Output slow start control method and system adaptive to weak power supply scene

Abstract

The embodiment of the invention provides an output slow start control method and system adaptive to a weak power supply scene, and belongs to the technical field of battery charging. The method comprises the following steps: taking initial voltage information and under-voltage protection point information as basic data for outputting slow start control; first input voltage information is obtained after current limiting starting is completed, and drop amplitude information and under-voltage margin information under the voltage are calculated based on the first input voltage information and the initial voltage information; after obtaining the next round of input voltage information, repeatedly executing judgment based on the voltage drop amplitude information and the under-voltage margin information and updating the output current information; and determining that the output slow start is completed based on the judgment that any round of judgment does not meet a preset judgment condition or based on the judgment that the updated output current information exceeds the allowable maximum output current information. According to the scheme, the control capability of establishing stable output current in a self-adaptive manner under a weak power supply condition is realized.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of battery charging, in particular to an output slow start control method for adaptive weak power supply scenarios and an output slow start control system for adaptive weak power supply scenarios. BACKGROUND

[0002] With the gradual popularity of various engineering vehicles such as arm trucks, forklifts, and fork trucks, the dependence on charging equipment during on-site operation is increasing. Existing chargers can usually complete the current rise process according to the established output slow start control strategy under normal power supply conditions, whether it is according to the charging request of the lithium battery management system or according to the default charging current of the lead-acid battery for current limiting start, the overall operation is relatively stable. However, in the actual use environment of the engineering site, the power supply conditions often cannot be maintained in standard working conditions for a long time, for example, there are power consumption peaks in some construction areas, temporary power distribution lines are too long, or the power cable voltage drop is too large, etc., so that the AC input supply voltage is in a state of surface normal but insufficient load capacity.

[0003] Under such weak power supply scenarios, the effective value of the input voltage detected by the charger before starting is usually still within the allowed range, but after starting to output current according to the default slow start strategy, the input voltage will instantaneously drop due to high grid impedance. When the drop amplitude reaches the input under-voltage protection point, the charger control system will immediately trigger under-voltage protection and shut down the output. Since the power supply capacity has not recovered, the subsequent restart often repeats the above process, causing the charger to fall into a "start-under-voltage-shutdown" cycle and unable to smoothly enter the normal charging phase.

[0004] The existing technology mainly controls through fixed slow start slope or fixed current rise curve, and usually does not have the ability to real-time evaluate and adjust to the dynamic changes of weak power grid. Once the dynamic response of the input voltage does not match the design conditions, the charger lacks a mechanism to further identify the loadable capacity, resulting in the inability to establish stable output, thereby affecting the normal energy supplement needs of engineering vehicles. With the increasing complexity of on-site application scenarios, the output establishment problem under weak power supply conditions has become a technical difficulty that is widely concerned in the field of charging equipment. SUMMARY

[0005] The purpose of the embodiments of the present application is to provide an output slow start control method and system for adaptive weak power supply scenarios to at least solve the problem that the existing charger cannot establish stable output due to the triggering of under-voltage protection caused by the instantaneous drop of the input voltage under insufficient power supply conditions.

[0006] To achieve the above object, the application provides a first aspect of an output slow start control method for an adaptive weak power supply scene, which comprises the following steps: obtaining an input voltage detection signal of an alternating current input power supply, determining initial voltage information and under-voltage protection point information based on the input voltage detection signal, and taking the initial voltage information and the under-voltage protection point information as basic data for output slow start control; generating initial output current information based on the basic data, obtaining first input voltage information after the completion of current-limiting start, and calculating voltage drop amplitude information and under-voltage margin information based on the first input voltage information and the initial voltage information; judging whether to generate current increment information and update output current information based on the difference between the voltage drop amplitude information and the under-voltage margin information, and repeatedly executing the judgment based on the voltage drop amplitude information and the under-voltage margin information and the output current information update after obtaining the next round of input voltage information; determining that the output slow start is completed based on the judgment that any round of judgment does not meet the preset judgment condition or the judgment that the updated output current information exceeds the allowed maximum output current information, and taking the output current information at the completion of slow start as the stable output current information of the charger.

[0007] Optionally, obtaining the input voltage detection signal of the alternating current input power supply comprises the following steps: performing differential sampling on the alternating current input power supply to form a differential sampling signal, and performing analog-to-digital conversion on the differential sampling signal to generate input voltage digital data; performing voltage amplitude analysis on the input voltage digital data, and taking the analyzed voltage data as input data for generating the initial voltage information and the under-voltage protection point information.

[0008] Optionally, calculating the voltage drop amplitude information based on the first input voltage information and the initial voltage information comprises the following steps: performing difference operation on the initial voltage information and the first input voltage information to generate first drop difference data, and taking the first drop difference data as the voltage drop amplitude information for difference judgment processing.

[0009] Optionally, calculating the under-voltage margin information based on the first input voltage information and the under-voltage protection point information comprises the following steps: performing amplitude difference operation on the first input voltage information and the under-voltage protection point information to generate first margin data, and taking the first margin data as the under-voltage margin information input into the difference judgment process together with the voltage drop amplitude information.

[0010] Optionally, the current increment information comprises the following steps: performing increment calculation on the previous round of output current information based on a preset current increment generation rule to form current increment data; combining the current increment data and the previous round of output current information to form the current increment information, and taking the current increment information as input data for updating the output current information for current regulation.

[0011] Optionally, the acquiring the next round of input voltage information comprises: re-acquiring an input voltage detection signal of the AC input power supply after the output current information is updated stably, performing analog-to-digital conversion and numerical analysis on the input voltage detection signal to form next round of input voltage digitized data; and generating next round of input voltage information based on the next round of input voltage digitized data, for calculating next round of voltage drop amplitude information and next round of under-voltage margin information.

[0012] Optionally, the preset judgment condition comprises: performing threshold comparison on the difference between the voltage drop amplitude information and the under-voltage margin information, taking the difference result satisfying the preset threshold condition as the judgment basis for generating the current increment information, and taking the difference result not satisfying the preset threshold condition as the judgment basis for determining that the output slow start is completed.

[0013] Optionally, the allowed maximum output current information is generated based on the input voltage detection signal and a preset voltage and current corresponding relationship, and an upper limit comparison is performed on the updated output current information, and the comparison result is taken as the judgment basis for determining whether the output slow start is completed.

[0014] The second aspect of the present application provides an output slow start control system for adaptive weak power supply scenarios, comprising: an acquisition unit configured to acquire an input voltage detection signal of an AC input power supply, determine initial voltage information and under-voltage protection point information based on the input voltage detection signal, and take the initial voltage information and the under-voltage protection point information as basic data for output slow start control; a processing unit configured to generate initial output current information based on the basic data by performing current limiting start, and acquire first input voltage information after the current limiting start is completed, calculate voltage drop amplitude information and under-voltage margin information based on the first input voltage information and the initial voltage information; an update unit configured to determine whether to generate current increment information and update output current information based on the difference between the voltage drop amplitude information and the under-voltage margin information, and repeatedly perform the judgment based on the voltage drop amplitude information and the under-voltage margin information and the output current information update after acquiring the next round of input voltage information; and a determination unit configured to determine that the output slow start is completed based on any one of the following conditions: the judgment does not satisfy a preset judgment condition, or the updated output current information exceeds the allowed maximum output current information, and take the output current information at the completion of the slow start as the stable output current information of the charger.

[0015] The third aspect of the present application provides a computer program product comprising a computer program, which, when executed by a processor, performs the output slow start control method for adaptive weak power supply scenarios as described above.

[0016] By the technical scheme, the input voltage detection signal of the alternating current input power supply is acquired to form initial voltage information and under-voltage protection point information, and the output slow start control has the basic data for judging the weak power supply condition, so that the initial output current information can be established under the quantifiable voltage reference in the current limiting start stage. After the current limiting start is ended, the voltage drop amplitude information and the under-voltage margin information are calculated, the current carrying capacity of the current input power supply to the output current change can be represented, so as to provide a clear judgment basis for the generation of the subsequent current increment. The difference between the two types of voltage characteristics is used to perform multiple rounds of judgment and gradually update the output current information, so that the output slow start can be established in stages under the dynamic changing power grid condition, and does not depend on the fixed rising curve. At the same time, the relationship between the updated output current information and the allowed maximum output current information is judged by constraint, so that the slow start process can be ended when the voltage margin is insufficient or reaches the output upper limit, so that the stable output current information formed finally is consistent with the actual power supply capacity, thereby avoiding the under-voltage shutdown cycle phenomenon in the weak power supply scene.

[0017] Other features and advantages of the present application will be illustrated in detail in the following specific embodiments. BRIEF DESCRIPTION OF DRAWINGS

[0018] The accompanying drawings are included to provide a further understanding of the embodiments of the application, and constitute a part of the specification, and are used together with the following specific embodiments to explain the embodiments of the application, but do not constitute a limitation on the embodiments of the application. In the drawings:

[0019] Figure 1 is a step flow chart of the output slow start control method for self-adapting to the weak power supply scene provided by an embodiment of the application;

[0020] Figure 2 is a whole structure block diagram of the output slow start control for self-adapting to the weak power supply scene provided by an embodiment of the application;

[0021] Figure 3 is a specific circuit structure schematic diagram of the alternating current input voltage detection circuit and the output slow start control circuit provided by an embodiment of the application;

[0022] Figure 4 is a system structure diagram of the output slow start control system for self-adapting to the weak power supply scene provided by an embodiment of the application. DETAILED DESCRIPTION

[0023] The specific embodiments of the application will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are only used to illustrate and explain the application, and are not used to limit the application.

[0024] As Figure 1As shown, the embodiment of the present application provides an output slow start control method for adaptive weak power supply scenarios, which comprises:

[0025] Step S10: obtaining an input voltage detection signal of the AC input power supply, determining initial voltage information and under-voltage protection point information based on the input voltage detection signal, and taking the initial voltage information and the under-voltage protection point information as basic data for output slow start control.

[0026] Specifically, obtaining the input voltage detection signal of the AC input power supply comprises: performing differential sampling on the AC input power supply to form a differential sampling signal, performing analog-to-digital conversion on the differential sampling signal to generate input voltage digitized data, and performing voltage amplitude analysis on the input voltage digitized data, and taking the analyzed voltage data as input data for generating initial voltage information and under-voltage protection point information.

[0027] In the embodiment of the present application, the acquisition of the input voltage is usually placed at the very beginning of the slow start process, because the entire control link relies on this kind of data to build a judgment basis. The waveform at the AC input end is not stable in the engineering field, and the cable length and load fluctuation can cause slight fluctuations in the amplitude. In order to enable the subsequent control to be carried out on the basis of a relatively clean signal, differential mode is often used to collect the voltage first. The differential structure directly suppresses common-mode interference, especially in the vicinity of construction equipment with many noise sources. This processing can reduce a lot of additional correction work. After differential sampling, it is necessary to enter the analog-to-digital conversion link, in which the analog signal is converted into digital quantity, facilitating the subsequent data analysis. The digitized result retains the key characteristics of the input waveform, and the continuity of the amplitude can also meet the accuracy requirements of the subsequent slow start control. After completing this small link, the basic data of the input voltage is formally established.

[0028] The analysis of the voltage amplitude is usually carried out along a relatively fixed logic. The digitized voltage contains amplitude changes of several cycles, in order to enable the slow start process to rely on a clear scale, the analysis process often outputs a relatively stable amplitude result through the peak value or effective value estimation rule of the sampling point. This kind of analysis method does not pursue complexity, but emphasizes the true reflection of the waveform itself.

[0029] The effective value is widely used in the field of motor and power supply control, and can maintain a relatively reliable value under different noise conditions. The analyzed amplitude will be used as the basis for deriving the initial voltage information, and this step is an important calibration action in the slow start strategy.

[0030] Initial voltage information is primarily used to characterize the initial state of the input power supply. During the startup phase, before any output current is generated, the input typically maintains a relatively high voltage level. This voltage does not represent the actual power supply capacity, but it serves as a reference point for subsequent comparisons. As the output current begins to build up, line impedance, transformer capacity, and contact conditions all contribute to a voltage drop. The initial voltage information acts as a static reference, making the calculation of the subsequent voltage drop more accurate. Once the reference is established, undervoltage protection information is also recorded simultaneously. The undervoltage protection point is often set as a safety threshold, indicating that the device should not continue outputting voltage if the input voltage falls below this value.

[0031] The initial voltage information and the undervoltage protection point information are combined to form a set of basic data for judgment. This set of data does not directly participate in control execution, but serves as a range benchmark to determine whether the subsequent soft start process has the conditions to continue increasing the output current. When the drop amplitude is too large and the margin is too small, the soft start process needs to slow down or even stop to avoid triggering the undervoltage protection. Conversely, if the drop amplitude is small and the margin remains stable, the soft start process may have room to continue building up the output current.

[0032] In another possible implementation, a window-based filtering preprocessing step is added before the analysis of the digitized input voltage data to improve the identification of transient disturbances in weak power supply scenarios. In engineering settings, the input voltage often experiences various short-term disturbances during the startup phase. These disturbances do not represent the actual power supply capacity but can easily affect the judgment of initial voltage information. Therefore, a short-time sliding window can be constructed to smooth the acquired digitized input voltage data. The length of the sliding window should not be too large, only covering a few sampling periods, allowing high-frequency noise to naturally decrease during averaging. After this processing, the effective value obtained in the amplitude analysis stage will be closer to the actual load state of the power supply, rather than being affected by short-period fluctuations.

[0033] After window filtering, a logic segment is added to the amplitude analysis stage to detect the degree of waveform distortion. Weak power grids often exhibit small distortions preceding voltage collapses, which are often a precursor. Judging solely by single-cycle amplitudes can sometimes be insufficient to distinguish between collapse trends and normal fluctuations. Therefore, distortion coefficients can be calculated for the amplitude sequence within the sliding window, for example, by using the average change in amplitude gradient. If the average change remains stable within a preset range, initial voltage information can be generated according to the conventional path; if the change continues to rise, the amplitude at the corresponding moment can be marked as an unreliable sample, and the generation of initial voltage information can be delayed until the data within the window stabilizes again.

[0034] Step S20: Based on the basic data, perform current limiting start to generate initial output current information, and after the current limiting start is completed, obtain the first input voltage information, and calculate the voltage drop amplitude information and undervoltage margin information based on the first input voltage information and the initial voltage information.

[0035] Specifically, calculating the voltage drop magnitude information based on the first input voltage information and the initial voltage information includes: performing a difference operation on the initial voltage information and the first input voltage information to generate first drop difference data, and using the first drop difference data as voltage drop magnitude information for difference judgment processing.

[0036] Furthermore, calculating the undervoltage margin information based on the first input voltage information and the undervoltage protection point information includes: performing an amplitude difference calculation on the first input voltage information and the undervoltage protection point information to generate first margin data, and inputting the first margin data as undervoltage margin information into the difference judgment process for use together with the voltage drop amplitude information.

[0037] In this embodiment of the invention, the input terminal under weak power supply conditions is often quite sensitive. Even a slight increase in output current can cause a brief voltage drop. Therefore, current-limiting startup is more like a probing action. The initial output current information generated during current-limiting startup does not aim for a large output, but rather provides a relatively gentle load change, allowing the input voltage to express its true load-carrying capacity. After the initial output current information is established, the state of the input terminal will adjust accordingly. This change phase is usually short but crucial because the magnitude of the first drop often reveals the basic condition of the input circuit.

[0038] After current limiting is initiated, the initial input voltage information comes into play. This initial input voltage information acts as immediate feedback after startup, recording the voltage level at the input terminal after the initial load. Engineers in this field typically use the magnitude of this first voltage drop as a reference point for assessing grid capacity, as it is related to line impedance, power supply capacity, and temporary load changes. To quantify this drop, a set of rules needs to be established to directly reflect the magnitude of the change. Difference calculation is the most common method because it visually presents relative relationships, facilitating subsequent judgments. When calculating the voltage drop magnitude, the initial voltage information and the initial input voltage information are compared on the same scale. This result reflects the stability of the input terminal during the first load. A small drop magnitude usually indicates that the input terminal can withstand subsequent increases; a large drop magnitude indicates that the input terminal may be approaching a critical state. The difference itself does not require further modification; it can be directly used in difference judgment processing as a numerical value.

[0039] The calculation logic for undervoltage margin information is similar to that for the drop amplitude, but the focus is different. Undervoltage protection point information is typically a safety threshold used to assess the distance between the input and the protection point. To quantify this distance, the amplitude difference calculation needs to be performed again. The larger the difference, the farther the input is from the protection point; the smaller the difference, the more strained the input is. Margin data is not used alone in the judgment process but is compared together with the drop amplitude. These two sets of data are often placed in the same judgment framework. Engineers usually focus on the relative relationship between the drop amplitude and the margin, rather than the absolute value of a single variable. If the drop amplitude is covered by the margin, the input still has some capacity; if the drop amplitude approaches the margin, the output increase action must be more cautious. This judgment method maintains high interpretability in weak power supply scenarios and allows the control strategy to more closely reflect the actual state of the input.

[0040] Step S30: Based on the difference between the voltage drop amplitude information and the undervoltage margin information, determine whether to generate current increment information and update the output current information. After obtaining the next round of input voltage information, repeat the judgment based on the voltage drop amplitude information and the undervoltage margin information and the output current information update.

[0041] Specifically, generating current increment information includes: performing incremental calculations on the previous round of output current information based on a preset current increment generation rule to form current increment data; combining the current increment data with the previous round of output current information to form current increment information; and using the current increment information as input data for updating output current information for current regulation.

[0042] Furthermore, obtaining the next round of input voltage information includes: after the output current information is updated and stabilized, re-acquiring the input voltage detection signal of the AC input power supply; performing analog-to-digital conversion and numerical analysis on the input voltage detection signal to form the next round of input voltage digital data; generating the next round of input voltage information based on the next round of input voltage digital data, which is used to calculate the next round of voltage drop amplitude information and the next round of undervoltage margin information.

[0043] In this embodiment of the invention, determining whether to generate current increment information is typically placed at a critical point in the soft-start process, as this determination directly relates to whether the output current can continue to rise. Voltage drop magnitude information and undervoltage margin information constitute two core quantities in the judgment framework, jointly depicting the input's tolerance range for the current output load. When the voltage drop magnitude information is large, the input often exhibits significant pressure, while when the margin information is small, the input may already be approaching the undervoltage boundary. Comparing the two together provides a clearer view of whether the input has the conditions to continue increasing the load. The judgment process does not pursue complex logic; simply grasping the difference itself yields a relatively reliable trend judgment.

[0044] The part that generates the current increment information is responsible for realizing the actual change in the output current. Current updates cannot be blindly pushed forward, so a set of preset current increment generation rules is usually defined first. The content of the rules is not necessarily fixed and can be adjusted appropriately according to the device's design habits or different scenarios. For example, some scenarios use a fixed increment, while others use an increment mode with slightly adaptive characteristics. Regardless of the method used, the previous round of output current information is the foundation, and then a current increment data is generated according to the rules. This data itself has no meaning, but once combined with the previous round of output current information, it forms a more complete current increment information, which is ultimately used to drive the output current to the next stage.

[0045] Current regulation typically occurs after the update logic is complete. When the updated output current information reaches the actual output terminal, the input terminal will respond again. The degree and direction of this response need to be reflected by the next round of input voltage information, making the observation of the next round of input voltage information essential. Instead of directly referencing the previous round's data, we wait for the output current information to reach a relatively stable state before re-acquiring the AC input voltage detection signal. The amplitude change exhibited by the input terminal at this moment more accurately reflects the line condition because the current change from the previous round has been fully transmitted to the input terminal. After re-acquisition, the signal still undergoes analog-to-digital conversion and numerical analysis to present the input voltage information in digital form again.

[0046] The next round of digitized input voltage data will be further refined into the next round of input voltage information. This step is responsible for extracting the amplitude characteristics from the waveform, making subsequent calculations more direct. After the next round of input voltage information enters the calculation of the drop amplitude and undervoltage margin, two new types of judgment quantities will be generated. The drop amplitude information tells the engineer the burden that the current output current places on the input terminal, while the margin information gives the leeway between the input terminal and the undervoltage protection point. After the difference between the two is judged, it returns to the judgment framework of the previous round, forming a closed-loop update rhythm.

[0047] This loop repeats multiple times during the soft start-up phase, each loop revolving around the same set of variables: the magnitude of the voltage drop, the undervoltage margin, the current increment, and the input voltage for the next round. As the output current gradually builds up, the input response becomes clearer. In some cases, the differential judgment may fail to meet the preset conditions, and the loop will temporarily pause at this point, waiting for the input to recover its margin. In other cases, the output current may be approaching the boundary of the maximum allowable output current, and the loop needs to terminate in a timely manner to avoid exceeding the limit. Overall, this control flow, through continuous acquisition, continuous judgment, and continuous updating, makes the soft start-up process closer to the actual state of the input, giving the output establishment process a certain degree of adaptability in weak power supply scenarios.

[0048] Step S40: Based on the judgment that the preset judgment condition is not met in any round of judgment or based on the judgment that the updated output current information exceeds the maximum allowable output current information, determine that the output soft start is completed, and use the output current information when the soft start is completed as the stable output current information of the charger.

[0049] Specifically, the preset judgment conditions include: performing a threshold comparison on the difference between the voltage drop amplitude information and the undervoltage margin information; using the difference result that meets the preset threshold conditions as the judgment basis for generating current increment information; and using the difference result that does not meet the preset threshold conditions as the judgment basis for determining that the output soft start is complete.

[0050] Furthermore, the maximum allowable output current information is generated based on the input voltage detection signal and the preset voltage and current correspondence, and an upper limit comparison is performed on the updated output current information. The comparison result is used as the basis for determining whether the output soft start is complete.

[0051] In this embodiment of the invention, each round of judgment revolves around the same set of data: the magnitude of the drop, the undervoltage margin, and the updated output current. When any round of judgment no longer meets the preset judgment conditions, the upward trend of the output current will pause. This pause is not a fault, but rather indicates that the input can no longer support a larger load. This situation is more common in weak power supply scenarios, where line impedance and power supply capacity both affect the input response. The judgment logic here acts like a "gate," blocking inappropriate output changes and keeping the output current within a steady-state range.

[0052] The preset judgment condition itself is not complex, but its function is crucial. The judgment condition determines the next step by comparing the difference between the decrease in current and the undervoltage margin information. When the difference is large enough, it indicates that there is still margin at the input, and the process of generating the current increment information can continue. If the difference narrows to near or even below the threshold, the pressure at the input becomes clear, and continuing to increase the output current may trigger the undervoltage protection. To avoid this risk, the judgment condition will change course at this point, ending the soft-start process. The difference comparison method is both simple and intuitive, facilitating a quick response in practical applications.

[0053] Threshold comparisons are typically based on a preset numerical range, which defines whether the input can withstand the next current increment. The threshold value can be preset according to the device characteristics or operating scenario, rather than dynamically adjusted during operation. This maintains the stability of the judgment process and makes it easier for developers to verify the reliability of the control logic. The threshold judgment has only two outcomes: continue increasing or terminate the process. This binary logic reduces complexity and minimizes the possibility of errors.

[0054] Besides judging based on the difference, it's sometimes necessary to consider whether the output current itself is approaching the maximum permissible level. The maximum permissible output current information typically comes from a set of preset voltage-current relationships, which describe the acceptable output range of the device under different input conditions. To determine if the upper limit has been reached, an upper limit comparison needs to be performed on the updated output current information. The soft-start process will stop at the boundary of the relationship as soon as the output approaches it.

[0055] Upper limit comparison and difference judgment together constitute the dual basis for the completion of soft start. Difference judgment focuses on the immediate response at the input end, while upper limit comparison focuses on the safety limit on the output side. Both types of judgments aim at the same goal—to provide the charger with a stable output level that matches its power supply capacity. When the soft start process ends, the final output current information is recorded as stable output current information and serves as a long-term operating point in subsequent charging stages. This operating point reflects the true state of the input voltage and is consistent with the weak power supply environment, making the subsequent charging process smoother.

[0056] To better explain the execution process of the adaptive output soft-start control for weak power supply scenarios proposed in this invention, an explanation is given based on a specific implementation method. However, it should be noted that this method is not limited to this one. Other control methods, structural configurations, or signal processing paths formed under the same principle should also be considered to fall within the protection scope of this invention.

[0057] To make the technical means of realizing this invention clearer, the front-end PFC and the back-end DC-DC power conversion, detection and phase-closed-loop control inside the charger will not be elaborated in this section, because these parts belong to the scope of conventional design and have no direct impact on the output soft start control logic that this invention focuses on.

[0058] like Figure 2 and Figure 3 As shown, the circuit consists of AC input power supplies Vin_L and Vin_N, an AC / DC power conversion and control unit, charger output positive signal Vout_P and negative signal Vout_N, an AC input voltage detection circuit, and an output soft-start control circuit. In a typical application, the AC input power supply is converted by the AC / DC power conversion and control unit to output Vout_P and Vout_N, which are connected to the positive and negative terminals of the battery pack, respectively, during the charging phase.

[0059] In the voltage detection path, Vin_L and Vin_N first enter the AC input voltage detection circuit, forming a detection signal for monitoring the input power supply status. Specifically, the input power supply is differentially sampled through differential operational amplifier D1 and a surrounding resistor network to form a voltage signal Vln_SE. This signal is then sent to the front-end main control chip digital signal processor DSC1 for real-time detection and analysis of the input voltage. After performing necessary processing on the detected input voltage, DSC1 transmits the processed digital signal to the subsequent main control chip digital signal processor DSC2 via communication optocouplers D2 and D3. It should be noted that DSC1 is responsible for front-end PFC calculation, closed-loop control, and abnormal protection functions; DSC2 is responsible for the subsequent DC-DC calculation, closed-loop control, and output current limiting strategy functions. These conventional parts will not be described again.

[0060] Based on this, the downstream main control chip, the digital signal processor DSC2, combined with the output soft-start control circuit, judges the AC input voltage detection signal to execute the adaptive weak power supply output soft-start process proposed in this invention.

[0061] Figure 3 The corresponding embodiment illustrates the working principle of this technical solution. Under normal AC input power conditions, the charger executes the output soft-start step according to the default startup logic:

[0062] 1) When charging the lithium battery, current limiting is performed based on the target current requested by the battery management system (BMS).

[0063] 2) When charging lead-acid batteries, the current limit is set according to the maximum output current of the corresponding battery type.

[0064] 3) Under normal power grid conditions, this type of startup process can usually establish and maintain output stably.

[0065] In scenarios with weak AC input power, conventional startup logic often fails to establish output. During the first startup, the charger triggers input undervoltage protection and shuts down due to a significant voltage drop at the moment of loading. In subsequent startups, the control logic switches to an optimized output soft-start strategy to adapt to the characteristics of weak power grids.

[0066] In the optimized strategy, the initial voltage V of the input power supply is first detected. in0 And determine the input undervoltage protection point V. inuv For example, 85VAC. Then, a smaller initial output current I is used. out0 (For example, 0.5A) Perform current-limited startup. After this stage is completed, check the input voltage Vin1 again and calculate the drop amplitude DV. in0 =V in0 -V in1At the same time, calculate the voltage difference DV between the current voltage and the undervoltage protection point. inuv0 =V in1 -V inuv If DV is satisfied inuv0 -DV in0 If the output current ΔIout is ≥ ΔV (ΔV is, for example, 10V), then it is safe to increase the output current ΔIout.

[0067] In addition, when DV in0 Smaller and DV inuv0 When the current increment is significantly larger (e.g., more than 30 times larger), it indicates that the input terminal can withstand a larger current increment. In this case, the current increment ΔIout (e.g., 5A) can be appropriately increased to shorten the overall output soft start time.

[0068] After the output stabilizes, the next input voltage V is detected. in2 Calculate DV in1 =V in1 -V in2 and DV inuv1 =V in2 -V inuv If DV is satisfied inuv1 -DV in1 If the current is greater than or equal to ΔV, then the output current ΔI will be increased further. out (e.g., 0.5A). This process continues until DV. inuv -DV in The current rise stops when the current is less than ΔV. To ensure the safe operation of the charger, the final stable output current I is determined. out It should be less than the maximum allowable output current Iout corresponding to the input voltage under normal power supply conditions. max .

[0069] The above embodiments illustrate the specific implementation of the present invention in scenarios with weak power supply. The present invention is not limited to single-phase AC input, but is also applicable to power supply conditions such as three-phase AC input and DC input. All technical adjustments or modifications made based on the principles of this invention are considered to fall within the protection scope of this invention.

[0070] like Figure 4As shown, this invention provides an adaptive output soft-start control system for weak power supply scenarios. The system includes: a data acquisition unit, used to acquire an input voltage detection signal of AC input power supply, determine initial voltage information and undervoltage protection point information based on the input voltage detection signal, and use the initial voltage information and the undervoltage protection point information as basic data for output soft-start control; a processing unit, used to perform current limiting start to generate initial output current information based on the basic data, and acquire first input voltage information after current limiting start is completed, and calculate voltage drop amplitude information and undervoltage margin information based on the first input voltage information and the initial voltage information; an update unit, used to determine whether to generate current increment information and update output current information based on the difference between the voltage drop amplitude information and the undervoltage margin information, and repeat the judgment based on voltage drop amplitude information and undervoltage margin information and output current information update after acquiring the next round of input voltage information; and a judgment unit, used to determine that output soft start is completed based on the judgment that any round of judgment does not meet the preset judgment condition or the judgment that the updated output current information exceeds the maximum allowable output current information, and use the output current information at the time of soft start completion as the stable output current information of the charger.

[0071] The present invention also provides a computer program product, including a computer program, wherein the computer program is executed by a processor to perform the above-described adaptive weak power supply scenario output soft start control method.

[0072] Those skilled in the art will understand that all or part of the steps in the methods of the above embodiments can be implemented by a program instructing related hardware. This program is stored in a storage medium and includes several instructions to cause a microcontroller, chip, or processor to execute all or part of the steps of the methods described in the various embodiments of the present invention. The aforementioned storage medium includes various media capable of storing program code, such as a USB flash drive, a portable hard drive, a read-only memory (ROM), a random access memory (RAM), a magnetic disk, or an optical disk.

[0073] The optional embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the embodiments of the present invention are not limited to the specific details described above. Within the scope of the technical concept of the embodiments of the present invention, various simple modifications can be made to the technical solutions of the embodiments of the present invention, and these simple modifications all fall within the protection scope of the embodiments of the present invention. It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. To avoid unnecessary repetition, the embodiments of the present invention will not further describe the various possible combinations.

[0074] Furthermore, various different embodiments of the present invention can be combined in any way, as long as they do not violate the spirit of the embodiments of the present invention, they should also be regarded as the content disclosed by the embodiments of the present invention.

Claims

1. An output soft start control method for an adaptive weak supply scenario, characterized in that, The method comprises: obtaining an input voltage detection signal of an AC input power supply, determining initial voltage information and under-voltage protection point information based on the input voltage detection signal, and taking the initial voltage information and the under-voltage protection point information as basic data for output slow start control; generating initial output current information based on the basic data by performing current limiting start, and obtaining first input voltage information after the current limiting start is completed, calculating voltage drop amplitude information and under-voltage margin information based on the first input voltage information and the initial voltage information; determining whether to generate current increment information and update output current information based on the difference between the voltage drop amplitude information and the under-voltage margin information, and repeatedly performing the determination based on the voltage drop amplitude information and the under-voltage margin information and the output current information update after obtaining next round input voltage information; determining that the output slow start is completed based on the determination that any round determination does not meet a preset determination condition or that the updated output current information exceeds the allowed maximum output current information, and taking the output current information at the slow start completion time as the stable output current information of the charger.

2. The method of claim 1, wherein, Obtaining an input voltage detection signal of an AC input power supply comprises: performing differential sampling on the AC input power supply to form a differential sampling signal, and performing analog-to-digital conversion on the differential sampling signal to generate input voltage digitized data; performing voltage amplitude analysis on the input voltage digitized data, and taking the analyzed voltage data as input data for generating initial voltage information and under-voltage protection point information.

3. The method of claim 2, wherein, Calculating voltage drop amplitude information based on the first input voltage information and the initial voltage information comprises: performing difference operation on the initial voltage information and the first input voltage information to generate first drop difference data, and taking the first drop difference data as voltage drop amplitude information for difference determination processing.

4. The method of claim 2, wherein, Calculating under-voltage margin information based on the first input voltage information and the under-voltage protection point information comprises: performing amplitude difference operation on the first input voltage information and the under-voltage protection point information to generate first margin data, and taking the first margin data as under-voltage margin information input into the difference determination process together with the voltage drop amplitude information.

5. The method of claim 2, wherein, Generating current increment information comprises: performing increment calculation on the previous round output current information based on a preset current increment generation rule to form current increment data; combining the current increment data and the previous round output current information to form current increment information, and taking the current increment information as input data for updating the output current information for current regulation.

6. The method of claim 1, wherein, Obtaining next round input voltage information comprises: after the output current information is updated stably, re-collecting the input voltage detection signal of the AC input power supply, performing analog-to-digital conversion and numerical analysis on the input voltage detection signal to form next round input voltage digitized data; generating next round input voltage information based on the next round input voltage digitized data, for calculating next round voltage drop amplitude information and next round under-voltage margin information.

7. The method of claim 1, wherein, The preset determination condition comprises: The threshold comparison is performed on the difference between the voltage drop amplitude information and the under-voltage margin information, the difference result meeting the preset threshold condition is taken as the judgment basis for generating the current increment information, and the difference result not meeting the preset threshold condition is taken as the judgment basis for determining that the output slow start is completed.

8. The method of claim 1, wherein, The allowed maximum output current information is generated based on the input voltage detection signal and a preset voltage-current correspondence relationship, and an upper limit comparison is performed on the updated output current information, and the comparison result is taken as the judgment basis for determining whether the output slow start is completed.

9. An output soft start control system that is adaptive to a weak supply scenario, characterized by, The system comprises: An acquisition unit is configured to acquire an input voltage detection signal of an alternating input power supply, determine initial voltage information and under-voltage protection point information based on the input voltage detection signal, and take the initial voltage information and the under-voltage protection point information as basic data for output slow start control; A processing unit is configured to generate initial output current information based on the basic data by performing current-limiting start, and acquire first input voltage information after the current-limiting start is completed, calculate voltage drop amplitude information and under-voltage margin information based on the first input voltage information and the initial voltage information; An updating unit is configured to judge whether to generate current increment information and update output current information based on the difference between the voltage drop amplitude information and the under-voltage margin information, and repeatedly perform the judgment based on the voltage drop amplitude information and the under-voltage margin information and the output current information updating after acquiring next round input voltage information; A determination unit is configured to determine that the output slow start is completed based on the judgment not meeting a preset judgment condition in any round or the judgment based on the updated output current information exceeding the allowed maximum output current information, and take the output current information at the completion of the slow start as stable output current information of the charger.

10. A computer program product comprising a computer program, characterized in that, The computer program, when executed by a processor, implements the output slow start control method in an adaptive weak power supply scenario according to any one of claims 1-8.

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