Electric vehicle energy allocation method, device, system and medium

Abstract

The present application relates to the field of engineering machinery, and specifically relates to an electric vehicle energy distribution method, device, system and medium. The electric vehicle energy distribution system comprises a power battery, a walking motor and a working motor, the power battery provides power for the walking motor and the working motor, and the electric vehicle energy distribution method comprises: obtaining the current state of charge and the current battery temperature of the power battery, and matching the current discharge power of the power battery from the database according to the current state of charge and the current battery temperature; obtaining the current walking power of the walking motor and the current working power of the working motor; and adjusting the power of the walking motor and the working motor based on the relationship between the current discharge power and the current walking power and the current working power. The present application prevents the occurrence of the situation that the walking power and the working power are greater than the current discharge power of the power battery, thereby causing the over-power discharge of the power battery, so as to protect the safety of the power battery and prolong the service life.

Description

Technical Field

[0001] This invention relates to the field of engineering machinery technology, specifically to an energy distribution method, device, system, and medium for electric vehicles. Background Technology

[0002] The current discharge power of a power battery is limited by its current state of charge (SOC) and temperature. Excessive heat or cold, or a decrease in SOC, will lead to a reduction in discharge power. Electric vehicles have a driving system driven by a drive motor and a working system driven by a duty motor. The power battery provides power to both motors. During operation, a mismatch often exists between the power available from the power battery and the power required by the driving and working systems.

[0003] However, current energy distribution methods for electric vehicles often only limit the total output power of the controller, without considering the impact of temperature and SOC changes on the power battery and making real-time power adjustments. Therefore, there is a risk of over-discharge due to excessive power, which cannot effectively protect the battery. Summary of the Invention

[0004] Therefore, the technical problem to be solved by the present invention is to overcome the defect that the vehicle energy distribution method in the prior art cannot adjust the power in real time according to the actual power change of the power battery, and thus provide an electric vehicle energy distribution method, device, system and medium that can adjust the power in real time according to the actual power change of the power battery.

[0005] According to a first aspect, embodiments of the present invention provide an energy distribution method for an electric vehicle. The energy distribution system for the electric vehicle includes a power battery, a drive motor, and a working motor. The power battery provides power to the drive motor and the working motor. The energy distribution method for the electric vehicle includes:

[0006] The current state of charge and current battery temperature of the power battery are obtained, and the current discharge power of the power battery is obtained by matching the current state of charge and current battery temperature from the database.

[0007] Obtain the current walking power of the walking motor and the current working power of the working motor;

[0008] Based on the relationship between the current discharge power, the current walking power, and the current working power, the power of the walking motor and the working motor is adjusted.

[0009] Optionally, the working motor is adapted to drive the vehicle's steering and the operation of the working mechanism. The current working power includes the current steering power and the current working power. Adjusting the power of the travel motor and the working motor based on the relationship between the current discharge power, the current travel power, and the current working power includes:

[0010] When the current discharge power is less than the current steering power, both the working motor and the walking motor are controlled to stop working.

[0011] When the current discharge power is greater than the current steering power but less than the sum of the current steering power and the current travel power, the travel motor is controlled to stop working, and the working motor is controlled to rotate at a preset speed so that the working motor drives the vehicle body to turn.

[0012] When the current discharge power is greater than the sum of the current steering power and the current walking power but less than the sum of the current working power and the current walking power, the power of the walking motor is maintained at the current walking power, while the power of the working motor is reduced and the speed of the working motor is controlled to be no lower than the preset speed.

[0013] When the current discharge power is greater than the sum of the current working power and the current walking power, the power of the walking motor is maintained at the current walking power, and the power of the working motor is maintained at the current working power.

[0014] Optionally, before obtaining the current walking power of the walking motor and the current working power of the working motor, the method further includes:

[0015] Obtain the initial walking power of the walking motor and the initial working power of the working motor;

[0016] When the current state of charge is greater than or equal to the first preset value, the current walking power is determined to be the initial walking power and the current working power is determined to be the initial working power;

[0017] When the current state of charge is greater than or equal to the second preset value and less than the first preset value, the current walking power is determined to be half of the initial walking power, the current working power is half of the initial working power, and the speed of the working motor is controlled to be no less than the preset speed.

[0018] When the current state of charge is less than the second preset value, both the working motor and the walking motor are controlled to stop working.

[0019] Wherein, the second preset value is less than the first preset value.

[0020] Optionally, when the electric vehicle brakes, the drive motor converts into a generator, and the power generated by the drive motor is feedback power; after obtaining the current state of charge and current battery temperature of the power battery, the method further includes:

[0021] Determine the operating status of the electric vehicle;

[0022] When the electric vehicle is not under braking, the step of matching the current discharge power of the power battery from the database based on the current state of charge and the current battery temperature is executed.

[0023] When the electric vehicle is under braking, the following steps are performed:

[0024] The current charging power of the power battery is obtained by matching the current state of charge and the current battery temperature from the database.

[0025] When the current state of charge is less than or equal to a third preset value, the walking motor charges the power battery with the feedback power;

[0026] When the current state of charge is greater than the third preset value, the walking motor is controlled to charge the power battery based on the relationship between the feedback power and the current charging power.

[0027] The third preset value is greater than the first preset value.

[0028] Optionally, the electric vehicle energy distribution system further includes a first switch connected in series with the power battery and a resistor branch connected in parallel with the power battery and the first switch. The step of controlling whether the drive motor charges the power battery based on the relationship between the feedback power and the current charging power includes:

[0029] When the feedback power is greater than the current charging power, the first switch is controlled to open and the resistor branch is connected, so that the walking motor is disconnected from the power battery and the walking motor and the resistor branch form a current loop;

[0030] When the feedback power is less than or equal to the current charging power, the first switch is turned on and the resistor branch is turned off, so that the walking motor charges the power battery.

[0031] Optionally, the electric vehicle energy distribution system further includes a resistor control unit, the first switch is a bidirectional thyristor, the resistor branch includes a resistor and a unidirectional thyristor connected in series, the resistor control unit is connected to the bidirectional thyristor and the unidirectional thyristor respectively, and the step of controlling the driving motor to charge the power battery based on the relationship between the feedback power and the current charging power further includes:

[0032] When the feedback power is greater than the current charging power, the resistor control unit controls the bidirectional thyristor to conduct unidirectionally, so as to disconnect the charging circuit between the walking motor and the power battery, and controls the unidirectional thyristor to conduct.

[0033] The resistor control unit does not operate when the feedback power is less than or equal to the current charging power.

[0034] According to a second aspect, embodiments of the present invention provide an energy distribution device for an electric vehicle, comprising:

[0035] The first acquisition module is used to acquire the current state of charge and current battery temperature of the power battery, and to obtain the current discharge power of the power battery by matching the current state of charge and current battery temperature from the database.

[0036] The second acquisition module is used to acquire the current walking power of the walking motor and the current working power of the working motor;

[0037] The first processing module is used to adjust the power of the walking motor and the working motor based on the relationship between the current discharge power, the current walking power, and the current working power.

[0038] According to a third aspect, embodiments of the present invention provide an energy distribution system for an electric vehicle, comprising:

[0039] The system includes a power battery, a walking motor, a working motor, and a control unit. The power battery provides power to the walking motor and the working motor. The control unit includes a memory and a processor, which are interconnected. The memory stores computer instructions, and the processor executes the computer instructions to perform the electric vehicle energy distribution method described in the first aspect and any of its optional embodiments.

[0040] Optionally, the control unit includes a vehicle controller, a battery controller, a drive motor controller, a work motor controller, and a resistor control unit connected by a CAN bus system.

[0041] According to a fourth aspect, embodiments of the present invention provide a computer-readable storage medium storing computer instructions for causing a computer to perform the electric vehicle energy distribution method described in the first aspect, or any alternative embodiment thereof.

[0042] The technical solution of this invention has the following advantages:

[0043] The electric vehicle energy distribution method and apparatus provided in this invention obtain the current discharge power of the power battery by matching it with a database based on the current state of charge and the current battery temperature. This yields the real-time available discharge power of the power battery. Based on the relationship between the current discharge power and the current travel power required by the travel motor and the current operating power required by the operating motor, the power of the travel motor and the operating motor is adjusted. This achieves real-time power distribution and limitation of the travel power and operating power according to the discharge power of the power battery, thereby preventing the power battery from over-discharge due to the travel power and operating power exceeding the current discharge power of the power battery. This protects the safety of the power battery and extends its service life. Attached Figure Description

[0044] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0045] Figure 1 This is a circuit connection diagram of the electric vehicle energy distribution system according to an embodiment of the present invention;

[0046] Figure 2 This is a schematic diagram of the connection of the vehicle communication network according to an embodiment of the present invention;

[0047] Figure 3 This is a flowchart of an electric vehicle energy distribution method according to an embodiment of the present invention;

[0048] Figure 4 This is a flowchart of the discharge control process according to an embodiment of the present invention;

[0049] Figure 5 This is a flowchart of the regenerative braking energy recovery process according to an embodiment of the present invention;

[0050] Figure 6 This is a schematic diagram of the structure of an electric vehicle energy distribution device according to an embodiment of the present invention;

[0051] Figure 7This is a schematic diagram of the structure of an electronic device according to an embodiment of the present invention. Detailed Implementation

[0052] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0053] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for 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. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0054] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can also refer to the internal connection of two components; and they can refer to a wireless connection or a wired connection. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0055] The technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0056] The current discharge power of a power battery is limited by its current state of charge (SOC) and temperature. Excessive heat or cold, or a decrease in SOC, will lead to a reduction in discharge power. Electric vehicles have a driving system driven by a drive motor and a working system driven by a duty motor. The power battery provides power to both motors. During operation, a mismatch often exists between the power available from the battery and the power required by the driving and working systems. However, current energy distribution methods in electric vehicles often only limit the total output power of the controller, without considering the impact of temperature and SOC changes on the battery's power and implementing real-time power adjustment. Therefore, there is a risk of over-discharge and over-power discharge, which fails to adequately protect the battery.

[0057] To address the aforementioned problems, embodiments of the present invention provide an energy distribution system for electric vehicles, such as... Figures 1 to 2 As shown, the electric vehicle energy distribution system includes a power battery 10, a drive motor 21, a work motor 22, and a control unit. The power battery 10 provides power to the drive motor 21 and the work motor 22. The control unit includes a vehicle controller (VCU) 31, a battery management system (BMS) 32, a drive motor controller (drive MCU) 33, a work motor controller (work MCU) 34, and a resistor control unit 35, all connected via a CAN bus system. The CAN bus system connects all controllers and control units, enabling real-time data transmission on the CAN bus.

[0058] In this embodiment, the travel motor controller (travel MCU) 33 in the control unit is connected between the power battery 10 and the travel motor 21 to control the travel motor 21; the work motor controller (work MCU) 34 is connected between the power battery 10 and the work motor 22 to control the work motor 22. The travel motor 21 is adapted to drive the travel mechanism to travel, thereby driving the electric vehicle to travel, and the work motor 22 is adapted to drive the vehicle body steering and the operation of the working mechanism. Specifically, the work motor 22 first drives the oil pump to rotate, and the oil pump delivers hydraulic oil to each working mechanism, thereby driving the operation of each working mechanism. Specifically, the electric vehicle can be an electric forklift, and the operation of the working mechanism includes lifting, tilting, and lateral movement.

[0059] In this embodiment, the electric vehicle energy distribution system further includes a first switch 41 connected in series with the power battery 10, a resistor branch connected in parallel with the power battery 10 and the first switch 41, and a resistor control unit 35. The first switch 41 controls the connection or disconnection of the charging circuit of the power battery 10 by its own on / off state. The resistor branch is connected in parallel to the positive and negative terminals of the input terminal of the power battery 10, including a resistor 50 connected in series and a second switch 42. The second switch 42 controls the on / off state of the resistor branch by its own on / off state. The resistor control unit 35 is electrically connected to the first switch 41 and the second switch 42 respectively to control the on / off state of the first switch 41 and the second switch 42. When the resistor control unit 35 is not activated, the first switch 41 is on and the second switch 42 is off. At this time, during vehicle regenerative braking, the drive motor 21, which is converted into a generator, can charge the power battery 10. However, when the resistor control unit 35 is activated, controlling the first switch 41 to open and the second switch 42 to close, the power battery 10 is disconnected from the circuit, and the resistor branch forms a new circuit with the drive motor 21. At this time, the drive motor 21, which is converted into a generator, does not charge the power battery 10. The current generated by the drive motor 21 is dissipated by the resistor 50 in the resistor branch through heating, ensuring circuit safety. Optionally, the resistor 50 is a metal alloy resistor.

[0060] Specifically, the first switch 41 is a bidirectional thyristor, and the second switch 42 is a unidirectional thyristor V3. The bidirectional thyristor includes thyristors V1 and V2 connected in parallel with opposite conduction directions. Thyristor V1 is connected to the discharge circuit of the power battery 10 and is always conducting, ensuring that the discharge circuit of the power battery 10 is conducting. When the power battery 10 is in a discharge state, it can always supply power to the walking motor 21 and the working motor 22. Thyristor V2 is connected to the charging circuit of the power battery 10. When thyristor V2 is conducting and unidirectional thyristor V3 is off, the feedback energy generated by the walking motor 21 can charge the power battery 10. When thyristor V2 is off, the charging circuit of the power battery 10 is disconnected, and the feedback energy generated by the walking motor 21 cannot charge the power battery 10. The resistor control unit 35 is connected to both a bidirectional thyristor and a unidirectional thyristor. When the resistor control unit 35 is not activated, the bidirectional thyristor is bidirectionally conductive, the first switch 41 is on, and both the charging and discharging circuits of the power battery 10 are connected. When the resistor control unit 35 controls the bidirectional thyristor to conduct unidirectionally (i.e., when the resistor control unit 35 controls thyristor V2 to disconnect), the first switch 41 is off, and the charging circuit of the power battery 10 is disconnected. When the resistor control unit 35 controls the unidirectional thyristor to conduct, the second switch 42 is on, and the resistor branch is conductive. When the resistor control unit 35 is not activated, the unidirectional thyristor V3 is not conductive, and the resistor branch is disconnected. By controlling the conduction state of the bidirectional thyristor through the resistor control unit 35, the charging circuit of the power battery 10 is connected and disconnected. Furthermore, by controlling the on / off state of the unidirectional thyristor, the resistor branch is connected and disconnected. This design is simple, convenient, and highly automated. It is understood that, as an alternative implementation, the first switch 41 and the second switch 42 may also be common switches such as electromagnetic relays.

[0061] This invention provides an energy distribution method for electric vehicles, such as... Figure 3 As shown, the energy distribution method for electric vehicles specifically includes the following steps:

[0062] Step S101: Obtain the current state of charge and current battery temperature of the power battery 10, and obtain the current discharge power of the power battery 10 from the database based on the current state of charge and current battery temperature.

[0063] It should be noted that the discharge power of the power battery is affected by the state of charge (SOC) and temperature. Based on the characteristics of the selected power battery, a discharge power map table of the power battery at different SOCs and temperatures is measured in advance and the data is saved to the battery controller (BMS) 32. The database is the data in the discharge power map table in the BMS. During operation, the BMS compares the current temperature (i.e., current battery temperature) and SOC (i.e., current state of charge) of the power battery with the discharge power map table to obtain the current discharge power of the power battery, i.e., the current discharge power.

[0064] It should be noted that excessively high or low temperatures will affect the discharge power of the power battery, reducing its discharge capacity and hindering its energy utilization. Preferably, water cooling can be used to dissipate heat when the power battery is at high temperatures, while heating can be used when the power battery is at low temperatures, thereby increasing the discharge capacity and improving the battery's discharge performance.

[0065] Step S102: Obtain the current walking power of the walking motor 21 and the current working power of the working motor 22.

[0066] When the electric vehicle starts running, the vehicle controller (VCU) 31 calculates the current travel power requirement based on the accelerator pedal signal, brake signal, and working mode, which is the current travel power; the VCU calculates the oil pump power requirement based on the lifting potentiometer signal, tilt signal, lateral movement signal, and steering signal, which is the current working power.

[0067] Step S103: Based on the relationship between the current discharge power, the current walking power, and the current working power, adjust the power of the walking motor 21 and the working motor 22.

[0068] The power of both the walking motor 21 and the working motor 22 is provided by the current discharge power of the power battery 10. The VCU compares the calculated current walking power and current working power with the current discharge power in the BMS in real time via the CAN bus. After calculation, it allocates power to the walking motor controller 33 and the working motor controller 34 respectively, and then controls the rotation of the walking motor 21 through the walking motor controller 33 and the rotation of the working motor 22 through the working motor controller 34.

[0069] By performing the above steps, the electric vehicle energy distribution method provided in this embodiment of the invention obtains the current discharge power of the power battery 10 by matching it with the database based on the current state of charge and the current battery temperature, thus obtaining the real-time discharge power that the power battery 10 can provide. Based on the relationship between the current discharge power and the current walking power required by the walking motor 21 and the current working power required by the working motor 22, the power of the walking motor 21 and the working motor 22 is adjusted. This achieves real-time power distribution and limitation of the walking power and working power according to the discharge power of the power battery, thereby preventing the power battery 10 from being over-discharged due to the walking power and working power exceeding the current discharge power of the power battery, thus protecting the safety of the power battery 10 and extending its service life.

[0070] like Figure 4 As shown, in this embodiment, step S103 specifically includes the following steps:

[0071] Step S201: When the current discharge power is less than the current steering power, control both the working motor 22 and the walking motor 21 to stop working.

[0072] It should be noted that the working motor 22 is suitable for driving the vehicle body steering and the operation mechanism. The current working power includes the current steering power and the current operation power. The vehicle controller 31 allocates power to the travel motor controller 33 and the working motor controller 34 respectively. The allocation principle is to prioritize meeting the power required for vehicle body steering. If the current discharge power is less than the current steering power, it means that the current discharge power is insufficient to meet the power required for steering. At this time, both the working motor 22 and the travel motor 21 need to stop rotating to ensure the safety of the vehicle.

[0073] Step S202: When the current discharge power is greater than the current steering power and less than the sum of the current steering power and the current travel power, control the travel motor 21 to stop working and control the working motor 22 to rotate at a preset speed so that the working motor 22 drives the vehicle body to turn.

[0074] It should be noted that if the current discharge power is greater than the current steering power but less than the sum of the current steering power and the current travel power, then the current discharge power can meet the power required for steering, but cannot simultaneously meet the power required for both steering and travel. In this case, the travel motor 21 stops rotating, prioritizing the power required for steering to ensure the vehicle can steer. Only after meeting the power required for steering can the power requirement of the travel motor 21 be met to ensure driving safety. The preset speed is the speed of the travel motor 21 that ensures vehicle steering; optionally, the preset speed is 600 rpm. rpm。

[0075] Step S203: When the current discharge power is greater than the sum of the current steering power and the current travel power but less than the sum of the current working power and the current travel power, maintain the power of the travel motor 21 at the current travel power, reduce the power of the working motor 22, and control the speed of the working motor 22 to be no lower than the preset speed.

[0076] It should be noted that if the current discharge power is greater than the sum of the current steering power and the current travel power but less than the sum of the current working power and the current travel power, then the current discharge power can meet the power requirements for steering and travel, but cannot simultaneously meet the combined operational requirements of steering, travel, and working actions. In this case, while meeting the power requirements for steering, the travel power requirements are also met to ensure that the electric vehicle can steer and travel. Simultaneously, reducing the power of the working motor 22 can prevent the sum of the current working power and the current travel power from exceeding the current discharge power, thereby avoiding over-discharge and protecting battery safety. It is important to note that when reducing the power of the working motor 22, the rotational speed of the working motor 22 must not be lower than the preset rotational speed, ensuring that the working motor 22 can drive the vehicle body to achieve steering. The working actions include lifting, tilting, and lateral movement. Preferably, the rotational speed of the working motor 22 is controlled to be equal to the preset rotational speed of 600. rpm。

[0077] Step S204: When the current discharge power is greater than the sum of the current working power and the current walking power, maintain the power of the walking motor 21 at the current walking power and maintain the power of the working motor 22 at the current working power.

[0078] It should be noted that if the current discharge power is greater than the sum of the current working power and the current traveling power, then the current discharge power can meet the power required for steering, traveling and operation. In this case, both the traveling motor 21 and the working motor 22 can operate at the current power without adjustment.

[0079] The electric vehicle energy distribution method provided in this embodiment allocates power according to the following principles: First, it prioritizes meeting the current steering power required for vehicle steering; second, it meets the power requirements of the travel motor 21 for movement, provided that steering needs are met; and finally, it meets the power requirements for actions such as lifting, tilting, and lateral movement. This method prevents over-power discharge while ensuring steering and driving safety, thus improving operational safety. During operation, the travel MCU controls the travel motor 21 according to instructions from the VCU, and the work MCU controls the work motor 22 according to instructions from the VCU.

[0080] In this embodiment, the following steps are included before step S102 described above:

[0081] Step S104: Obtain the initial walking power of the walking motor 21 and the initial working power of the working motor 22.

[0082] The initial walking power is the power of the walking motor 21 when it is turned on, and the initial working power is the power of the working motor 22 when it is turned on.

[0083] Step S105: When the current state of charge is greater than or equal to the first preset value, determine the current walking power as the initial walking power and the current working power as the initial working power.

[0084] It should be noted that the power battery 10 has poor discharge performance and low discharge power when at a low SOC (State of Charge), making it difficult to meet the power requirements of the vehicle. Therefore, extra attention is needed when the power battery is at a low SOC. The first preset value is a critical value for defining a low SOC. When the current state of charge is greater than or equal to the first preset value, no additional processing is needed for the motor power. At this time, the current driving power is determined to be equal to the initial driving power, and the current operating power is determined to be equal to the initial operating power. The first preset value is derived from the battery performance and testing experience, and preferably, the first preset value is 20%.

[0085] Step S106: When the current state of charge is greater than or equal to the second preset value and less than the first preset value, determine that the current walking power is half of the initial walking power, the current working power is half of the initial working power, and control the speed of the working motor 22 to be no less than the preset speed.

[0086] It should be noted that the second preset value is less than the first preset value. When the current state of charge is between the second and first preset values, the power of the travel motor 21 and the work motor 22 needs to be reduced. Specifically, the power of both the travel motor 21 and the work motor 22 is reduced to half of their initial power, and the reduced power is used as the current power. It is important to note that at this time, the speed of the work motor 22 must still be maintained at a preset speed to ensure that the work motor 22 can meet the vehicle steering requirements. That is, under the premise of ensuring steering requirements, the VCU halves the travel power requirement of the travel motor 21 and the working power requirement of the work motor 22 generated by lifting, tilting, and lateral movement, thereby preventing the sum of the power of the travel motor 21 and the work motor 22 from exceeding the current discharge power to protect discharge safety. Preferably, the first preset value is 20% and the second preset value is 10%.

[0087] Step S107: When the current state of charge is less than the second preset value, control both the working motor 22 and the walking motor 21 to stop working.

[0088] It should be noted that the second preset value is the minimum state of charge that the current discharge power of the power battery 10 can maintain the operation of the motor. If the current state of charge is less than the second preset value, the current discharge power cannot meet the needs of the motor operation or there will be an over-power discharge, which will cause greater damage to the power battery 10. Therefore, when the current state of charge is less than the second preset value, it is necessary to control both the working motor 22 and the walking motor 21 to stop working, and the entire electric vehicle will stop working to ensure the safety of the battery and the vehicle.

[0089] It should be noted that when the electric vehicle brakes, energy recovery can be achieved. At this time, the drive motor 21 transforms into a generator, converting mechanical energy into electrical energy to charge the power battery 10. However, when the power battery has a high SOC (above 95%) or is too cold, its rechargeable power is very small. On steep or long slopes, energy recovery during descent may cause overcharging of the power battery 10, posing a certain danger. However, reducing the feedback power would weaken the electric braking force, also posing a certain danger. Therefore, it is necessary to rationally distribute the electrical energy generated during the electric vehicle's braking process. To solve the above problems, after obtaining the current state of charge and current battery temperature of the power battery 10, the following steps are also included:

[0090] Step S301: Determine the working status of the electric vehicle.

[0091] It should be noted that the electric vehicle energy distribution method in this embodiment is executed during the operation of the electric vehicle, which has a normal driving operation state and a braking operation state.

[0092] Step S302: When the electric vehicle is not under braking, the step of matching the current discharge power of the power battery from the database based on the current state of charge and the current battery temperature is executed. That is, when the electric vehicle is in normal driving operation, the step of matching the current discharge power of the power battery 10 from the database based on the current state of charge and the current battery temperature in step S101 above, and subsequent steps, are executed.

[0093] Step S303: When the electric vehicle is under braking, perform the following steps:

[0094] Step S401: Obtain the current charging power of the power battery 10 from the database based on the current state of charge and the current battery temperature.

[0095] It should be noted that when the electric vehicle is braking, the power generated by the drive motor 21 is regenerative power. The drive motor 21 can charge the power battery 10 with regenerative power, but it is necessary to first determine whether the power battery 10 can withstand the charging power of the regenerative power. The charging power of the power battery is affected by the state of charge (SOC) and temperature. Based on the characteristics of the selected power battery, a charging power map table of the power battery at different SOCs and temperatures is measured in advance and the data is saved to the BMS. The database is the data in the charging power map table in the BMS. During operation, the BMS compares the current temperature (i.e., current battery temperature) and SOC (i.e., current state of charge) of the power battery with the charging power map table to obtain the current rechargeability of the power battery, i.e., the current charging power.

[0096] Step S402: When the current state of charge is less than or equal to the third preset value, the walking motor 21 charges the power battery 10 with feedback power.

[0097] It should be noted that when the power battery 10 is at a high SOC, its rechargeable power is very small, which may lead to a dangerous situation where the feedback power exceeds the rechargeable power of the power battery. Conversely, when the power battery 10 is not at a high SOC, its rechargeable power is relatively large, allowing it to be charged using the feedback power provided by the walking motor 21. The third preset value is greater than the first preset value. The third preset value is the critical value used to determine whether the power battery 10 is at a high SOC. When the current state of charge is less than or equal to the third preset value, it indicates that the power battery 10 is not at a high SOC, and the power generated by braking can be entirely used to charge the power battery 10. Preferably, the third preset value is 95%.

[0098] Step S403: When the current state of charge is greater than the third preset value, based on the relationship between the feedback power and the current charging power, control whether the walking motor 21 charges the power battery 10.

[0099] It should be noted that if the current state of charge is greater than the third preset value, there are two situations: the feedback power is greater than the current charging power and the feedback power is less than or equal to the current charging power. In this case, it is necessary to first determine the relationship between the feedback power and the current charging power, and then control whether the walking motor 21 charges the power battery 10. This is to prevent the power battery 10 from being overcharged when the feedback power is greater than the charging power of the power battery, thus avoiding damage to the battery due to overcharging.

[0100] In this embodiment, the step of controlling the walking motor 21 to charge the power battery 10 based on the relationship between the feedback power and the current charging power in step S403 specifically includes the following steps:

[0101] Step S501: When the feedback power is greater than the current charging power, the first switch 41 is opened and the resistor branch is connected, so that the walking motor 21 is disconnected from the power battery 10 and the walking motor 21 and the resistor branch form a current loop.

[0102] Step S502: When the feedback power is less than or equal to the current charging power, control the first switch 41 to turn on and the resistor branch to turn off, so that the walking motor 21 charges the power battery 10.

[0103] It should be noted that the circuit of the electric vehicle includes a first switch 41 connected in series with the power battery 10, and a resistor branch connected in parallel with the power battery 10 and the first switch 41. The first switch 41 is used to control whether the power battery 10 is connected to the circuit. The resistor branch and the first switch 41 do not conduct at the same time. Specifically, when the electric vehicle is in a braking state, the first switch 41 is connected in series with the power battery 10. When the first switch 41 is closed, the resistor branch is open, thus connecting the power battery 10 to the circuit. The power battery 10 and the drive motor 21 form a complete circuit loop, and the electrical energy generated by the drive motor 21 charges the power battery 10 during braking. When the first switch 41 is open, the power battery 10 is disconnected from the circuit. At this time, the resistor branch is open, and the drive motor 21 and the resistor branch form a closed circuit. The electrical energy generated by the drive motor 21 during braking no longer charges the power battery 10, but is consumed by the resistor branch. By controlling the first switch 41 to open and the resistor branch to close when the feedback power exceeds the current charging power, the system prevents the walking motor 21 from charging the power battery 10 and causing overcharging, thus protecting the battery's safety. Simultaneously, the resistor branch dissipates the electrical energy generated by the walking motor 21, forming a complete circuit system. It can be understood that when the electric vehicle is in normal operation, the first switch 41 is closed, the resistor branch is open, and the power battery 10 is connected in the circuit, providing power to the walking motor 21 and the working motor 22.

[0104] In this embodiment, the electric vehicle energy distribution system further includes a resistor control unit 35. The first switch 41 is a bidirectional thyristor. The resistor branch includes a resistor 50 connected in series and a unidirectional thyristor. The resistor control unit 35 is connected to both the bidirectional and unidirectional thyristors. Figure 5 As shown, the step S403 above, which controls the walking motor 21 to charge the power battery 10 based on the relationship between the feedback power and the current charging power, specifically includes the following steps:

[0105] Step S601: When the feedback power is greater than the current charging power, the resistor control unit 35 controls the bidirectional thyristor to conduct unidirectionally, so as to disconnect the charging circuit between the walking motor 21 and the power battery 10, and controls the unidirectional thyristor to conduct.

[0106] It should be noted that the bidirectional thyristor includes thyristors V1 and V2 with opposite conduction directions. During the braking process that causes the travel motor 21 to generate electricity, the resistor control unit 35 controls the bidirectional thyristor to conduct unidirectionally, meaning that the resistor control unit 35 controls thyristor V1 while thyristor V2 is disconnected. The charging circuit of the power battery 10 is disconnected, and the energy fed back by the travel motor 21 cannot charge the power battery 10. The unidirectional thyristor V3 is initially in a disconnected state. When the feedback power is greater than the current charging power, the resistor control unit 35 controls the unidirectional thyristor V3 to conduct, and the resistor branch is in a conducting state. The resistor branch is connected in series with the travel motor 21, and the regenerative braking current of the travel motor 21 is dissipated by the resistor 50 as heat. The disconnection of thyristor V2 and the conduction of unidirectional thyristor V3 occur simultaneously. Preferably, the resistor 50 is an alloy resistor, which is inexpensive and has good stability. It can be understood that, as an alternative implementation, the unidirectional thyristor can also be replaced by devices such as IGBTs (Insulated Gate Bipolar Transistors). The common practice in the prior art is to add a supercapacitor connected to the walking motor 21 to absorb excess energy, but supercapacitors are expensive and have low cost performance.

[0107] Step S602: When the feedback power is less than or equal to the current charging power, the resistor control unit 35 does not operate.

[0108] When the resistor control unit 35 is not activated, both thyristors V1 and V2 are in the conducting state, meaning the bidirectional thyristor is in a bidirectional conducting state, and the power battery 10 is connected in the circuit. Meanwhile, the unidirectional thyristor V3 is in the disconnected state, meaning the resistor branch is disconnected, and the charging circuit of the power battery 10 is connected. At this time, the walking motor 21 can charge the power battery 10. The control of the thyristors is simple and has good stability.

[0109] Preferably, to prevent the metal alloy resistor from overheating, a fan can be installed to blow air and dissipate heat from the metal alloy.

[0110] This invention also provides an energy distribution device for electric vehicles, such as... Figure 6 As shown, the energy distribution device for the electric vehicle includes:

[0111] The first acquisition module 101 is used to acquire the current state of charge and current battery temperature of the power battery 10, and to obtain the current discharge power of the power battery 10 by matching the current state of charge and current battery temperature from the database.

[0112] The second acquisition module 102 is used to acquire the current walking power of the walking motor 21 and the current working power of the working motor 22;

[0113] The first processing module 103 is used to adjust the power of the walking motor 21 and the working motor 22 based on the relationship between the current discharge power, the current walking power and the current working power.

[0114] The electric vehicle energy distribution device provided in this embodiment of the invention is used to execute the electric vehicle energy distribution method provided in the above embodiment. Its implementation method and principle are the same. For details, please refer to the relevant description of the above method embodiment, which will not be repeated here.

[0115] The control unit provided in this embodiment of the invention includes a processor 901 and a memory 902, wherein the processor 901 and the memory 902 can be connected via a bus or other means. Figure 7 Taking the example of a connection between China and Israel via a bus.

[0116] Processor 901 can be a Central Processing Unit (CPU). Processor 901 can also be other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, or combinations of the above types of chips.

[0117] The memory 902, as a non-transitory computer-readable storage medium, can be used to store non-transitory software programs, non-transitory computer-executable programs, and modules, such as the program instructions / modules corresponding to the methods in the above method embodiments. The processor 901 executes various functional applications and data processing of the processor by running the non-transitory software programs, instructions, and modules stored in the memory 902, thereby implementing the methods in the above method embodiments.

[0118] The memory 902 may include a program storage area and a data storage area. The program storage area may store the operating system and applications required for at least one function; the data storage area may store data created by the processor 901, etc. Furthermore, the memory 902 may include high-speed random access memory and may also include non-transitory memory, such as at least one disk storage device, flash memory device, or other non-transitory solid-state storage device. In some embodiments, the memory 902 may optionally include memory remotely located relative to the processor 901, and these remote memories may be connected to the processor 901 via a network. Examples of such networks include, but are not limited to, the Internet, corporate intranets, local area networks, mobile communication networks, and combinations thereof.

[0119] One or more modules are stored in memory 902, and when executed by processor 901, they perform the methods described in the above method embodiments.

[0120] The specific details of the control unit can be understood by referring to the relevant descriptions and effects in the above method embodiments, and will not be repeated here.

[0121] Those skilled in the art will understand that all or part of the processes in the methods of the above embodiments can be implemented by a computer program instructing related hardware. The implemented program can be stored in a computer-readable storage medium. When executed, the program can include the processes of the embodiments of the above methods. The storage medium can be a magnetic disk, optical disk, read-only memory (ROM), random access memory (RAM), flash memory, hard disk drive (HDD), or solid-state drive (SSD), etc.; the storage medium can also include combinations of the above types of memory.

[0122] As can be seen from the above description, the embodiments of the present invention achieve the following technical effects:

[0123] 1. By connecting the VCU, BMS, walking MCU, and working MCU via the CAN bus, real-time data transmission on the CAN bus can be achieved;

[0124] 2. The power battery can be protected in real time based on the discharge power map table to prevent over-discharge;

[0125] 3. The power battery can be protected in real time based on the charging power map table to prevent overcharging;

[0126] 4. Prioritizing vehicle steering and movement ensures better driving safety;

[0127] 5. Using metal alloy resistors is less expensive than adding supercapacitors and safer than reducing the feedback current.

[0128] Although embodiments of the invention have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the invention, and such modifications and variations all fall within the scope defined by the appended claims.

Claims

1. A method for energy distribution in an electric vehicle, characterized in that, The electric vehicle energy distribution system includes a power battery, a drive motor, and a drive motor. The power battery provides power to the drive motor and the drive motor. The electric vehicle energy distribution method includes: The current state of charge and current battery temperature of the power battery are obtained, and the current discharge power of the power battery is obtained by matching the current state of charge and current battery temperature from the database. Obtain the current walking power of the walking motor and the current working power of the working motor; Based on the relationship between the current discharge power, the current walking power, and the current working power, adjust the power of the walking motor and the working motor; The working motor is adapted to drive the vehicle's steering and operating mechanism movements. The current working power includes the current steering power and the current operating power. Adjusting the power of the travel motor and the working motor based on the relationship between the current discharge power, the current travel power, and the current working power includes: When the current discharge power is less than the current steering power, both the working motor and the walking motor are controlled to stop working. When the current discharge power is greater than the current steering power but less than the sum of the current steering power and the current travel power, the travel motor is controlled to stop working, and the working motor is controlled to rotate at a preset speed so that the working motor drives the vehicle body to turn. When the current discharge power is greater than the sum of the current steering power and the current walking power but less than the sum of the current working power and the current walking power, the power of the walking motor is maintained at the current walking power, while the power of the working motor is reduced and the speed of the working motor is controlled to be no lower than the preset speed. When the current discharge power is greater than the sum of the current working power and the current walking power, the power of the walking motor is maintained at the current walking power, and the power of the working motor is maintained at the current working power.

2. The energy distribution method for electric vehicles according to claim 1, characterized in that, Before obtaining the current walking power of the walking motor and the current working power of the working motor, the method further includes: Obtain the initial walking power of the walking motor and the initial working power of the working motor; When the current state of charge is greater than or equal to the first preset value, the current walking power is determined to be the initial walking power and the current working power is determined to be the initial working power; When the current state of charge is greater than or equal to the second preset value and less than the first preset value, the current walking power is determined to be half of the initial walking power, the current working power is half of the initial working power, and the speed of the working motor is controlled to be no less than the preset speed. When the current state of charge is less than the second preset value, both the working motor and the walking motor are controlled to stop working. Wherein, the second preset value is less than the first preset value.

3. The energy distribution method for electric vehicles according to claim 2, characterized in that, When the electric vehicle brakes, the walking motor transforms into a generator, and the power generated by the walking motor is the feedback power. After obtaining the current state of charge and current battery temperature of the power battery, the method further includes: Determine the operating status of the electric vehicle; When the electric vehicle is not under braking, the step of matching the current discharge power of the power battery from the database based on the current state of charge and the current battery temperature is executed. When the electric vehicle is under braking, the following steps are performed: The current charging power of the power battery is obtained by matching the current state of charge and the current battery temperature from the database. When the current state of charge is less than or equal to a third preset value, the walking motor charges the power battery with the feedback power; When the current state of charge is greater than the third preset value, the walking motor is controlled to charge the power battery based on the relationship between the feedback power and the current charging power. The third preset value is greater than the first preset value.

4. The energy distribution method for electric vehicles according to claim 3, characterized in that, The electric vehicle energy distribution system further includes a first switch connected in series with the power battery and a resistor branch connected in parallel with the power battery and the first switch. The step of controlling whether the drive motor charges the power battery based on the relationship between the feedback power and the current charging power includes: When the feedback power is greater than the current charging power, the first switch is controlled to open and the resistor branch is connected, so that the walking motor is disconnected from the power battery and the walking motor and the resistor branch form a current loop; When the feedback power is less than or equal to the current charging power, the first switch is turned on and the resistor branch is turned off, so that the walking motor charges the power battery.

5. The energy distribution method for electric vehicles according to claim 4, characterized in that, The electric vehicle energy distribution system further includes a resistor control unit. The first switch is a bidirectional thyristor. The resistor branch includes a resistor and a unidirectional thyristor connected in series. The resistor control unit is connected to both the bidirectional thyristor and the unidirectional thyristor. The method of controlling the driving motor to charge the power battery based on the relationship between the feedback power and the current charging power also includes: When the feedback power is greater than the current charging power, the resistor control unit controls the bidirectional thyristor to conduct unidirectionally, so as to disconnect the charging circuit between the walking motor and the power battery, and controls the unidirectional thyristor to conduct. The resistor control unit does not operate when the feedback power is less than or equal to the current charging power.

6. An energy distribution device for an electric vehicle, used to execute the energy distribution method for an electric vehicle according to any one of claims 1-5, characterized in that, The electric vehicle energy distribution device includes: The first acquisition module is used to acquire the current state of charge and current battery temperature of the power battery, and to obtain the current discharge power of the power battery by matching the current state of charge and current battery temperature from the database. The second acquisition module is used to acquire the current walking power of the walking motor and the current working power of the working motor; The first processing module is used to adjust the power of the walking motor and the working motor based on the relationship between the current discharge power, the current walking power, and the current working power.

7. An energy distribution system for an electric vehicle, characterized in that, include: The system includes a power battery, a walking motor, a working motor, and a control unit. The power battery provides power to the walking motor and the working motor. The control unit includes a memory and a processor, which are communicatively connected. The memory stores computer instructions, and the processor executes the computer instructions to perform the method as described in any one of claims 1-5.

8. The electric vehicle energy distribution system according to claim 7, characterized in that, The control unit includes a vehicle controller, a battery controller, a drive motor controller, a work motor controller, and a resistor control unit connected by a CAN bus system.

9. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores computer instructions for causing the computer to perform the method as described in any one of claims 1-5.

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