A rapid heating control strategy for power batteries

Abstract

A power battery rapid heating control strategy executes corresponding battery heating strategies according to different detected charging scenarios and battery temperatures, so that the heating effect is more in line with the working conditions and reduces energy loss and failure rate. It detects faults before starting the battery heating function to ensure that heating is performed in a fault-free state. It controls the power of other high-voltage loads before starting the heating circuit to prevent circuit fusing. It matches the corresponding heating power according to different charging scenarios and battery temperatures, improves heating efficiency, and reduces energy consumption. In addition, the power battery rapid heating control strategy of the present invention also sets multiple safety thresholds. During the operation of the heating function, it detects signals such as current, voltage, temperature, and capacity in real time, and stops heating immediately when the threshold is exceeded to ensure the safety of the heating process, greatly reducing safety risks.

Description

Technical Field

[0001] The present invention relates to the field of new energy technology, and in particular to a power battery rapid heating control strategy. Background Art

[0002] Pure electric vehicles have the advantages of zero emissions, high energy utilization and low energy costs, and are being vigorously developed in a wide range of areas. However, under low temperature conditions, the electrode reaction rate of the battery will decrease, the allowed charge and discharge current will be very small, and charging and discharging will be difficult. In extreme cases, such as when the battery temperature is less than -20°C, the current is even 0A, which will lead to weaker vehicle power and longer battery charging time, and poor convenience of use; in addition, low temperature environments will also aggravate the lithium plating of the negative electrode of lithium batteries, which will cause the battery life to decay faster at the least, and cause battery safety problems at the worst. Therefore, overcoming the limitations of batteries under low temperature conditions, solving the problem of the convenience of pure electric vehicles at low temperatures, and thus opening up the pure electric vehicle market in high-cold areas is one of the main research and development directions of OEMs. Summary of the invention

[0003] In view of this, the present invention provides a power battery rapid heating control strategy suitable for low temperature conditions.

[0004] The power battery rapid heating control strategy of the present invention comprises the following steps:

[0005] Step S1: Detect the minimum battery temperature and the battery charging scenario to determine whether the battery meets the heating conditions;

[0006] Step S2: If the battery meets the heating conditions, then perform fault detection;

[0007] Step S3: If no fault is detected, the battery controller sends a heating instruction to the heating circuit according to the battery minimum temperature and the battery charging scenario;

[0008] Step S4: the heating circuit receives the heating instruction and performs rapid battery heating according to the heating instruction;

[0009] Step S5: The battery controller sends a stop command to the heating circuit to stop rapid battery heating.

[0010] Furthermore, the step S1 of determining whether the battery meets the heating condition includes:

[0011] The battery minimum temperature is compared with the heating temperature threshold. If the battery minimum temperature is less than the heating temperature threshold, the process proceeds to step S2.

[0012] Further, the fault detection in step S2 includes:

[0013] While the heating circuit is being tested for faults, the high-voltage circuit is also tested for faults. If no faults are detected in either the heating circuit or the high-voltage circuit, the process proceeds to step S3.

[0014] Furthermore, the fault detection in step S2 further includes: if no fault is detected, stopping the rapid battery heating and limiting the power of the electrical equipment on the high-voltage circuit.

[0015] Furthermore, if it is detected that the heating circuit operates stably or the current temperature of the battery is greater than a set temperature threshold or a fault occurs, the power restriction on the electrical equipment on the high-voltage circuit is released.

[0016] Further, the temperature threshold includes a first threshold, a second threshold, a third threshold and a fourth threshold, the third threshold is greater than the first threshold, the second threshold and the fourth threshold, and the temperature threshold has an interval of ±5°C.

[0017] Furthermore, the heating instruction includes a low-range power signal, a mid-range power signal and a high-range power signal, and the heating circuit heats the battery at low-range power, mid-range power and high-range power respectively according to the heating instruction.

[0018] Furthermore, sending a heating instruction to the heating circuit in step S3 includes the following steps:

[0019] If the battery is in an AC charging scenario, sending the mid-range power signal;

[0020] If the battery is in a DC charging scenario, sending the high-end power signal;

[0021] If the battery is in a parking state and the minimum battery temperature is less than a first threshold, sending the high-end power signal;

[0022] If the battery is in a parking state and the lowest battery temperature is greater than or equal to a first threshold, sending the low-power signal;

[0023] If the battery is in a driving state and the lowest battery temperature is less than a first threshold, sending the mid-range power signal;

[0024] If the battery is in a driving state and the lowest battery temperature is greater than or equal to a first threshold, the low-power signal is sent.

[0025] Furthermore, sending a stop instruction to the heating circuit in step S5 includes the following steps:

[0026] If the battery is in an AC charging scenario and the current battery temperature is greater than the second threshold, sending a stop instruction;

[0027] If the battery is in a DC charging scenario and the current temperature of the battery is greater than the third threshold, sending a stop instruction;

[0028] If the battery is in a parking state or a driving state and the current temperature of the battery is greater than the fourth threshold, a stop command is sent.

[0029] Furthermore, the battery controller in step S5 sends a stop instruction to the heating circuit, including: the battery controller detects the current battery temperature and faults in real time, and stops rapid battery heating when the battery controller detects that the current battery temperature is greater than the set temperature threshold or detects a fault.

[0030] The power battery rapid heating control strategy of the present invention ensures that heating is performed in a fault-free state by detecting faults before the battery heating function is started, and controls the power of other high-voltage loads before starting the heating circuit to prevent circuit fusing. According to the different charging scenarios and battery temperatures detected, the corresponding battery heating strategy is executed to make the heating effect more in line with the working conditions, and reduce energy loss and failure rate. The corresponding heating power is matched according to different charging scenarios and battery temperatures, which improves heating efficiency and reduces energy consumption. In addition, the power battery rapid heating control strategy of the present invention also sets multiple thresholds. During the operation of the heating function, the current, voltage, temperature, capacity and other signals are detected in real time, and the heating is stopped immediately when the threshold is exceeded to ensure the safety of the heating process and greatly reduce safety risks.

[0031] 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

[0032] Figure 1 A schematic diagram of the power battery rapid heating control strategy provided by the present invention. DETAILED DESCRIPTION

[0033] In order to further explain the technical means and effects adopted by the present invention to achieve the predetermined invention purpose, the present invention is described in detail below in conjunction with the accompanying drawings and preferred embodiments.

[0034] The new energy vehicle components on which the power battery rapid heating control strategy of the present invention is based include: a battery, a battery controller, a vehicle controller, a heating circuit and a detection module, wherein the battery controller can control the battery charging and discharging and the operation of the heating circuit, the vehicle controller can control the high-voltage distribution circuit and the low-voltage distribution circuit of the vehicle, the heating circuit is used to quickly heat the battery, and the detection module includes a temperature detection module for detecting temperature, a current detection module for detecting current, a voltage detection module for detecting voltage and a fault detection module for detecting faults.

[0035] See also Figure 1 The power battery rapid heating control strategy of the present invention includes the following steps:

[0036] Step S1: Detect the minimum battery temperature and battery charging scenario to determine whether the battery meets the heating conditions.

[0037] Specifically, determining whether the battery meets the heating conditions in step S1 includes: comparing the minimum temperature of the battery with the heating temperature threshold. If the minimum temperature of the battery is less than the heating temperature threshold, then entering step S2. In this embodiment, the minimum temperature refers to the lowest temperature of the battery detected by the detection module within a certain period of time. In addition to detecting and comparing the battery temperature, it is also necessary to detect the SOC value that can support the heating function and compare it with the set SOC threshold. If the SOC value reaches the set SOC threshold, then enter step S2.

[0038] Step S2: If the battery meets the heating conditions, fault detection is performed.

[0039] Specifically, the fault detection in step S1 includes: performing fault detection on the high-voltage circuit while performing fault detection on the heating circuit. If no fault is detected in either the heating circuit or the high-voltage circuit, the power of other high-voltage loads needs to be controlled before starting to prevent circuit fusing and even safety risks, that is, power limitation of electrical equipment on the high-voltage circuit, and then entering step S3. If it is detected that the heating circuit is running stably or the current battery temperature is greater than the set temperature threshold or a fault occurs, the power limitation of the electrical equipment on the high-voltage circuit is released.

[0040] Step S3: If no fault is detected, the battery controller sends a heating instruction to the heating circuit according to the minimum battery temperature and the battery charging scenario.

[0041] Specifically, sending a heating instruction to the heating circuit in step S3 includes the following steps:

[0042] If the battery is in AC charging scenario, a mid-range power signal is sent;

[0043] If the battery is in a DC charging scenario, a high-power signal is sent;

[0044] If the battery is in parking state and the minimum battery temperature is less than a first threshold, a high-power signal is sent;

[0045] If the battery is in parking state and the minimum battery temperature is greater than or equal to the first threshold, a low power signal is sent;

[0046] If the battery is in driving state and the minimum battery temperature is less than the first threshold, a mid-range power signal is sent;

[0047] If the battery is in a driving state and the lowest battery temperature is greater than or equal to a first threshold, a low power signal is sent.

[0048] Further, the heating instruction includes a low-range power signal, a mid-range power signal and a high-range power signal, and the heating circuit heats the battery with low-range power, mid-range power and high-range power respectively according to the heating instruction. The temperature threshold includes a first threshold, a second threshold, a third threshold and a fourth threshold, the third threshold is greater than the first threshold, the second threshold and the fourth threshold, and the temperature threshold has an interval of ±7°C. In this embodiment, the first threshold is 0°C, the second threshold is 5°C, the third threshold is 20°C, and the fourth threshold is 5°C.

[0049] Step S4: The heating circuit receives the heating instruction and performs rapid battery heating according to the heating instruction.

[0050] Step S5: The battery controller sends a stop command to the heating circuit to stop rapid battery heating.

[0051] Specifically, the battery controller and the vehicle controller control the detection module to detect the current battery temperature and faults in real time. When the battery controller detects that the current battery temperature is greater than a set temperature threshold or detects a fault, the rapid battery heating is stopped to ensure the safety of heating. The sending of the stop instruction to the heating circuit in step S5 includes the following steps:

[0052] If the battery is in an AC charging scenario and the current battery temperature is greater than a second threshold, a stop instruction is sent;

[0053] If the battery is in a DC charging scenario and the current battery temperature is greater than a third threshold, a stop command is sent;

[0054] If the battery is in a parking state or a driving state and the current temperature of the battery is greater than a fourth threshold, a stop command is sent.

[0055] In summary, the power battery rapid heating control strategy of the present invention ensures that heating is performed in a fault-free state by detecting faults before the battery heating function is started, and controls the power of other high-voltage loads before starting the heating circuit to prevent circuit fusing. According to the different charging scenarios and battery temperatures detected, the corresponding battery heating strategy is executed to make the heating effect more in line with the working conditions, and reduce energy loss and failure rate. The corresponding heating power is matched according to different charging scenarios and battery temperatures, which improves heating efficiency and reduces energy consumption. In addition, the power battery rapid heating control strategy of the present invention also sets multiple thresholds. During the operation of the heating function, the current, voltage, temperature, capacity and other signals are detected in real time, and the heating is stopped immediately when the threshold is exceeded to ensure the safety of the heating process and greatly reduce safety risks.

[0056] The above are only preferred embodiments of the present invention, and are not intended to limit the present invention in any form. Although the present invention has been disclosed as a preferred embodiment as above, it is not intended to limit the present invention. Any technician familiar with the profession can make some changes or modifications to equivalent embodiments of equivalent changes using the technical contents disclosed above without departing from the scope of the technical solution of the present invention. However, any simple modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention are still within the scope of the technical solution of the present invention.

Claims

1. A power battery rapid heating control strategy, characterized in that: The power battery rapid heating control strategy includes the following steps: Step S1: Detect the minimum battery temperature and the battery charging scenario to determine whether the battery meets the heating conditions; Step S2: If the battery meets the heating conditions, then perform fault detection; Step S3: If no fault is detected, the battery controller sends a heating instruction to the heating circuit according to the battery minimum temperature and the battery charging scenario; Step S4: the heating circuit receives the heating instruction and performs rapid battery heating according to the heating instruction; Step S5: the battery controller sends a stop command to the heating circuit to stop rapid battery heating; The heating instruction includes a low-range power signal, a mid-range power signal and a high-range power signal, and the heating circuit heats the battery at low-range power, mid-range power and high-range power respectively according to the heating instruction; The sending of the heating instruction to the heating circuit in step S3 comprises the following steps: If the battery is in an AC charging scenario, sending the medium or low power signal; If the battery is in a DC charging scenario, sending the high-end power signal; If the battery is in a parking state and the minimum battery temperature is less than a first threshold, sending the high-end power signal; If the battery is in a parking state and the lowest battery temperature is greater than or equal to a first threshold, sending the low-power signal; If the battery is in a driving state and the lowest battery temperature is less than a first threshold, sending the mid-range power signal; If the battery is in a driving state and the lowest battery temperature is greater than or equal to a first threshold, the low-power signal is sent.

2. The power battery rapid heating control strategy according to claim 1, characterized in that: The step S1 of determining whether the battery meets the heating condition includes: The battery minimum temperature is compared with the heating temperature threshold. If the battery minimum temperature is less than the heating temperature threshold, the process proceeds to step S2.

3. The power battery rapid heating control strategy according to claim 1, characterized in that: The fault detection in step S2 includes: While the heating circuit is being tested for faults, the high-voltage circuit is also tested for faults. If no faults are detected in either the heating circuit or the high-voltage circuit, the process proceeds to step S3.

4. The power battery rapid heating control strategy according to claim 1, characterized in that: The fault detection in step S2 further includes: if no fault is detected, power limitation is performed on the electrical equipment on the high voltage circuit.

5. The power battery rapid heating control strategy according to claim 1, characterized in that: If it is detected that the heating circuit is operating stably or the current battery temperature is greater than the set temperature threshold or a fault occurs, the rapid battery heating is stopped and the power limit on the electrical equipment on the high-voltage circuit is released.

6. The power battery rapid heating control strategy according to claim 5 is characterized in that: The temperature threshold includes a first threshold, a second threshold, a third threshold and a fourth threshold, the third threshold is greater than the first threshold, the second threshold and the fourth threshold, and the temperature threshold has an interval of ±7°C.

7. The power battery rapid heating control strategy according to claim 6, characterized in that: The step S5 of sending a stop instruction to the heating circuit comprises the following steps: If the battery is in an AC charging scenario and the current battery temperature is greater than the second threshold, sending a stop instruction; If the battery is in a DC charging scenario and the current temperature of the battery is greater than the third threshold, sending a stop instruction; If the battery is in a parking state or a driving state and the current temperature of the battery is greater than the fourth threshold, a stop command is sent.

8. The power battery rapid heating control strategy according to claim 6, characterized in that: The battery controller in step S5 sends a stop command to the heating circuit, including: the battery controller detects the current battery temperature and faults in real time, and stops rapid battery heating when the battery controller detects that the current battery temperature is greater than the set temperature threshold or detects a fault.

Images