Method for managing and controlling low-temperature energy of extended-range automobile

Abstract

The invention discloses a low-temperature energy management control method for an extended-range automobile, which comprises the following steps of: electrifying, acquiring an environment temperature value and assigning the environment temperature value to Tminnow as an initial value of the Tminnow, acquiring the environment temperature Tnow in a current state in real time, calculating the lowest loop temperature Tminnow = min of a current stroke, inquiring a low-temperature electric balance SOC correction coefficient table according to the Tmin, adding normal-temperature electric balance SOC according to the inquired electric balance correction coefficient, and controlling the low-temperature energy of the extended-range automobile according to the normal-temperature electric balance SOC. According to the method, low-temperature correction is based on the total lowest environment temperature of the whole stroke instead of the environment temperature at the last moment, and the situation that the difference between the temperature at the power-off moment and the lowest temperature of the whole stroke is large, and correction of the SOC balance point is unreasonable is avoided; the temperature of two strokes is used as a judgment basis, the time length of temperature collection can be increased, and the situation that the deviation between the SOC balance point correction reference temperature and the environment temperature during next power-on is large due to the fact that the strokes are short and the temperature collected during short power-off is small is reduced.

Description

Technical Field

[0001] The present invention relates to the field of automobile technology, and in particular to a low-temperature energy management control method for an extended-range automobile. Background Art

[0002] The driving power of the extended-range vehicle drive motor mainly comes from the range extender and the battery pack. Considering the cost, the power of the range extender matched with the extended-range vehicle is usually less than the peak power of the drive motor. The operation of the range extender alone cannot fully meet the power demand of the drive motor, and the discharge power of the battery pack is also required. However, when the battery pack is at low SOC, due to the small battery discharge power, the battery pack discharge power plus the range extender power still cannot meet the power demand of the drive motor, which will not only affect the power performance of the whole vehicle, but also cause the engine to be unable to operate in the high-efficiency range, and the fuel consumption will be worsened.

[0003] In order to ensure the pure electric endurance of extended-range vehicles, extended-range vehicles will mainly drive on pure electricity when the SOC is high. Only when it reaches the electric balance SOC, the range extender will be used to adjust the battery pack SOC to maintain it near the electric balance SOC. Therefore, the electric balance SOC is generally selected to be near the battery pack power plus the range extender power to just meet the peak power demand of the drive motor. Under normal temperature conditions, the vehicle can maintain operation near the electric balance SOC to meet the power requirements of the entire vehicle and allow the engine to operate in the economic range. However, in low temperature environments, due to the attenuation of the battery pack discharge power, if the same electric balance SOC as normal temperature is maintained, the range extender plus the battery pack power will not be able to meet the power requirements of the drive motor, resulting in a decrease in the power of the entire vehicle, the engine operating point will also deviate from the economic zone, and the fuel consumption of the entire vehicle will deteriorate. In addition, the SOC of the vehicle will further decrease after being immersed in a low temperature environment, and it is easy to have a low battery and stall.

[0004] The existing technology adopts the following solutions to solve the problem: 1. By monitoring the real-time temperature of the battery pack cells, the SOC balance point is corrected according to the cell temperature. When the cell temperature is low, the SOC balance point is increased to ensure that the battery pack SOC will not drop to a low power range that cannot meet the power requirements of the drive motor when the cell temperature is low; Second, by monitoring the real-time ambient temperature, the SOC balance point is corrected according to the ambient temperature. When the ambient temperature is low, the SOC balance point is increased to ensure that the discharge power of the battery pack plus the range extender power under the low-temperature electrical balance SOC can meet the power requirements of the drive motor.

[0005] However, the above solution has the following problems: 1. The above solution 1 can only solve the problem of electric balance point correction when the battery cell temperature is low. However, the battery cell temperature will change with driving time. After driving for a period of time in a low temperature environment, the battery cell temperature will gradually rise to a state close to normal temperature, and the electric balance point will also be corrected to the normal temperature level (lower SOC point). However, the ambient temperature is still low. After parking for a period of time, the battery cell will drop to the ambient temperature level (low temperature state). At this time, the actual SOC is low and cannot meet the power demand of the drive motor, which will lead to the situation of limited drive motor power (poor power) and high-power power generation of the range extender (poor fuel consumption); 2. In the above-mentioned scheme 2, using ambient temperature as a reference can solve the misjudgment of the adjustment of the SOC balance point due to the increase in battery cell temperature during driving. When the ambient temperature is low, the SOC balance is improved. Even after the vehicle is soaked, the battery pack can be guaranteed to be at a relatively high SOC value to meet the discharge power requirement. However, this scheme can only rely on the current ambient temperature to correct the SOC balance point, and cannot consider the impact of the ambient temperature of the entire journey or the whole day. When the journey ends at noon when the temperature is high, the vehicle is soaked overnight, and the vehicle is started the next morning when the temperature is low, the ambient temperature at the end of the journey and when the vehicle is started again is quite different, which will also lead to large SOC correction deviations that cannot meet the driving power requirements and high fuel consumption for high-power power generation.

[0006] In view of this, the present invention is used to solve the problem that the extended-range vehicle easily enters low power at low temperatures and has poor power and fuel consumption. Summary of the invention

[0007] In order to overcome the deficiencies of the prior art, one of the objectives of the present invention is to provide a low-temperature energy management control method for an extended-range vehicle.

[0008] One of the purposes of the present invention is achieved by the following technical solution: A low-temperature energy management control method for an extended-range vehicle comprises the following steps: Step 1: Power on and obtain the ambient temperature and assign it to T min_now , as T min_now Initial value; Step 2: Get the current ambient temperature T in real time now ; Step 3: Calculate the minimum ring temperature T of the current trip min_now =min(T min_now , T now ); Step 4: Compare the lowest ambient temperature T of the previous trip min_before , calculate the minimum ambient temperature T of the two trips min =min(T min_befor , T min_now ); Step 5: According to Tmin Query the low temperature electric balance SOC correction coefficient table; Step 6: Add the normal temperature electric balance SOC to the queried electric balance correction coefficient to obtain the current electric balance SOC value; Step 7: When the trip is over and the power is turned off, turn T min_now Assign to T min_before for storage.

[0009] Further, in step 3, the current real-time temperature T now The lowest temperature of the current trip T min_now Compare and reassign the smaller value to T min_now .

[0010] Furthermore, in step 4, the current lowest ambient temperature T min_now and the lowest ambient temperature T of the previous trip min_before The smaller value of the two is assigned to T min .

[0011] Furthermore, in step 4, the default T min_before The value is 23℃.

[0012] Furthermore, in step five, the current electric balance correction coefficient is determined after querying.

[0013] Furthermore, in step seven, the information is stored after power is turned off for use in the next trip.

[0014] Compared with the prior art, the present invention has the following beneficial effects: 1. The present invention provides a low-temperature energy management control method for an extended-range vehicle. The low-temperature correction is based on the overall lowest ambient temperature of the entire journey, rather than the ambient temperature at the last moment, so as to avoid a large deviation between the temperature at the power-off moment and the lowest temperature of the entire journey, resulting in unreasonable correction of the SOC balance point; 2. The present invention provides a low-temperature energy management control method for an extended-range vehicle. The temperature of two trips is used as a basis for judgment, which can increase the duration of temperature collection and reduce the large deviation between the reference temperature for SOC balance point correction and the ambient temperature at the next power-on due to the short trip and short power-off.

[0015] The above description is only an overview of the technical solution of the present invention. In order to more clearly understand the technical means of the present invention, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present invention more obvious and easy to understand, the following specifically cites a preferred embodiment and describes it in detail with the accompanying drawings as follows. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a flow chart of the present invention. DETAILED DESCRIPTION

[0017] The present invention is further described below in conjunction with the accompanying drawings and specific implementation methods. It should be noted that, under the premise of no conflict, the various embodiments or technical features described below can be arbitrarily combined to form a new embodiment.

[0018] It should be noted that when a component is referred to as being "fixed to" another component, it may be directly on the other component or there may also be a component centered. When a component is considered to be "connected to" another component, it may be directly connected to the other component or there may also be a component centered. When a component is considered to be "set on" another component, it may be directly set on the other component or there may also be a component centered. The terms "vertical", "horizontal", "left", "right" and similar expressions used herein are for illustrative purposes only.

[0019] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which the present invention belongs. The terms used herein in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more of the related listed items.

[0020] Embodiment 1: See also Figure 1 The present invention provides the following technical solution: a low-temperature energy management control method for an extended-range vehicle, comprising the following steps: Step 1: Power on and obtain the ambient temperature and assign it to T min_now , as T min_now Initial value; Step 2: Get the current ambient temperature T in real time now ; Step 3: Calculate the minimum ring temperature T of the current trip min_now =min(T min_now , T now ), using the current real-time temperature T now The lowest temperature of the current trip T min_now Compare and reassign the smaller value to T min_now ; Step 4: Compare the lowest ambient temperature T of the previous trip min_before , if there is no previous trip T min_before The default value is T min_before The value is 23℃, calculate the minimum ambient temperature T of the two trips min =min(T min_befor , T min_now), the current minimum ambient temperature T min_now and the lowest ambient temperature T of the previous trip min_before The smaller value of the two is assigned to T min ; Step 5: According to T min Query the low-temperature electric balance SOC correction coefficient table to determine the current electric balance correction coefficient; Step 6: Add the normal temperature electric balance SOC to the queried electric balance correction coefficient to obtain the current electric balance SOC value; Step 7: When the trip is over and the power is turned off, turn T min_now Assign to T min_before Store it for use in the next trip.

[0021] Embodiment 2: According to the discharge power of the battery pack at different ambient temperatures and SOCs, combined with the power requirements of the drive motor and the discharge capacity of the range extender, the correction coefficient of the electric balance SOC at different ambient temperatures is determined. For example, the peak power of the drive motor is 130kw, the peak power of the range extender is 90kw, and the battery pack needs to provide a discharge power of more than 40kw. By querying the battery pack discharge power map table (such as Table 1), the low temperature correction coefficient is determined in combination with the battery pack discharge capacity (such as Table 2, which can be calibrated according to actual conditions). The vehicle will adjust the current electric balance SOC point according to the temperature correction coefficient. For example, the electric balance SOC at normal temperature is 20%, and the electric balance SOC at -10℃ is 35% SOC (20% plus a correction coefficient of 15%).

[0022] The temperature referenced by the temperature correction of the present invention is the lowest ambient temperature of the current trip and the previous trip as a whole, rather than only referring to the ambient temperature at the last point of the trip, thereby avoiding unreasonable temperature correction caused by a large temperature difference between the end of the trip and the ambient temperature of the entire trip.

[0023] Table 1 is the discharge power map of the battery pack at different SOC and temperature Table 2 is the low temperature electric balance SOC correction coefficient table The key to low-temperature SOC balance point correction is to ensure that the reference ambient temperature for correction when the power is turned off does not deviate too much from the ambient temperature when the power is turned on next time. Take a car that starts driving every morning and ends the trip at noon as an example: Assuming that the ambient temperature is -10℃ in the morning, as the temperature rises during the day to 0℃ at noon, if the vehicle uses the ambient temperature at the last moment as the reference for the SOC balance point correction, the SOC will be corrected by 5%, which is shown in Table 2, and the electric balance SOC is 25%. After a night of cold driving, the ambient temperature is -10℃ when the vehicle is started again the next morning. This temperature assumes that the battery pack has cooled to -10℃, but the SOC at this time is 25%, and the power that the battery pack can provide is about 33kw, which is shown in Table 1. In addition, the maximum power of the range extender is 90kw, which still does not meet the demand of the drive motor of 135kwh, and the power will be weakened; at the same time, due to the small power provided by the battery pack, the range extender needs to work at high power for a long time, cannot work in the economic zone, and fuel consumption will also deteriorate. According to the method of the present invention, the lowest temperature of the entire journey will be used as the basis for the correction of the SOC balance point, that is, -10℃ will be used as the basis for correction, and the above problems will not occur.

[0024] The low temperature correction of the present invention is based on the overall minimum ambient temperature of the entire journey, rather than the ambient temperature at the last moment, to avoid a large deviation between the temperature at the power-off moment and the minimum temperature of the entire journey, resulting in unreasonable correction of the SOC balance point.

[0025] The present invention uses the temperatures of two trips as a basis for judgment, which can increase the duration of temperature collection and reduce the situation in which the SOC balance point correction reference temperature and the ambient temperature at the next power-on have a large deviation due to the small amount of temperature collected during a short trip and a brief power-off.

[0026] The advantage of the present invention is that the lowest ambient temperature of the entire journey can be obtained more accurately, and a more accurate prediction can be provided for reserving a suitable SOC to better meet the needs of the next journey.

[0027] In the description of the present invention, it is to be understood that the terms “center”, “longitudinal”, “lateral”, “length”, “width”, “thickness”, “up”, “down”, “front”, “back”, “left”, “right”, “vertical”, “horizontal”, “top”, “bottom”, “inside”, “outside”, “clockwise”, “counterclockwise”, “axial”, “radial”, “circumferential”, etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0028] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0029] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0030] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being "above", "above" or "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" or "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0031] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0032] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations of the present invention. A person skilled in the art may change, modify, replace and vary the above embodiments within the scope of the present invention.

Claims

1. A low-temperature energy management control method for an extended-range vehicle, characterized in that: The following steps are involved: Step 1: Power on and obtain the ambient temperature and assign it to T min_now , as T min_now Initial value; Step 2: Get the current ambient temperature T in real time now ; Step 3: Calculate the minimum ring temperature T of the current trip min_now =min(T min_now , T now ); Step 4: Compare the lowest ambient temperature T of the previous trip min_before , calculate the minimum ambient temperature T of the two trips min =min(T min_befor , T min_now ); Step 5: According to T min Query the low temperature electric balance SOC correction coefficient table; Step 6: Add the normal temperature electric balance SOC to the queried electric balance correction coefficient to obtain the current electric balance SOC value; Step 7: When the trip is over and the power is turned off, turn T min_now Assign to T min_before for storage.

2. A low temperature energy management control method for an extended range vehicle as claimed in claim 1, characterized in that: In step 3, use the current real-time temperature T now The lowest temperature of the current trip T min_now Compare and reassign the smaller value to T min_now .

3. A low temperature energy management control method for an extended range vehicle as claimed in claim 1, characterized in that: In step 4, the current lowest ambient temperature T min_now and the lowest ambient temperature T of the previous trip min_before The smaller value of the two is assigned to T min .

4. A low temperature energy management control method for an extended range vehicle as claimed in claim 1, characterized in that: In step 4, the default T min_before The value is 23℃.

5. The low temperature energy management control method for an extended range vehicle according to claim 1, characterized in that: In step 5, the current electric balance correction coefficient is determined after querying.

6. A low temperature energy management control method for an extended range vehicle as claimed in claim 1, characterized in that: In step seven, the information is stored after powering off for use in the next trip.

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