Battery charging equalization maintenance method for pure electric wide-body self-unloading truck

Abstract

This invention relates to a battery charging equalization and maintenance method for a pure electric wide-body dump truck, belonging to the field of battery charging technology. The VCU detects the highest voltage value of individual battery cells, the dynamic voltage difference between cells, and the number of charging cycles. It promptly adjusts the requested constant current charging current value and, by subtracting the smaller of the requested constant current charging current value and the current requested by the BMS based on the charging current MAP, charges the battery pack. This invention dynamically adjusts the charging current of the battery pack. When the voltage is low, the original charging current MAP request logic of the battery system is maintained, and the battery pack is charged with a constant current charging current for rapid charging. When the voltage is high, or when the dynamic voltage difference between cells changes significantly, or when the number of charging cycles is high, the VCU requests the smaller of the requested constant current charging current value and the charging current MAP request current for stable charging. This reduces energy waste during charging, minimizes battery damage during charging, and reduces the frequency of battery maintenance.

Description

Technical Field

[0001] This invention belongs to the field of battery charging technology, specifically a method for equalizing and maintaining the battery charging of a pure electric wide-body dump truck. Background Technology

[0002] With increasing global emphasis on environmental protection and energy efficiency, the use of new energy equipment is becoming more widespread, especially in the field of large-scale machinery, such as wide-body mining trucks. However, these devices typically require high power and operate for extended periods, often at full load for at least 20 hours a day. This presents challenges to battery capacity, charging efficiency, and the maintenance of the power battery system. Traditional solutions often involve increasing battery capacity to ensure operational efficiency and meet the demands of high-power charging and discharging, followed by rapid recharging using multi-gun (three or four guns or more) charging devices. However, prolonged high-current charging and discharging without sufficient resting time for the battery system leads to excessive charging and discharging, accelerating battery degradation and potentially causing polarization and lithium plating over time. Conversely, prolonged shutdown for maintenance can negatively impact operational efficiency.

[0003] Existing technical solutions involve acquiring battery parameters at preset time intervals during battery charging; determining the target charging current based on the battery voltage when it is within a preset voltage range; outputting a control signal to control the target charging current to charge the battery; and continuously varying the charging current to charge the battery, which can improve charging efficiency, effectively reduce the generation of internal polarization resistance during charging, and reduce battery heat generation. Therefore, existing technical solutions mainly divide the battery charging process into constant current charging and constant voltage charging processes. Acquiring battery parameters at preset time intervals allows for real-time monitoring of battery parameters during charging, ensuring safety. Battery maintenance primarily involves periodically discharging the power battery to below 20% SOC, allowing it to rest for more than 2 hours, and then performing a full charge calibration using the aforementioned charging control method.

[0004] Although the above-mentioned charging control methods and battery static maintenance can meet the requirements of battery system use, in large-tonnage equipment, when the battery system's charging and discharging power is high and the SOC is below 20%, the battery system's discharge performance is weak and cannot meet the requirements of continuous high-power discharge. This causes the power battery system to be in the 20% to 90% operating range for a long time, making it more prone to the problem of high charging and low discharging. Consequently, the frequency of battery maintenance and static maintenance is required to be higher. Secondly, since most electric mining trucks adopt a multi-gun high-current energy replenishment scheme, during the constant voltage charging control of the charging current, due to the constant voltage charging at the end, the current changes in real time and the charging current of multiple guns is large. The charging device cannot keep up with the change of the output target charging current at the rate, which can easily lead to the battery system reporting charging overcurrent faults. Summary of the Invention

[0005] 1. The technical problem that the invention aims to solve

[0006] The purpose of this invention is to solve the problem that existing charging methods cannot meet the needs of long-term operation of large-tonnage, high-capacity equipment, as well as the problem of high-frequency static maintenance of power batteries during equipment use.

[0007] 2. Technical Solution

[0008] To achieve the above objectives, the technical solution provided by the present invention is as follows:

[0009] This invention relates to a method for equalizing battery charging in a pure electric wide-body dump truck.

[0010] S1. During battery charging, the vehicle's VCU detects the highest voltage value of a single battery cell and determines whether the current highest voltage value of the cell is within the range of threshold C or threshold D. When the highest voltage value of the cell is within the range of threshold C, step S2 is executed; when the highest voltage value of the cell is within the range of threshold D, step S3 is executed.

[0011] S2. During battery charging, the vehicle's VCU detects the dynamic voltage difference of the battery cells and determines whether it is less than the threshold U1. If the detected dynamic voltage difference of the battery cells is less than the threshold U1, step S4 is executed; if the detected dynamic voltage difference of the battery cells is not less than the threshold U1, step S5 is executed.

[0012] S3. During battery charging, the vehicle's VCU detects the dynamic voltage difference of the battery cells and the number of charging cycles, and determines whether the dynamic voltage difference of the battery cells is greater than the threshold U2 and whether the number of charging cycles is greater than the threshold N. If the dynamic voltage difference of the battery cells is greater than the threshold U2 and the number of charging cycles is greater than the threshold N, proceed to step S6; if the dynamic voltage difference of the battery cells is not greater than the threshold U2 or the number of charging cycles is not greater than the threshold N, proceed to step S7.

[0013] S4. Maintain the original charging current MAP request logic of the battery system and charge the battery pack with a constant current charging current value I0.

[0014] S5. The vehicle VCU requests the output of constant current charging current value I1. The BMS takes the smaller of the requested current I0 and the constant current charging current value I1 according to the charging current MAP and outputs the final requested charging current value (I1, I0)min to charge the battery pack.

[0015] S6. Request the output constant current charging current value I through the vehicle VCU. 1i The BMS requests current I based on the charging current MAP. 0i With constant current charging current value I1i The smaller value is taken, and the final requested charging current value (I) is output. 1i I 0i )min, charge the battery pack;

[0016] S7, BMS requests current I based on charging current MAP. 0i To request current I 0i Charge the battery pack.

[0017] Preferably, during the battery charging process in steps S1 to S7, I 1i and I 0i As the individual battery cell voltages change in real time and the minimum value is output to charge the battery pack, when the vehicle's VCU detects that the rate of voltage rise at the charging end of the cell exceeds threshold A or the rate of voltage difference increase exceeds threshold B or I... 0i When the charging rate decreases beyond the threshold E, the vehicle's VCU actively intervenes to reduce the constant current charging current value I. 1i The BMS requests current I based on the charging current MAP. 0i With the constant current charging current value I of the vehicle VCU 1i The smaller value is taken, and the final requested charging current value (I) is output. 1i I 0i )min, charge the battery pack.

[0018] Preferably, the threshold A is 0.06 mv / s, the threshold B is 250 mv, and the threshold E is 20 A / s.

[0019] Preferably, in step S1, the range of the highest voltage threshold C of the single cell is (3.0V, 3.55V), and the range of threshold C is the constant current charging control stage; the range of threshold D is (3.55V, 3.7V), and the range of threshold D is the constant voltage charging control stage.

[0020] Preferably, in step S3, the dynamic voltage difference threshold U1 of the battery cell is 200mV.

[0021] Preferably, in step S4, the dynamic voltage difference threshold U2 of the battery cell is 250mV, and the cycle number threshold N is 10 times.

[0022] Preferably, the charging equalization maintenance method includes three charging modes:

[0023] (1) Mode 1: Charging control is performed using the original charging current MAP of the battery system BMS, which is divided into a constant current charging control stage and a constant voltage charging control stage. In the constant current charging control stage, the charging current is I0, and in the constant voltage charging control stage, the charging current is I... 0i ;

[0024] (2) Mode 2: During the constant voltage charging control phase, the BMS requests current I based on the charging current MAP. 0i With the constant current charging current value I of the vehicle VCU 1i Use a small control unit to charge the battery pack;

[0025] (3) Mode 3: Full stage, BMS requests current I based on charging current MAP 0i With the constant current charging current value I of the vehicle VCU 1i Use a small control to charge the battery pack.

[0026] 3. Beneficial effects

[0027] Compared with the prior art, the technical solution provided by this invention has the following advantages:

[0028] The present invention discloses a battery charging equalization maintenance method for a pure electric wide-body dump truck, which specifically involves: the VCU detecting the highest voltage value of a single battery cell, the dynamic voltage difference of the cell, and the number of cycles, adjusting the requested constant current charging current value in a timely manner, and taking the smaller of the requested constant current charging current value and the current requested by the BMS based on the charging current MAP, to charge the battery pack. This invention dynamically adjusts the charging current of the battery pack. When the voltage is low, the original charging current MAP request logic of the battery system is maintained, and the battery pack is charged with a constant current to quickly charge the battery. When the voltage is high, or when the dynamic voltage difference of the cells changes significantly and the number of charging cycles is high, the VCU requests the output constant current charging current value to be smaller than the charging current MAP request current, so as to achieve stable charging, reduce energy waste during the charging process, reduce battery damage during the charging process, and reduce the frequency of battery maintenance. At the same time, in large-tonnage, high-capacity equipment, large-capacity power batteries must be matched. However, large-capacity batteries often have the problem of high charging and low discharging during use, which affects the service life and charge capacity of the power battery. Through the charging equalization maintenance method of this application, the service life and duration of large-tonnage, high-capacity equipment are improved to meet the needs of long-term operation of the equipment. Attached Figure Description

[0029] Figure 1 This is a schematic flowchart of a battery charging equalization maintenance method for a pure electric wide-body dump truck according to the present invention.

[0030] Figure 2 This is a schematic diagram of the charging mode for a battery equalization maintenance method for a pure electric wide-body dump truck according to the present invention. Detailed Implementation

[0031] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present application, and not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort should fall within the scope of protection of the present application.

[0032] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate for the embodiments of this application described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0033] In this application, the terms "upper," "lower," "left," "right," "front," "rear," "top," "bottom," "inner," "outer," "middle," "vertical," "horizontal," "lateral," and "longitudinal" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. These terms are primarily for the purpose of better describing this application and its embodiments, and are not intended to limit the indicated device, element, or component to having a specific orientation, or to be constructed and operated in a specific orientation.

[0034] Furthermore, in addition to indicating location or positional relationship, some of the aforementioned terms may also have other meanings. For example, the term "above" may also be used in some cases to indicate a certain dependency or connection relationship. Those skilled in the art can understand the specific meaning of these terms in this application based on the specific circumstances.

[0035] Furthermore, the terms "installation," "setup," "equipped with," "connection," "linking," and "socketing" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral structure; 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, or an internal connection between two devices, components, or parts. Those skilled in the art can understand the specific meaning of these terms in this application based on the specific circumstances.

[0036] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. This application will now be described in detail with reference to the accompanying drawings and embodiments.

[0037] Example 1

[0038] See attached document Figure 1-2 The battery charging equalization maintenance method for a pure electric wide-body dump truck according to this embodiment is as follows:

[0039] S1. During battery charging, the vehicle VCU detects the highest voltage value of a single battery cell and determines whether the current highest voltage value of the cell is within the range of threshold C or threshold D. When the highest voltage value of the cell is within the range of threshold C, step S2 is executed. When the highest voltage value of the cell is within the range of threshold D, step S3 is executed. The vehicle VCU detects the highest voltage value of a single battery cell and determines its range. The vehicle VCU charges the battery pack according to different charging logics to improve charging efficiency.

[0040] S2. During battery charging, the vehicle VCU detects the dynamic voltage difference of the cells and determines whether it is less than the threshold U1. When the detected dynamic voltage difference of the cells is less than the threshold U1, step S4 is executed; when the detected dynamic voltage difference of the cells is not less than the threshold U1, step S5 is executed. The vehicle VCU detects the dynamic voltage difference of the cells and determines the magnitude of the change in the dynamic voltage difference of the cells, and selects an appropriate charging logic to charge the battery pack.

[0041] S3. During battery charging, the vehicle's VCU detects the dynamic voltage difference of the battery cells and the number of charging cycles, and determines whether the dynamic voltage difference of the battery cells is greater than the threshold U2 and whether the number of charging cycles is greater than the threshold N. If the dynamic voltage difference of the battery cells is greater than the threshold U2 and the number of charging cycles is greater than the threshold N, step S6 is executed; if the dynamic voltage difference of the battery cells is not greater than the threshold U2 or the number of charging cycles is not greater than the threshold N, step S7 is executed, and the vehicle's VCU detects the dynamic voltage difference of the battery cells and the number of charging cycles, and selects an appropriate charging logic to charge the battery pack.

[0042] S4. Maintain the original charging current MAP request logic of the battery system and charge the battery pack with a constant current charging current value I0.

[0043] S5. The vehicle VCU requests a constant current charging current value I1. The BMS calculates the smaller of the requested current I0 from the charging current MAP and the constant current charging current value I1, and outputs the final requested charging current value (I1, I0)min to charge the battery pack. Specifically, when I0 > I1, the battery pack is charged using the constant current charging current value I1 requested by the vehicle VCU; when I0 < I1, the battery pack is charged using the current I0 requested by the BMS from the charging current MAP.

[0044] S6. Request the output constant current charging current value I through the vehicle VCU. 1i The BMS requests current I based on the charging current MAP. 0i With constant current charging current value I 1i The smaller value is taken, and the final requested charging current value (I) is output. 1i I 0i )min, charge the battery pack, when I 1i Less than I 0i At that time, the constant current charging current value I requested by the vehicle VCU is... 1i Charge the battery pack; when I 1i Greater than I 0i At that time, the BMS requests current I based on the charging current MAP. 0i Charge the battery pack;

[0045] S7, BMS requests current I based on charging current MAP. 0i To request current I 0i Charge the battery pack.

[0046] In step S1, the range of the highest voltage threshold C of the single cell is (3.0V, 3.55V), and the range of threshold C is the constant current charging control stage. The range of threshold D is (3.55V, 3.7V), and the range of threshold D is the constant voltage charging control stage.

[0047] In step S3, the dynamic voltage difference threshold U1 of the battery cell is 200mV.

[0048] In step S4, the dynamic voltage difference threshold U2 of the battery cell is 250mV, and the cycle number threshold N is 10 times.

[0049] During battery charging, the vehicle's VCU detects the highest voltage of individual battery cells, the dynamic voltage difference between cells, and the number of charging cycles. When the highest voltage of an individual battery cell is low, the original charging current MAP request logic of the battery system is maintained to charge the battery pack with a constant current charging current, thus charging the battery quickly. When the highest voltage of an individual battery cell rises to a higher range during fast charging, or when the dynamic voltage difference between cells changes significantly and the number of charging cycles is high, the vehicle's VCU requests the smaller of the constant current charging current value and the charging current MAP request current to provide stable charging for the battery, reduce energy waste during charging, reduce battery damage during charging, and reduce the frequency of battery maintenance.

[0050] During the battery charging process in steps S1 to S7, I 1i and I 0iAs the individual battery cell voltages change in real time and the minimum value is output to charge the battery pack, when the vehicle's VCU detects that the rate of voltage rise at the charging end of the cell exceeds threshold A or the rate of voltage difference increase exceeds threshold B or I... 0i If the rate of reduction exceeds threshold E, where threshold A is 0.06 mV / s, threshold B is 250 mV, and threshold E is 20 A / s, the vehicle's VCU actively intervenes to reduce the constant current charging current value I. 1i The BMS requests current I based on the charging current MAP. 0i With the constant current charging current value I of the vehicle VCU 1i The smaller value is taken, and the final requested charging current value (I) is output. 1i I 0i )min, charge the battery pack, when I 1i Less than I 0i At that time, the constant current charging current value I requested by the vehicle VCU is... 1i Charge the battery pack; when I 1i Greater than I 0i At that time, the BMS requests current I based on the charging current MAP. 0i Charge the battery pack.

[0051] When the vehicle's VCU detects that the voltage rise rate of the battery cell at the charging end exceeds 0.06 mV / s or the voltage difference increase rate exceeds 250 mV or I... 0i When the charging rate is reduced to more than 20A / s, the vehicle's VCU actively intervenes to reduce the constant current charging current. The BMS requests the current based on the charging current MAP and takes the smaller value of the constant current charging current of the vehicle's VCU to charge the battery pack. This achieves balanced maintenance at the end of the battery charging process, improves cell consistency, and extends the service life of the power battery in long-cycle, high-frequency charge and discharge scenarios.

[0052] The charging equalization maintenance method includes three charging modes, specifically:

[0053] (1) Mode 1: Charging control is performed using the existing charging current MAP of the battery system BMS, which is divided into a constant current charging control stage and a constant voltage charging control stage. The constant current charging control stage corresponds to... Figure 2 In the A-B stage, the charging current is I0, and the corresponding constant voltage charging control stage is... Figure 2 During the B-C stage, the charging current is I. 0i I 0i Corresponding to "Current 1 Curve";

[0054] (2) Mode 2: During the constant voltage charging control phase, the BMS requests current I based on the charging current MAP. 0i With the constant current charging current value I of the vehicle VCU 1i The small control is used to charge the battery pack; the constant voltage charging control stage corresponds to... Figure 2 In the upper B-C stages, the charging current corresponds to the "current 2 curve";

[0055] (3) Mode 3: Full stage, BMS requests current I based on charging current MAP 0i With the constant current charging current value I of the vehicle VCU 1i Take small control to charge the battery pack; the entire process corresponds to... Figure 2 In the A-B-C stage, the charging current corresponds to the "current curve 3".

[0056] The vehicle's VCU monitors the battery system's cell health and consistency in real time, switching charging modes and optimizing the charging phase. 1i Without altering the original charging current MAP of the battery management system (BMS), this method performs charging maintenance balancing to assess battery health status. By reducing the end-of-charge trickle charging current, the extended charging time is less than 20 minutes. However, the charging mode used in this method triggers maintenance twice a week. Although this method reduces the charging rate of the power battery, it significantly reduces the risk and cost of manual battery maintenance and improves battery charging safety and lifespan. Furthermore, large-tonnage, high-capacity equipment requires high-capacity power batteries, which often experience high-charge-low-discharge issues during use, affecting battery lifespan and charge capacity. This charging balancing maintenance method improves the lifespan and duration of large-tonnage, high-capacity equipment, meeting the needs of long-term operation.

[0057] The above-described embodiments are merely illustrative of certain implementations of the present invention, and are described in a relatively specific and detailed manner. However, they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements are all within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the appended claims.

Claims

1. A method for equalizing battery charging in a pure electric wide-body dump truck, characterized in that: S1. During battery charging, the vehicle's VCU detects the highest voltage value of a single battery cell and determines whether the current highest voltage value of the cell is within the range of threshold C or threshold D. When the highest voltage value of the cell is within the range of threshold C, step S2 is executed; when the highest voltage value of the cell is within the range of threshold D, step S3 is executed. S2. During battery charging, the vehicle's VCU detects the dynamic voltage difference of the battery cells and determines whether it is less than the threshold U1. If the detected dynamic voltage difference of the battery cells is less than the threshold U1, step S4 is executed; if the detected dynamic voltage difference of the battery cells is not less than the threshold U1, step S5 is executed. S3. During battery charging, the vehicle's VCU detects the dynamic voltage difference of the battery cells and the number of charging cycles, and determines whether the dynamic voltage difference of the battery cells is greater than the threshold U2 and whether the number of charging cycles is greater than the threshold N. If the dynamic voltage difference of the battery cells is greater than the threshold U2 and the number of charging cycles is greater than the threshold N, proceed to step S6; if the dynamic voltage difference of the battery cells is not greater than the threshold U2 or the number of charging cycles is not greater than the threshold N, proceed to step S7. S4. Maintain the original charging current MAP request logic of the battery system and charge the battery pack with a constant current charging current value I0. S5. The vehicle VCU requests the output of constant current charging current value I1. The BMS takes the smaller of the requested current I0 and the constant current charging current value I1 according to the charging current MAP and outputs the final requested charging current value (I1, I0)min to charge the battery pack. S6. Request the output constant current charging current value I through the vehicle VCU. 1i The BMS requests current I based on the charging current MAP. 0i With constant current charging current value I 1i The smaller value is taken, and the final requested charging current value (I) is output. 1i I 0i )min, charge the battery pack; S7, BMS requests current I based on charging current MAP. 0i To request current I 0i Charge the battery pack.

2. The battery charging equalization maintenance method for a pure electric wide-body dump truck according to claim 1, characterized in that: During the battery charging process in steps S1 to S7, I 1i and I 0i As the individual battery cell voltages change in real time and the minimum value is output to charge the battery pack, when the vehicle's VCU detects that the rate of voltage rise at the charging end of the cell exceeds threshold A or the rate of voltage difference increase exceeds threshold B or I... 0i When the charging rate decreases beyond the threshold E, the vehicle's VCU actively intervenes to reduce the constant current charging current value I. 1i The BMS requests current I based on the charging current MAP. 0i With the constant current charging current value I of the vehicle VCU 1i The smaller value is taken, and the final requested charging current value (I) is output. 1i I 0i )min, charge the battery pack.

3. The battery charging equalization maintenance method for a pure electric wide-body dump truck according to claim 2, characterized in that: The threshold A is 0.06 mv / s, the threshold B is 250 mv, and the threshold E is 20 A / s.

4. The battery charging equalization maintenance method for a pure electric wide-body dump truck according to claim 2, characterized in that: In step S1, the range of the highest voltage threshold C of the single cell is (3.0V, 3.55V), and the range of threshold C is the constant current charging control stage. The range of threshold D is (3.55V, 3.7V), and the range of threshold D is the constant voltage charging control stage.

5. A method for equalizing battery charging in a pure electric wide-body dump truck according to claim 2, characterized in that: In step S3, the dynamic voltage difference threshold U1 of the battery cell is 200mV.

6. The battery charging equalization maintenance method for a pure electric wide-body dump truck according to claim 2, characterized in that: In step S4, the dynamic voltage difference threshold U2 of the battery cell is 250mV, and the cycle number threshold N is 10 times.

7. A method for equalizing battery charging in a pure electric wide-body dump truck according to any one of claims 1-6, characterized in that, The charging equalization maintenance method includes three charging modes: (1) Mode 1: Charging control is performed using the original charging current MAP of the battery system BMS, which is divided into a constant current charging control stage and a constant voltage charging control stage. In the constant current charging control stage, the charging current is I0, and in the constant voltage charging control stage, the charging current is I... 0i ; (2) Mode 2: During the constant voltage charging control phase, the BMS requests current I based on the charging current MAP. 0i With the constant current charging current value I of the vehicle VCU 1i Use a small control unit to charge the battery pack; (3) Mode 3: Full stage, BMS requests current I based on charging current MAP 0i With the constant current charging current value I of the vehicle VCU 1i Use a small control to charge the battery pack.

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