A multi-specification battery safety activation system and control method

Abstract

This invention relates to a multi-specification battery safety activation system and control method, comprising an adjustable wide-voltage power supply module, a main switch module, a safety detection module, an activation current limiting module, and a control unit. The adjustable wide-voltage power supply module provides a wide-range, continuously adjustable DC output voltage. The main switch module is connected in series in the positive output path of the adjustable wide-voltage power supply module and includes a relay serving as the main power switch. The safety detection module is used to acquire the output voltage of the adjustable wide-voltage power supply module and the voltage of the external battery pack in real time. The activation current limiting module is connected in parallel with the switch contacts of the relay and includes a current-limiting resistor connected in series. The control unit is electrically connected to the adjustable wide-voltage power supply module, the main switch module, the safety detection module, and the activation current limiting module. This solution can automatically match the battery voltage, actively prevent connection surges and current backflow, and safely and controllably activate deeply discharged batteries.

Description

Technical Field

[0001] This invention relates to the field of battery charging technology, and more specifically, to a multi-specification battery safety activation system and control method. Background Technology

[0002] In fields such as power tools, energy storage systems, and electric vehicles, it is common to use multiple lithium-ion batteries connected in series to form battery packs. When charging these battery packs or attempting to activate batteries with low voltage due to over-discharge, existing technologies typically face the following prominent challenges:

[0003] Poor connection safety: Traditional chargers lack effective mechanisms to suppress instantaneous surge currents during connection; when there is a large voltage difference between the charger output voltage and the battery pack voltage, direct connection will generate huge surge currents, which may damage the battery electrodes, connectors, or even the charging power supply itself; in addition, if the battery is reverse-connected or has an internal short circuit, conventional chargers lack effective active isolation and protection capabilities.

[0004] Risk of reverse current: When the charger is not working, if the battery pack voltage is higher than the charger's no-load output voltage, the battery energy may flow back into the charger's internal circuitry, causing damage; traditional solutions usually rely on software protection, which is slow to respond and lacks reliability.

[0005] Insufficient versatility and adaptability: Different devices require dedicated chargers with different rated voltages (such as 12V, 24V, 48V, 72V, etc.), resulting in low versatility; for "starved" batteries that have been stored for a long time and whose voltage is too low (below the cutoff voltage of the battery protection board), traditional constant voltage source chargers cannot provide initial energy, causing the batteries to be mistakenly judged as failed.

[0006] The activation process is crude: Some existing activation methods may use direct application of high voltage or high current, which lacks fine control and can easily cause secondary damage to the already damaged battery, posing a risk of thermal runaway.

[0007] Most existing charging solutions adopt a fixed constant current-constant voltage mode, lacking intelligent and systematic solutions to address the comprehensive issues of connection safety, backflow prevention, wide voltage adaptation, and safe activation. Therefore, there is an urgent need for a charging system that can fundamentally improve the safety, adaptability, and intelligence of the charging process. Summary of the Invention

[0008] The technical problem to be solved by the present invention is to provide a multi-specification battery safety activation system and a control method for the multi-specification battery safety activation system, in view of the above-mentioned defects of the prior art.

[0009] The technical solution adopted by this invention to solve its technical problem is:

[0010] Construct a multi - specification battery safety activation system, characterized in that it includes:

[0011] An adjustable wide - voltage power supply module for providing a continuously adjustable DC output voltage within a wide range;

[0012] A main switch module connected in series on the output positive path of the adjustable wide - voltage power supply module, and the main switch module includes a relay as the main power switch;

[0013] A safety detection module for real - time collecting the output voltage V_out of the adjustable wide - voltage power supply module and the voltage V_bat of the external battery pack;

[0014] An activation current - limiting module connected in parallel with the switch contacts of the relay, and a current - limiting resistor is connected in series in the activation current - limiting module;

[0015] A control unit electrically connected to the adjustable wide - voltage power supply module, the main switch module, the safety detection module and the activation current - limiting module respectively;

[0016] Wherein, the control unit is configured to execute a core process including the following steps:

[0017] S1: After the system is powered on, control the relay to remain open, and obtain V_out and V_bat through the safety detection module.

[0018] S2: Perform anti - backflow safety judgment: Compare V_out with V_bat. If V_out < V_bat, it is determined that there is a risk of current backflow, the system alarms and locks, and subsequent operations are prohibited; if V_out ≥ V_bat, control the adjustable wide - voltage power supply module to adjust its output voltage to a preset voltage value slightly higher than V_bat (such as V_bat + 0.5V) to achieve "voltage pre - synchronization" before connection.

[0019] S3: Intelligent activation judgment: Judge whether V_bat is lower than a preset activation threshold (for example, 20% of the battery nominal voltage or the protection board lock - out voltage); if so, start the activation process, control the activation current - limiting module to conduct, and output a lower initial test voltage (such as 5V) to the battery pack through the current - limiting resistor path.

[0020] S4: Step - by - step trial activation: During the conduction of the activation current - limiting module, if no effective charging current is detected within the set time, gradually increase the output voltage of the adjustable wide - voltage power supply module in small steps (such as 0.1V or 0.5V), and continuously monitor the current; this process loops until a stable and tiny charging current is detected, or the output voltage reaches the preset safety upper limit; once current is detected, it can enter the constant - power pre - charge mode.

[0021] S5: Main path charging: When the battery pack voltage rises to the preset safe voltage threshold (such as the undervoltage protection release value) after activation and pre-charge, the current limiting module is turned off and the relay is activated to establish a low-impedance main charging path. Then, the adjustable wide voltage power supply module is switched to the conventional constant current-constant voltage (CC-CV) charging mode to complete the charging.

[0022] Preferably, after detecting an effective charging current in step S4 and before step S5, the control unit is further configured to perform a constant power pre-charging step: controlling the adjustable wide voltage power supply module to enter a constant power pre-charging mode, and dynamically adjusting its output voltage to maintain the power input to the battery pack at a set low constant value (e.g., 20W), thereby achieving controllable and gentle pre-charging until the battery voltage reaches the safe voltage threshold.

[0023] Preferably, the activation current limiting module includes a controlled switching device, the current limiting resistor, and an anti-reverse current diode, which are connected in series and then in parallel with the switch contacts of the relay. The controlled switching device can be implemented by a composite transistor driving circuit composed of PNP and NPN transistors, and its control terminal is controlled by the control unit. The cathode of the anti-reverse current diode faces the positive terminal of the battery pack to prevent battery current from flowing back when the activation current limiting module is turned off. The control unit interlocks the drive signal of the relay with the drive signal of the activation current limiting module in software to ensure that the two do not conduct at the same time, thus preventing the current limiting resistor from being bypassed by the main path.

[0024] Preferably, the main switch module further includes a fuse, which is connected in series in the positive output path of the adjustable wide voltage power supply module and located in front of the relay, serving as the final hardware overcurrent protection barrier.

[0025] Preferably, the adjustable wide-range power supply module includes a front-end power factor correction (PFC) circuit and a rear-end DC-DC converter circuit; the control unit is configured to coordinately adjust the DC bus voltage of the front-end circuit and the operating frequency or duty cycle of the rear-end circuit according to the target output voltage to achieve high-efficiency wide-range output voltage regulation; an efficient implementation method is: the front-end adopts a totem-pole bridgeless PFC circuit, and the rear-end adopts a full-bridge LLC resonant converter.

[0026] Preferably, the safety detection module further includes a current detection module, which is based on a sampling resistor and a differential amplifier circuit, for real-time high-precision monitoring of the magnitude and direction of the current in the charging circuit, providing feedback for constant power control, activation judgment and fault protection.

[0027] Preferably, the system further includes a human-machine interaction module, such as a touch screen and / or a Bluetooth communication module. The user can set charging parameters (maximum voltage, current), view the real-time status, and manually enable the "dead battery activation mode" through it; when receiving this instruction, the control unit will enforce the stepped trial activation process.

[0028] The present invention also provides a control method applied to the above system, which is characterized by including the steps:

[0029] Physical isolation and safety detection: Initialize the system, keep the relay disconnected, and detect the power output voltage V_out and the battery voltage V_bat;

[0030] Backflow prevention judgment and voltage pre-synchronization: If V_out≥V_bat, adjust the power output voltage to V_bat + ΔV to achieve voltage pre-synchronization; if V_out < V_bat, report an error and lock;

[0031] Intelligent activation judgment and execution: If V_bat is lower than the activation threshold, conduct the activated current-limiting path in parallel, and charge the battery in a stepped boost manner through a current-limiting resistor until activation is successful or the attempt limit is reached;

[0032] Controlled pre-charging: After the battery is activated, control the power supply to pre-charge the battery with a constant small power until the battery voltage rises back to the safety threshold;

[0033] Main path charging: Turn off the activated current-limiting path, close the relay, and switch to the conventional constant current-constant voltage charging mode to complete charging.

[0034] The beneficial effects of the present invention are as follows: This solution can automatically match the battery voltage, actively prevent connection shocks and current backflows, and can safely and controllably activate deeply discharged batteries. Specifically:

[0035] 1. Extremely high connection security: Through the mechanism of "detect first, adjust voltage later, and then connect", and an independent current-limiting activation path, the risk of connection surge current is completely eliminated, achieving "zero impact" safe connection.

[0036] 2. Have the ability of active backflow prevention: Through hardware relay isolation, real-time voltage comparison, and diodes in the activation current-limiting module, a multiple backflow prevention protection combining software and hardware is constructed, and the safety is far beyond pure software solutions.

[0037] 3. Powerful safe activation ability: The strategy of "low-voltage trial, stepped boost, and constant power pre-charging" can wake up deeply discharged batteries in an extremely gentle way, avoid damage caused by large current shocks, and significantly improve the success rate of "saving".

[0038] 4. Wide range adaptive: Wide voltage output combined with automatic voltage recognition and following allows a single device to be safely used with battery packs of various voltage specifications, making it extremely versatile.

[0039] 5. Intelligent and controllable energy throughout the entire process: From safety self-check, voltage following, intelligent activation, constant power pre-charging to standard charging, the entire process is automated. During the pre-charging stage, energy is controlled, heat generation is low, safety is high, and user operation is simple. Attached Figure Description

[0040] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the present invention will be further described below in conjunction with the accompanying drawings and embodiments. The drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort:

[0041] Figure 1 This is a block diagram illustrating the principle of a multi-specification battery safety activation system according to a preferred embodiment of the present invention.

[0042] Figure 2 This is a block diagram of the adjustable wide voltage power supply module of the multi-specification battery safety activation system according to a preferred embodiment of the present invention.

[0043] Figure 3 This is a circuit diagram of the activation current limiting module of the multi-specification battery safety activation system according to a preferred embodiment of the present invention;

[0044] Figure 4 This is a circuit diagram of the activation current limiting module connected to the relay in a multi-specification battery safety activation system according to a preferred embodiment of the present invention;

[0045] Figure 5 This is a flowchart of the control method for a multi-specification battery safety activation system according to a preferred embodiment of the present invention. Detailed Implementation

[0046] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, a clear and complete description will be provided below in conjunction with the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the protection scope of the present invention.

[0047] The preferred embodiment of the present invention is a multi-specification battery safety activation system, such as... Figure 1 As shown, see also Figures 2-5It mainly includes an adjustable wide voltage power supply module 1, a fuse 2, a relay K1, a detection module, a control unit 5, an activation current limiting module 6, and a user setting interface 7; the relay K1 and the fuse 2 are connected in series to form the main switch module, which is connected in series in the positive path of the power output; the activation current limiting module 6 is connected in parallel across the contacts of the relay K1.

[0048] The adjustable wide-voltage power supply module 1 is used to convert AC input into a wide-range, continuously adjustable DC output, such as 56V-180V. Figure 2 An efficient implementation scheme is shown: the front stage adopts a totem pole bridgeless PFC circuit to achieve high-efficiency power factor correction and adjustable bus voltage Vbus; the rear stage adopts a full-bridge LLC resonant converter, and the output voltage is adjusted by adjusting the switching frequency fs; the control unit 5 is preferably a digital signal processor (DSP) to coordinate the control of Vbus and fs, and quickly and accurately establish the required output voltage V_out.

[0049] More specifically:

[0050] The adjustable wide voltage power supply module 1 includes an input filter module, a totem pole PFC circuit, a full-bridge LLC resonant cavity, a full-bridge synchronous rectifier circuit, and a multi-mode digital control unit connected in sequence.

[0051] The full-bridge LLC resonant cavity includes a primary-side full-bridge switching circuit, a resonant inductor Lr, a resonant capacitor Cr, and the primary winding of transformer T1 connected in sequence. The magnetizing inductance Lm of transformer T1 is equivalently connected in parallel across the primary winding.

[0052] The multi-mode digital control unit is configured to divide the entire target output voltage range into at least three operating intervals based on the output voltage feedback value of the converter, and independently set the corresponding bus voltage Vbus control target and switching frequency fs operating range for each operating interval.

[0053] The control unit outputs a PWM signal to the totem-pole PFC circuit to adjust its output bus voltage Vbus, and outputs a PWM signal to the primary-side switch of the full-bridge LLC resonant cavity to adjust its switching frequency fs. By coordinating the control of Vbus and fs, the converter operates in an optimized operating mode under any output voltage.

[0054] The three operating ranges include a high-voltage range, a medium-voltage range, and a low-voltage range. In the high-voltage range, the control bus voltage Vbus is maintained within a first high-voltage range, and the switching frequency fs is controlled to operate within a first frequency range. In the medium-voltage range, the control bus voltage Vbus is maintained within a second medium-voltage range, which is lower than the first high-voltage range, and the switching frequency fs is controlled to operate within a second frequency range, which is higher than the first frequency range. In the low-voltage range, the control bus voltage Vbus varies within a third low-voltage range, and the switching frequency fs is controlled to operate within a third frequency range, which is higher than the second frequency range.

[0055] In the high-voltage range, the full-bridge LLC resonant cavity operates in under-resonance or quasi-resonance mode; in the medium-voltage range, it operates in over-resonance mode close to the resonant point; in the low-voltage range, it operates in over-resonance mode, and the bus voltage Vbus is controlled to allow it to drop to a level slightly higher than the rectified AC input voltage.

[0056] The multi-mode digital control unit switches between high-voltage, medium-voltage, and low-voltage ranges based on the output voltage feedback value, and hysteresis control logic is set at the switching point to prevent mode oscillation.

[0057] The application method includes the following steps:

[0058] Sampling steps: Sample the output voltage Vo of the converter in real time.

[0059] Judgment steps: Compare the output voltage Vo with the preset threshold to determine its operating range. The operating range includes at least the high voltage range, the medium voltage range, and the low voltage range.

[0060] Target determination steps: Based on the determined operating range, determine the corresponding target values ​​for bus voltage Vbus and switching frequency fs.

[0061] Control output steps:

[0062] a. Generate and output the PWM signal to control the totem pole PFC circuit, so that its output bus voltage Vbus tracks the Vbus control target value.

[0063] b. Generate and output the PWM signal to control the primary-side switching transistor of the full-bridge LLC resonant cavity, so that its switching frequency fs tracks the target value of fs control.

[0064] The specific steps for making the judgment are as follows:

[0065] Preset first voltage threshold V th1 With the second voltage threshold V th2 And V th1 >V th2 ;

[0066] When Vo≥Vth1 When it is, it is determined as the high - voltage range;

[0067] When V th2 ≤Vo<Vth1, it is determined as the medium - voltage range;

[0068] When Vo<V th2 it is determined as the low - voltage range.

[0069] In the judgment step, a hysteresis comparison logic is adopted, including:

[0070] When switching from the high - voltage range to the medium - voltage range, the switching threshold used is V th1 -Δ1; when switching from the medium - voltage range to the high - voltage range, the switching threshold used is V th1 ; when switching from the medium - voltage range to the low - voltage range, the switching threshold used is V th2 -Δ2; when switching from the low - voltage range to the medium - voltage range, the switching threshold used is V th2 ; where Δ1 and Δ2 are the hysteresis widths.

[0071] The target determination step includes:

[0072] In the high - voltage range, control Vbus to be stable near the first high - voltage target value and adjust fs to vary within the first frequency range; in the medium - voltage range, control Vbus to be stable near the second medium - voltage target value lower than the first high - voltage target value and adjust fs to vary within the second frequency range; in the low - voltage range, dynamically set the target value of Vbus according to the output voltage Vo, and the target value of Vbus decreases as Vo decreases, while adjusting fs to vary within the third frequency range.

[0073] Through an innovative system - level cooperative control strategy, the gain requirements for wide - range voltage output are reasonably decomposed and optimally allocated, thus significantly narrowing the working frequency change range and comprehensively improving the efficiency, dynamic performance and reliability of the converter within the ultra - wide output voltage range, specifically as follows:

[0074] 1. Achieved efficient output of ultra - wide continuous voltage: Through the cooperative control strategy of "bus voltage following" and "three - stage gain mode division", the total voltage gain requirement of up to 3.3 times is decomposed into three optimally designed sub - working modes; in each sub - mode, the required frequency adjustment ratio and gain adjustment ratio are significantly reduced, fundamentally avoiding the problem of too wide switching frequency change range in traditional schemes.

[0075] 2. Improved overall operating efficiency: Each operating range is configured to operate under the optimal (Vbus, fs) parameter combination; especially in the low-voltage output range where the traditional LLC efficiency is the lowest, this invention actively reduces the bus voltage Vbus, so that the LLC does not need to operate at extremely high switching frequencies, thereby significantly reducing switching losses and core losses, filling the "dip" in the efficiency curve, and greatly improving the average efficiency over the entire wide output voltage range.

[0076] 3. Improved dynamic performance and reliability: The digital control unit responds quickly, the two-stage converter works in concert, the mode switching process is smooth, and the output ripple is small; the hysteresis control logic effectively prevents mode boundary oscillations; at the same time, since the switching frequency is limited to a reasonable range (e.g., no more than 200kHz), the influence of circuit parasitic parameters is reduced, and the waveform quality and system reliability are improved.

[0077] 4. Solved the problem of insufficient gain under light load / low voltage: In the low voltage range, the required gain of the LLC stage is reduced by lowering Vbus, so that the LLC resonant cavity always works in the over-resonance region with sufficient gain capability, ensuring that good soft-switching characteristics can be maintained in the entire voltage range, and solving the problem that traditional LLC is difficult to work or even detuned under low voltage full load.

[0078] The detection module includes an output voltage detection module 40, a battery voltage detection module 41, and a current detection module 42. These modules convert V_out, V_bat, and the loop current signals into signals suitable for sampling by the ADC of the control unit 5 through a voltage divider network and a high-precision operational amplifier circuit, respectively.

[0079] Figure 3 A specific circuit for activating the current limiting module 6 is shown in detail. It includes a composite transistor drive circuit composed of PNP transistor FQ1 and NPN transistor PQ1, a power current limiting resistor R_limit, and an anti-reverse current diode D13. The DSP's control signal drives PQ1, thereby controlling the on / off state of FQ1. When activation or pre-charging is required, the DSP outputs a signal to turn on PQ1 and FQ1, and the current flows from the positive terminal of the power supply through FQ1, R_limit (RN1), and D13 to the battery. R_limit strictly limits the current to a safe range, such as below 0.5A. D13 prevents the battery current from flowing back into this branch. Before the relay K1 is energized, the DSP ensures that this branch is turned off first.

[0080] Control unit 5 is the core of the system, and its software flow is as follows: Figure 5 As shown, the working process is as follows:

[0081] The system is powered on and initialized, with relay K1 remaining open; the user connects the battery and sets the parameters.

[0082] The control unit 5 reads V_out and V_bat through the detection module.

[0083] Safety judgment: If V_out < V_bat, alarm and lock to prevent backflow; if normal, control the adjustable wide - voltage power supply module 1 to adjust V_out to V_bat + 0.5V.

[0084] Activation judgment: Judge whether V_bat is too low, such as lower than 30% of the nominal voltage; if so, enter the "dead battery activation mode".

[0085] Activation process: Control the activation current - limiting module 6 to conduct; set the initial trial voltage V_try = 5V. Control the power supply to output V_try, and charge the battery through the current - limiting resistor R_limit; wait and monitor the current; if there is no effective current within the time T, increase V_try by a step ΔV such as 0.5V and try again; repeat this process until the current is greater than the set threshold I_active, or V_try reaches the upper limit V_max. If there is still no current when reaching V_max, alarm to indicate that the battery may be damaged.

[0086] Constant - power pre - charging: Once the current is successfully detected during activation, the control unit 5 switches to the constant - power control mode; for example, set the target power P_pre = 20W. Dynamically adjust the power supply output voltage according to the real - time detected V_bat and current I, so that P_bat = V_bat * I ≈ P_pre. This process continues until V_bat rises back to the safe voltage V_safe, such as 3.0V for a single cell.

[0087] Main - path charging: When V_bat ≥ V_safe, the control unit 5 first turns off the activation current - limiting module 6, then controls the power supply to output a voltage slightly higher than the current V_bat, and finally closes the relay K1; thereafter, the system enters the standard constant - current CC charging stage, and switches to constant - voltage CV charging after reaching the set voltage until the charging is completed.

[0088] During the entire charging process, the control unit 5 continuously monitors the current and voltage. If it exceeds the set value or an abnormality is detected, immediately disconnect the relay K1 and alarm.

[0089] The user can set the charging target voltage and current limit through the touch screen 7, and can manually trigger the "forced activation" mode; the system status, real - time data and alarm information are also displayed through this interface.

[0090] It should be understood that those of ordinary skill in the art can make improvements or transformations according to the above description, and all such improvements and transformations should fall within the protection scope of the appended claims of this invention.

Claims

1. A multi-specification battery safety activation system, characterized in that, It includes an adjustable wide - voltage power supply module, a main switch module, a safety detection module, an activation current - limiting module and a control unit; The adjustable wide - voltage power supply module is used to provide a continuously adjustable DC output voltage within a wide range; The main switch module is connected in series on the output positive path of the adjustable wide - voltage power supply module. The main switch module includes a relay as the main power switch; The safety detection module is used to collect the output voltage V_out of the adjustable wide - voltage power supply module and the voltage V_bat of the external battery pack in real - time; The activation current - limiting module is connected in parallel with the switch contacts of the relay, and a current - limiting resistor is connected in series in the activation current - limiting module; The control unit is electrically connected to the adjustable wide - voltage power supply module, the main switch module, the safety detection module and the activation current - limiting module respectively; Among them, the control unit is configured to execute the following steps: S1: After the system is powered on, control the relay to remain open, and obtain V_out and V_bat through the safety detection module; S2: Judge the difference between V_out and V_bat. If V_out < V_bat, it is determined that there is a risk of current reverse flow, and the system alarms and locks; if V_out≥V_bat, control the adjustable wide - voltage power supply module to adjust its output voltage to a preset voltage value higher than V_bat; S3: When V_bat is lower than the preset activation threshold, control the activation current - limiting module to conduct, and output an initial test voltage to the battery pack through the current - limiting resistor; S4: During the conduction of the activation current - limiting module, gradually increase the output voltage in a step - up manner, and monitor the charging circuit current in real - time until a stable charging current is detected or the output voltage reaches the preset upper limit; S5: When the battery pack voltage rises back to the preset safety voltage, control the activation current - limiting module to turn off, and control the relay to pull in to establish the main charging path.

2. The multi-specification battery safety activation system according to claim 1, characterized in that, Between steps S4 and S5, the control unit is configured to execute a constant - power pre - charge step: After detecting an effective charging current, control the adjustable wide - voltage power supply module to enter the constant - power pre - charge mode, and dynamically adjust its output voltage to keep the power input to the battery pack at a set constant power value until the battery pack voltage reaches the safety voltage.

3. The multi-specification battery safety activation system according to claim 1, characterized in that, The activation current - limiting module includes a controlled switch device, the current - limiting resistor and an anti - reverse - flow diode. The three are connected in series and then connected in parallel with the switch contacts of the relay; the control end of the controlled switch device is connected to the control unit, and the cathode of the anti - reverse - flow diode faces the positive pole of the battery pack.

4. The multi-specification battery safety activation system according to claim 3, characterized in that, The control unit is configured to interlock the drive signal of the relay and the drive signal of the controlled switch device to ensure that the two do not conduct simultaneously.

5. The multi-specification battery safety activation system according to claim 1, characterized in that, The main switch module further includes a fuse, which is connected in series on the output positive path of the adjustable wide - voltage power supply module and is located in front of the relay.

6. The multi-specification battery safety activation system according to claim 1, characterized in that, The adjustable-width voltage supply module includes a pre-stage power factor correction circuit and a post-stage DC-DC conversion circuit; the control unit is configured to cooperatively adjust the DC bus voltage of the pre-stage power factor correction circuit and the operating frequency or duty cycle of the post-stage DC-DC conversion circuit according to the target output voltage.

7. The multi-specification battery safety activation system according to claim 6, characterized in that, The pre-stage power factor correction circuit is a totem-pole bridgeless PFC circuit, and the post-stage DC-DC conversion circuit is an LLC resonant converter.

8. The multi-specification battery safety activation system according to claim 1, characterized in that, The safety detection module further includes a current detection module for real-time monitoring of the magnitude and direction of the current in the charging circuit.

9. The multi-specification battery safety activation system according to claim 1, characterized in that, It further includes a human-computer interaction module for setting charging parameters, displaying status, and receiving user instructions; The control unit is configured to enforce steps S3 and S4 when a dead battery activation instruction is received through the human-computer interaction module.

10. A control method for a multi-specification battery safety activation system according to any one of claims 1-9, characterized in that, It includes the following steps: Physical isolation and safety detection: Initialize the system, keep the relay disconnected, and detect the power supply output voltage V_out and the battery voltage V_bat; Reverse current prevention judgment and voltage pre-synchronization: If V_out≥V_bat, adjust the power supply output voltage to V_bat+ΔV to achieve voltage pre-synchronization; if V_out<V_bat, report an error and lock; Intelligent activation judgment and execution: If V_bat is lower than the activation threshold, conduct the parallel activation current-limiting path, and perform low-voltage probing charging on the battery in a stepped boost manner through a current-limiting resistor until activation is successful or the attempt limit is reached; Controlled pre-charging: After the battery is activated, control the power supply to pre-charge the battery with a constant small power until the battery voltage rises back to the safety threshold; Main path charging: Shut off the activation current-limiting path, close the relay, and switch to the conventional constant current-constant voltage charging mode to complete the charging.

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