Low-temperature charging compensation method and new energy source vehicle

Abstract

The invention discloses a low-temperature charging compensation method and a new energy source vehicle. The low-temperature charging compensation method comprises the steps that whether the current lowest monomer temperature Tmin is lower than a preset low-temperature threshold value or not is judged; if yes, charging preheating is carried out, and charging compensation is carried out in the charging preheating process; and if not, a charging and heating stage is entered, the WPTC continuously works to heat the battery, the battery charging window is released, and the battery is allowed to be charged. According to the low-temperature charging compensation method and the new energy material source vehicle, when the current lowest monomer temperature Tmin is lower than the preset low-temperature threshold value, the charging preheating process based on the charging compensation strategy is carried out, the low-temperature charging efficiency of the new energy material source vehicle is improved, and the charging waiting time is shortened; the charging current value request problem when the battery temperature is below 0 DEG C is optimized, the charging energy complementing efficiency is improved, and the low-temperature charging problem when the Tmin is below-20 DEG C can be solved.

Description

Technical Field

[0001] This invention relates to the field of new energy logistics vehicle technology, and more specifically, to a low-temperature charging compensation method and a new energy logistics vehicle. Background Technology

[0002] The charging efficiency of new energy vehicles has always been a major bottleneck restricting their replacement of gasoline vehicles. Various technological approaches have been implemented to address this, such as battery swapping, which can fully charge a vehicle in 3 minutes, approaching the charging efficiency of gasoline vehicles. Another approach is fast charging. However, new energy vehicle batteries still primarily use liquid electrolytes, and the inherent fast-charging capability of these energy-type batteries is limited. With the expansion of new energy logistics vehicle manufacturers, the charging speed in cold regions has become a hot research topic.

[0003] With the advancement of technology, low-temperature charging compensation technology has a promising market prospect. Its biggest advantage is that it improves the energy replenishment efficiency of fast charging of new energy pure electric light trucks in low-temperature areas.

[0004] Therefore, there is an urgent need for a low-temperature charging compensation method and a new energy source flow vehicle. Summary of the Invention

[0005] The purpose of this invention is to provide a low-temperature charging compensation method and a new energy logistics vehicle to solve the problems in the prior art, thereby improving the low-temperature charging efficiency of new energy logistics vehicles and reducing charging waiting time.

[0006] This invention provides a low-temperature charging compensation method and a new energy source flow vehicle, comprising:

[0007] Determine the current lowest monomer temperature T min Is it below the preset low temperature threshold?

[0008] If so, preheating for charging will be performed, and charging compensation will be performed during the preheating process.

[0009] If not, it enters the charging and heating phase, where the WPTC continues to heat the battery, and the battery charging window is opened to allow the battery to charge.

[0010] In the low-temperature charging compensation method described above, preferably, the preset low-temperature threshold is -20°C.

[0011] The low-temperature charging compensation method described above, preferably, includes the following steps: performing charging preheating and charging compensation during the charging preheating process:

[0012] Set the initial requested pile current to 5A;

[0013] Real-time detection of battery charging current value, and dynamic compensation and adjustment of battery charging current value;

[0014] After the battery charging current value stabilizes, turn on the air conditioning for heating, adjust the pile output current, and trigger the dynamic compensation adjustment of the battery charging current value again.

[0015] After the air conditioning and heating are running stably, turn off the air conditioning and heating and lower the current requested by the pile.

[0016] The low-temperature charging compensation method described above, preferably, includes the following: real-time detection of the battery charging current value and dynamic compensation adjustment of the battery charging current value.

[0017] If the initial requested charging pile current is 5A, then the charging pile output current is 5A. The current consumption of WPTC heat is 14.5A-15.5A, and the external discharge current of the battery is 9.5A-10.5A. At this time, the dynamic adjustment strategy is triggered, increasing the requested current of the BMS to the charging pile at a rate of 2A / s until the external discharge of the battery is detected to be 1A-2A. Finally, the output current of the charging pile is 12.5A-13.5A, the battery output current is 1.5A-2.5A, and the current consumption of WPTC is 14.5A-15.5A.

[0018] In the low-temperature charging compensation method described above, preferably, during the process of BMS dynamically adjusting the requested current, the conditions for stopping the adjustment include: the difference between the real-time detected battery charging current value and the current value obtained by looking up the table through MAP is within 2A.

[0019] The low-temperature charging compensation method described above, preferably, further includes the real-time detection of the battery charging current value and the dynamic compensation adjustment of the battery charging current value, as well as:

[0020] During the process of dynamically adjusting the requested current by the BMS, if the real-time detected battery charging current value cannot reach the current value obtained by looking up the table through MAP due to the power limitation of the charging pile, then the upper limit adjustment value of the battery charging current value is set.

[0021] In the low-temperature charging compensation method described above, preferably, the upper limit adjustment value of the battery charging current is 40A.

[0022] The low-temperature charging compensation method described above, preferably, further includes the real-time detection of the battery charging current value and the dynamic compensation adjustment of the battery charging current value, as well as:

[0023] If the battery charging current still cannot reach the current MAP lookup value due to the charging pile power limitation, the BMS request current value is increased by the upper limit adjustment value, and the battery charging current is still limited by the current MAP lookup value. The steady-state output is based on the maximum adjusted request current value.

[0024] If the power release of the charging pile is tested and the output current suddenly increases, and the actual value of the battery charging current detected by the BMS exceeds the MAP query value of 5A, then in the next second, the dynamically adjusted charging request increase value will be directly subtracted, and the charging current will be requested according to the MAP query value.

[0025] After 1 minute of steady-state operation, the dynamic adjustment of the battery charging current value is triggered again.

[0026] The low-temperature charging compensation method described above, preferably, includes the following steps: activating the air conditioning for heating, adjusting the pile output current, and triggering dynamic compensation adjustment of the battery charging current value again.

[0027] When the passenger compartment's air conditioning heating is turned on, the current consumption of electrical appliances in the vehicle increases by 7A. After the battery discharges, the current increases to 8A-9A. At this point, the charging pile's requested current continues to be adjusted at a rate of 2A / s, eventually reaching a charging pile output current of 19A-21A, a battery output current of 1.5A-2.5A, and WPTC and air conditioning heating consumption of 22A-24A.

[0028] After the air conditioning and heating system is running stably, turning off the air conditioning and heating system and lowering the requested current for the pile includes:

[0029] After the air conditioning and heating system has been running stably, if the air conditioning and heating system is suddenly turned off, the original 7A current from the air conditioning and heating system will enter the battery. The battery will detect a -5A charging current. Since charging is not allowed at this time, the BMS will adjust the current requested by the pile to 7A in the next second to restore the dynamic adjustment balance.

[0030] The present invention also provides a new energy source flow vehicle, which adopts the above-mentioned low-temperature charging compensation method.

[0031] This invention provides a low-temperature charging compensation method and a new energy source flow vehicle, which operates at the current lowest single-cell temperature T. min When the temperature is below a preset low temperature threshold, a charging preheating process based on a charging compensation strategy is implemented, improving the low-temperature charging efficiency of new energy logistics vehicles and reducing charging waiting time; the issue of charging current value requests when the battery temperature is below 0℃ is optimized, accelerating charging efficiency and solving the problem of T min The solution addresses the issue of low-temperature charging below -20℃, which can resolve the lithium plating problem caused by charging current exceeding permissible values ​​during low-temperature charging of new energy logistics vehicles. Attached Figure Description

[0032] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described below with reference to the accompanying drawings, wherein:

[0033] Figure 1 An example of setting up a charging window for new energy logistics vehicles in existing technologies;

[0034] Figure 2 A flowchart illustrating an embodiment of the low-temperature charging compensation method provided by the present invention. Detailed Implementation

[0035] Various exemplary embodiments of the present disclosure will now be described in detail with reference to the accompanying drawings. The descriptions of the exemplary embodiments are merely illustrative and are in no way intended to limit the present disclosure or its application or use. The present disclosure may be implemented in many different forms and is not limited to the embodiments described herein. These embodiments are provided so that the present disclosure will be thorough and complete, and will fully express the scope of the disclosure to those skilled in the art. It should be noted that, unless specifically stated otherwise, the relative arrangement of components and steps, the composition of materials, numerical expressions, and values ​​set forth in these embodiments should be interpreted as exemplary only and not as limiting.

[0036] The terms “first,” “second,” and similar terms used in this disclosure do not indicate any order, quantity, or importance, but are merely used to distinguish different parts. Terms such as “including” or “contains” mean that the element preceding the term encompasses the element listed after it, and do not exclude the possibility of encompassing other elements as well. Terms such as “above” and “below” are used only to indicate relative positional relationships; when the absolute position of the described object changes, this relative positional relationship may also change accordingly.

[0037] In this disclosure, when a specific component is described as being located between a first component and a second component, an intermediary component may or may not be present between the specific component and the first or second component. When a specific component is described as connecting to other components, the specific component may be directly connected to the other components without having an intermediary component, or it may not be directly connected to the other components but may have an intermediary component.

[0038] All terms used in this disclosure (including technical or scientific terms) have the same meaning as understood by one of ordinary skill in the art to which this disclosure pertains, unless otherwise specifically defined. It should also be understood that terms defined in a general dictionary, such as a dictionary, should be interpreted as having a meaning consistent with their meaning in the context of the relevant art, and not as having an idealized or highly formalized meaning, unless expressly defined herein.

[0039] Techniques, methods, and equipment known to those skilled in the art may not be discussed in detail, but where appropriate, they should be considered part of the specification.

[0040] Taking a certain model of new energy logistics vehicle as an example, the maximum charging rate is designed to be 2C. The current current value requested from the charging pile is calculated by looking up the table according to the set charging window map. Figure 1 This illustrates the charging window settings for new energy logistics vehicles in the prior art, such as... Figure 1 As shown, the charging rate lookup table result is affected by T min -The current lowest single-cell temperature and SOC influence the calculation of the corresponding charging rate by using the linear difference method between the set points.

[0041] For example, if the battery design capacity is 185Ah, a rate of 1 requires a charging current of 185A, and a rate of 2 requires a charging current of 370A. When used in cold regions, when T... min At temperatures below -20℃, charging is not permitted within the current SOC range. The BMS requests a charging station current of 0A. To restore battery activity, the onboard WPTC needs to be activated to heat the battery. The WPTC consumes approximately 15A (corresponding to 7-8kW), and the battery's external discharge current is approximately 15A. If the current SOC is high, the impact is smaller; the SOC will decrease by 5-10%, heating the battery temperature to -20℃, opening the battery charging window, and the BMS will look up the charging station current value in a table. If the current SOC is 5% or below, the battery may experience over-discharge if it is not heated to -20℃, resulting in low charging efficiency or inability to charge at low temperatures.

[0042] If the battery is heated to -20°C and the current SOC is 20%, then a current rate of 0.15C is requested, which is equivalent to 27.8A. At this time, the WPTC heating continues, consuming 15A of current, so the current entering the battery is about 12.8A, that is, the battery is in a slow charging process.

[0043] like Figure 2 As shown, the low-temperature charging compensation method provided in this embodiment includes the following steps in actual implementation:

[0044] Step S1: Determine the current lowest monomer temperature T min Is it below the preset low temperature threshold?

[0045] For example, the preset low temperature threshold is -20°C.

[0046] Step S2: If yes, then perform preheating for charging and perform charging compensation during the preheating process.

[0047] In this invention, when T min When charging is initiated below -20°C, in one embodiment of the low-temperature charging compensation method of the present invention, step S2 may specifically include:

[0048] Step S21: Set the initial requested pile current to 5A.

[0049] Step S22: Real-time detection of battery charging current value, and dynamic compensation and adjustment of battery charging current value.

[0050] In one embodiment of the low-temperature charging compensation method of the present invention, step S22 may specifically include:

[0051] Step S221: If the initial requested charging pile current is 5A, then the charging pile output current is 5A. The current heat consumption current of the current WPTC (vehicle-side water heater) is 14.5A-15.5A (e.g., 15A), and the battery external discharge current is 9.5A-10.5A (e.g., 10A). At this time, the dynamic adjustment strategy is triggered to increase the requested current of the BMS to the charging pile at a rate of 2A / s until the battery discharge detects an external discharge of 1A-2A. Finally, the output current of the charging pile is 12.5A-13.5A (e.g., 13A), the battery output current is 1.5A-2.5A (e.g., 2A), and the current consumption of the WPTC is 14.5A-15.5A (e.g., 15A).

[0052] Among them, WPTC is the main power consumption device for heating the battery.

[0053] Among them, the conditions for stopping the adjustment during the dynamic adjustment of the requested current by the BMS include: the difference between the real-time detected battery charging current value and the current value obtained by looking up the table through MAP is within 2A. At this time, it can be considered that the adjustment has reached a steady state and the adjustment process stops.

[0054] Furthermore, in one embodiment of the low-temperature charging compensation method of the present invention, step S22 further includes:

[0055] Step S222: During the process of dynamically adjusting the requested current by the BMS, if the real-time detected battery charging current value cannot reach the current value obtained by looking up the table through MAP due to the power limitation of the charging pile, then set the upper limit adjustment value of the battery charging current value.

[0056] The upper limit adjustment value of the battery charging current is 40A, meaning that when the charging pile power limit cannot be reached, the maximum dynamic adjustment value is 40A.

[0057] Furthermore, in one embodiment of the low-temperature charging compensation method of the present invention, step S22 further includes:

[0058] Step S223: If the upper limit adjustment value (40A) of the BMS request current value is increased due to the power limitation of the charging pile, and the battery charging current still cannot reach the current MAP lookup value, then the steady-state output is based on the maximum adjustment request current value.

[0059] Step S224: If the power release of the test charging pile causes a sudden increase in output current, and the actual value of the battery charging current detected by the BMS exceeds the MAP query value of 5A, then in the next second, the dynamically adjusted charging request increase value will be directly subtracted, and the charging current will be requested according to the MAP query value.

[0060] Step S225: After 1 minute of steady-state operation, the dynamic adjustment of the battery charging current value is triggered again.

[0061] The dynamic adjustment process of the battery charging current value can be referred to in steps S221-S224, and will not be repeated here.

[0062] Step S23: After the battery charging current value stabilizes, turn on the air conditioning for heating, adjust the pile output current, and trigger the dynamic compensation adjustment of the battery charging current value again.

[0063] Specifically, when the passenger compartment's air conditioning heating is turned on, the current consumption of electrical appliances in the vehicle increases by 7A. After the battery discharges, the current increases to 8A-9A. At this point, the charging pile request current continues to be adjusted at a rate of 2A / s, eventually reaching a charging pile output current of 19A-21A (e.g., 20A), a battery output current of 1.5A-2.5A (e.g., 2A), and WPTC and air conditioning heating consumption of 22A-24A (e.g., 23A). The dynamic compensation adjustment process for the battery charging current value can be referred to step S22, and will not be repeated here.

[0064] Step S24: After the air conditioning and heating are running stably, turn off the air conditioning and heating and lower the current requested by the pile.

[0065] Specifically, after the air conditioning and heating have been running stably, if the air conditioning and heating are suddenly turned off, the original 7A current from the air conditioning and heating will enter the battery. The battery will detect a charging current of -5A. Since charging is not allowed at this time, the BMS will reduce the current requested by the pile to 7A in the next second to restore the dynamic adjustment balance.

[0066] Step S3: If not, then enter the charging and heating phase (referred to as charging and heating). The WPTC continues to work to heat the battery, and the battery charging window is released to allow the battery to charge.

[0067] Correspondingly, the present invention also provides a new energy source flow vehicle employing the above-mentioned low-temperature charging compensation method.

[0068] The low-temperature charging compensation method and new energy source flow vehicle provided in this embodiment of the invention, at the current lowest single-cell temperature T min When the temperature is below a preset low temperature threshold, a charging preheating process based on a charging compensation strategy is implemented, improving the low-temperature charging efficiency of new energy logistics vehicles and reducing charging waiting time; the issue of charging current value requests when the battery temperature is below 0℃ is optimized, accelerating charging efficiency and solving the problem of T min The solution addresses the issue of low-temperature charging below -20℃, which can resolve the lithium plating problem caused by charging current exceeding permissible values ​​during low-temperature charging of new energy logistics vehicles.

[0069] The embodiments of this disclosure have now been described in detail. To avoid obscuring the concept of this disclosure, some details known in the art have not been described. Those skilled in the art can fully understand how to implement the technical solutions disclosed herein based on the above description.

[0070] While specific embodiments of this disclosure have been described in detail by way of examples, those skilled in the art should understand that the examples are for illustrative purposes only and not intended to limit the scope of this disclosure. Those skilled in the art should understand that modifications can be made to the above embodiments or equivalent substitutions can be made to some technical features without departing from the scope and spirit of this disclosure. The scope of this disclosure is defined by the appended claims.

Claims

1. A low-temperature charging compensation method, characterized in that, include: Determine the current lowest monomer temperature T min Is it below the preset low temperature threshold? If so, preheating for charging will be performed, and charging compensation will be performed during the preheating process. If not, it enters the charging and heating phase, where the WPTC continues to heat the battery, and the battery charging window is opened to allow the battery to charge.

2. The low-temperature charging compensation method according to claim 1, characterized in that, The preset low temperature threshold is -20℃.

3. The low-temperature charging compensation method according to claim 1, characterized in that, The process of preheating for charging and compensating for charging during the preheating process includes: Set the initial requested pile current to 5A; Real-time detection of battery charging current value, and dynamic compensation and adjustment of battery charging current value; After the battery charging current value stabilizes, turn on the air conditioning for heating, adjust the pile output current, and trigger the dynamic compensation adjustment of the battery charging current value again. After the air conditioning and heating are running stably, turn off the air conditioning and heating and lower the current requested by the pile.

4. The low-temperature charging compensation method according to claim 3, characterized in that, The real-time detection of the battery charging current value, and the dynamic compensation and adjustment of the battery charging current value, include: If the initial requested charging pile current is 5A, then the charging pile output current is 5A. The current consumption of WPTC heat is 14.5A-15.5A, and the external discharge current of the battery is 9.5A-10.5A. At this time, the dynamic adjustment strategy is triggered, increasing the requested current of the BMS to the charging pile at a rate of 2A / s until the external discharge of the battery is detected to be 1A-2A. Finally, the output current of the charging pile is 12.5A-13.5A, the battery output current is 1.5A-2.5A, and the current consumption of WPTC is 14.5A-15.5A.

5. The low-temperature charging compensation method according to claim 4, characterized in that, The real-time detection of battery charging current value, and the dynamic compensation and adjustment of battery charging current value, further includes: During the process of BMS dynamically adjusting the requested current, the conditions for stopping the adjustment include: the difference between the real-time detected battery charging current value and the current value obtained by looking up the table through MAP is within 2A.

6. The low-temperature charging compensation method according to claim 4, characterized in that, During the process of dynamically adjusting the requested current by the BMS, if the real-time detected battery charging current value cannot reach the current value obtained by looking up the table through MAP due to the power limitation of the charging pile, then the upper limit adjustment value of the battery charging current value is set.

7. The low-temperature charging compensation method according to claim 6, characterized in that, The upper limit of the battery charging current value is adjusted to 40A.

8. The low-temperature charging compensation method according to claim 4, characterized in that, The real-time detection of battery charging current value, and the dynamic compensation and adjustment of battery charging current value, further includes: If the battery charging current still cannot reach the current MAP lookup value due to the charging pile power limitation by increasing the upper limit adjustment value of the BMS request current value, then the steady-state output should be based on the maximum adjustment request current value. If the power release of the charging pile is tested and the output current suddenly increases, and the actual value of the battery charging current detected by the BMS exceeds the MAP query value of 5A, then in the next second, the dynamically adjusted charging request increase value will be directly subtracted, and the charging current will be requested according to the MAP query value. After 1 minute of steady-state operation, the dynamic adjustment of the battery charging current value is triggered again.

9. The low-temperature charging compensation method according to claim 3, characterized in that, The process of activating the air conditioning heating, adjusting the pile output current, and triggering dynamic compensation adjustment of the battery charging current value again includes: When the passenger compartment's air conditioning heating is turned on, the current consumption of electrical appliances in the vehicle increases by 7A. After the battery discharges, the current increases to 8A-9A. At this point, the charging pile's requested current continues to be adjusted at a rate of 2A / s, eventually reaching a charging pile output current of 19A-21A, a battery output current of 1.5A-2.5A, and WPTC and air conditioning heating consumption of 22A-24A. After the air conditioning and heating system is running stably, turning off the air conditioning and heating system and lowering the requested current for the pile includes: After the air conditioning and heating system has been running stably, if the air conditioning and heating system is suddenly turned off, the original 7A current from the air conditioning and heating system will enter the battery. The battery will detect a -5A charging current. Since charging is not allowed at this time, the BMS will adjust the current requested by the pile to 7A in the next second to restore the dynamic adjustment balance.

10. A new type of energy resource flow vehicle, characterized in that, The low-temperature charging compensation method according to any one of claims 1-8 is adopted.

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