the traction motor 4. Generally, the traction inverter module 3 can integrate a traction inverter and a traction control unit (DCU). The traction inverter can include an inverter module, a rectifier module, a DC voltage sensor, a brake chopper, a filter capacitor, a brake current sensor, etc. During traction operation, the traction inverter can convert the DC power supplied on the bus into three-phase adjustable voltage and frequency AC power for the traction motor 4. During electric braking, the traction motor 4 operates as a generator, and the traction inverter rectifies the AC power generated by the traction motor 4 into DC power to feed back to the power grid, achieving regenerative braking. The traction control unit can at least be used for vector control of the traction motor 4.

[0038] The specific solution in this application is as follows:

[0039] At least see Figure 2 As shown in the figure, an embodiment of the present invention illustrates a vehicle control method, which includes the following steps:

[0040] S11: Under electric braking conditions, obtain the current voltage on the bus;

[0041] As mentioned above, under electric braking conditions, the current voltage on the bus can be obtained through the DC voltage sensor of the traction inverter.

[0042] The current voltage can be obtained from the bus at a certain frequency, the specific frequency of which can be determined according to the control accuracy and the magnitude of the traction motor's feedback power. For example, but not limited to, the current voltage can be obtained from the bus once every 0.1 seconds. The figures here are only for illustrative purposes and are not intended to limit the uniqueness of this application.

[0043] S12: Determine the current traction motor feedback power corresponding to the current voltage based on the correspondence between the bus voltage and the traction motor feedback power;

[0044] The relationship between bus voltage and traction motor regenerative power can be preset. The rule for this relationship could be that as the bus voltage increases, the traction motor regenerative power decreases accordingly.

[0045] For different types of electrically driven vehicles, the pre-set relationship between the bus voltage and the traction motor feedback power may differ.

[0046] The relationship between bus voltage and traction motor feedback power can be determined based on the strength of the traction motor's ability to boost bus voltage. For example, but not limited to, for two different types of vehicles, A and B, if the bus voltage boost of vehicle A is greater than that of vehicle B, then, with the same bus voltage boost value, the power fed back by traction motor 4 to the bus of vehicle A is less than the power fed back by traction motor 4 to the bus of vehicle B.

[0047] S13: Control the traction motor 4 to feed power back to the bus using the current traction motor feedback power.

[0048] The above scheme determines the current traction motor feedback power based on the current voltage on the busbar; and controls the traction motor 4 to feed power back to the busbar based on the current traction motor feedback power. Since the feedback power can be adjusted according to the current voltage, it avoids the problem of the busbar voltage rising above the overvoltage protection threshold of connected appliances due to excessive feedback power, thus preventing the appliances from malfunctioning.

[0049] As an implementation method, the relationship between the bus voltage and the traction motor feedback power is specifically as follows:

[0050] If the bus voltage is less than the first voltage threshold, then the traction motor feedback power is the first power.

[0051] If the bus voltage is greater than or equal to the first voltage threshold and less than the second threshold voltage, then the traction motor feedback power is the second power.

[0052] If the bus voltage is greater than or equal to the second voltage threshold, then the traction motor feedback power is the third power.

[0053] The first electrical power is greater than the second electrical power, and the second electrical power is greater than the third electrical power.

[0054] When determining the current traction motor feedback power based on the above correspondence, either a parallel judgment method or a sequential judgment method can be used. The parallel judgment method refers to simultaneously and directly judging the relationship between the current voltage and the first voltage threshold, as well as the second power. The sequential judgment method refers to first judging the relationship between the current voltage and the first voltage threshold, and then, if the current voltage is greater than or equal to the first voltage threshold, judging the relationship between the current voltage and the second voltage threshold. The following specific examples illustrate the sequential judgment method in detail.

[0055] As one possible implementation, the first electrical power is the rated regenerative power of the traction motor 4; and / or,

[0056] The second electrical power is P = P_rated - (P_rated - P1)·(Ua) / (ba); and / or,

[0057] The third electrical power is the sum of the operating power of each electrical appliance connected to the busbar under the electric braking condition;

[0058] Wherein, P is the second electric power, P_rated is the rated feedback electric power of the traction motor 4, P1 is the third electric power, U is the current voltage, a is the first voltage threshold, and b is the second voltage threshold.

[0059] When the bus voltage is less than the first voltage threshold, the circuit connected to the bus can withstand a large amount of feedback power. The first power is set as the rated feedback power of the traction motor 4. That is, when the bus voltage is less than the first voltage threshold, the traction motor 4 can feed back power to the bus at full load to maximize the conversion of the vehicle's kinetic energy into electrical energy for feedback, and can provide the maximum electric braking torque, shorten the braking distance, and provide braking safety.

[0060] When the current voltage is between the first voltage threshold and the second voltage threshold, the current traction motor feedback power obtained by using the above formula can ensure that the bus voltage boost meets the requirements.

[0061] When the current voltage is greater than or equal to the second voltage threshold, the circuit connected to the bus can withstand a relatively low amount of feedback power. To ensure the feedback power meets the power supply requirements of the loads connected to the bus, the third power is set to the sum of the operating power of all electrical appliances connected to the bus under electric braking conditions. That is, the feedback power from the traction motor 4 is just consumed by the electrical appliances connected to the bus, thus preventing a rise in bus voltage. Here, the electrical appliances connected to the bus under electric braking conditions refer to appliances directly connected to the bus, excluding the traction inverter module 3, such as, but not limited to, the auxiliary converter 1, air conditioner 5, and other electrical appliances 2. At this time, the traction inverter module 3 is used to supply DC power to the bus; therefore, the traction inverter module 3 is not considered one of the aforementioned electrical appliances.

[0062] As an implementation method, the first voltage threshold is a = bc;

[0063] In order to ensure that all electrical appliances connected to the busbar can be used normally and to prevent some electrical appliances from malfunctioning due to overvoltage protection, the second voltage threshold is the lowest overvoltage protection voltage threshold among all electrical appliances connected to the busbar.

[0064] Wherein, a is the first voltage threshold, b is the second voltage threshold, and c is a preset value. The specific value of c can be determined according to the specific voltage level of the circuit, the electrical power fed back by the traction motor 4, etc. For example, but not limited to, if the bus is connected to 750V DC, then c can be set to 50, etc. The values ​​here are only for illustrative purposes and are not a unique limitation of this patent.

[0065] The vehicle control method of the present invention will be described below by way of example in a specific implementation.

[0066] like Figure 3 As shown, the vehicle control method includes the following steps:

[0067] S21: After the process begins, determine whether the vehicle is under high pressure;

[0068] Whether a vehicle is in a high-voltage state refers to whether the vehicle is connected to a power source (connected to the power grid, conductive rails, power battery, etc.) and whether it is in operation. If it is in a high-voltage state, it means that the vehicle is in operation; if it is not in a high-voltage state, it means that the vehicle is not in operation.

[0069] S22: When the vehicle is under high voltage, determine whether the traction inverter is in electric braking mode;

[0070] Otherwise, terminate the process;

[0071] S23: If the traction inverter is in electric braking mode, obtain the current voltage on the bus and determine whether the current voltage is greater than or equal to the first voltage threshold.

[0072] Wherein, the first voltage threshold is a = bc; b is the second voltage threshold, and c is a preset value.

[0073] S24: If not, control the traction motor 4 to feed back power to the bus at the rated feedback power of the traction motor 4.

[0074] S25: If so, control the traction motor 4 to feed back electrical power to the bus with the second electrical power, where the second electrical power is P = P rated - (P rated - P1)·(Ua) / (ba);

[0075] S26: After feeding back electrical power to the bus with the second electrical power, the current voltage on the bus is collected again, and it is determined whether the collected current voltage is greater than or equal to the second voltage threshold.

[0076] S27: If yes, then control the traction motor 4 to feed back electrical power to the bus with the third electrical power, which is the sum of the working power of each electrical appliance connected to the bus under the electric braking condition; otherwise, execute the above step S23.

[0077] Secondly, such as Figure 4 As shown, the present invention provides a vehicle control device, comprising:

[0078] The voltage monitoring module 41 is used at least to acquire the current voltage on the bus during electric braking operation.

[0079] The feedback power determination module 42 is used to determine the current traction motor feedback power corresponding to the current voltage based on the correspondence between the bus voltage and the traction motor feedback power.

[0080] Control module 43 is used to control the traction motor 4 to feed power back to the bus based on the current traction motor feed-back power.

[0081] The vehicle control device can implement the above-mentioned vehicle control method. Its working principle is described in the above embodiments and will not be repeated here.

[0082] As an implementation method, the relationship between the bus voltage and the traction motor feedback power is specifically as follows:

[0083] If the bus voltage is less than the first voltage threshold, then the traction motor feedback power is the first power.

[0084] If the bus voltage is greater than or equal to the first voltage threshold and less than the second threshold voltage, then the traction motor feedback power is the second power.

[0085] If the bus voltage is greater than or equal to the second voltage threshold, then the traction motor feedback power is the third power.

[0086] The first electrical power is greater than the second electrical power, and the second electrical power is greater than the third electrical power.

[0087] As one possible implementation, the first electrical power is the rated regenerative power of the traction motor 4; and / or,

[0088] The second electrical power is P = P_rated - (P_rated - P1)·(Ua) / (ba); and / or,

[0089] The third electrical power is the sum of the operating power of each electrical appliance connected to the busbar under the electric braking condition;

[0090] Wherein, P is the second electric power, P_rated is the rated feedback electric power of the traction motor 4, P1 is the third electric power, U is the current voltage, a is the first voltage threshold, and b is the second voltage threshold.

[0091] As an implementation method, the first voltage threshold is a = bc;

[0092] The second voltage threshold is the lowest overvoltage protection voltage threshold among all electrical appliances connected to the busbar;

[0093] Where a is the first voltage threshold, b is the second voltage threshold, and c is a preset value.

[0094] Thirdly, the present invention provides a vehicle including the vehicle control device described above.

[0095] Fourthly, the present invention provides a computer-readable storage medium having a computer program stored thereon, wherein the computer program may be one or more. The aforementioned program is used by one or more processors to execute the vehicle control method described in this application.

[0096] It should be understood that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., used above to indicate orientation or positional relationships are based on the orientation or positional relationships shown in the accompanying drawings and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined with "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of the present invention, unless otherwise stated, "a plurality of" means two or more.

[0097] The above description is merely a preferred embodiment of this application and an explanation of the technical principles employed. Those skilled in the art should understand that the scope of the invention involved in this application is not limited to technical solutions formed by specific combinations of the above-described technical features, but should also cover other technical solutions formed by arbitrary combinations of the above-described technical features or their equivalents without departing from the inventive concept. For example, technical solutions formed by substituting the above features with (but not limited to) technical features with similar functions disclosed in this application.

Claims

1. A vehicle control method, characterized in that, Includes the following steps: Under electric braking conditions, obtain the current voltage on the bus. Based on the correspondence between bus voltage and traction motor feedback power, determine the current traction motor feedback power corresponding to the current voltage; The current traction motor feedback power is used to control the traction motor to feed power back to the bus. The relationship between the bus voltage and the traction motor feedback power is as follows: If the bus voltage is less than the first voltage threshold, then the traction motor feedback power is the first power. If the bus voltage is greater than or equal to the first voltage threshold and less than the second voltage threshold, then the traction motor feedback power is the second power. If the bus voltage is greater than or equal to the second voltage threshold, then the traction motor feedback power is the third power. The first electrical power is greater than the second electrical power, and the second electrical power is greater than the third electrical power; The first electrical power is the rated regenerative power of the traction motor; the second electrical power is P=P 额定 -(P 额定 -P1)·(Ua) / (ba); The third electric power is the sum of the working power of each electrical appliance connected to the busbar under the electric braking condition; Where P is the second electric power, P 额定 P1 is the rated regenerative power of the traction motor, U is the current voltage, a is the first voltage threshold, and b is the second voltage threshold.

2. The vehicle control method according to claim 1, characterized in that, The first voltage threshold is a = bc; The second voltage threshold is the lowest overvoltage protection voltage threshold among all electrical appliances connected to the busbar; Where a is the first voltage threshold, b is the second voltage threshold, and c is a preset value.

3. A vehicle control device, characterized in that, include: The voltage monitoring module is used, at least under electric braking conditions, to obtain the current voltage on the bus. The feedback power determination module is used to determine the current traction motor feedback power corresponding to the current voltage based on the correspondence between the bus voltage and the traction motor feedback power. The control module is used to control the traction motor to feed power back to the bus based on the current traction motor feed power. The relationship between the bus voltage and the traction motor feedback power is as follows: If the bus voltage is less than the first voltage threshold, then the traction motor feedback power is the first power. If the bus voltage is greater than or equal to the first voltage threshold and less than the second voltage threshold, then the traction motor feedback power is the second power. If the bus voltage is greater than or equal to the second voltage threshold, then the traction motor feedback power is the third power. The first electrical power is greater than the second electrical power, and the second electrical power is greater than the third electrical power; The first electrical power is the rated regenerative power of the traction motor; the second electrical power is P=P 额定 -(P 额定 -P1)·(Ua) / (ba); The third electric power is the sum of the working power of each electrical appliance connected to the busbar under the electric braking condition; Where P is the second electric power, P 额定 P1 is the rated regenerative power of the traction motor, U is the current voltage, a is the first voltage threshold, and b is the second voltage threshold.

4. The vehicle control device according to claim 3, characterized in that, The first voltage threshold is a = bc; The second voltage threshold is the lowest overvoltage protection voltage threshold among all electrical appliances connected to the busbar; Where a is the first voltage threshold, b is the second voltage threshold, and c is a preset value.

5. A vehicle, characterized in that, Includes the vehicle control device as described in any one of claims 3-4.

6. A computer-readable storage medium, characterized in that, It stores a computer program for implementing the vehicle control method as described in any one of claims 1-2.

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