Charging communication stability optimization method and system based on parallel resistor number control

Abstract

The invention belongs to the technical field of electric vehicle charging, and discloses a parallel resistor number control-based charging communication stability optimization method and system, and the method comprises the steps: capturing the access number of charging guns in real time through a multi-gun detection module, and generating an initial resistance adjustment instruction through a cooperative scheduling module according to a preset corresponding relation table; the impedance control module is combined with a PWM modulation technology and closed-loop control logic to drive the adjustable resistor module to accurately adjust the number of parallel resistors; according to the invention, communication hidden troubles caused by impedance mismatch are avoided, high-frequency noise can be effectively absorbed, faults such as communication error codes and interruption are reduced, and extra current driving loss caused by too small resistance is avoided; custom updating of an access number-initial resistance configuration corresponding table is supported, and the communication impedance requirements of BMS of different vehicle types can be flexibly met; the load balancing algorithm of the collaborative scheduling module can dynamically distribute the working priorities of the charging guns, is adaptive to access scenes of 2-4 or even more charging guns, and does not need to independently research and develop equipment for a specific vehicle type.

Description

Technical Field

[0001] This invention belongs to the field of electric vehicle charging technology, specifically a method and system for optimizing charging communication stability based on the control of the number of parallel resistors. Background Technology

[0002] With the rapid development of the new energy vehicle industry, especially in sectors with high charging power requirements such as heavy-duty trucks and commercial vehicles, multi-gun charging technology has become a core means to improve charging efficiency. Currently, in mainstream multi-gun charging solutions on the market, vehicles often share a single battery management system, while charging piles generally default to a single-interface communication matching 120Ω standard resistor.

[0003] However, due to the lack of a unified industry standard for multi-gun charging, when 2-4 or even more charging guns are connected simultaneously, the communication interface matching resistors of each charging gun will form a parallel relationship, causing the equivalent resistance value to decrease non-linearly. Specifically, the equivalent resistance is 60Ω when two 120Ω resistors are connected in parallel, 40Ω when three are connected in parallel, only 30Ω when four are connected in parallel, and drops to 20Ω when six are connected in parallel. This value has deviated significantly from the core range of 40Ω-60Ω for communication impedance matching. This abnormal change in the equivalent resistance value will cause a series of problems: On the one hand, excessively small resistance values ​​require a larger current to drive the dominant state, increasing energy loss. On the other hand, it leads to communication signal attenuation and distortion, and an inability to effectively absorb high-frequency noise, making the system susceptible to electromagnetic interference. This, in turn, causes communication errors, interruptions, and other faults, directly threatening charging safety and efficiency. Existing solutions to this problem have significant drawbacks: some solutions adopt a customized approach for developing charging equipment for specific vehicle models, resulting in poor versatility and high R&D costs; other solutions ignore the impact of matching resistors on communication quality, only compensating for communication defects by adding software verification logic, but failing to fundamentally solve the signal integrity problem caused by impedance mismatch, resulting in limited improvement in communication stability. Summary of the Invention

[0004] The purpose of this invention is to provide a method and system for optimizing charging communication stability based on the control of the number of parallel resistors, so as to solve the problems mentioned in the background art.

[0005] To achieve the above objectives, the present invention provides the following technical solution: a charging communication stability optimization system based on parallel resistor quantity control, comprising the following modules: Preferably, the multi-gun detection module is responsible for real-time detection of the number of charging guns connected to the electric vehicle, the interface connection status and the interface type, providing basic data support for coordinated scheduling and resistance adjustment; each charging interface has a built-in Hall sensor and a contact detection unit. The Hall sensor identifies the charging gun insertion and removal actions through changes in the magnetic field, and the contact detection unit adopts an anti-oxidation and anti-wear contact design, and further confirms the effective connection of the charging gun by checking the circuit current conduction. It adopts the CAN bus communication protocol and is equipped with a CRC check mechanism to push the information of each interface to the collaborative scheduling module in real time, ensuring that there is no data loss and the timeliness meets the standard. It also has an interface fault detection function, which can identify abnormal states and directly trigger the initial warning signal of the interactive warning module. It works bidirectionally with the collaborative scheduling module, both outputting access status data to the collaborative scheduling module and receiving self-test commands issued by the collaborative scheduling module.

[0006] Preferably, the collaborative scheduling module receives the access status data of the multi-gun detection module and the user charging demand transmitted by the interactive early warning module, and calculates the optimal charging gun working combination through a load balancing algorithm. The algorithm dynamically allocates working priorities based on the rated power and interface aging degree of each charging gun. Meanwhile, based on the preset "access quantity - initial resistance configuration" correspondence table, it can customize the configuration and dynamically update it according to the communication impedance requirements of different vehicle models' BMS, generating two core commands: one is sent to the impedance control module to specify the initial resistance adjustment parameters; the other is sent to the power distribution module to formulate the initial power distribution scheme, and the resistance adjustment command has a higher priority than the power distribution command. It receives communication quality data from the communication evaluation module in real time. If a non-compliance is detected, it immediately triggers a resistance adjustment optimization command, synchronously updates the operating parameters of the impedance control module and the power distribution module, and stores historical scheduling data. It then optimizes the current logic by analyzing the best strategies from the past.

[0007] Preferably, the adjustable resistor module receives the switch control signal sent by the impedance control module and performs resistor connection or disconnection operation through the built-in switchable resistor array to realize the adjustment of the equivalent resistance value; the resistor array adopts a distributed layout to reduce electromagnetic interference between resistors, and consists of 4 groups of 120Ω standard resistors and 8 high-speed semiconductor MOS transistors, supporting independent control of single resistors or combined control of multiple resistors. The resistor array adopts a redundant design, with each group of resistors equipped with a spare resistor, which can automatically switch in case of failure; each group of resistors is also equipped with a fault detection unit, which monitors the on / off status of the resistor in real time through voltage signal, with a feedback delay of no more than 1ms. The switching module features electromagnetic interference resistance and high-frequency switching capability. It has a built-in temperature detection unit to monitor the resistor's operating temperature in real time, and the resistor configuration status is synchronously fed back to the communication evaluation module.

[0008] Preferably, the communication evaluation module synchronously collects the CAN bus signal and the resistance configuration status of the adjustable resistor module in the communication line, and focuses on monitoring core indicators including eye diagram opening, bit error rate, signal rise / fall time, and high-frequency noise amplitude. A communication quality assessment model is constructed using the analytic hierarchy process (AHP). Weights are assigned to each indicator based on the impact of different communication faults, with the bit error rate having a higher weight than the noise amplitude. The model is trained using machine learning algorithms on historical monitoring data covering different temperatures and electromagnetic interference intensities to predict interference patterns corresponding to different equivalent resistance values. The communication assessment module also has a data filtering function to remove abnormal interference data. If the monitored index exceeds the preset threshold, a resistance adjustment demand signal is immediately generated to clarify the deviation between the current equivalent resistance and the optimal range. At the same time, a warning level is divided into slight deviation, moderate deviation and severe deviation, corresponding to different adjustment degrees, and sent to the impedance control module and the collaborative scheduling module.

[0009] Details of the Analytic Hierarchy Process (AHP) Evaluation Model Construction The indicator system is defined as follows: the core evaluation indicators are eye opening (A), bit error rate (B), signal rise time (C), signal fall time (D), and high-frequency noise amplitude (E), forming a primary indicator system with no secondary sub-indicators. Judgment Matrix Construction: Based on the degree of impact of communication failures, a pairwise comparison judgment matrix is ​​constructed using the 1-9 scaling method. The specific comparison relationships are as follows: The eye diagram opening (A) is 1 compared to itself, 1 / 3 compared to the bit error rate (B), 1 / 2 compared to the signal rise time (C), 1 / 2 compared to the signal fall time (D), and 1 / 4 compared to the high-frequency noise amplitude (E). The bit error rate (B) is 3 compared to the eye diagram opening (A), 1 compared to itself, 2 compared to the signal rise time (C), 2 compared to the signal fall time (D), and 1 / 2 compared to the high-frequency noise amplitude (E). The signal rise time (C) is 2 compared to the eye opening (A), 1 / 2 compared to the bit error rate (B), 1 compared to itself, 1 compared to the signal fall time (D), and 1 / 3 compared to the high-frequency noise amplitude (E). The signal falling edge time (D) is 2 compared to the eye opening (A), 1 / 2 compared to the bit error rate (B), 1 compared to the signal rising edge time (C), 1 compared to itself, and 1 / 3 compared to the high-frequency noise amplitude (E). The high-frequency noise amplitude (E) is 4 compared to the eye opening (A), 2 compared to the bit error rate (B), 3 compared to the signal rise time (C), 3 compared to the signal fall time (D), and 1 compared to itself. Weight Calculation: The index weights are calculated using the sum-product method, with the following steps: (1) Normalize each column of the judgment matrix; (2) Sum the normalized matrix row by row to obtain the initial weight vector; (3) After normalizing the initial weight vector, the final weight allocation is as follows: bit error rate (B) 0.32, high frequency noise amplitude (E) 0.28, eye opening (A) 0.15, signal rise time (C) 0.12, signal fall time (D) 0.12; Consistency check: The consistency index CI is calculated to be 0.032. The random consistency index RI corresponding to the 5 indicators is 1.12. The consistency ratio CR = CI / RI = 0.028 < 0.1, which meets the consistency requirements and the weight allocation is effective.

[0010] Machine learning algorithm implementation and training parameters Algorithm type: The backpropagation (BP) neural network algorithm is used, and the model structure is a three-layer fully connected network consisting of an input layer, a hidden layer, and an output layer. Model structure: (1) Input layer: Number of neurons = 5, corresponding to the standardized data of 5 core monitoring indicators; (2) Hidden layer: Number of neurons = 12, activation function is ReLU function; (3) Output layer: Number of neurons = 3, corresponding to three types of output results: "equivalent resistance deviation value, interference type, and adjustment strength level" respectively; Training data parameters: (1) Data scale: 10,000 sets of sample data were collected, covering the temperature range of -20℃ to 60℃ and the electromagnetic interference intensity of 1V / m to 10V / m; (2) Feature dimensions: Each sample contains 7 dimensions of data, namely eye opening (unit: V), bit error rate (unit: ‰), rise time (unit: ns), fall time (unit: ns), high frequency noise amplitude (unit: mV), equivalent resistance (unit: Ω), and actual interference type; (3) Data preprocessing: Z-score standardization was used to process the input features (mean μ=0, standard deviation σ=1), and outliers were removed by the 3σ criterion (outliers accounted for about 0.8%). (4) Data set partitioning: The dataset is divided into training set (7000 sets), validation set (2000 sets), and test set (1000 sets) in a ratio of 7:2:1. Training process parameters: (1) Parameter initialization: The weights are initialized using the Xavier normal distribution, and the initial value of the bias is set to 0; (2) Loss function: Mean squared error (MSE) is used; (3) Optimizer: The Adam optimizer is used, with an initial learning rate of 0.001 and a decay of 10% every 100 iterations; (4) Iteration control: Maximum number of iterations = 500 rounds, early stopping condition is that the validation set loss has not decreased for 20 consecutive rounds; (5) Convergence criteria: Training is stopped when the training set loss is ≤0.005 and the validation set accuracy is ≥95%.

[0011] Integration of the model with charging scenarios and the correlation between inputs and outputs: Input data: Real-time acquired CAN bus signal characteristic data (5 core indicators after standardization) + current resistance configuration value of the adjustable resistor module (unit: Ω); Output data: (1) Equivalent resistance deviation (unit: Ω): The difference between the current equivalent resistance and the optimal range (40Ω-60Ω); (2) Interference types (classified output): including three types: electromagnetic interference, resistor heating interference, and signal attenuation interference; (3) Adjust the intensity level (levels 1-5): linked with the warning level, mild deviation corresponds to level 1-2, moderate deviation corresponds to level 3, and severe deviation corresponds to level 4-5; Correlation logic: The output "deviation value + adjustment level" is directly used as the basis for the resistance adjustment of the impedance control module; the "interference type" is fed back to the collaborative scheduling module to optimize the priority allocation of the charging gun (such as reducing the load of high-power charging guns when electromagnetic interference is detected).

[0012] Preferably, the impedance control module receives the initial resistance configuration command from the collaborative scheduling module and the adjustment suggestion from the communication evaluation module, and performs logic operations through a built-in industrial-grade microcontroller. This MCU supports multi-channel signal output, has strong anti-interference capabilities, and can adapt to complex charging environments. After the operation, it generates a switch control signal for the adjustable resistor module, and optimizes the switch control using PWM pulse width modulation technology with a 10kHz modulation frequency and an adjustable duty cycle of 0-100%. It has closed-loop control logic and completes a detection-adjustment-feedback cycle every 20ms. After the adjustable resistor module completes the resistance switching, it receives secondary monitoring data from the communication evaluation module in real time. If the equivalent resistance does not reach the target range, it immediately readjusts the switch state until the requirements are met. The switch control signal is transmitted using differential signals. Simultaneously, the final state after resistor adjustment is fed back to the collaborative scheduling module and the power distribution module respectively. If a fault feedback from the adjustable resistor module is detected, or if an abnormality occurs in the control logic itself, the control signal is immediately cut off and the fault alarm signal of the interactive early warning module is triggered.

[0013] Preferably, the power distribution module is based on the initial power distribution scheme of the collaborative scheduling module, combined with the real-time resistance configuration status fed back by the impedance control module, and monitors the total charging power, the output power of each charging gun and the circuit energy consumption in real time through a built-in high-precision power detection unit with an error of no more than ±1% and an energy distribution algorithm; the algorithm can be dynamically adapted according to the charging stage, and adopts a differentiated power distribution strategy in the constant current stage and the constant voltage stage, so that the charging power matches the equivalent resistance value by adjusting the current output ratio of each charging gun. It has overcurrent, overvoltage and overtemperature protection functions. The protection threshold can be customized according to the rated parameters of the charging gun. When abnormal circuit parameters are detected, the power output of the corresponding charging gun is immediately cut off. It also has a power compensation function to make up for the power loss generated during the resistance adjustment process. Furthermore, the fault information is synchronized to the interactive early warning module and the collaborative scheduling module, and the collaborative scheduling module triggers subsequent emergency scheduling strategies.

[0014] Preferably, the interactive early warning module receives charging requests input by the user through a touch screen or a modular APP. The APP interface includes core functions such as real-time charging status refresh, fault history query, and charging parameter preset, and transmits the requests to the collaborative scheduling module in real time. It receives interface fault signals from the multi-gun detection module, resistance fault signals from the impedance control module, and circuit abnormal signals from the power distribution module. Through a preset multi-level early warning mechanism, it alerts the user through audible and visual alarms and APP push notifications. The audible and visual alarms continue until the fault is resolved or the user confirms, while displaying the cause of the fault and handling suggestions. The system collects real-time operational status data from each module and stores it in CSV format. It supports user queries and after-sales personnel exporting and analyzing the data. The stored data covers key information including the number of connected devices, resistor configuration, communication quality level, charging power, and remaining charging time, forming an interactive link between user input, system response, and status feedback.

[0015] This invention also provides a method for optimizing charging communication stability based on the control of the number of parallel resistors. Based on the above system, the specific steps are as follows: Charging gun access detection phase: Through the Hall sensor and contact detection unit built into the charging interface, combined with CAN bus communication and CRC verification, the number of connected charging guns, interface connection status and fault conditions are identified in real time, and an initial abnormality warning is triggered at the same time. Initial strategy formulation phase: The control center receives access data and user charging needs, determines the optimal charging gun working combination through a load balancing algorithm, and generates initial resistance adjustment instructions and power allocation schemes based on the correspondence between the number of accesses and the initial resistance configuration, which are then sent to the resistance control unit and the power supply unit respectively. Dynamic resistance adjustment stage: The resistance control unit adopts PWM pulse width modulation technology to drive the high-speed switching action of the adjustable resistor array, connecting or disconnecting the 120Ω standard resistor to achieve precise adjustment of the equivalent resistance; Communication quality monitoring and feedback phase: Acquire CAN bus signals and resistor configuration status at a high sampling rate, construct an evaluation model through the analytic hierarchy process, monitor indicators including eye opening and bit error rate, and generate adjustment suggestions according to the deviation level; The specific steps for this stage are as follows: Data acquisition: Acquire CAN bus signals (CANH / CANL) and adjustable resistor configuration status at a sampling rate of 1MHz, and extract raw data of five core indicators: eye diagram opening, bit error rate, signal rise / fall time, and high-frequency noise amplitude. Data preprocessing: Z-score standardization (mean μ=0, standard deviation σ=1) is performed on the raw data, and outliers are removed using the 3σ criterion to ensure data validity; Model inference: Input the preprocessed data of the five core indicators into the trained BP neural network model, and combine it with the current configuration value of the adjustable resistor to output the equivalent resistance deviation value, interference type and adjustment level; Warning level determination: Based on the magnitude of the equivalent resistance deviation, warnings are divided into three levels: slight deviation (deviation value ≤ 5Ω), moderate deviation (5Ω < deviation value ≤ 10Ω), and severe deviation (deviation value > 10Ω). Adjustment suggestion generation: Based on the type of interference and the level of adjustment, differentiated adjustment suggestions are generated (slight deviation corresponds to fine-tuning a single group of resistors, moderate deviation corresponds to combined adjustment of 2-3 groups of resistors, and severe deviation corresponds to full array optimization configuration). Feedback execution: Adjustment suggestions are sent to the impedance control module (for precise resistance adjustment) and the collaborative scheduling module (for optimizing power allocation strategies) respectively, completing the closed-loop process of "acquisition-processing-inference-feedback".

[0016] Emergency troubleshooting phase: If a loose interface, resistor failure, or circuit abnormality is detected, immediately cut off the power supply to the faulty unit, issue an audible and visual alarm and a notification via the APP, and simultaneously adjust the remaining resistance and power configuration.

[0017] The beneficial effects of this invention are as follows: 1. This invention utilizes a multi-gun detection module to capture the number of charging guns connected in real time, a collaborative scheduling module to generate an initial resistance adjustment command based on a preset correspondence table, and an impedance control module to drive an adjustable resistor module to precisely adjust the number of parallel resistors by combining PWM modulation technology and closed-loop control logic. This avoids communication risks caused by impedance mismatch, effectively absorbs high-frequency noise, reduces communication errors and interruptions, and avoids additional current drive losses caused by insufficient resistance. While ensuring stable charging communication, it also improves energy utilization efficiency.

[0018] 2. This invention supports custom updates to the correspondence table between the number of connected vehicles and the initial resistance configuration, flexibly adapting to the communication impedance requirements of different vehicle models' BMS. The load balancing algorithm of the collaborative scheduling module can dynamically allocate the working priority of charging guns, adapting to access scenarios with 2-4 or even more charging guns, eliminating the need for separate equipment development for specific vehicle models. Whether it's high-power charging scenarios such as commercial vehicles and heavy trucks, or mixed charging scenarios involving different brands of vehicles, the system can respond stably, significantly expanding the applicability of charging equipment and reducing the equipment investment and subsequent maintenance costs for charging pile operators.

[0019] 3. This invention ensures stable operation through multiple redundancy designs and a full-process fault prevention and control mechanism: the adjustable resistor module is equipped with a backup resistor and a fault detection unit for each group of resistors, enabling automatic fault switching and rapid feedback; each module has fault identification function, and the interactive early warning module promptly informs users of the cause of the fault and handling suggestions through multiple levels of early warning methods such as audible and visual alarms and APP push, avoiding fault omissions; the closed-loop control mechanism completes a detection-adjustment-feedback cycle every 20ms to ensure the accuracy of equivalent resistance adjustment; the power distribution module's overcurrent, overvoltage, and overtemperature protection and power compensation functions further mitigate charging safety risks; at the same time, the system stores key operating status data in a standardized format, supports querying and exporting, facilitates after-sales maintenance, reduces downtime due to faults, and provides users with a safe and smooth charging experience. Attached Figure Description

[0020] Figure 1 This is the overall system flowchart of the present invention. Detailed Implementation

[0021] 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 scope of protection of the present invention.

[0022] like Figure 1As shown, this embodiment of the invention provides a charging communication stability optimization system based on parallel resistor quantity control, including the following modules: The multi-gun detection module serves as the system's sensing entry point, responsible for real-time detection of the number of charging guns connected to the electric vehicle, the interface connection status, and the interface type, providing fundamental data support for subsequent coordinated scheduling and resistance adjustment. Each charging interface incorporates a Hall sensor and a contact detection unit. The Hall sensor accurately identifies the charging gun insertion and removal actions through changes in the magnetic field, while the contact detection unit employs an anti-oxidation and anti-wear contact design, further confirming the effective connection of the charging gun by monitoring the circuit current continuity.

[0023] It adopts the CAN bus communication protocol and is equipped with a CRC check mechanism to push information such as the access status (access / disconnection) and interface number of each interface to the collaborative scheduling module in real time, ensuring that there is no data loss and the timeliness meets the standard. It also has an interface fault detection function, which can identify abnormal states such as loose interface and poor contact and directly trigger the initial warning signal of the interactive warning module.

[0024] This module works bidirectionally with the collaborative scheduling module, both outputting accurate access status data to it and receiving self-check instructions issued by the collaborative scheduling module every 50ms to perform interface status verification to ensure data reliability and further improve the continuity and accuracy of access detection.

[0025] CRC check configuration: The CRC-16 check standard is adopted, the check polynomial is a commonly used industrial standard polynomial, the check bit length is 16 bits, and a check code is appended to the end of the data frame. After receiving the data, the collaborative scheduling module performs reverse check. If the check result does not match, it immediately requests retransmission. The number of retransmissions shall not exceed 3. If the retransmission fails 3 times, an interface communication failure warning will be triggered. Interface fault judgment threshold: The contact resistance of the circuit is monitored by the contact detection unit. Under normal access conditions, the contact resistance should be ≤50mΩ. When the contact resistance is >50mΩ and the duration is ≥100ms, it is judged as "poor contact" fault. When the circuit current is detected to be 0 and the Hall sensor does not recognize the plugging and unplugging action, it is judged as "interface open circuit" fault. Both faults directly trigger the initial audible and visual warning of the interactive warning module.

[0026] The collaborative scheduling module, as the decision-making center of the system, receives access status data from the multi-gun detection module and user charging requirements (such as charging power and charging time) from the interactive early warning module. It calculates the optimal working combination of charging guns through a load balancing algorithm (such as when 4 guns are connected, 2-4 guns can be selected to work simultaneously according to the requirements). The algorithm dynamically allocates working priorities based on the rated power and interface aging degree of each charging gun to ensure a stable and efficient charging process.

[0027] Meanwhile, based on the preset "access quantity - initial resistance configuration" correspondence table (e.g., 2 gun accesses correspond to an initial parallel resistance of 60Ω, 3 gun accesses correspond to an initial parallel resistance of 40Ω), this table can be customized and dynamically updated according to the communication impedance requirements of different vehicle models' BMS, generating two core commands: one is sent to the impedance control module to specify the initial resistance adjustment parameters; the other is sent to the power distribution module to formulate the initial power distribution scheme, and the resistance adjustment command has higher priority than the power distribution command to ensure communication stability.

[0028] In addition, this module receives communication quality data from the communication evaluation module in real time. If it detects non-compliance such as excessive bit error rate, it immediately triggers a resistance adjustment optimization command, synchronously updates the working parameters of the impedance control module and the power distribution module, and stores historical scheduling data. By analyzing the best strategies in the past, it optimizes the current logic, realizes dynamic iteration of scheduling strategies, and ensures that each module responds in a coordinated manner to different charging scenarios.

[0029] The core execution logic of the load balancing algorithm is as follows: Priority evaluation index quantification: The "rated power" and "interface aging degree" of each charging gun are converted into calculable quantitative values. Rated power is mapped from 0 to 10 points (e.g., 50kW = 5 points, 100kW = 10 points), and interface aging degree is mapped inversely from 0 to 10 points (new interface = 10 points, wear rate 50% = 5 points, wear rate 80% and above = 2 points). Priority calculation rules: Work priority score = (rated power score × 0.6) + (interface aging score × 0.4), the higher the score, the higher the priority; Optimal combination selection logic: When the number of connected charging guns exceeds the actual working demand, filter them from high to low priority scores, and prioritize the top N charging guns (N is the actual number of working guns); if the scores are the same, prioritize the charging gun with the most recent no-fault record. Dynamic update mechanism: Every 30 seconds, the interface aging degree of each charging gun (determined by the change in contact resistance value fed back by the multi-gun detection module) and real-time load rate are re-collected, and the priority score is recalculated to achieve dynamic adjustment.

[0030] The adjustable resistor module, serving as the system's execution terminal, directly receives switching control signals (closing / opening) from the impedance control module. Through its built-in switchable resistor array, it performs resistor connection or disconnection operations, achieving precise adjustment of the equivalent resistance value. The resistor array employs a distributed layout to reduce electromagnetic interference between resistors. It consists of four groups of 120Ω standard resistors and eight high-speed semiconductor MOSFETs. MOSFETs offer advantages such as fast response speed, low power consumption, and long lifespan, supporting independent control of a single resistor or combined control of multiple resistors.

[0031] The resistor array adopts a redundant design, with each group of resistors equipped with a spare resistor, which can automatically switch in case of failure to avoid system regulation failure due to the failure of a single resistor; each group of resistors is also equipped with a fault detection unit, which monitors the on / off status of the resistor in real time through voltage signal, with a feedback delay of no more than 1ms, to ensure that faults are detected in a timely manner.

[0032] The switching module features electromagnetic interference resistance and high-frequency switching capability. The module has a built-in temperature detection unit to monitor the resistor's operating temperature in real time, avoiding performance degradation caused by prolonged high-load operation and ensuring long-term reliability of the stability, real-time performance, and adjustment accuracy of the adjustment action. The resistor configuration status is synchronously fed back to the communication evaluation module, providing real-time reference for signal integrity monitoring.

[0033] Fault detection voltage threshold: The normal operating voltage range across each group of resistors is 0.5V-5V. When a voltage < 0.5V is detected and the duration is ≥ 500μs, it is determined to be a "resistor short circuit" fault; when a voltage > 5V is detected and the duration is ≥ 500μs, it is determined to be a "resistor open circuit" fault. Both faults trigger automatic switching of the backup resistor. Temperature protection threshold: The normal operating temperature range of the resistor is -20℃ to 85℃. When the temperature reaches 80℃, a temperature warning is triggered and the corresponding resistor load is appropriately reduced by the collaborative scheduling module. When the temperature exceeds 85℃ and the duration is ≥1s, the MOSFET switch of the resistor group is immediately cut off, the resistor stops working and a moderate warning is triggered by the interactive warning module. The system can only resume operation when the temperature drops below 70℃.

[0034] The specific control logic and timing requirements for switching the resistor array are as follows: Switching strategy selection: When the target equivalent resistance is ≥60Ω, use single resistor independent control (select a single 120Ω resistor or a spare resistor); when 30Ω < target equivalent resistance <60Ω, use dual resistor parallel combination control; when the target equivalent resistance is ≤30Ω, use 3-4 sets of resistors in parallel combination control. MOSFET control timing: The high-level duration of the switch control signal is ≥5μs, and the low-level duration is ≥3μs to avoid the MOSFET being in a half-conducting state; when switching multiple resistors, the "turn on first, then turn off" timing is adopted (the MOSFET of the newly connected resistor is turned on, and then the MOSFET of the original connected resistor is turned off), with a switching interval of ≤1ms to prevent instantaneous impedance changes in the communication line; Fault switching logic: When the fault detection unit detects an abnormality in the continuity of a certain group of resistors, it immediately triggers the MOSFET of the backup resistor to turn on (response time ≤ 0.5ms), and at the same time cuts off the MOSFET of the faulty resistor, and synchronously sends a "fault switching completed" signal to the communication evaluation module to ensure the continuity of adjustment.

[0035] The communication evaluation module serves as the core of the system's monitoring. It synchronously collects the CAN bus signals (CANH / CANL) and the resistance configuration status of the adjustable resistor module in the communication line. With a sampling rate of 1MHz, it ensures that no signal details are missed and focuses on monitoring key indicators such as eye diagram opening, bit error rate, signal rise / fall time, and high-frequency noise amplitude.

[0036] A communication quality assessment model is constructed using the Analytic Hierarchy Process (AHP). Weights are assigned to each indicator based on the impact of different communication faults, with bit error rate (BER) weighted higher than noise amplitude. The model is then trained using machine learning algorithms on historical monitoring data covering different temperatures and electromagnetic interference intensities to predict interference patterns corresponding to different equivalent resistance values. The module also includes data filtering capabilities to remove abnormal interference data.

[0037] If the monitored index exceeds the preset threshold, a resistance adjustment demand signal is immediately generated to clarify the deviation of the current equivalent resistance from the optimal range (30Ω-60Ω). At the same time, a warning level is divided into slight deviation, moderate deviation, and severe deviation, corresponding to different adjustment intensities. On the one hand, it is sent to the impedance control module to provide a precise adjustment basis, and on the other hand, it is simultaneously fed back to the collaborative scheduling module to provide data support for its optimized scheduling strategy, forming a closed-loop linkage of "monitoring-feedback-adjustment".

[0038] The preset thresholds and corresponding rules for early warning levels for each core monitoring indicator are as follows: Bit error rate: Normal range ≤0.1‰, 0.1‰ < slight deviation ≤0.3‰, 0.3‰ < moderate deviation ≤0.5‰, severe deviation >0.5‰; Eye opening: Normal range ≥0.8V, 0.6V≤slight deviation <0.8V, 0.4V≤smoderate deviation <0.6V, severe deviation <0.4V; Signal rise / fall time: Normal range ≤10ns, 10ns < slight deviation ≤15ns, 15ns < moderate deviation ≤20ns, severe deviation >20ns; High-frequency noise amplitude: Normal range ≤50mV, 50mV < slight deviation ≤100mV, 100mV < moderate deviation ≤150mV, severe deviation >150mV; If any one of the indicators reaches the corresponding deviation level, an early warning will be triggered according to that level. If multiple indicators exceed the standard at the same time, the highest deviation level will be used for judgment.

[0039] The impedance control module, serving as the system's execution control center, receives initial resistance configuration instructions from the collaborative scheduling module and adjustment suggestions from the communication evaluation module. It performs logic operations using a built-in industrial-grade microcontroller (MCU), which supports multi-channel signal output, possesses strong anti-interference capabilities, and can adapt to complex charging environments. After calculation, it generates a switching control signal for the adjustable resistor module. PWM pulse width modulation technology with a 10kHz modulation frequency and an adjustable duty cycle of 0-100% optimizes the switching control, effectively avoiding voltage fluctuations caused by switching actions and ensuring stable communication line signals.

[0040] This module has closed-loop control logic, completing a "detection-adjustment-feedback" cycle every 20ms. After the adjustable resistor module completes the resistance switching, it receives secondary monitoring data from the communication evaluation module in real time. If the equivalent resistance does not reach the target range, it immediately readjusts the switch state until the requirements are met. The switch control signal uses differential signal transmission to reduce the influence of external electromagnetic interference.

[0041] Simultaneously, the final state after resistor adjustment is fed back to the collaborative scheduling module and the power distribution module, respectively, so that the two can update their strategies synchronously. If a fault feedback from the adjustable resistor module is detected, or if there is an abnormality in the control logic itself, the control signal is immediately cut off and the fault alarm signal of the interactive early warning module is triggered to avoid incorrect adjustment.

[0042] The detection and judgment criteria and adjustment step rules for closed-loop control are as follows: Equivalent resistance compliance determination: Based on the measured equivalent resistance value fed back by the communication evaluation module, when the difference between the measured value and the target value is ≤2Ω, it is determined to be compliant; when the difference is >2Ω, a secondary adjustment is triggered. Adjust the stepping rules: Difference 2Ω-5Ω (small deviation): Adjust the connection / disconnection status of one group of resistors (e.g., switch a single resistor to a dual resistor in parallel, or vice versa); Difference 5Ω-10Ω (medium amplitude deviation): Adjust the connection / disconnection status of the two sets of resistors; If the difference is greater than 10Ω (significant deviation): switch to the full range directly according to the optimal resistance combination corresponding to the target value; Adjustment restrictions: A maximum of 2 adjustment actions can be performed within the same closed loop. If the target is still not met after 2 adjustments, a moderate warning will be triggered by the interactive warning module, and the fault information will be fed back to the collaborative scheduling module to suspend the power allocation of the charging gun and prioritize communication stability.

[0043] The power distribution module is based on the initial power distribution scheme of the collaborative scheduling module, combined with the real-time resistance configuration status fed back by the impedance control module. Through a built-in high-precision power detection unit with an error not exceeding ±1% and an energy distribution algorithm, it monitors the total charging power, the output power of each charging gun, and the circuit energy consumption in real time. The algorithm can dynamically adapt according to the charging stage, employing differentiated power distribution strategies in the constant current and constant voltage stages. By adjusting the current output ratio of each charging gun, the charging power is matched to the equivalent resistance value (e.g., when the equivalent resistance is small, the output current of a single gun is appropriately reduced to avoid increased energy consumption due to excessive drive current).

[0044] This module features overcurrent, overvoltage, and overtemperature protection. The protection thresholds can be customized based on the rated parameters of the charging gun. When abnormal circuit parameters are detected, the power output of the corresponding charging gun is immediately cut off. It also has a power compensation function to make up for the power loss generated during the resistance adjustment process and ensure that the total charging power meets the user's needs.

[0045] Furthermore, the fault information is synchronized to the interactive early warning module and the collaborative scheduling module, which then triggers subsequent emergency scheduling strategies to ensure charging safety and system stability.

[0046] Differentiated power allocation rules: Constant current stage: Output current ratio of each charging gun = (priority score of the charging gun / total priority score of all working guns) × total charging current, to ensure that high priority charging guns receive better current distribution; Constant voltage stage: The output voltage of each charging gun remains consistent (matching the battery's rated voltage), and the output power ratio = (the rated power of this charging gun / the sum of the rated power of all working guns) × the total charging power, to avoid overloading of charging guns with low rated power; Power compensation logic: Power compensation value = power loss difference before and after resistor adjustment (calculated by collecting circuit energy consumption before and after adjustment through a high-precision power detection unit). The compensation method is to distribute the compensation power according to the power distribution ratio of each charging gun to ensure that the total output power meets the user's preset requirements. The compensation response delay is ≤10ms.

[0047] The interactive early warning module serves as an interactive bridge between the system and the user. On the one hand, it receives the charging request input by the user through an 800×480 high-definition touch screen (vehicle terminal) or a modular APP (mobile terminal). The APP interface includes core functions such as real-time refresh of charging status, fault history query, and preset charging parameters, and transmits the request to the collaborative scheduling module in real time.

[0048] On the other hand, it simultaneously receives interface fault signals from the multi-gun detection module, resistance fault signals from the impedance control module, and circuit abnormal signals from the power distribution module. Through a preset multi-level early warning mechanism, it alerts the user through audible and visual alarms (vehicle-mounted terminal) and APP push notifications (mobile terminal). The audible and visual alarms continue until the fault is resolved or the user confirms, to avoid omissions. At the same time, it displays the cause of the fault and handling suggestions.

[0049] This module collects real-time operating status data from each module and stores it in CSV format. It supports user queries and after-sales personnel exporting and analyzing the data. The stored data covers key information such as the number of connected devices, resistor configuration, communication quality level, charging power, and remaining charging time, forming a complete interactive link of "user input - system response - status feedback" to improve user experience and system maintainability.

[0050] Multi-level early warning trigger conditions: Mild warning: slight deviation in communication evaluation module, poor contact in multi-gun detection module, resistance temperature warning; Moderate warning: Moderate deviation in communication evaluation module, single resistor fault in adjustable resistor module, slight overcurrent in power distribution module (not exceeding 10% of rated value); Serious warning: Communication evaluation module has serious deviation, multi-gun detection module interface is open circuit, two or more sets of resistors in adjustable resistor module are faulty, power distribution module overcurrent / overvoltage exceeds rated value by 10%, impedance control module logic is abnormal; Audible and visual alarm parameters: Mild warning: The indicator light flashes green once per second, with no alarm sound; Moderate warning: The indicator light flashes yellow twice per second, and the alarm sound is continuous at a frequency of 1 kHz (with a 1-second interval). Serious warning: The indicator light stays red and the alarm sound at a frequency of 2kHz will continue to beep until the fault is cleared or the user confirms it via the touch screen / APP; APP push notification rules: All alerts will be pushed in real time, including the faulty module, fault type, and handling suggestions. Minor alerts will be pushed only once, while moderate / severe alerts will be pushed repeatedly every 30 seconds until the fault is resolved.

[0051] This invention also provides a charging communication stability optimization method based on parallel resistor quantity control. Based on the above system, the specific steps are as follows: During the charging gun connection detection phase: The Hall sensor and contact detection unit built into the charging interface, combined with CAN bus communication and CRC verification, identify the number of connected charging guns, interface connection status and fault conditions in real time, synchronize the data to the control center, and trigger an initial warning of abnormality.

[0052] The second step is the initial strategy formulation stage: the control center receives access data and user charging needs, determines the optimal charging gun working combination through a load balancing algorithm, and generates initial resistance adjustment instructions and power allocation schemes based on the correspondence between "access quantity - initial resistance configuration", which are then sent to the resistance control unit and the power supply unit respectively.

[0053] Complete initial resistor configuration rules: One charging gun connected: Initial parallel resistance = 120Ω (single set of resistors connected); Two charging guns are connected: Initial parallel resistance = 60Ω (two sets of resistors in parallel); Three charging guns are connected: Initial parallel resistance = 40Ω (three sets of resistors in parallel); For 4 or more charging guns connected: Initial parallel resistance = 30Ω (all four sets of resistors are connected in parallel); Adaptation rules: If the vehicle model's BMS communication impedance requirements exceed the above configuration range, the initial resistance value for the corresponding number of connections can be adjusted through the custom update function; Custom update operation steps: Step 1: Access the "Resistor Configuration Management" interface via the touchscreen display of the interactive warning module or the APP; Step 2: Select "Add Configuration" or "Modify Existing Configuration", enter the target number of connections, the corresponding initial resistance value (range 10Ω-120Ω) and the compatible vehicle model BMS model; Step 3: The system automatically verifies whether the configuration value meets the circuit safety threshold (to avoid short circuit risk). After the verification is successful, the system saves and overwrites the original corresponding relationship table. Step 4: After the update is complete, the system will confirm with an audio and visual prompt. The new configuration will take effect immediately, and the historical configuration will be automatically backed up to a CSV storage file.

[0054] Dynamic resistance adjustment stage: The resistance control unit adopts PWM pulse width modulation technology to drive the high-speed switching action of the adjustable resistor array, connecting or disconnecting the 120Ω standard resistor to achieve precise adjustment of the equivalent resistance. At the same time, through redundant design and fault detection unit, the adjustment action is ensured to be stable and reliable.

[0055] Communication quality monitoring and feedback phase: CAN bus signals and resistor configuration status are collected at a high sampling rate. An evaluation model is built using the analytic hierarchy process (AHP). Indicators such as eye opening and bit error rate are monitored. Adjustment suggestions are generated according to the deviation level and fed back to the control center to dynamically optimize the number of resistors and power allocation.

[0056] Emergency troubleshooting phase: If a loose interface, resistor failure, or circuit abnormality is detected, immediately cut off the power supply to the faulty unit, issue a warning via audible and visual alarms and APP notifications, and simultaneously adjust the remaining resistance and power configuration to ensure continuous and stable charging communication.

[0057] The logic for refactoring remaining resources after a failure is as follows: Resistor configuration reconfiguration: Single resistor group failure: Activate the backup resistor group. If the backup resistor also fails, compensate for the equivalent resistance by adjusting the combination of other normal resistor groups (e.g., if there are 3 resistor groups in parallel, after 1 group fails, switch to 2 resistor groups + another backup resistor group in parallel to ensure that the equivalent resistance is still within the target range). For two or more sets of resistors in failure: If the remaining normal resistors (including spares) can be combined to form the target equivalent resistance, then the combination should be prioritized; if this cannot be achieved, then the adjustment should be made according to the principle of "close to the optimal range", while reducing the charging power to ensure communication stability. Power configuration reconfiguration: Single charging gun failure: Distribute the rated power of the gun according to the priority score ratio of the remaining normal guns to ensure that the total power does not exceed the system's rated total power; Multiple charging gun malfunctions: Keep the 1-2 highest priority normal charging guns working, concentrate the total power to the reserved guns, and ensure that the power value does not exceed the rated power limit of the reserved guns. At the same time, adjust the equivalent resistance to the appropriate range.

[0058] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0059] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A charging communication stability optimization system based on parallel resistor quantity control, characterized in that, Includes the following modules: Multi-gun detection module: Real-time detection of the number of charging guns connected to electric vehicles, connection status and interface type, output detection data and interface fault detection and early warning triggering functions, and a self-testing mechanism to ensure data reliability; The collaborative scheduling module receives access data from the multi-gun detection module and user charging requirements, determines the optimal charging gun working combination through a load balancing algorithm, generates core instructions for resistance adjustment and power allocation based on custom configuration rules, receives real-time communication quality feedback and dynamically optimizes instructions, and stores historical data to iterate scheduling strategies. Adjustable resistor module: Receives the switching control signal from the impedance control module, and performs resistor connection or disconnection operations through the built-in resistor array to adjust the equivalent resistance. It adopts distributed layout, redundancy design and fault detection technology, and synchronously feeds back the configuration status. Communication evaluation module: synchronously collects communication line signals and adjustable resistor module configuration status, monitors key indicators of signal integrity, identifies indicator deviations and classifies early warning levels through evaluation model, and generates adjustment suggestions to be fed back to impedance control module and collaborative scheduling module; Impedance control module: Receives initial instructions from the collaborative scheduling module and adjustment suggestions from the communication evaluation module, generates switch control signals to drive the adjustable resistor module to adjust the equivalent resistance, adopts closed-loop control technology to ensure adjustment accuracy, provides feedback on adjustment status, and has fault identification and alarm triggering functions; Power distribution module: Based on the power scheme and resistor configuration status of the collaborative scheduling module, it dynamically adjusts the output of each charging gun and has overcurrent protection, overvoltage protection and power compensation functions. Interactive early warning module: Receives user charging requests and transmits them to the collaborative scheduling module, collects fault signals from various modules, reminds users and provides handling suggestions through a multi-level early warning mechanism, and stores and displays system working status data.

2. The charging communication stability optimization system based on parallel resistor quantity control according to claim 1, characterized in that, The multi-gun detection module identifies the plugging and unplugging actions and valid access status of the charging gun through the built-in sensor detection unit, and pushes the interface information to the collaborative scheduling module using a reliable communication protocol to ensure the effectiveness of data transmission. Its fault detection function can directly trigger the initial warning signal of the interactive warning module and cooperate with the collaborative scheduling module to execute self-test instructions in both directions.

3. The charging communication stability optimization system based on parallel resistor quantity control according to claim 2, characterized in that, The collaborative scheduling module dynamically allocates working priorities based on the rated power and interface working status of each charging gun. Based on the preset "number of accesses - initial resistance configuration" correspondence table, it adapts to the communication impedance requirements of different vehicle model BMS and updates them dynamically, generating initial resistance adjustment instructions and power allocation schemes, with the resistance adjustment instructions having higher priority than the power allocation instructions [D1][2]. It triggers optimization instructions by receiving quality data from the communication evaluation module, synchronously updates the working parameters of relevant modules, and iterates the scheduling strategy.

4. The charging communication stability optimization system based on parallel resistor quantity control according to claim 3, characterized in that, The adjustable resistor module's resistor array supports independent control of a single resistor or combined control of multiple resistors. Each group of resistors is equipped with a spare resistor and a fault detection unit to achieve automatic fault switching and status monitoring. The switching module has anti-interference design and high-frequency switching capability, and synchronously feeds back the resistor configuration status to the communication evaluation module.

5. The charging communication stability optimization system based on parallel resistor quantity control according to claim 4, characterized in that, The communication evaluation module focuses on monitoring core indicators including eye opening, bit error rate, signal rise time, fall time, and high-frequency noise amplitude. It constructs an evaluation model using the analytic hierarchy process and assigns weights to each indicator. It combines data training to predict interference patterns and has a data filtering function to remove abnormal data. The warning levels are divided into three levels: mild, moderate, and severe, based on the degree of deviation of the indicators, and corresponding differentiated adjustment suggestions are generated.

6. The charging communication stability optimization system based on parallel resistor quantity control according to claim 5, characterized in that, The impedance control module implements logic operations through an industrial-grade microcontroller, optimizes the output of the switch control signal using PWM modulation technology, and completes the detection-adjustment-feedback process through closed-loop control to ensure that the equivalent resistance reaches the target range. The switch control signal adopts an anti-interference transmission method, and cuts off the control signal and triggers an alarm from the interactive early warning module when a fault is detected.

7. The charging communication stability optimization system based on parallel resistor quantity control according to claim 6, characterized in that, The power distribution module monitors the total charging power, the output power of each charging gun, and the circuit energy consumption in real time through a high-precision power detection unit and energy distribution algorithm. It adopts a differentiated power distribution strategy according to the charging stage to match the charging power with the equivalent resistance value. The protection threshold can be customized. When an abnormality occurs, the power output of the corresponding charging gun is cut off and the fault information is synchronized to the interactive early warning module and the collaborative scheduling module.

8. The charging communication stability optimization system based on parallel resistor quantity control according to claim 7, characterized in that, The interactive early warning module receives user charging requests via a touch screen or an app. The app has functions including charging status refresh, fault query, and parameter preset. It executes multi-level early warnings using methods including audible and visual alarms and app push notifications, displays fault causes and handling suggestions, stores key system operating status data in a standardized format, and supports querying and exporting.

9. A method for optimizing charging communication stability based on parallel resistor quantity control, based on the system described in claim 8, characterized in that, The specific steps are as follows: Charging gun access detection phase: The built-in detection unit of the charging interface identifies the number of connected devices, connection status and fault conditions, performs data transmission and triggers an initial warning; Initial strategy formulation phase: Receive access data and user charging needs, determine the optimal charging gun combination through load balancing algorithm, and generate and issue initial resistance adjustment instructions and power allocation schemes based on the correspondence between the number of accesses and the initial resistance configuration. Dynamic resistance adjustment stage: PWM modulation technology is used to drive the switching action of the adjustable resistor array, and the equivalent resistance is precisely adjusted by connecting or disconnecting the standard resistor; Communication quality monitoring and feedback phase: Collect communication signals and resistor configuration status, monitor core indicators through evaluation models, and generate adjustment suggestions according to deviation levels; Emergency troubleshooting phase: When an interface, resistor or circuit abnormality is detected, the power supply to the faulty unit is cut off, an early warning notification is executed and the remaining resistance and power configuration are adjusted.

10. [D1] I don't quite understand~ [2] During the charging process, “ensuring stable communication first” takes priority over “pursuing charging power / efficiency”. Essentially, by “first solving whether communication can be secure, and then optimizing how fast it can be charged”, the design avoids the impact of power distribution on communication stability, and ultimately ensures a balance between charging safety and efficiency.

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