An electrically driven auxiliary battery pack heating method

Abstract

The application belongs to the technical field of electric drive, and particularly relates to a battery pack auxiliary heating technology. The electric drive auxiliary battery pack heating method comprises the following steps: detecting electric drive and vehicle parameters; comparing the electric drive and vehicle parameters with set values; and adjusting the heating output power of the current electric drive according to the comparison result; wherein the IGBT temperature is taken as the main reference object. Through the detection of the IGBT temperature and the real-time calculation of the heating power, the original single threshold switch control is changed into dynamic temperature slope control. The output heating power of the active heating function is controlled according to the IGBT temperature, the dynamic balance stability of heating is realized, the function continuous activation state time is increased, the efficiency of the active heating function is improved, and the voltage, current oscillation and NVH problems caused by the frequent switching of the active heating function are reduced.

Description

Technical Field

[0001] This invention belongs to the field of electric drive technology, specifically relating to a battery pack auxiliary heating technology. Background Technology

[0002] The range of electric vehicles in low-temperature environments remains a significant issue affecting user experience and quality. Previous methods involved raising the battery pack temperature through PTC (Positive Temperature Coefficient) heating or stall-heating, thereby improving charging and discharging efficiency in low temperatures. However, PTC heating is criticized for its low efficiency and heavy load on the battery. Stall-heating, on the other hand, puts the electric drive in an unstable state, posing a risk of overheating. Furthermore, the vehicle cannot operate normally in a stalled state. Active electric drive heating, compared to previous methods, offers advantages such as higher heating efficiency, lower cost, higher safety, and wider application (it can be activated both when the vehicle is moving and stationary), and has been widely adopted by OEMs. Typically, active heating in the vehicle uses a single threshold setting, and the active heating function is controlled based on this threshold.

[0003] Because the active heating switch logic is controlled by a single threshold, it outputs maximum power when the function is activated. Under maximum power heating, the IGBT (Insulated Gate Bipolar Transistor) temperature rises rapidly. When the IGBT temperature rises to the set threshold temperature for turning off active heating, the active heating function exits, the heating power drops to zero, and the IGBT temperature drops rapidly. When the IGBT temperature falls below the threshold temperature for turning on active heating, the active heating function is reactivated, and it heats again at maximum power output, causing the IGBT temperature to rise rapidly again. Current technology simply controls the on / off of the active heating function by changing the IGBT temperature. Because the power output is based on maximum heating power, the IGBT temperature changes very rapidly. With the IGBT temperature changing, the active heating function switches on and off frequently, leading to reduced active heating efficiency. Furthermore, frequent switching of the active heating function can cause voltage and current oscillations, as well as NVH (Noise, Vibration, and Harshness) issues.

[0004] Therefore, there is an urgent need to develop a new method for heating the electric drive-assisted battery pack to solve the above problems. Summary of the Invention

[0005] The purpose of this invention is to provide a method for heating an electric drive auxiliary battery pack.

[0006] To address the aforementioned technical problems, this invention provides a method for heating an electric drive-assisted battery pack, comprising: detecting electric drive and vehicle parameters; comparing the electric drive and vehicle parameters with set values; and adjusting the current heating output power of the electric drive based on the comparison results.

[0007] Specifically, the method for detecting electric drive and vehicle parameters includes: detecting the current temperature value of the IGBT.

[0008] Specifically, the method for detecting electric drive and vehicle parameters further includes: detecting the current heating output power value of the electric drive.

[0009] Specifically, the method for comparing the electric drive and vehicle parameters with the set values ​​includes: setting a first set temperature value; determining whether the IGBT is in a heating state and whether the current temperature value is less than the first set temperature value.

[0010] Specifically, the method for adjusting the heating output power of the current electric drive based on the comparison results includes: when the IGBT is in a heating state and the current temperature value is less than the first set temperature value, controlling the electric drive to output at the maximum heating power.

[0011] Specifically, the method for comparing electric drive and vehicle parameters with set values ​​further includes: setting a second set temperature value; determining whether the IGBT is in a heating state and whether the current temperature value is between the first set temperature value and the second set temperature value.

[0012] Specifically, the method for adjusting the heating output power of the current electric drive based on the comparison result further includes: when the IGBT is in a heating state and the current temperature value is between the first set temperature value and the second set temperature value, controlling the electric drive to derating output according to the current output power value of the electric drive until the current temperature value of the IGBT is greater than the second set temperature value, and then controlling the electric drive to stop output.

[0013] Specifically, the method for comparing electric drive and vehicle parameters with set values ​​further includes: setting a third set temperature value and a fourth set temperature value; determining whether the IGBT is in a cooling state and whether the current temperature value is greater than the third set temperature value, or whether the current temperature value is between the third set temperature value and the fourth set temperature value, or whether the current temperature value is less than the fourth set temperature value.

[0014] Specifically, the method for adjusting the heating output power of the current electric drive based on the comparison results further includes: when the IGBT is in a cooling state and the current temperature value is between the third set temperature value and the fourth set temperature value, controlling the electric drive to derating output based on the current output power value of the electric drive.

[0015] Specifically, the method for adjusting the heating output power of the current electric drive based on the comparison results further includes: when the IGBT is in a cooling state and the current temperature value is greater than the third set temperature value, controlling the electric drive to stop the heating power output; when the IGBT is in a cooling state and the current temperature value is less than the fourth set temperature value, controlling the electric drive to heat at the maximum output heating power.

[0016] The beneficial effects of this invention are that by detecting the IGBT temperature and calculating the heating power in real time, the original single threshold switching control can be transformed into dynamic temperature slope control. The output power of the active heating function is controlled according to the IGBT temperature, thereby achieving dynamic balance and stability of heating, increasing the continuous activation time of the function, improving the efficiency of the active heating function, and reducing voltage and current oscillations and NVH problems caused by frequent switching of the active heating function.

[0017] Other features and advantages of the invention will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the invention.

[0018] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, preferred embodiments are described below in detail with reference to the accompanying drawings. Attached Figure Description

[0019] 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.

[0020] Figure 1 This is a flowchart illustrating the process of electric drive-assisted battery pack heating according to the present invention;

[0021] Figure 2 This is the output control diagram of the electric drive output heating power of the present invention. Detailed Implementation

[0022] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions 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.

[0023] Example 1, in this example, as Figures 1 to 2As shown in the figure, this embodiment provides a method for heating an electric drive-assisted battery pack, which includes: detecting the operating parameters of the electric drive and the vehicle; comparing the electric drive and vehicle parameters with set values; and adjusting the heating output power of the current electric drive based on the comparison results.

[0024] In this embodiment, by detecting the IGBT temperature and calculating the heating power in real time, the original single threshold switching control can be transformed into dynamic temperature slope control. The output power of the active heating function is controlled according to the IGBT temperature, so as to achieve dynamic balance and stability of heating, increase the continuous activation time of the function, improve the efficiency of the active heating function, and reduce voltage oscillation and NVH problems caused by frequent switching of the active heating function.

[0025] Specifically, NVH issues refer to noise, vibration, and harmlessness.

[0026] In order to enable comparison with the set value, the method for detecting the operating parameters of the IGBT includes: detecting the current temperature value of the IGBT.

[0027] In order to enable comparison with set values, the method for detecting electric drive and vehicle parameters further includes: detecting the current heating output power value of the electric drive.

[0028] Specifically, the temperature change of the IGBT and the change in the current output electrothermal power of the electric drive can be used to determine whether the IGBT is in a heating or cooling state.

[0029] To determine whether the IGBT needs to output maximum power during the heating process, the method of comparing the electric drive and vehicle parameters with the set value includes: setting a first set temperature value; determining whether the IGBT is in a heating state and whether the current temperature value is less than the first set temperature value.

[0030] In order to achieve rapid heating of the battery pack by the electric drive, the method of adjusting the heating output power of the electric drive according to the comparison results includes: when the IGBT is in a heating state and the current temperature value is less than the first set temperature value, controlling the electric drive to heat at the maximum output power.

[0031] Specifically, the first set temperature value is the active heating derating point. When the current temperature value of the IGBT is less than the first set temperature value and the heating function activation condition is met, the heating function of the electric drive is activated normally, and the electric drive outputs the maximum heating power to realize the heating function of the battery pack.

[0032] To determine whether the IGBT needs to derating its output during the heating process, the method of comparing the electric drive and vehicle parameters with the set values ​​further includes: setting a second set temperature value; and determining whether the IGBT is in a heating state and whether the current temperature value is between the first set temperature value and the second set temperature value.

[0033] In order to reduce the switching frequency of the electric drive active heating function and improve the heating efficiency, the method of adjusting the current heating output power of the electric drive according to the comparison result further includes: when the IGBT is in the heating state and the current temperature value is between the first set temperature value and the second set temperature value, the electric drive is controlled to derating output according to the current heating output power value of the electric drive until the current temperature value of the IGBT is greater than the second set temperature value, and then the electric drive is controlled to stop heating output.

[0034] Specifically, the second set temperature value is the derating end point. During the heating process of the IGBT, when the current temperature value of the IGBT is greater than the first set temperature value, the electric drive derating the heating power output. As the current temperature value of the IGBT gradually increases, the derating value of the IGBT gradually increases until the current temperature value of the IGBT reaches the second set temperature value, at which point the active heating function of the electric drive is completely turned off.

[0035] To determine whether the heating function is activated during the cooling process of the IGBT and how to adjust the current output power value, the method of comparing the electric drive and vehicle parameters with the set values ​​further includes: setting a third set temperature value and a fourth set temperature value; determining whether the IGBT is in a cooling state and whether the current temperature value is greater than the third set temperature value, or whether the current temperature value is between the third set temperature value and the fourth set temperature value, or whether the current temperature value is less than the fourth set temperature value.

[0036] As an optional implementation of the first set temperature value, second set temperature value, third set temperature value, and fourth set temperature value, the second set temperature value is greater than the first set temperature value, the third set temperature value is greater than the fourth set temperature value, and the second set temperature value is greater than the third set temperature value.

[0037] In order to reduce the switching frequency of the electric drive active heating function and improve the heating efficiency, the method of adjusting the current heating output power of the electric drive according to the comparison results further includes: when the IGBT is in a cooling state and the current temperature value is between the third set temperature value and the fourth set temperature value, controlling the electric drive heating power to be derated according to the current heating output power value of the electric drive.

[0038] To optimize voltage oscillations and NVH issues caused by frequently shutting down the active heating of the electric drive, the method for adjusting the heating output power of the electric drive based on the comparison results further includes: when the IGBT is in a cooling state and the current temperature value is greater than the third set temperature value, controlling the electric drive to stop the heating power output; when the IGBT is in a cooling state and the current temperature value is less than the fourth set temperature value, controlling the electric drive to output at the maximum heating power.

[0039] Specifically, during the cooling process of the IGBT, when the current temperature of the IGBT drops below the third set temperature value, the active heating function of the electric drive is reactivated. The current heating power output value of the electric drive is affected by the current temperature value of the IGBT and is output in a derating form. When the current temperature value of the IGBT drops below the fourth set temperature value, the electric drive outputs at the maximum heating power. This can reduce the switching frequency of the active heating function, improve heating efficiency, and optimize voltage and current oscillations and NVH problems caused by frequent shutdown of active heating.

[0040] In summary, this invention, by detecting IGBT temperature and calculating heating power in real time, transforms the original single threshold switching control into dynamic temperature slope control. It controls the output power of the active heating function based on the IGBT temperature, achieving dynamic balance and stability of heating, extending the continuous activation time of the function, thereby improving the efficiency of the active heating function. At the same time, it reduces voltage oscillations and NVH problems caused by frequent switching of the active heating function.

[0041] All the devices (parts whose specific structures are not specified) selected in this application are general standard parts or parts known to those skilled in the art. Their structures and principles can be learned by those skilled in the art through technical manuals or conventional experimental methods.

[0042] In the description of the embodiments of the present invention, 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; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in the present invention based on the specific circumstances.

[0043] 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.

[0044] In the several embodiments provided in this application, it should be understood that the disclosed systems, apparatuses, and methods can be implemented in other ways. The apparatus embodiments described above are merely illustrative. For example, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. Furthermore, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Additionally, the shown or discussed mutual couplings, direct couplings, or communication connections may be through some communication interfaces; indirect couplings or communication connections between devices or units may be electrical, mechanical, or other forms.

[0045] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0046] In addition, the functional units in the various embodiments of the present invention can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit.

[0047] Based on the above-described preferred embodiments of the present invention, and through the foregoing description, those skilled in the art can make various changes and modifications without departing from the inventive concept. The technical scope of this invention is not limited to the contents of the specification, but must be determined according to the scope of the claims.

Claims

1. A method for heating an electric drive-assisted battery pack, characterized in that, include: Detect electric drive and vehicle parameters; Compare the electric drive and vehicle parameters with the set values; Adjust the heating output power of the electric drive based on the comparison results; The method for detecting electric drive and vehicle parameters includes: Detect the current temperature value of the IGBT and the current heating output power value of the electric drive; The method for comparing electric drive and vehicle parameters with set values ​​includes: Set the first preset temperature value; Determine whether the IGBT is in a heating state and whether the current temperature value is less than the first set temperature value; Set the second preset temperature value; Determine whether the IGBT is in a heating state and whether the current temperature value is between the first set temperature value and the second set temperature value; Set the third and fourth set temperature values; Determine whether the IGBT is in a cooling state and whether the current temperature value is greater than the third set temperature value, or whether the current temperature value is between the third set temperature value and the fourth set temperature value, or whether the current temperature value is less than the fourth set temperature value. The method for adjusting the heating output power of the current electric drive based on the comparison results includes: When the IGBT is in a heating state and the current temperature value is less than the first set temperature value, the control electric drive outputs at the maximum heating power; When the IGBT is in a heating state and the current temperature value is between the first set temperature value and the second set temperature value, the electric drive is controlled to derating output according to the current output power value of the electric drive until the current temperature value of the IGBT is greater than the second set temperature value, and then the electric drive is controlled to stop output. When the IGBT is in a cooling state and the current temperature value is between the third and fourth set temperature values, the electric drive is controlled to derating output according to the current output power value of the electric drive. When the IGBT is in a cooling state and the current temperature value is greater than the third set temperature value, the control electric drive stops the heating power output. When the IGBT is in a cooling state and the current temperature value is less than the fourth set temperature value, the control electric drive will heat the device at the maximum output heating power.

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