Compatible charging control method for electric vehicle battery management system and charging pile
By calculating the compatibility boundary during the handshake phase, controlling the current in segments during the charging phase, and dynamically updating the boundary during the monitoring phase, the compatibility problem between electric vehicles and charging piles is solved. This enables intelligent adaptation between the battery management system and the charging pile, improves the charging success rate and efficiency, and ensures the stability and safety of the charging process.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-01-20
- Publication Date
- 2026-03-06
AI Technical Summary
Compatibility issues between existing electric vehicles and charging stations lead to charging failures or reduced efficiency. Existing technologies lack intelligent adaptation mechanisms and cannot cope with dynamic changes in the capabilities of charging stations.
By calculating the compatibility boundary during the handshake phase, controlling the current in segments during the charging phase, detecting anomalies in real time and dynamically updating the boundary during the monitoring phase, and adopting an adaptive ramp rate adjustment strategy, intelligent compatibility control between the battery management system and the charging pile is achieved.
It improves the compatibility of electric vehicles with various charging piles, ensures the stability and safety of the charging process, avoids charging failures caused by parameter mismatch, and improves charging efficiency and user experience.
Smart Images
Figure CN121608641A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of electric vehicle charging technology, and more specifically to a compatible charging control method for electric vehicle battery management systems and charging piles. Background Technology
[0002] With the rapid popularization of electric vehicles, the construction of public charging infrastructure is also constantly improving. However, due to the large number of electric vehicle brands, different battery specifications, and public charging piles coming from different manufacturers and using different technical standards, the compatibility issues between electric vehicles and charging piles are becoming increasingly prominent.
[0003] Existing electric vehicle battery management systems (BMS) typically calculate the requested voltage and current during charging based on the battery's Mapping Table (MAP), which is a pre-calibrated theoretically optimal charging parameter based on the battery's characteristics. When the requested parameters sent by the BMS to the charging station exceed the actual output capacity of the charging station, the charging station cannot meet the request, often leading to charging failure or a significant decrease in charging efficiency. For example, if a vehicle designed for 150A fast charging encounters a charging station with a maximum output current of only 100A, and the BMS still requests charging at 150A, it may trigger the charging station's protection mechanism and stop charging.
[0004] Current technologies lack mechanisms for intelligent adaptation based on the actual capabilities of charging piles. Most solutions only perform a simple capability matching judgment before charging, and refuse charging directly if there is a mismatch. This rigid approach severely impacts the user's charging experience. Furthermore, the output capacity of charging piles may dynamically change during charging due to factors such as grid load fluctuations and equipment temperature rise, which current technologies struggle to effectively address.
[0005] Therefore, there is an urgent need for a compatible charging control method that can intelligently adapt to the capabilities of charging piles and dynamically adjust charging parameters to improve the compatibility of electric vehicles with various types of charging piles and ensure the stability and safety of the charging process. Summary of the Invention
[0006] This invention provides a compatible charging control method for electric vehicle battery management systems and charging piles. The charging process is divided into three sequentially executed stages: a handshake stage, a charging stage, and a monitoring stage. By intelligently calculating compatibility boundaries during the handshake stage, controlling the current in segments based on the battery's state of charge during the charging stage, and detecting anomalies and dynamically updating boundaries in real time during the monitoring stage, the method addresses the compatibility issues of existing charging solutions. To solve the above technical problems, this invention provides a compatible charging control method for electric vehicle battery management systems and charging piles, comprising the following steps: Handshake phase: The battery management system obtains the maximum output voltage and maximum output current of the charging pile. Based on the requested voltage and requested current of the battery management system, it performs a capability boundary comparison and calculates the compatibility voltage boundary and compatibility current boundary by considering the safety margin coefficient. Charging phase: The charging process is divided into at least two phases based on the battery's state of charge (SOC). A target current and ramp rate are configured for each phase. The battery management system gradually adjusts the charging current to the target current according to the ramp rate of the current phase. Monitoring phase: Continuously monitor the deviation between the actual output current of the charging pile and the requested current of the battery management system. When the deviation exceeds a preset threshold, update the compatibility current boundary and adjust the charging current.
[0007] Preferably, during the handshake phase, the compatibility voltage boundary V compat The calculation formula is V compat =min(V BMS V charger ×k), the compatibility current boundary I compat The calculation formula is I compat =min(I BMS I charger ×k), where V BMS For the requested voltage, V charger I is the maximum output voltage of the charging pile. BMS For the requested current, I charger The maximum output current of the charging pile is given by k, where k is the safety margin coefficient and 0. <k<1。
[0008] Preferably, the safety margin coefficient k ranges from 0.93 to 0.97.
[0009] Preferably, in the charging stage, the charging process is divided into three stages according to the battery's state of charge (SOC): a preheating stage, executed when SOC < SOC1, using a first target current and a first ramp rate; a fast charging stage, executed when SOC1 ≤ SOC < SOC2, using a second target current and a second ramp rate; and a trickle charging stage, executed when SOC ≥ SOC2, using a third target current and a third ramp rate; wherein SOC1 and SOC2 are preset state of charge thresholds, the first target current is less than the second target current, and the third target current is less than the second target current.
[0010] Preferably, the value of SOC1 ranges from 15% to 25%, and the value of SOC2 ranges from 75% to 85%.
[0011] Preferably, in the monitoring phase, an adaptive ramp rate adjustment strategy is adopted according to the magnitude of the deviation, including: when the deviation is less than a first deviation threshold, maintaining the current ramp rate unchanged; when the deviation is greater than or equal to the first deviation threshold and less than a second deviation threshold, reducing the current ramp rate to a preset proportion of the original rate; when the deviation is greater than or equal to the second deviation threshold, pausing current ramping; wherein the first deviation threshold is less than the second deviation threshold.
[0012] Preferably, the first deviation threshold ranges from 3A to 8A, the second deviation threshold ranges from 12A to 20A, and the preset ratio ranges from 50% to 70%.
[0013] Preferably, the monitoring phase further includes an anomaly detection step, which includes detecting at least one of the following anomaly types: insufficient output anomaly, determined when the actual output current of the charging pile is continuously lower than the requested current for a first preset duration; voltage instability anomaly, determined when the output voltage fluctuation of the charging pile exceeds a preset voltage threshold; and ramp-up failure anomaly, determined when the actual current fails to follow the change of the requested current for a second preset duration during the current ramp-up process.
[0014] Preferably, when any of the anomaly types is detected, a boundary update operation is performed, which includes updating the compatibility current boundary to the current actual output current and resetting the charging current to a preset starting ratio of the updated compatibility current boundary.
[0015] Preferably, the monitoring phase further includes a capability recovery detection step: after performing the boundary update operation, the charging current is increased by a preset increment every preset detection cycle. If the charging pile can stably output the increased current for a preset stable duration, the compatibility current boundary is updated to the increased current value.
[0016] The beneficial effects of the present invention include at least the following: First, by calculating the compatibility boundary during the handshake phase, the present invention intelligently matches the request parameters of the battery management system with the actual capabilities of the charging pile and reserves a safety margin, enabling the vehicle to adapt to charging piles with various output capabilities, effectively avoiding charging failures caused by parameter mismatch, and significantly improving charging compatibility.
[0017] Secondly, this invention employs segmented parameter configuration based on the battery's state of charge, setting differentiated target currents and ramp rates for the preheating, fast charging, and trickle charging stages. The preheating stage uses a conservative strategy to avoid the risk of lithium plating caused by high-current charging at low temperatures; the fast charging stage fully utilizes the battery's optimal charging window to quickly reach the maximum allowable current; and the trickle charging stage gradually reduces the current to ensure the battery is safely fully charged. This segmented control strategy balances charging efficiency and battery safety.
[0018] Third, this invention introduces an adaptive ramp rate adjustment mechanism, which dynamically adjusts the ramp rate based on the deviation between the actual output current of the charging pile and the requested current. When the deviation is small, normal ramping is maintained; when the deviation increases, the ramp rate is reduced or ramping is paused, thus avoiding current oscillations caused by the charging pile's delayed response and improving the stability of the charging process.
[0019] Fourth, this invention incorporates a robust anomaly detection and boundary update mechanism, capable of promptly identifying abnormal situations such as insufficient output, unstable voltage, and ramp-up failure, and automatically updating compatibility boundaries and adjusting the charging current. Simultaneously, through periodic capability recovery detection, the charging power is gradually increased once the charging station's capability is restored. This dynamic adjustment mechanism ensures that the charging process is not interrupted by temporary reductions in the charging station's capability.
[0020] Fifth, the three-stage control logic of this invention adopts a serial execution method, with handshake to determine boundaries, charging execution control, and operation monitoring and adjustment. Each stage has clearly defined responsibilities, no parallel conflicts, clear logic, and is easy to implement and maintain. All functions can be implemented through a battery management system software upgrade, without requiring hardware modifications to the vehicle or charging station, resulting in low implementation costs and convenient promotion. Attached Figure Description
[0021] Figure 1 This is a schematic diagram of the method flow according to an embodiment of the present invention. Detailed Implementation
[0022] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of the present invention.
[0023] This invention provides a compatible charging control method for electric vehicle battery management systems and charging piles, comprising the following steps.
[0024] Handshake phase: The battery management system obtains the maximum output voltage and maximum output current of the charging pile. Based on the requested voltage and requested current of the battery management system, it performs a capability boundary comparison and calculates the compatibility voltage boundary and compatibility current boundary by considering the safety margin coefficient.
[0025] The handshake phase is the initial stage of the charging process, performed after the vehicle is plugged in but before formal charging begins. The main tasks of this phase are to establish a communication connection between the battery management system and the charging station, obtain the charging station's capability parameters, and calculate the compatibility boundaries for this charging operation.
[0026] After communication is established, the battery management system reads the maximum output voltage V of the charging pile through the standard communication protocol. charger and maximum output current I charger These two parameters reflect the actual output capacity of the charging station. Simultaneously, the battery management system determines the requested voltage V based on the battery's MAP (Magnetic Mapping Table) for the current battery state. BMS and requested current I BMS Next, the battery management system performs a capability boundary comparison and calculates the compatibility voltage boundary V, taking into account the safety margin factor k. compat and compatibility current boundary I compat .
[0027] The formula for calculating the compatibility voltage boundary is V. compat =min(V BMS V charger ×k), the formula for calculating the compatibility current boundary is I compat =min(I BMS I charger ×k). Here, the min function represents taking the smaller of the two parameters, and k is the safety margin coefficient, ranging from 0 to 1. The purpose of reserving a safety margin is to avoid potential output instability issues that may occur when the charging pile operates at its full load boundary. In a preferred embodiment, the safety margin coefficient k ranges from 0.93 to 0.97, with a typical value of 0.95, meaning a 5% safety margin is reserved.
[0028] The following examples illustrate the calculation process for compatibility boundaries.
[0029] Scenario 1, Full Compatibility: Assume the battery management system's request parameters are 380V, 150A, the charging pile's maximum output capacity is 500V, 200A, and the safety margin coefficient k is 0.95. According to the calculation formula, V compat =min(380,500×0.95)=min(380,475)=380V,I compat=min(150, 200 × 0.95) = min(150, 190) = 150A. Since the charging station has ample capacity, the compatibility boundary equals the battery management system's requested value, allowing the vehicle to be charged according to ideal parameters.
[0030] Scenario 2, Current-Constrained Situation: Assume the battery management system requests 380V, 150A, while the charging station's maximum output is only 500V, 100A. The calculated V... compat =380V, I compat =min(150, 100×0.95)=95A. The current boundary is limited by the charging station's capacity, but the vehicle can still be charged at a lower power.
[0031] Scenario 3, Voltage-Limited Situation: Assume the battery management system requests 750V, 300A, while the charging station's maximum output is 500V, 400A. Calculate V... compat =min(750,500×0.95)=475V,I compat =300A. The voltage limit is constrained by the charging station's capacity.
[0032] Scenario 4, Double Constraints: Assume the battery management system requests 750V, 300A, but the charging pile's maximum output is only 500V, 120A. The calculated V... compat =475V, I compat =114A. Both voltage and current are limited by the charging station's capacity, but through intelligent adaptation, the vehicle can still complete charging instead of failing outright.
[0033] Charging phase: The charging process is divided into at least two phases based on the battery's state of charge (SOC). For each phase, a corresponding target current and ramp rate are configured. The battery management system gradually adjusts the charging current to the target current according to the ramp rate of the current phase.
[0034] After determining the compatibility boundaries, the charging phase begins, and the battery management system sets the requested voltage to V. compat The current is dynamically controlled based on the battery's state of charge (SOC). This invention divides the charging process into at least two stages, and in a preferred embodiment, into three stages: a preheating stage, a fast charging stage, and a trickle charging stage, with corresponding target current and ramp rate configured for each stage.
[0035] The preheating phase is performed when the battery's state of charge (SOC) is below a first threshold SOC1. During this phase, the battery's internal resistance is relatively high, and to avoid safety risks such as lithium plating that may be caused by high-current charging, a relatively conservative charging strategy is adopted. The target current for the preheating phase is set to a first target current, which is less than the target current for the fast charging phase, and a first ramp rate is used. In a typical embodiment, SOC1 ranges from 5% to 15%, preferably 10%. The target current for the preheating phase is typically set to the compatibility current boundary I. compat The initial current is set to 30% of the target current, and the baseline ramp rate is set to 10A / s.
[0036] The fast charging phase occurs when the battery's state of charge (SOC) reaches a first threshold (SOC1) but falls below a second threshold (SOC2). This phase represents the battery's optimal charging window, allowing it to withstand a larger charging current; therefore, this window should be fully utilized to complete charging as quickly as possible. The target current for the fast charging phase is set to the second target current, typically the compatibility current boundary I. compat The initial current is set to 50% of the target current, and the baseline ramp rate is set to 25A / s. The SOC2 value ranges from 75% to 85%, with 80% being preferred. The second target current is greater than the first and third target currents to achieve efficient charging during the fast charging phase.
[0037] The trickle charging phase is executed after the battery's State of Charge (SOC) reaches the second threshold, SOC2. At this point, the battery is close to fully charged, and the charging current needs to be gradually reduced to safely fully charge the battery and protect its lifespan. The target current for the trickle charging phase is set as the third target current, using the third ramp rate. The third target current is lower than the second target current and further decreases as the SOC increases. In a typical embodiment, the target current for the trickle charging phase is determined according to Formula I. target =I compat The rate decreases linearly by ×(1-(SOC-SOC2) / (100%-SOC2)), with the baseline climbing rate set at 15A / s.
[0038] During the charging phase, the battery management system gradually adjusts the charging current to the target current according to the current ramp rate. The specific execution process of current control is as follows: First, the current SOC value is read to determine the current phase; then, the target current I is calculated based on the phase parameters. target The target current is taken as the theoretical target and the compatibility current boundary I of the stage. compat The smaller of the two values is selected; if the current requested current is less than the target current, a ramp-up operation is performed, gradually increasing the requested current at the set ramp-up rate. This judgment and adjustment is performed approximately once every 100ms in each control cycle, forming a closed-loop control.
[0039] Monitoring phase: Continuously monitor the deviation between the actual output current of the charging pile and the requested current of the battery management system. When the deviation exceeds the preset threshold, update the compatibility current boundary and adjust the charging current.
[0040] The monitoring phase runs in parallel with the charging phase, continuously monitoring the deviation between the actual output current of the charging pile and the requested current of the battery management system. When the deviation exceeds a preset threshold, the battery management system takes corresponding adjustment measures, including adjusting the ramp rate and updating compatibility boundaries.
[0041] This invention employs an adaptive ramp rate adjustment strategy. Let the deviation ΔI be the requested current I. request With actual output current I actual The absolute value of the difference. Based on the magnitude of the deviation, different ramp rate adjustment strategies are adopted: when the deviation ΔI is less than the first deviation threshold ΔI1, it indicates that the charging pile is responding well, and the current ramp rate remains unchanged; when the deviation ΔI is greater than or equal to the first deviation threshold ΔI1 and less than the second deviation threshold ΔI2, it indicates that the charging pile has a certain response delay, and the current ramp rate is reduced to a preset proportion of the original rate; when the deviation ΔI is greater than or equal to the second deviation threshold ΔI2, it indicates that the charging pile response is severely lagging, and the current ramp is paused, waiting for the deviation to decrease before continuing.
[0042] In a typical embodiment, the first deviation threshold ΔI1 ranges from 3A to 8A, preferably 5A; the second deviation threshold ΔI2 ranges from 12A to 20A, preferably 15A; and the preset ratio ranges from 50% to 70%, preferably 60%. This adaptive speed control mechanism can dynamically adjust the ramp speed according to the actual response capability of the charging pile, avoiding current oscillations caused by excessively rapid changes in the requested current.
[0043] The monitoring phase also includes an anomaly detection step to identify potential abnormalities during charging. This invention defines three typical anomalies: insufficient output anomaly, voltage instability anomaly, and ramp-up failure anomaly.
[0044] The condition for determining insufficient output is that the actual output current of the charging pile remains lower than the requested current for a first preset duration. In a typical embodiment, when the actual output current is lower than 80% of the requested current and this state lasts for more than 5 seconds, it is determined to be an insufficient output anomaly. This indicates that the actual output capacity of the charging pile is lower than its nominal capacity.
[0045] The condition for determining voltage instability is that the output voltage fluctuation of the charging station exceeds a preset voltage threshold. In a typical embodiment, a voltage instability is determined when the voltage fluctuation exceeds 10V within 0.5 seconds. Voltage instability may lead to decreased charging efficiency or even damage to the battery.
[0046] The criterion for determining a current ramp-up failure is that the actual current fails to follow the requested current change for a second preset time during the current ramp-up process. In a typical embodiment, when the current increment is less than 2A after three consecutive ramp-up requests, it is determined to be a ramp-up failure. This indicates that the charging pile is no longer able to respond to higher current requests.
[0047] When any of the above anomaly types are detected, a boundary update operation is performed. The boundary update operation includes: adjusting the compatibility current boundary I... compat Update the current to the current actual output current and reset the charging current to a preset starting ratio of the updated compatibility current boundary. In a typical embodiment, I... compat Update the current to 95% of the current stable output value, reduce the requested current to 80% of the new boundary, observe for 30 seconds to confirm that the abnormality has been eliminated, and then climb back to the new boundary at a conservative rate (e.g., 10A / s).
[0048] The monitoring phase also includes a capability recovery detection step. Since factors causing a downgrade in the compatibility boundary (such as peak grid load or temporary equipment overheating) may be temporary, the system periodically detects whether the charging pile's capability has recovered after the boundary is downgraded. Specifically, after performing a boundary update operation, the system attempts to increase the charging current by a preset increment every preset detection cycle. If the charging pile can stably output the increased current for a preset stable duration, the compatibility current boundary is updated to the increased current value. In a typical embodiment, the preset detection cycle is 5 minutes, and the preset increment is the current compatibility current boundary I. compat The charging power is reduced by 5% to 15%, with a preset stabilization time of 2 seconds. Through this periodic capability recovery detection, the charging power can be gradually increased once the charging station's capability is restored, thereby improving overall charging efficiency.
[0049] The technical solution of the present invention will be further illustrated below through two specific embodiments.
[0050] Example 1: Current-limited scenario An electric vehicle's battery has a rated voltage of 400V. The battery management system, based on the MAP (Magnetic Mapping Table), determines a requested voltage of 380V and a requested current of 150A. The vehicle is connected to a public charging station with a maximum output voltage of 500V and a maximum output current of 100A.
[0051] During the handshake phase, after reading the charging pile parameters, the battery management system calculates the compatibility boundary using a safety margin coefficient k=0.95: V compat =min(380,500×0.95)=380V,I compat =min(150, 100×0.95)=95A. The current boundary is limited by the charging pile's capacity.
[0052] During the charging phase, assuming the current SOC is 30% and it's in the fast charging stage, the target current I... target =95A, initial current I init =47.5A, ramping up to 95A at a base rate of 25A / s. Although the charging current is limited to 95A, only 63% of the ideal value, the vehicle successfully completed charging, avoiding charging failure due to parameter mismatch.
[0053] Example 2: Scenario of decreased capacity during operation After an electric vehicle is connected to a charging station, the compatibility current boundary I determined during the handshake phase is... compat =120A, the vehicle is charged at a stable 120A.
[0054] During peak electricity consumption periods, the charging station's actual output current drops to 90A due to grid load. If this condition persists for more than 5 seconds, the system detects an abnormality of insufficient output.
[0055] Perform boundary update operation: I compat Update to 90 × 0.95 = 85.5A, requesting the current to drop to 68A. After stabilizing for 30 seconds, resume ramping up to 85.5A at a conservative rate of 10A / s.
[0056] When the grid load decreased overnight, the system detected that the charging station could respond with a higher current during the 5-minute capacity recovery detection cycle. Through multiple detections, the compatibility boundary gradually recovered to the original value of 120A, and the vehicle resumed charging at maximum power.
[0057] In summary, this invention achieves intelligent compatibility between the electric vehicle battery management system and various charging piles through a three-stage serial execution mechanism: determining compatibility boundaries during the handshake phase, segmented control based on SOC during the charging phase, and anomaly detection and boundary update during the monitoring phase. This effectively improves the charging success rate and charging efficiency, while ensuring the safety and stability of the charging process.
[0058] The technical features of the above embodiments can be combined arbitrarily. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described; only preferred embodiments of the present invention are illustrated. The descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the present invention. As long as the combination of these technical features does not contradict each other, it should be considered within the scope of this specification.
[0059] It should be noted that those skilled in the art can make various modifications and improvements without departing from the inventive concept, and these all fall within the scope of protection of this invention. Therefore, the scope of protection of this invention should be determined by the appended claims.
Claims
1. A method for compatibility charging control of an electric vehicle battery management system and a charging pile, characterized in that, The method comprises the following steps: a handshake phase: the battery management system acquires the maximum output voltage and the maximum output current of the charging pile, compares the capability boundary according to the requested voltage and the requested current of the battery management system, and calculates the compatibility voltage boundary and the compatibility current boundary by considering the safety margin coefficient; a charging phase: the charging process is divided into at least two stages according to the state of charge (SOC) of the battery, and the corresponding target current and ramp rate are configured for each stage; the battery management system gradually adjusts the charging current to the target current according to the ramp rate of the current stage; a monitoring phase: the deviation between the actual output current of the charging pile and the requested current of the battery management system is continuously monitored, and when the deviation exceeds a preset threshold, the compatibility current boundary is updated and the charging current is adjusted.
2. The compatibility charging control method according to claim 1, wherein In the handshake phase, the compatibility voltage boundary V compat is calculated as V compat =min(V BMS , V charger ×k), and the compatibility current boundary I compat is calculated as I compat =min(I BMS , I charger ×k), where V BMS is the request voltage, V charger is the maximum output voltage of the charging pile, I BMS is the request current, I charger is the maximum output current of the charging pile, and k is the safety margin coefficient and 0<k<1.
3. The compatibility charging control method according to claim 2, wherein The safety margin coefficient k ranges from 0.93 to 0.
97.
4. The compatibility charging control method of claim 1, wherein, In the charging phase, the charging process is divided into three stages according to the state of charge (SOC) of the battery, including: a preheating stage, when SOC < SOC1, a first target current and a first ramp rate are used; a fast charging stage, when SOC1 ≤ SOC < SOC2, a second target current and a second ramp rate are used; a trickle charging stage, when SOC ≥ SOC2, a third target current and a third ramp rate are used; wherein SOC1 and SOC2 are preset state of charge thresholds, the first target current is less than the second target current, and the third target current is less than the second target current.
5. The compatibility charging control method according to claim 4, wherein The value of SOC1 ranges from 15% to 25%, and the value of SOC2 ranges from 75% to 85%.
6. The compatibility charging control method of claim 1, wherein, In the monitoring phase, an adaptive ramp rate adjustment strategy is used according to the size of the deviation, including: when the deviation is less than a first deviation threshold, the current ramp rate is maintained unchanged; when the deviation is greater than or equal to the first deviation threshold and less than a second deviation threshold, the current ramp rate is reduced to a preset proportion of the original rate; when the deviation is greater than or equal to the second deviation threshold, the current ramp rate is paused; wherein the first deviation threshold is less than the second deviation threshold.
7. The compatibility charging control method according to claim 6, wherein The value of the first deviation threshold ranges from 3A to 8A, the value of the second deviation threshold ranges from 12A to 20A, and the value of the preset proportion ranges from 50% to 70%.
8. The compatibility charging control method of claim 1, wherein, The monitoring phase further comprises an abnormality detection step, which comprises detecting at least one of the following abnormality types: output deficiency abnormality, when the actual output current of the charging pile is continuously lower than the requested current for a first preset time period; voltage instability abnormality, when the output voltage fluctuation amplitude of the charging pile exceeds a preset voltage threshold; ramp failure abnormality, when the actual current fails to follow the change of the requested current for a second preset time period during the current ramping process.
9. The compatibility charging control method according to claim 8, wherein, When any one of the abnormality types is detected, a boundary updating operation is performed, which comprises updating the compatibility current boundary to the current actual output current and resetting the charging current to a preset starting proportion of the updated compatibility current boundary.
10. The compatibility charging control method according to claim 9, wherein The monitoring stage further comprises a capability recovery detection step: after performing the boundary update operation, every preset detection period, attempt to increase the charging current by a preset increment, and if the charging pile can stably output the increased current for a preset stable duration, update the compatibility current boundary to the increased current value.