An electric vehicle charging control method and an electric vehicle

Abstract

The embodiment of the application discloses an electric vehicle charging control method and an electric vehicle. The electric vehicle charging control method comprises the following steps: setting a charging current model, a battery temperature change speed estimation model and a temperature estimation model, etc. The charging current model determines the charging current, the battery temperature change speed estimation model determines the battery temperature change estimation speed, the temperature estimation model estimates the battery temperature, the charging and temperature management model determines the battery temperature adjustment speed, and the battery temperature adjustment model determines the temperature change device power according to the battery temperature adjustment speed. The charging and temperature management model determines the actual current allocated to the temperature change device. The embodiment of the application controls the battery temperature in the normal temperature range as much as possible, thereby reducing the temperature fluctuation of the battery and maintaining a high charging speed. In the case that the charging pile is insufficient to supply the charging current and the temperature change device current at the same time, the supply of the charging current is given priority, and the charging speed is further ensured.

Description

Technical Field

[0001] The embodiments of the present invention relate to charging control technology, and more particularly to an electric vehicle charging control method and an electric vehicle. Background Technology

[0002] With the rapid development of electric vehicles, the issue of charging time has become an increasingly important concern.

[0003] In existing technologies, to reduce charging time, pure electric vehicles and some plug-in hybrid vehicles employ fast charging and cool the battery based on its real-time temperature. However, this cooling control strategy has a low level of intelligence, resulting in large fluctuations in battery temperature during charging. Battery temperature affects charging speed; charging is slower when the battery temperature is high. Since charging stations have limited power, excessively high power from the cooling device may preempt the charging station's power, causing the charging station to be unable to meet the battery's charging needs, further reducing the charging speed. Summary of the Invention

[0004] This invention provides an electric vehicle charging control method and an electric vehicle to improve charging speed.

[0005] In a first aspect, embodiments of the present invention provide an electric vehicle charging control method, including setting up a charging current model, a battery temperature change rate estimation model, a temperature estimation model, a charging and temperature management model, and a battery temperature regulation model respectively.

[0006] The charging current model obtains the battery temperature and battery state of charge, and determines the charging current based on the battery temperature and battery state of charge;

[0007] The battery temperature change rate estimation model obtains the ambient temperature and determines the battery temperature change rate estimation based on the ambient temperature and the charging current.

[0008] The temperature estimation model determines the estimated battery temperature when the battery state of charge reaches the upper limit of the current battery state of charge range based on the charging current and the battery temperature change estimation rate.

[0009] The charging and temperature management model determines whether the battery temperature is within the normal temperature range. If so, it determines whether the estimated battery temperature exceeds the normal temperature range. If so, it determines the battery temperature adjustment rate based on the battery temperature change estimation rate, wherein the battery temperature change estimation rate is less than or equal to the battery temperature adjustment rate.

[0010] The battery temperature regulation model determines the power of the variable temperature device based on the battery temperature regulation rate.

[0011] The charging and temperature management model determines the current required by the temperature-changing device based on its power, and determines whether the sum of the charging current and the current required by the temperature-changing device is greater than the upper limit of the current provided by the charging pile. If so, the current provided by the charging pile is prioritized to meet the supply of the charging current, and then supplied to the temperature-changing device.

[0012] Optionally, the temperature-changing device includes an air conditioner, a coolant pump, and refrigeration peripheral circuitry;

[0013] The battery temperature regulation model determines the power of the variable temperature device based on the battery temperature regulation rate, including determining the air conditioner power and coolant pump flow rate based on the battery temperature regulation rate, and determining the power of the variable temperature device based on the air conditioner power, the coolant pump flow rate, and the power of the refrigeration peripheral circuit.

[0014] Optionally, the temperature-changing device includes a heating device;

[0015] The battery temperature regulation model determines the power of the variable temperature device based on the battery temperature regulation rate, including determining the power of the heating device based on the battery temperature regulation rate, and determining the power of the variable temperature device based on the power of the heating device.

[0016] Optionally, the charging current model is also used to correct the determination relationship of the charging current based on the battery temperature and the battery state of charge as the battery health decreases.

[0017] Optionally, the battery temperature change rate estimation model is also used to correct the determination relationship of the battery temperature change rate estimation based on the ambient temperature and the charging current as the battery health decreases.

[0018] Optionally, the temperature estimation model determines the estimated battery temperature when the battery state of charge reaches the upper limit of the current battery state of charge range based on the charging current and the battery temperature change estimation rate, including:

[0019] The charging time required for the battery state of charge to reach the upper limit of the current battery state of charge range is the interval charging time. The interval charging time is calculated as (the upper limit of the current battery state of charge range - the battery state of charge) * battery capacity / the charging current.

[0020] The temperature rise during the process of the battery state of charge reaching the upper limit of the current battery state of charge range is the interval temperature rise. The interval temperature rise is calculated as the battery temperature change estimation rate * the interval charging time.

[0021] The estimated battery temperature is calculated as follows: Estimated battery temperature = Temperature rise range in the interval + Initial battery temperature.

[0022] Optionally, the temperature-changing device includes an air conditioner, a coolant pump, and refrigeration peripheral circuitry;

[0023] After determining whether the battery temperature is within the normal temperature range, the charging and temperature management model further includes, if not, and the battery temperature is higher than the normal temperature range, then determining the battery temperature regulation rate as the maximum cooling rate.

[0024] The battery temperature regulation model determines the power of the variable temperature device based on the battery temperature regulation rate, including determining the air conditioner power as the maximum power and the coolant pump flow rate as the maximum flow rate based on the maximum cooling rate, and determining the power of the variable temperature device based on the air conditioner power, the coolant pump flow rate, and the power of the refrigeration peripheral circuit.

[0025] Optionally, the temperature-changing device includes a heating device;

[0026] After determining whether the battery temperature is within the normal temperature range, the charging and temperature management model further includes, if not, and the battery temperature is below the normal temperature range, then determining the battery temperature regulation rate as the maximum heating rate.

[0027] The battery temperature regulation model determines the power of the variable temperature device based on the battery temperature regulation rate, including determining the power of the heating device as the maximum power based on the maximum heating rate, and determining the power of the variable temperature device based on the power of the heating device.

[0028] Optionally, if so, after determining whether the estimated battery temperature exceeds the normal temperature range, the method further includes, if not, setting the battery temperature adjustment rate to 0.

[0029] Secondly, embodiments of the present invention also provide an electric vehicle that uses any of the above-described electric vehicle charging control methods.

[0030] This invention provides an electric vehicle charging control method, comprising setting up a charging current model, a battery temperature change rate estimation model, a temperature estimation model, a charging and temperature management model, and a battery temperature regulation model. By coordinating these models, even when the battery temperature is within the normal temperature range, the power of the temperature-regulating device is adjusted according to the estimated battery temperature change rate to keep the battery temperature as close to the normal temperature range as possible. This reduces battery temperature fluctuations and maintains a high charging speed. When the charging pile is insufficient to simultaneously supply both the charging current and the temperature-regulating device current, priority is given to supplying the charging current, further ensuring the charging speed. Attached Figure Description

[0031] Figure 1 This is a schematic diagram of the inter-model structure of an electric vehicle charging control method provided in an embodiment of the present invention. Detailed Implementation

[0032] The present invention 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, the accompanying drawings show only the parts relevant to the present invention, and not all of the structures.

[0033] Figure 1 This is a schematic diagram of the inter-model structure of an electric vehicle charging control method provided in an embodiment of the present invention, with reference to... Figure 1 This invention provides an electric vehicle charging control method, including setting up a charging current model 1, a battery temperature change rate estimation model 2, a temperature estimation model 3, a charging and temperature management model 4, and a battery temperature regulation model 5.

[0034] Charging current model 1 obtains the battery temperature and battery state of charge, and determines the charging current based on the battery temperature and battery state of charge.

[0035] In this model, the charging current model 1 determines the charging current based on battery temperature and battery state of charge (SOC). This can be done in any way, such as calculating the charging current based on battery temperature and SOC, or obtaining the corresponding charging current from a pre-established data table. The data in the data table can be obtained experimentally. Optionally, the charging current model 1 also corrects the relationship between battery temperature and SOC as battery health decreases. During battery use, battery health decreases with the number of charge-discharge cycles. This decrease in battery health can lead to deviations in the relationship between battery temperature and SOC. Therefore, this relationship can be corrected proportionally according to actual needs, or by using data from a big data platform, ensuring accurate determination of the charging current during use. In the charging current determination table, the battery capacity range SOC can be defined as SOC1, SOC2…SOCn, and the battery temperature range can be defined as T1, T2…Tm. The currents corresponding to the SOC1 range in the temperature ranges T1, T2...Tm are A11, A21...Am1, and the currents corresponding to the SOCn range in the temperature ranges T1, T2...Tn are A1n, A2n...Amn. Both SOC and temperature ranges are continuous intervals, i.e., SOC1max = SOC2min, T1max = T2min, and so on. A normal temperature range can be set within the battery temperature range according to actual needs. Ranges above the normal temperature range are considered high-temperature ranges, and ranges below the normal temperature range are considered low-temperature ranges. The charging current determination table is shown below, used to input battery temperature and battery state of charge to query the charging current. The specific values ​​of the battery temperature range, battery state of charge range, and charging current can be determined according to actual needs.

[0036]

[0037] Battery temperature change rate estimation model 2 obtains the ambient temperature and determines the battery temperature change rate estimation based on the ambient temperature and charging current.

[0038] In this model, if the battery's temperature control device does not regulate the battery temperature under the current condition, the predicted rate of temperature change is the battery temperature estimation rate. The battery temperature estimation model 2 can determine the battery temperature estimation rate based on ambient temperature and charging current using any method. For example, it can calculate the battery temperature estimation rate based on ambient temperature and charging current, or it can obtain the battery temperature estimation rate corresponding to ambient temperature and charging current by looking up a pre-established data table. The data in the data table can be obtained experimentally. Optionally, the battery temperature estimation model 2 is also used to correct the determination relationship of the battery temperature estimation rate based on ambient temperature and charging current as the battery health decreases. Since battery health decreases with the increase of charge-discharge cycles during battery use, this decrease in battery health can lead to deviations in the determination relationship of the battery temperature estimation rate based on ambient temperature and charging current. Therefore, it can be corrected proportionally according to actual needs, or the determination relationship of the battery temperature estimation rate based on ambient temperature and charging current can be corrected using data obtained from a big data platform, thereby ensuring the accuracy of the battery temperature estimation rate. In the charging current determination table, the charging current ranges are Current1, Current2…Currentv. The ambient temperature ranges are AT1, AT2…ATu. The temperature change rates corresponding to the Current1 range within the AT1, AT2…ATu temperature ranges are C11, C21…Cu1, and the temperature change rates corresponding to the Currentv range within the AT1, AT2…ATj temperature ranges are C1v, C2v…Cuv. The ambient temperature ranges are continuous, i.e., AT1max = AT2min, and so on. The charging current is set with n reference values, and the ranges are set as narrow-amplitude current oscillation ranges, which are discontinuous. The ambient temperature ranges are determined according to the battery characteristics. The charging current determination table can be shown below, used to input the charging current and ambient temperature to query the estimated battery temperature change rate.

[0039]

[0040]

[0041] Temperature estimation model 3 determines the estimated battery temperature when the battery state of charge reaches the upper limit of the current battery state of charge range based on the charging current and the battery temperature change estimation rate.

[0042] The method for determining the estimated battery temperature when the battery's state of charge (SOC) reaches the upper limit of the current SOC range based on the charging current and the battery temperature change estimation rate can be any method. For example, it can be obtained by looking up the corresponding table. Alternatively, the estimated battery temperature can be calculated based on the charging current and the battery temperature change estimation rate. For example, the calculation method for the estimated battery temperature can be as follows: the charging time required for the battery's SOC to reach the upper limit of the current SOC range is defined as the interval charging time; the interval charging time is calculated as (upper limit of the current SOC range - battery SOC) * battery capacity / charging current; the temperature rise during the process of the battery's SOC reaching the upper limit of the current SOC range is defined as the interval temperature rise amplitude; the interval temperature rise amplitude is calculated as the battery temperature change estimation rate * the interval charging time; the estimated battery temperature is calculated as the interval temperature rise amplitude + the initial battery temperature.

[0043] The charging and temperature management model 4 determines whether the battery temperature is within the normal temperature range. If so, it determines whether the estimated battery temperature exceeds the normal temperature range. If so, it determines the battery temperature adjustment rate based on the battery temperature change estimation rate, where the battery temperature change estimation rate is less than or equal to the battery temperature adjustment rate.

[0044] Battery temperature regulation model 5 determines the power of the variable temperature device based on the battery temperature regulation rate.

[0045] The charging and temperature management model 4 determines the current required by the temperature-changing device based on its power. It then determines whether the sum of the charging current and the current required by the temperature-changing device is greater than the upper limit of the current provided by the charging pile. If so, the current provided by the charging pile will be prioritized to meet the supply of the charging current, and then supplied to the temperature-changing device.

[0046] The charging and temperature management model 4 determines whether the current battery temperature is within the normal temperature range. If it is, the battery temperature is relatively suitable for fast charging. The model can then determine whether the future battery temperature will remain within the normal temperature range based on the estimated battery temperature. If the future battery temperature is still within the normal temperature range, the battery temperature adjustment rate is set to 0, meaning no adjustment is needed. If the future battery temperature is not within the normal temperature range, the battery temperature adjustment rate needs to be determined based on the estimated battery temperature change rate. The rule for determining the battery temperature adjustment rate based on the estimated battery temperature change rate can be determined according to actual needs. For example, the estimated battery temperature change rate can be multiplied by a fixed coefficient to obtain the battery temperature adjustment rate. The estimated battery temperature change rate should be less than or equal to the battery temperature adjustment rate to ensure that the future battery temperature remains within the normal temperature range. For example, the temperature control device may include an air conditioner, a coolant pump, and peripheral cooling circuitry. The coolant pump drives the coolant, causing it to flow between the air conditioner and the battery. After obtaining the battery temperature adjustment rate, the air conditioner power and coolant pump flow rate can be determined based on the battery temperature adjustment rate. The method for determining the air conditioner power and coolant pump flow rate can be determined according to actual needs. For example, the air conditioner power and the coolant pump flow rate can be obtained by looking up a table based on the battery temperature regulation rate. The coolant flow rate is categorized into four combinations: low, medium, high, and off. The air conditioner power is categorized into four combinations: low, medium, high, and off. Flow rate control is prioritized, and air conditioner control is used only if cooling is insufficient. The input is the required cooling rate, and the output is the corresponding coolant flow rate and air conditioner power.

[0047]

[0048] Then, the power of the temperature control device is determined based on the air conditioner power, coolant pump flow rate, and power of the refrigeration peripheral circuit.

[0049] For example, the temperature-regulating device includes a heating element. The battery temperature regulation model 5, which determines the power of the temperature-regulating device based on the battery temperature regulation rate, includes determining the power of the heating element based on the battery temperature regulation rate and determining the power of the temperature-regulating device based on the power of the heating element.

[0050] The method for determining the heating device power based on the battery temperature regulation rate can be determined according to actual needs. For example, a correspondence table between the heating device power and the battery temperature regulation rate can be established. The heating device power can then be obtained by looking up the table.

[0051] After determining whether the sum of the charging current and the current required by the temperature-changing device is greater than the upper limit of the current provided by the charging pile, if the sum of the charging current and the current required by the temperature-changing device is less than or equal to the current provided by the charging pile, the current of the charging pile shall be allocated according to the charging current and the current required by the temperature-changing device.

[0052] The above describes the handling method when the battery temperature is within the normal temperature range. If the battery temperature is outside the normal temperature range, resulting in excessively high or low battery temperatures, it affects charging efficiency. The power of the temperature-regulating device can be set to maximum to quickly correct the battery temperature to the normal temperature range. For example, the temperature-regulating device includes an air conditioner, a coolant pump, and peripheral cooling circuitry. After determining whether the battery temperature is within the normal temperature range, the charging and temperature management model 4 further includes, if not, and the battery temperature is above the normal temperature range, determining the battery temperature regulation rate as the maximum cooling rate. The battery temperature regulation model 5 determines the power of the temperature-regulating device based on the battery temperature regulation rate, including, based on the maximum cooling rate, determining the air conditioner power as the maximum power, the coolant pump flow rate as the maximum flow rate, and determining the power of the temperature-regulating device based on the air conditioner power, coolant pump flow rate, and the power of the peripheral cooling circuitry. Furthermore, if the power provided by the charging pile is insufficient to simultaneously supply battery charging and cooling, the charging pile power is prioritized for battery charging. If there is remaining power, all remaining power is used to supply the operation of the air conditioner, coolant pump, and peripheral cooling circuitry.

[0053] For example, a temperature-changing device includes a heating element;

[0054] After determining whether the battery temperature is within the normal temperature range, the charging and temperature management model 4 further includes determining the battery temperature regulation rate as the maximum heating rate if the battery temperature is below the normal temperature range. The battery temperature regulation model 5 determines the power of the variable temperature device based on the battery temperature regulation rate, including determining the heating device power as the maximum power based on the maximum heating rate, and determining the variable temperature device power based on the heating device power.

[0055] If the current battery temperature is below normal operating temperature, it indicates that the battery temperature is too low, affecting charging efficiency. Therefore, the heating element can be activated to heat the battery. Furthermore, if the power provided by the charging station is insufficient to simultaneously supply battery charging and battery heating, the charging station's power will be prioritized for battery charging. Any remaining power will be used entirely for heating the battery.

[0056] After completing the above steps, one control process is finished, and the process can return to the initial steps for the next round of control. It should be noted that if the power provided by the charging pile is insufficient to simultaneously supply battery charging and battery temperature control, resulting in insufficient cooling or heating power, the battery temperature may deviate from the normal temperature range. In this case, the charging current will be re-determined based on the updated battery temperature in the next round of control. Changing the charging current can also alter the battery temperature trend, preventing battery temperature runaway. The electric vehicle charging control method of this embodiment, through the cooperation of the above models, adjusts the power of the temperature-changing device based on the estimated rate of battery temperature change, even when the battery temperature is within the normal temperature range, to keep the battery temperature as close to the normal temperature range as possible. This reduces battery temperature fluctuations and maintains a high charging speed. When the charging pile is insufficient to simultaneously supply charging current and temperature-changing device current, priority is given to supplying the charging current, further ensuring the charging speed.

[0057] This invention also provides an electric vehicle that uses any of the above-described electric vehicle charging control methods.

[0058] Since the electric vehicle provided in this embodiment of the invention uses any of the above-mentioned electric vehicle charging control methods, it has corresponding beneficial effects.

[0059] Note that the above description is merely a preferred embodiment of the present invention and the technical principles employed. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described herein, and various obvious changes, readjustments, combinations, and substitutions can be made without departing from the scope of protection of the present invention. Therefore, although the present invention has been described in detail through the above embodiments, the present invention is not limited to the above embodiments, and may include many other equivalent embodiments without departing from the concept of the present invention, the scope of which is determined by the scope of the appended claims.

Claims

1. A method for controlling the charging of an electric vehicle, characterized in that, This includes setting up charging current model, battery temperature change rate estimation model, temperature estimation model, charging and temperature management model, and battery temperature regulation model, respectively; The charging current model obtains the battery temperature and battery state of charge, and determines the charging current based on the battery temperature and battery state of charge; The battery temperature change rate estimation model obtains the ambient temperature and determines the battery temperature change rate estimation based on the ambient temperature and the charging current. The temperature estimation model determines the estimated battery temperature when the battery state of charge reaches the upper limit of the current battery state of charge range based on the charging current and the battery temperature change estimation rate. The charging and temperature management model determines whether the battery temperature is within the normal temperature range; if so, it determines whether the estimated battery temperature exceeds the normal temperature range. If so, the battery temperature regulation rate is determined based on the battery temperature change estimation rate, wherein the battery temperature change estimation rate is less than or equal to the battery temperature regulation rate. The battery temperature regulation model determines the power of the variable temperature device based on the battery temperature regulation rate. The charging and temperature management model determines the current required by the temperature-changing device based on its power, and determines whether the sum of the charging current and the current required by the temperature-changing device is greater than the upper limit of the current provided by the charging pile. If so, the current provided by the charging pile is prioritized to meet the supply of the charging current, and then supplied to the temperature-changing device.

2. The electric vehicle charging control method according to claim 1, characterized in that, The temperature-changing device includes an air conditioner, a coolant pump, and refrigeration peripheral circuitry. The battery temperature regulation model determines the power of the variable temperature device based on the battery temperature regulation rate, including determining the air conditioner power and coolant pump flow rate based on the battery temperature regulation rate, and determining the power of the variable temperature device based on the air conditioner power, the coolant pump flow rate, and the power of the refrigeration peripheral circuit.

3. The electric vehicle charging control method according to claim 1, characterized in that, The temperature-changing device includes a heating element; The battery temperature regulation model determines the power of the variable temperature device based on the battery temperature regulation rate, including determining the power of the heating device based on the battery temperature regulation rate, and determining the power of the variable temperature device based on the power of the heating device.

4. The electric vehicle charging control method according to claim 1, characterized in that, The charging current model is also used to correct the relationship between the battery temperature and the battery state of charge as the battery health decreases.

5. The electric vehicle charging control method according to claim 1, characterized in that, The battery temperature change rate estimation model is also used to correct the determination relationship of the battery temperature change rate estimation based on the ambient temperature and the charging current as the battery health decreases.

6. The electric vehicle charging control method according to claim 1, characterized in that, The temperature estimation model determines the estimated battery temperature when the battery state of charge reaches the upper limit of the current battery state of charge range based on the charging current and the battery temperature change estimation rate, including: The charging time required for the battery state of charge to reach the upper limit of the current battery state of charge range is the interval charging time. The interval charging time is calculated as (the upper limit of the current battery state of charge range - the battery state of charge) * battery capacity / the charging current. The temperature rise during the process of the battery state of charge reaching the upper limit of the current battery state of charge range is the interval temperature rise. The interval temperature rise is calculated as the battery temperature change estimation rate * the interval charging time. The estimated battery temperature is calculated as follows: Estimated battery temperature = Temperature rise range in the interval + Initial battery temperature.

7. The electric vehicle charging control method according to claim 1, characterized in that, The temperature-changing device includes an air conditioner, a coolant pump, and refrigeration peripheral circuitry. After determining whether the battery temperature is within the normal temperature range, the charging and temperature management model further includes, if not, and the battery temperature is higher than the normal temperature range, then determining the battery temperature regulation rate as the maximum cooling rate. The battery temperature regulation model determines the power of the variable temperature device based on the battery temperature regulation rate, including determining the air conditioner power as the maximum power and the coolant pump flow rate as the maximum flow rate based on the maximum cooling rate, and determining the power of the variable temperature device based on the air conditioner power, the coolant pump flow rate, and the power of the refrigeration peripheral circuit.

8. The electric vehicle charging control method according to claim 1, characterized in that, The temperature-changing device includes a heating element; After determining whether the battery temperature is within the normal temperature range, the charging and temperature management model further includes, if not, and the battery temperature is below the normal temperature range, then determining the battery temperature regulation rate as the maximum heating rate. The battery temperature regulation model determines the power of the variable temperature device based on the battery temperature regulation rate, including determining the power of the heating device as the maximum power based on the maximum heating rate, and determining the power of the variable temperature device based on the power of the heating device.

9. The electric vehicle charging control method according to claim 1, characterized in that, If so, after determining whether the estimated battery temperature exceeds the normal temperature range, the process further includes, if not, setting the battery temperature adjustment rate to 0.

10. An electric vehicle, characterized in that, Use the electric vehicle charging control method according to any one of claims 1-9.

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