A dual-charger blind charging equalization method and system

Abstract

This invention discloses a dual-charger blind charging equalization method and system. The dual-charger blind charging equalization method determines the master and slave devices by judging the order in which the two chargers are turned on. The charger that is turned on first is the slave device, and the charger that is turned on later is the master device. Then, the host computer controls the master device to output a discharge current, causing the battery to lose power. Thus, the master device learns the charging current output by the slave device to the battery and calculates the equalization charging current based on the discharge current of the master device at the time of battery power loss. Then, the host computer controls the master device to output and gradually increase the charging current to the equalization charging current value. As the charging current output by the master device increases, the charging current of the slave device decreases accordingly, so that the charging current output by the master device = the charging current of the slave device = the equalization charging current. Thus, the charging current of the two chargers is evenly distributed.

Description

Technical Field

[0001] This invention relates to the field of equalization charging technology, specifically to a dual-charger blind equalization charging method and system. Background Technology

[0002] In existing battery charging scenarios, for some large-capacity batteries, such as those used in excavators, two chargers need to be connected in parallel to improve the charging speed because the efficiency of a single charger is low.

[0003] If both chargers have communication capabilities and the battery has a communication protocol, they can intelligently and evenly adjust the charging voltage and charging current of the two chargers, so that the charging current and charging voltage output by the two chargers are balanced to charge the battery.

[0004] However, for lead-acid batteries, some lithium batteries, and other batteries that do not have communication protocols, they cannot communicate with the charger, and the BMS management system cannot be used to distribute current to the charger.

[0005] Due to the lack of an effective current sharing mechanism, there is usually an uneven load distribution between the two chargers. That is, during charging, one charger may be overloaded while the other is underloaded, or even compete with each other and fail to charge. Summary of the Invention

[0006] To address the shortcomings of existing technologies, a dual-charger blind charging equalization method and system are provided.

[0007] To achieve the above objectives, the present invention provides a dual-charger blind charging equalization method, comprising a first charger and a second charger connected in parallel between a battery and the power grid, wherein a host computer is connected to the first charger and the second charger respectively; the host computer controls the first charger to output a first discharge current. Upon connection to the power grid, the first charger detects whether the battery has lost power. If power is lost, the host computer determines that the first charger is on and the second charger is off. If power is not lost, the host computer determines that the first charger is on and the second charger is charging the battery. When the first charger is on and the second charger is off, the host computer controls the first charger to stop outputting the first discharge current. Connect to the power grid and control the first charger to output a gradually increasing first charging current. Charge the battery until the first charging current is reached. With battery charging current threshold The current is equal to the output current; then the host computer controls the second charger to turn on; the host computer controls the second charger to output a gradually increasing second discharge current. To the power grid; the second charger detects whether the battery is depleted; in the second discharge current If a power outage is detected before the second charger's maximum discharge current is reached, the host computer will control the second charger to stop outputting the second discharge current. The host computer uses the second discharge current at the moment of power failure. Calculate the first equalization charging current And according to the first equalization charging current Control the output of the second charger to gradually increase the second charging current. To the battery; in the second charging current As the current increases, the first charger gradually decreases the first charging current. until = = When the first charger is turned on and the second charger is charging the battery, the second charger outputs a third charging current. The host computer controls the first charger to continue outputting and increases the first discharge current. The process continues until the first charger detects that the battery has lost power; the host computer then controls the first charger to stop outputting the first discharge current. And based on the first discharge current at the moment of power failure Calculate the second equalization charging current And according to the second equalization charging current Control the first charger to output a gradually increasing third charging current To the battery; at the third charging current While increasing the current, the second charger gradually decreases the second charging current. until = = .

[0008] According to one embodiment of the present invention, the method further includes the following step: a preset interval time t, when = = At every interval t, the host computer controls the second charger to stop outputting the second charging current. The host computer controls the second charger to output a gradually increasing second discharge current. The process continues until the battery is fully charged, including the steps to connect to the grid and subsequent steps. = = At every interval t, the host computer controls the first charger to stop outputting the fourth charging current. The host computer controls the first charger to output a gradually increasing first discharge current. The process continues from the step of connecting to the power grid and the subsequent steps until the battery is fully charged.

[0009] According to one embodiment of the present invention, when the second discharge current If the battery still doesn't lose power after the discharge current of the second charger is increased to the maximum, the host computer will control the second charger to stop outputting the second discharge current. Then the host computer outputs the second charger and gradually increases the second charging current. When the second charging current Increase the current to the maximum output current of the second charger, and the host computer controls the second charger to maintain the maximum current output for the second charging current. At the same time, the first charger outputs the first charging current at its maximum current. Charge the battery.

[0010] According to one embodiment of the present invention, when the second charger outputs a second charging current During the increase, the current suddenly increases, and the host computer controls the second charger to stop increasing the second charging current. At this time, the second charger records the current value before the sudden change in the second charging current. and the current value after the sudden change in the second charging current The second charger calculates the second equalization charging current. , = ( + ) × 50%; The host computer controls the second charger according to the equalization charging current. Reduce the second charging current Until the second charging current output by the second charger. With the second equalization charging current Equal; in the second charging current Increase the first charging current Gradually decrease until = = .

[0011] According to one embodiment of the present invention, when the first discharge current If the battery still does not lose power after the discharge current of the first charger is increased to the maximum discharge current, the host computer controls the first charger to stop outputting the first discharge current. Then, the host computer controls the first charger to output a gradually increasing fourth charging current. When the fourth charging current Increase the current to the maximum output current of the second charger, and the host computer controls the first charger to maintain the maximum current output of the fourth charging current. At the same time, the second charger outputs the third charging current at maximum current. Charge the battery.

[0012] According to one embodiment of the present invention, when the fourth charging current output by the first charger During the increase, the current suddenly increases, and the host computer controls the first charger to stop increasing the fourth charging current. At this point, the first charger records the current value before the fourth charging current abrupt change. and the current value after the fourth charging current change The first charger calculates the third equalization charging current. , = ( + ) × 50%; The host computer controls the first charger according to the third equalization charging current. Reduce the fourth charging current Until the fourth charging current output by the first charger. With the third equalization charging current Equal; in the fourth charging current The third charging current gradually increases. Gradually decrease until = = .

[0013] The present invention also provides a dual-charger parallel charging system, which adopts the above-mentioned dual-charger parallel charging method. It includes a host computer, a first charger, a second charger, and a battery. One end of the first charger is connected to the power grid, and the other end is connected to the positive terminal and the negative terminal of the battery, respectively. One end of the second charger is connected to the power grid, and the other end is connected to the positive terminal and the negative terminal of the battery, respectively. The host computer is connected to the first charger and the second charger, respectively.

[0014] According to one embodiment of the present invention, the first charger and the second charger have the same model number.

[0015] According to one embodiment of the present invention, the first charger includes a first H-bridge portion, an LLC portion (12) and a second H-bridge portion. The first H-bridge portion, the LLC portion and the second H-bridge portion each have a first end and a second end. The first end of the first H-bridge portion is connected to the power grid, and its second end is connected to the first end of the LLC portion. The second end of the LLC portion is connected to the first end of the second H-bridge portion, and the second end of the second H-bridge portion is electrically connected to the battery.

[0016] The beneficial effect of this invention is that when the first charger acts as a slave and the second charger acts as a master to charge the battery, the second discharge current at the moment of power failure is utilized. Calculate the first equalization current Then the second charger outputs and gradually increases the second charging current. In the second charging current Increase the first charging current Gradually decrease, eventually the second charging current =First charging current =First equalization charging current This allows the first and second chargers to charge the battery evenly when they are not communicating. This ensures that the first and second chargers output a balanced current to charge the battery, avoiding uneven load distribution between the two chargers. Attached Figure Description

[0017] The accompanying drawings, which are included to provide a further understanding of this application and form part of this application, illustrate exemplary embodiments and are used to explain this application, but do not constitute an undue limitation of this application. In the drawings:

[0018] Figure 1 This is a charging flowchart in the embodiment where the first charger is a slave device and the second charger is a master device.

[0019] Figure 2 This is another charging flowchart in the embodiment where the first charger is a slave device and the second charger is a master device;

[0020] Figure 3 This is a schematic diagram of the first charger charging the battery and the second charger being turned off in the embodiment;

[0021] Figure 4 This is a schematic diagram of the battery power failure in the embodiment;

[0022] Figure 5 The flowchart illustrates the charging process where the first charger is the host and the second charger is the slave in this embodiment.

[0023] Figure 6 The flowchart illustrates another charging process where the first charger in the embodiment is the host and the second charger is the slave.

[0024] Figure 7 This is a circuit diagram of the first charger in the embodiment.

[0025] Explanation of reference numerals in the attached figures

[0026] 11. First H-bridge section; 12. LLC section; 13. Second H-bridge section. Detailed Implementation

[0027] The following drawings disclose several embodiments of the present invention. For clarity, many practical details will be described in the following description. However, it should be understood that these practical details are not intended to limit the invention. That is, in some embodiments of the invention, these practical details are not essential. Furthermore, for the sake of simplicity, some conventional structures and components will be shown in the drawings in a simple schematic manner.

[0028] Furthermore, in this invention, the use of terms such as "first" and "second" is for descriptive purposes only and does not specifically refer to any order or sequence, nor is it intended to limit the invention. They are merely used to distinguish components or operations described using the same technical terms, and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the technical solutions of various embodiments can be combined with each other, but only if they are feasible for those skilled in the art. If a combination of technical solutions is contradictory or impossible to implement, such a combination should be considered nonexistent and not within the scope of protection claimed by this invention.

[0029] Please refer to Figures 1-4 , Figure 1 This is a charging flowchart where the first charger is the slave device and the second charger is the master device. Figure 2 This is another charging flowchart where the first charger is the slave device and the second charger is the master device. Figure 3 This is a schematic diagram showing the first charger charging the battery while the second charger is off. Figure 4 This is a schematic diagram of a battery when it is depleted. This embodiment provides a dual-charger blind charging equalization method, including the following steps:

[0030] The first charger, the second charger, the battery, and the power grid are electrically connected, with the first charger and the second charger connected in parallel. The host computer is electrically connected to the first charger and the second charger. One end of the first charger is connected to the power grid, and the other end is connected to the battery; one end of the second charger is connected to the power grid, and the other end is connected to the battery, so that the first charger and the second charger are connected in parallel to charge the battery, thereby improving charging efficiency.

[0031] During the initial connection, it was not possible to determine whether the first charger and the second charger were already turned on and charging the battery. Therefore, after completing the connection of the first charger, the second charger, the battery and the power grid, it is necessary to determine how many chargers are currently charging the battery.

[0032] The host computer controls the first charger to output the first discharge current. The system connects to the power grid. At the same time, the first charger detects whether the battery is de-energized. If the first charger detects that the battery is de-energized, the host computer determines that only the first charger is currently powered on. If the first charger detects that the battery is not de-energized, the host computer determines that the second charger is currently charging the battery in addition to the first charger.

[0033] It should be noted that the first discharge current The current gradually increases from 0A. When the battery is depleted, only the first charger is activated, and the second charger is not charging the battery. The first charger outputs the initial discharge current. The current originates from the battery, hence the battery discharge. When the battery is not discharged, it indicates that the second charger is charging the battery, and the first charger outputs the first discharge current. The charging current originates from the charging current supplied to the battery by the second charger. At this point, the battery can be considered as a node in the circuit. The charging current output by the second charger to the battery passes through the battery, is input into the first charger, and then is discharged through the first charger. Therefore, the battery voltage does not decrease.

[0034] If the battery is depleted, it means that only the first charger is currently active. Although the second charger is connected to the battery, it is not active. Since the first charger is activated before the second charger in this state, the first charger acts as a slave charger, charging the battery. The second charger will then act as the master charger when activated later. It should be noted that only the master charger can control its own output current; the slave charger cannot control its own output current.

[0035] Please refer to Figure 3 When the system detects that the battery is depleted, and the first charger is the slave device while the second charger is not turned on, the host computer controls the first charger to stop outputting the first discharge current. The power grid is connected, and then the host computer controls the first charger to output the first charging current. To the battery. First charging current. Gradually increase from 0A until the first charging current is reached. With the charging current required by the battery They are equal. It should be noted that the charging current required by the battery is... Determined by the battery's inherent characteristics, this is the current threshold for the battery charging phase. The current threshold for the battery charging phase refers to the highest allowable charging current value set at different stages of battery charging, based on the battery voltage. Therefore, when the first charging current... Increase to the charging current required by the battery When they are equal, the first charging current It cannot be increased further. At this point, the battery's charging current is entirely provided by the first charger. That is, the first charging current output by the first charger at this time... = .

[0036] Please refer to Figure 4 Then the host computer turns on the second charger, which acts as the main unit, and the host computer controls the second charger to output the second discharge current. To the power grid. The second discharge current output by the second charger. The current gradually increases from 0A. The second charger detects whether the battery is depleted; if it detects a battery depletion, the second charger stops outputting the second discharge current. If the battery is detected as not depleted, the second charger increases the second discharge current. The second charger continues to operate until it detects a battery power failure. Once the power failure is detected, the host computer controls the second charger to stop outputting the second discharge current. .

[0037] During the initial discharge period of the second charger, the second discharge current output by the second charger Gradually increase from 0A, ≤ At that time, the second discharge current output by the second charger All of it comes from the first charging current output by the first charger to the battery. Therefore, the battery did not lose power. With the second discharge current... Gradually increase, when > At that time, the second discharge current Part of it comes from the first charging current that the first charger uses to charge the battery. The other part of the current is supplied to the second charger by the battery's discharge current. Therefore, when the battery loses power, the discharge current supplied by the battery to the second charger is set. At this moment, the second discharge current at the moment of power failure. = + Because the first charger and the second charger are not connected, the second charger cannot know the first charging current output by the first charger. The size of the second charger is such that it can only detect the second discharge current it emits. To determine the magnitude of the battery charging current.

[0038] When the battery loses power, it indicates that the second charger is outputting the second discharge current. The critical value for causing the battery to shut down has been met, which is the second discharge current at this point. = =Battery charging current required To ensure that the first charger and the second charger charge the battery at an equal rate, the first charger outputs a first charging current. The second charging current needs to be output from the second charger. Equal, and the first charging current With the second charging current The sum equals the charging current required by the battery. At this time, the second charger calculates the second discharge current based on the power outage time. Calculate the first equalization charging current ,in, = ×50%.

[0039] Then, the host computer controls the second charger to turn on and charge the battery, and the second charger outputs a second charging current. To the battery, where the second charging current Gradually increase from 0A to Due to the battery charging current threshold The maximum charging current that the battery can absorb, within the battery charging current threshold. With the second charging current remaining unchanged, The first charging current of the first charger gradually increases as it charges the battery. Gradually decrease until the second charging current. =First charging current =First equalization charging current First equalization charging current This refers to the charging current when the first charger and the second charger charge the battery to an equalization state. The first charger and the second charger each output the first equalization charging current to the battery. This allows the first and second chargers to charge the battery evenly when they are not communicating. This ensures that the first and second chargers output a balanced current to charge the battery, avoiding uneven load distribution between the two chargers.

[0040] When the first charger acts as the slave and the second charger acts as the master, after the second charger is turned on, the host computer controls the second charger to output a second discharge current. And the second discharge current As the current gradually increases from 0A, the second charger detects whether the battery is depleted. When the second discharge current... If the second charger detects that the battery is still charged when the current is increased to the maximum output current of the second charger, it means that the first charger is outputting the first charging current at maximum power. Charge the battery. When the second discharge current... When the current is increased to the maximum output current of the second charger, the host computer controls the second charger to stop outputting the second discharge current. The host computer controls the second charger to output a second charging current. And gradually increase the second charging current. If the second charging current When the current is increased to the maximum output current of the second charger, the first charger maintains its maximum current output as the first charging current. The battery is being charged. At this time, both the first and second chargers maintain maximum current for equalization charging of the battery. This indicates the required charging current for the battery at this point. It is greater than the sum of the maximum value of the first charging current and the maximum value of the second charging current.

[0041] Furthermore, if the second charging current The current suddenly increases during the gradual increase, and the increase is greater than 5A, which is the second charging current at this point. A sudden change occurs, at which point the second charger stops increasing the second charging current. Meanwhile, the second charger records the current value before the sudden change in the second charging current. and the current value after the sudden change in the second charging current When the second charging current When a sudden change occurs, it indicates that the second charging current is at this time. With the first charging current The sum of these amounts already meets the charging current required by the battery. This leads to a second charging current. The sudden increase, and the first charging current The corresponding decrease. The current value of the second charger before the sudden change in the second charging current. and the current value after the sudden change in the second charging current Calculate the second equalization charging current , = ( + () × 50%. The host computer controls the second charger according to the second equalization charging current. Reduce the second charging current after the sudden change until = At the same time, the first charging current output by the first charger Increase accordingly, until = .at this time, = = .

[0042] As charging time increases, the battery capacity gradually increases, causing the battery's internal resistance to gradually increase, thus raising the battery's charging current threshold. The current decreases, so the charging current output of the first and second chargers needs to be readjusted to match the charging current required by the battery at this time.

[0043] Therefore, after the first charger and the second charger have equalized the charging of the battery, the above steps need to be repeated every preset interval t to recalculate the equalization charging current and adjust the first charging current output by the first charger. and the second charging current output by the second charger Adjustments are made to match the charging current required by the battery. After each preset interval t, the host computer controls the second charger to stop outputting the second charging current. The host computer controls the second charger to output a gradually increasing second discharge current. The process continues from the step of connecting to the grid to the battery, and the subsequent steps, until the battery is fully charged. It should be noted that the preset time t can be set according to the actual charging needs, such as 5 minutes / 10 minutes, etc., and is not limited here.

[0044] Please refer to Figures 5-6 , Figure 5 The flowchart shows a process where the first charger is the host and the second charger is the slave device. Figure 6 This is a flowchart illustrating another charging process where the first charger is the host and the second charger is the slave. The flowchart describes the first charger outputting a first discharge current. When the first charger detects that the battery has not lost power, it indicates that, in addition to the first charger, the second charger is outputting a third charging current. The battery is being charged, and at this time the first charger outputs the first discharge current. By the third charging current Therefore, the battery did not lose power. Since the second charger is turned on before the first charger, the first charger acts as the master charger, and the second charger acts as the slave charger to charge the battery.

[0045] Once the first charger detects that the battery has not lost power, the host computer controls the first charger to continue outputting power and increases the first discharge current. The first charger detects whether the battery is depleted. When the battery is depleted, it indicates the first discharge current... Part of it is the third charging current In addition, some current comes from the battery. At this time, the host computer controls the first charger to stop discharging, and calculates the first discharge current at the moment of power failure. Calculate the third equalization charging current , = ×50%. The host computer controls the output of the first charger and gradually increases the fourth charging current. Charge the battery until the fourth charging current. = With the first charging current The third charging current output by the second charger gradually increases. Gradually decrease until = = Thus, in the second state, the first charger acts as the master charger, and the second charger acts as the slave charger to perform equalization charging of the battery.

[0046] When the first charger outputs the first discharge current When the current is increased to the maximum output current of the first charger, the host computer controls the first charger to stop outputting the first discharge current. The host computer controls the output of the first charger and gradually increases the fourth charging current. If the fourth charging current When the current is increased to the maximum output current of the first charger, the host computer controls the first charger to maintain the maximum current output of the third charging current. The battery is being charged. At this time, both the first and second chargers maintain maximum current for equalization charging of the battery. The required charging current for the battery... It is greater than the sum of the maximum value of the third charging current and the maximum value of the fourth charging current.

[0047] Furthermore, if the fourth charging current The current suddenly increases during the gradual increase, and the increase is greater than 5A. At this point, the fourth charging current... A sudden change occurred. The host computer controlled the first charger to stop increasing the fourth charging current. Meanwhile, the first charger records the current value before the fourth charging current abrupt change. and the current value after the fourth charging current change And calculate the fourth equalization charging current. , = ( + ) × 50%.

[0048] After the first charger and the second charger have balanced the charging of the battery, the host computer controls the first charger to stop outputting the fourth charging current after every preset interval t. The host computer controls the first charger to gradually increase the first discharge current. The process continues from the step of connecting to the power grid and the subsequent steps until the battery is fully charged.

[0049] In summary, by employing the above method, when the first and second chargers are not communicating, the master and slave chargers are determined by the order in which they are turned on. The charger that is turned on first is the slave, and the charger that is turned on later is the master. Then, the host computer controls the master to output a discharge current, causing the battery to lose power. The master then learns the charging current output by the slave to the battery and calculates the equalization charging current based on the master's discharge current at the moment the battery loses power. The host computer then controls the master to output and gradually increase the charging current to the equalization charging current value. As the charging current output by the master increases, the charging current of the slave decreases accordingly, ultimately making the charging current output by the master equal to the charging current of the slave, which in turn equals the equalization charging current. Thus, the charging current of the two chargers is evenly distributed.

[0050] Example 2

[0051] This embodiment provides a dual-charger blind charging equalization system, which adopts the aforementioned dual-charger blind charging equalization method. It includes a host computer, a first charger, a second charger, and a battery. The host computer is connected to both the first and second chargers. One end of the first charger is connected to the power grid, and the other end is connected to [other components]. One end of the second charger is connected to the power grid, and the other end is connected to the battery.

[0052] In this implementation, the first charger and the second charger are of the same model to ensure that the output power of the first charger and the second charger is the same.

[0053] It should be noted that both the first and second chargers have both charging and discharging functions, requiring a full-bridge design. Please refer to [reference needed]. Figure 7 , Figure 7 This is a circuit diagram of the first charger. In this example, the first charger includes a first H-bridge section 11, an LLC section 12, and a second H-bridge section 13. The first H-bridge section 11, LLC section 12, and second H-bridge section 13 each have a first terminal and a second terminal. The first terminal of the first H-bridge section 11 is connected to the power grid, and its second terminal is connected to the first terminal of the LLC section 12. The second terminal of the LLC section is connected to the first terminal of the second H-bridge section 13, and the second terminal of the second H-bridge section 13 is electrically connected to the battery.

[0054] When the first charger charges the battery, the AC power output from the grid is rectified and filtered by the first H-bridge section 11 and converted into DC power. Then, the LLC section 12 receives the DC power output from the first H-bridge section 11, inverts the DC power back into AC power, and then steps down the AC power. The stepped-down AC power is output from the LLC section 12 and then input to the second H-bridge section 13. The second H-bridge section 13 rectifies the AC power output from the LLC section 12 and then outputs DC power to charge the battery.

[0055] When the first charger discharges, the battery outputs DC power to the second H-bridge section 13. The second H-bridge section 13 receives the DC power output from the battery, inverts it into AC power, and then outputs the AC power to the LLC section 12. The LLC section 12 receives the AC power output from the second H-bridge section 13, boosts and rectifies the AC power into high-voltage DC power, then modulates the phase of the high-voltage DC power, and finally inputs the phase-modulated high-voltage DC power to the first H-bridge section 11. The first H-bridge section 11 inverts it and then outputs it to the power grid, thereby discharging the battery to the power grid through the first charger.

[0056] It should be noted that the charging and discharging processes of the second charger are the same as those of the first charger, and will not be described in detail here.

[0057] The above description is merely an embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principle of the present invention should be included within the scope of the claims of the present invention.

Claims

1. A dual-charger blind charging equalization method, characterized in that, Includes the following steps: The first charger and the second charger are connected in parallel between the battery and the power grid, and the host computer is connected to the first charger and the second charger respectively. The host computer controls the first charger to output the first discharge current. Upon connection to the power grid, the first charger detects whether the battery has lost power; If there is a power outage, the host computer determines that the first charger is on and the second charger is off; if there is no power outage, the host computer determines that the first charger is on and the second charger is charging the battery. When the first charger is turned on and the second charger is not turned on, the host computer controls the first charger to stop outputting the first discharge current. Connect to the power grid and control the first charger to output a gradually increasing first charging current. Charge the battery until the first charging current is reached. With battery charging current threshold equal; Then the host computer controls the second charger to turn on; The host computer controls the second charger to output a gradually increasing second discharge current. To the power grid; The second charger detects whether the battery is depleted. Second discharge current If a power outage is detected before the second charger's maximum discharge current is reached, the host computer will control the second charger to stop outputting the second discharge current. ; The host computer uses the second discharge current at the moment of power failure. Calculate the first equalization charging current And according to the first equalization charging current Control the output of the second charger to gradually increase the second charging current. To the battery; in the second charging current As the current increases, the first charger gradually decreases the first charging current. until = = ; When the first charger is turned on and the second charger is charging the battery, the second charger outputs a third charging current. The host computer controls the first charger to continue outputting and increases the first discharge current. Until the first charger detects that the battery is dead; The host computer controls the first charger to stop outputting the first discharge current. And based on the first discharge current at the moment of power failure Calculate the second equalization charging current And according to the second equalization charging current Control the first charger to output a gradually increasing third charging current To the battery; at the third charging current While increasing the current, the second charger gradually decreases the second charging current. until = = .

2. The dual-charger blind charging equalization method according to claim 1, characterized in that, It also includes the following steps: Preset interval time t, when = = At every interval t, the host computer controls the second charger to stop outputting the second charging current. The host computer controls the second charger to output a gradually increasing second discharge current. The process continues until the battery is fully charged, including the steps to connect to the grid and subsequent steps. = = At every interval t, the host computer controls the first charger to stop outputting the fourth charging current. The host computer controls the first charger to output a gradually increasing first discharge current. The process continues from the step of connecting to the power grid and the subsequent steps until the battery is fully charged.

3. The dual-charger blind charging equalization method according to claim 1, characterized in that, When the second discharge current If the battery still doesn't lose power after the discharge current of the second charger is increased to the maximum, the host computer will control the second charger to stop outputting the second discharge current. Then the host computer controls the output of the second charger and gradually increases the second charging current. When the second charging current Increase the current to the maximum output current of the second charger, and the host computer controls the second charger to maintain the maximum current output for the second charging current. At the same time, the first charger outputs the first charging current at its maximum current. Charge the battery.

4. The dual-charger blind charging equalization method according to claim 3, characterized in that, When the second charger outputs the second charging current During the increase, the current suddenly increases, and the host computer controls the second charger to stop increasing the second charging current. At this time, the second charger records the current value before the sudden change in the second charging current. and the current value after the sudden change in the second charging current The second charger calculates the second equalization charging current. , = ( + ) × 50%; The host computer controls the second charger according to the equalization charging current. Reduce the second charging current Until the second charging current output by the second charger. With the second equalization charging current Equal; in the second charging current Increase the first charging current Gradually decrease until = = .

5. The dual-charger blind charging equalization method according to claim 1, characterized in that, When the first discharge current If the battery still does not lose power after the discharge current of the first charger is increased to the maximum discharge current, the host computer controls the first charger to stop outputting the first discharge current. Then, the host computer controls the first charger to output a gradually increasing fourth charging current. When the fourth charging current The current is increased to the maximum output current of the first charger, and the host computer controls the first charger to maintain the maximum current output of the fourth charging current. At the same time, the second charger outputs the third charging current at maximum current. Charge the battery.

6. The dual-charger blind charging equalization method according to claim 5, characterized in that, When the fourth charging current output by the first charger During the increase, the current suddenly increases, and the host computer controls the first charger to stop increasing the fourth charging current. At this point, the first charger records the current value before the fourth charging current abrupt change. and the current value after the fourth charging current change The first charger calculates the third equalization charging current. , = ( + ) × 50%; The host computer controls the first charger according to the third equalization charging current. Reduce the fourth charging current Until the fourth charging current output by the first charger. With the third equalization charging current Equal; in the fourth charging current The third charging current gradually increases. Gradually decrease until = = .

7. A dual-charger blind charging equalization system, characterized in that, The dual-charger blind charging equalization method according to any one of claims 1-6 includes a host computer, a first charger, a second charger, and a battery. One end of the first charger is connected to the power grid, and the other end is connected to the positive terminal and the negative terminal of the battery, respectively. One end of the second charger is connected to the power grid, and the other end is connected to the positive terminal and the negative terminal of the battery, respectively. The host computer is connected to the first charger and the second charger, respectively.

8. The dual-charger blind charging equalization system according to claim 7, characterized in that, The first charger and the second charger have the same model number.

9. The dual-charger blind charging equalization system according to claim 7, characterized in that, The first charger includes a first H-bridge section (11), an LLC section (12), and a second H-bridge section (13). The first H-bridge section (11), the LLC section (12), and the second H-bridge section (13) each have a first end and a second end. The first end of the first H-bridge section (11) is connected to the power grid, and its second end is connected to the first end of the LLC section (12). The second end of the LLC section (12) is connected to the first end of the second H-bridge section (13), and the second end of the second H-bridge section (13) is electrically connected to the battery.

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