Charging current control method and device based on pi regulation and vehicle

Abstract

This invention relates to the field of vehicle charging technology and discloses a charging current control method, device, and vehicle based on PI regulation. The method includes: responding to a vehicle charging process start signal and a pulse heating function activation signal, real-time monitoring of the absolute value of the difference between the charging pile's requested voltage and the vehicle's battery terminal voltage; when the absolute value of the difference is less than a preset voltage synchronization dead zone threshold, acquiring the actual output current of the charging pile; calculating the current deviation between the actual output current value and a preset target current; determining whether the current deviation exceeds a preset tolerance range: if it does, based on the current deviation, calculating the output voltage adjustment increment through a PI regulator to adjust the charging pile's requested voltage, so that the actual output current converges to the preset target current; if it does not exceed the tolerance range, maintaining the current charging pile's requested voltage unchanged. This enables precise control of the charging pile's output current, avoiding current overshoot triggering vehicle protection shutdown and ensuring stable charging power.

Description

Technical Field

[0001] This invention relates to the field of vehicle charging technology, and specifically to a charging current control method, device, and vehicle based on PI regulation. Background Technology

[0002] Lithium-ion batteries experience severe performance degradation under extremely cold conditions, and traditional external heating methods suffer from slow heating and large temperature differences. Pulse self-heating technology generates Joule heat through high-frequency, high-current pulses within the battery, achieving rapid temperature rise and offering advantages such as fast heating, good temperature uniformity, and low energy consumption. However, the high-frequency pulse current generated during charging can interfere with the charging station's power output, leading to charging interruptions. This technical challenge urgently needs to be addressed to improve the user experience. Summary of the Invention

[0003] In view of the shortcomings of the prior art, the purpose of this application is to provide a charging current control method, device and vehicle based on PI regulation, which aims to achieve precise control of the output current of the charging pile, avoid current overshoot triggering vehicle protection shutdown, and ensure stable charging power.

[0004] In a first aspect, embodiments of this application provide a charging current control method based on PI regulation, comprising:

[0005] In response to receiving the vehicle charging process start signal and the pulse heating function start signal, the absolute value of the difference between the charging pile requested voltage and the vehicle battery terminal voltage is monitored in real time.

[0006] When the absolute value of the difference is less than the preset voltage synchronization dead zone threshold, the actual output current of the charging pile is collected.

[0007] Calculate the current deviation between the actual output current value and the preset target current;

[0008] Determine whether the current deviation exceeds the preset tolerance range:

[0009] If the current deviation is exceeded, the output voltage adjustment increment is calculated by the PI regulator based on the current deviation, and the charging pile request voltage is adjusted according to the adjustment increment so that the actual output current converges to the preset target current.

[0010] If the voltage does not exceed the limit, the current requested voltage for the charging station will remain unchanged.

[0011] In the above technical solution, the charging pile request voltage and battery terminal voltage are first synchronously verified, and then the current closed-loop regulation is carried out. This can eliminate the instantaneous inrush current caused by the voltage difference at the beginning of charging, and reduce the impact loss of the vehicle's high-voltage components and the charging pile's power devices. In the scenario of pulse heating synchronous charging, by collecting the actual output current in real time and comparing it with the preset target current deviation, the charging pile request voltage is dynamically corrected with the help of a PI regulator. This can quickly suppress the large current fluctuations caused by pulse heating, stabilize the actual output current of the charging pile to the target range, avoid abnormal current fluctuations triggering the charging pile protection and causing charging interruption, and ensure the stable synchronous operation of low-temperature pulse heating and DC charging. When the current deviation is within the allowable tolerance range, the charging pile request voltage remains unchanged, eliminating the need for continuous adjustment, reducing the controller's computational load, and avoiding current oscillations caused by frequent voltage adjustments.

[0012] The entire control logic relies solely on software algorithms to adjust and issue voltage commands, requiring no modifications to the charging pile hardware. It is compatible with various DC charging devices, offering strong versatility. Simultaneously, the consistently stable current with minimal fluctuations reduces the voltage difference between charging and discharging battery cells, improves individual cell consistency, slows battery aging, and enhances low-temperature charging efficiency and user experience.

[0013] In one embodiment, a battery voltage pre-synchronization control step is further included: after the vehicle charging process starts but before entering PI regulation control, an open-loop control mode is adopted to request voltage from the charging pile at a preset adjustment slope. Make gradual adjustments until... , This refers to the vehicle battery terminal voltage. This is the preset voltage synchronization dead zone threshold.

[0014] In the above technical solution, an open-loop progressive voltage pre-synchronization control is added before the PI current closed-loop regulation. The charging pile request voltage is gradually adjusted with a fixed slope until the absolute value of the difference between the request voltage and the battery terminal voltage falls into the synchronization dead zone. This can eliminate the peak impact current generated by the voltage difference between the two at the moment of charging power-on, reduce the instantaneous electrical stress on the charging pile power devices and the vehicle high-voltage circuit, and improve the service life of the charging system hardware.

[0015] Employing open-loop uniform voltage regulation logic, the adjustment rate is controllable, preventing sudden voltage rises and falls. This provides a stable initial operating condition for subsequent PI closed-loop current regulation, significantly reducing the initial adjustment deviation of the PI controller and minimizing current overshoot and oscillation. This pre-synchronization logic is implemented solely through software timing control, requiring no additional hardware. It is adaptable to various DC charging scenarios and, in conjunction with back-end current closed-loop control, can further enhance the overall operational stability under pulse heating charging conditions.

[0016] In one embodiment, the use of open-loop control to gradually adjust the requested voltage of the charging pile with a preset adjustment slope specifically includes:

[0017] Calculate the maximum allowable voltage regulation in a single control cycle. K is the preset adjustment slope. The sampling period;

[0018] Targeted adjustment is performed based on the polarity of the voltage deviation.

[0019] when At that time, within each control cycle, Increasing ;

[0020] when At that time, within each control cycle, Decreasing ;

[0021] Request voltage for the adjusted charging station Limit the amplitude to ensure ,in This is the minimum output voltage limit for the charging station. This is the maximum output voltage limit.

[0022] In the above technical solution, the maximum voltage regulation step size per cycle is quantified by preset adjustment slope and sampling period. The voltage is oriented and uniformly adjusted according to the polarity deviation between the requested voltage and the battery voltage. The voltage regulation process is stable and controllable, effectively avoiding inrush current caused by voltage surges. At the same time, hard limits are set for the upper and lower limits of the charging pile output voltage to prevent the command voltage from exceeding the rated operating range of the equipment during the voltage regulation process, thus avoiding the risk of overvoltage damage to the charging pile power unit.

[0023] In one embodiment, the PI regulator employs a continuous-time PI control algorithm, and the output voltage adjustment increment of the PI regulator is composed of the superposition of the battery terminal voltage, the proportional adjustment component, and the integral adjustment component; the proportional adjustment component is the product of the current error signal and the proportional gain coefficient; the integral adjustment component is the product of the integral value of the current error signal in the time domain and the integral gain coefficient.

[0024] The current error signal is formed by adding the negative value of the preset current value to the negative value of the current deviation value. The current deviation value is the difference between the actual output current of the charging pile and the requested current of the charging pile. The preset current value is used to determine the preset target current, which is equal to the requested current of the charging pile minus the preset current value.

[0025] In the above technical solution, a continuous-time PI control algorithm is adopted. The voltage regulation increment is obtained by superimposing the proportional and integral components. The proportional component can quickly respond to current deviations and achieve dynamic correction, while the integral component can eliminate steady-state current error and improve steady-state current control accuracy. This solution reconstructs the current error signal and constrains the target current range with a preset current value, stabilizing the charging current within a safe range below the charging pile's requested current. This effectively offsets the current disturbance caused by pulse heating and avoids triggering the charging pile's protection shutdown due to current over-limit. This error construction method can accurately limit the upper limit of the charging current, achieving smooth current convergence in conjunction with PI regulation. At the same time, the algorithm's operation logic is simple, requiring low computing power from the vehicle controller, and does not require modification of the charging pile hardware. It can adapt to low-temperature pulse heating charging scenarios, balancing charging stability and equipment versatility.

[0026] In one embodiment, after adjusting the charging pile request voltage according to the adjustment increment, the charging pile request voltage is... Limit the amplitude to ensure ,in This is the minimum output voltage limit for the charging station. This is the maximum output voltage limit.

[0027] When the requested voltage of the charging pile reaches the limit boundary, the integral term of the PI regulator is frozen, and integral accumulation is stopped to achieve anti-integral saturation control.

[0028] In the above technical solution, setting hard upper and lower limits on the adjusted charging pile request voltage can prevent the issuance of voltage commands exceeding the rated operating range of the charging pile, protecting the charging pile power conversion unit from failure due to overvoltage or undervoltage. When the charging pile request voltage reaches the limit boundary, freezing the PI integral term and pausing integral accumulation can effectively suppress integral saturation and eliminate current overshoot and regulation lag caused by continuous integral accumulation during the voltage limiting stage. After leaving the limit range, the integral can resume normal operation, balancing dynamic adjustment response speed and steady-state current control accuracy, further improving the stability of current output under pulse heating charging conditions.

[0029] In one embodiment, after the PI regulator calculates the output voltage adjustment increment, the output voltage adjustment increment is compared with the maximum allowable voltage adjustment amount in a single control cycle, and the smaller absolute value of the two is taken as the actual adjustment amount to adjust the charging pile request voltage.

[0030] Among them, the maximum allowable voltage regulation in a single control cycle K is the preset adjustment slope, and t is the sampling period.

[0031] In the above technical solution, the voltage regulation increment calculated by PI is compared with the maximum allowable voltage regulation in a single cycle, and the value with the smaller absolute value is taken as the actual regulation amount. This can limit the voltage change amplitude within a single control cycle, avoid drastic current fluctuations caused by excessive voltage regulation amplitude in a single operation, and reduce the risk of current oscillation under pulse heating conditions. By using a preset regulation slope and sampling period to quantify the upper limit of voltage regulation in a single cycle, the voltage regulation rate is stable and controllable, allowing the charging current to converge smoothly to the target range.

[0032] In one embodiment, an abnormal state reset mechanism is also included. When a vehicle charging process termination signal is received or the actual output current of the charging pile is less than or equal to zero, the internal state variables of the PI regulator are immediately reset, and the charging pile requested voltage is reset to the vehicle battery terminal voltage currently collected in real time.

[0033] In the above technical solution, a charging anomaly reset mechanism is set up to clear all internal state variables of the PI regulator the instant the charging process ends or the charging pile output current returns to zero, thus eliminating historical integral accumulated errors and preventing residual adjustment parameters from the previous charging from interfering with the current charging. Simultaneously, the charging pile's requested voltage is directly reset to the real-time vehicle battery terminal voltage, resulting in a smaller initial voltage deviation upon the next charging start, reducing the inrush current, lowering the initial adjustment pressure on the PI regulator, improving the reliability of the control logic under pulse heating charging conditions, and preventing current runaway and charging interruption issues caused by accumulated errors from multiple charging cycles.

[0034] In one embodiment, when the actual charging current of the charging pile is greater than the preset target current, the PI regulator is activated to calculate the negative adjustment increment and lower the charging pile request voltage to reduce the actual charging current of the charging pile.

[0035] When the actual charging current of the charging pile is less than the preset target current, the PI regulator is activated to calculate the positive adjustment increment and increase the requested voltage of the charging pile to increase the actual charging current.

[0036] In the above technical solution, the adjustment direction is distinguished based on the magnitude of the actual charging current of the charging pile relative to the preset target current. When the actual charging current of the charging pile exceeds the standard, a negative adjustment increment is output to lower the requested voltage of the charging pile to reduce the current. When the actual charging current of the charging pile is too low, a positive adjustment increment is output to raise the requested voltage of the charging pile to increase the current. This can specifically eliminate current deviation and achieve bidirectional closed-loop correction of the charging current. This bidirectional adjustment logic can quickly offset the bidirectional current disturbance caused by pulse heating, continuously and stably constrain the output current within the preset safety range, and avoid triggering the charging pile protection shutdown due to excessive current or affecting charging efficiency due to excessively low current. The control logic has clear judgment and direct response. Combined with the PI algorithm, it can accelerate the current convergence speed and improve the current stability throughout the low-temperature pulse heating charging process.

[0037] Secondly, embodiments of this application provide a charging current control device based on PI regulation, comprising:

[0038] The voltage monitoring module is used to monitor the absolute value of the difference between the charging pile's requested voltage and the vehicle's battery terminal voltage in real time in response to the vehicle charging process start signal and the pulse heating function turn-on signal.

[0039] The current acquisition module is used to acquire the actual output current of the charging pile when the absolute value of the difference is less than the preset voltage synchronization dead zone threshold.

[0040] The deviation calculation module is used to calculate the current deviation between the actual output current value and the preset target current.

[0041] The PI regulation control module is used to determine whether the current deviation exceeds the preset tolerance range. If it does, the PI regulator calculates the output voltage adjustment increment based on the current deviation and adjusts the charging pile request voltage according to the adjustment increment so that the actual output current converges to the preset target current. If it does not exceed the tolerance range, the current charging pile request voltage remains unchanged.

[0042] In one embodiment, the PI control module includes:

[0043] The proportional adjustment unit is used to generate the product of the current error signal and the proportional gain coefficient as the proportional adjustment component.

[0044] An integral adjustment unit is used to generate the product of the integral value of the current error signal in the time domain and the integral gain coefficient as the integral adjustment component.

[0045] The voltage synthesis unit is used to superimpose the battery terminal voltage, the proportional regulation component, and the integral regulation component to form the output voltage regulation increment.

[0046] The amplitude limiting control unit is used to limit the amplitude of the regulated charging pile request voltage and freeze the integral term of the PI regulator when the amplitude limiting boundary is reached, stopping integral accumulation to achieve anti-integral saturation control.

[0047] In one embodiment, an abnormal reset module is further included, which is used to immediately reset the internal state variables of the PI regulation control module and reset the charging pile request voltage to the vehicle battery terminal voltage currently collected in real time when a vehicle charging process termination signal is received or the actual output current of the charging pile is detected to be less than or equal to zero.

[0048] Thirdly, embodiments of this application provide a vehicle including a memory and a processor, the memory being used to store a computer program; the processor being coupled to the memory and configured to execute the computer program to implement the above-described PI-based charging current control method;

[0049] Alternatively, it may include the aforementioned PI-based charging current control device. Attached Figure Description

[0050] To more clearly illustrate the technical solutions in the embodiments of this application or the background art, the accompanying drawings used in the embodiments of this application will be described below.

[0051] Figure 1 This is a schematic flowchart of the charging current control method based on PI regulation disclosed in an embodiment of this application;

[0052] Figure 2 This is a schematic diagram of one embodiment of the charging current control device based on PI regulation disclosed in this application.

[0053] Figure 3 This is a schematic diagram of another embodiment of the charging current control device based on PI regulation disclosed in the present application.

[0054] Figure 4 This is a schematic diagram of the PI regulation control module disclosed in the embodiments of this application;

[0055] Figure 5 This is a schematic diagram of one embodiment of the vehicle disclosed in this application;

[0056] Figure 6 This is a schematic diagram of one embodiment of the vehicle disclosed in this application.

[0057] Explanation of reference numerals in the attached figures:

[0058] 10-Control device, 11-Voltage monitoring module, 12-Current acquisition module, 13-Deviance calculation module, 14-PI regulation control module, 141-Proportional regulation unit, 142-Integral regulation unit, 143-Voltage synthesis unit, 144-Limiting control unit, 15-Abnormal reset module, 20-Vehicle, 21-Memory, 22-Processor. Detailed Implementation

[0059] Lithium-ion batteries commonly suffer from significant power performance and energy density degradation in extremely cold environments. Traditional battery pack heating solutions primarily rely on external heating elements (such as PTC heating wires) or coolant circulation systems. These methods inherently suffer from low heating rates, making it difficult to meet users' rapid temperature rise requirements. Furthermore, as the heating process continues, the temperature gradient between individual cells within the battery pack gradually increases, leading to deterioration in battery pack consistency and severely impacting the vehicle's range and lifespan. Therefore, developing efficient and reliable low-temperature battery heating technology is crucial for ensuring the normal start-up and continuous operation of electric vehicles in winter and extremely cold regions.

[0060] Pulse self-heating technology, with its unique internal heat generation mechanism, has become a mainstream solution in the industry. This technology requires no external heat source; instead, it utilizes the increased internal resistance of the battery under low-temperature conditions by applying high-frequency, high-current pulses inside the battery to achieve rapid Joule heating within the cell. Currently, this technology has been industrialized and applied by several major automakers. From a technical perspective, pulse heating generates a high-frequency AC pulse current that acts on the cell through the rapid switching of a power switch within the drive system, achieving efficient thermal conversion during rapid charging and discharging by utilizing the battery's internal resistance.

[0061] However, pulse heating technology still faces key challenges in practical applications. When pulse heating is initiated simultaneously during charging, the high-frequency, high-current pulses can generate significant electromagnetic interference to the charging pile's power output system, easily causing charging interruptions and severely impacting user experience and charging reliability. Therefore, effectively addressing the issue of charging pile power output stability under pulse heating conditions has become a core technical bottleneck restricting the widespread adoption of this technology.

[0062] In view of the shortcomings of the prior art, the purpose of this application is to provide a charging current control method, device, and vehicle based on PI regulation. This aims to solve the technical problem in the prior art where high-frequency pulse current interferes with the power output of the charging pile under pulse heating conditions, leading to charging interruptions. The goal is to achieve coordinated and stable operation of the charging process and the battery's pulse self-heating function. Specifically, through a precise PI closed-loop control mechanism, the requested voltage of the charging pile is dynamically adjusted during the battery's low-temperature pulse heating process. This effectively suppresses the impact of high-frequency pulse current on the charging pile's power output, avoiding charging interruptions. Simultaneously, it ensures that the charging current accurately tracks the target value. Therefore, while ensuring charging reliability, it fully leverages the advantages of pulse heating technology—rapid heating and good temperature consistency—significantly improving the user experience and range performance of electric vehicles in extremely cold environments.

[0063] The embodiments of this application are described below with reference to the accompanying drawings.

[0064] In one embodiment, see Figure 1 As shown in the figure, this application provides a charging current control method based on PI regulation, which includes the following steps:

[0065] Step S1, Charging Trigger Monitoring: In response to receiving the vehicle charging process start signal and the pulse heating function activation signal, the absolute value of the difference between the charging pile requested voltage and the vehicle battery terminal voltage is monitored in real time. Specifically: the controller receives the vehicle charging process start signal and the pulse heating function activation signal in real time. When both signals are valid simultaneously, the controller continuously collects the charging pile requested voltage and the vehicle battery terminal voltage, and calculates the absolute value of the difference between the two in real time.

[0066] Step S2, Voltage Synchronization Determination: When the absolute value of the difference is less than the preset voltage synchronization dead zone threshold, the actual output current of the charging pile is collected. Specifically, the absolute value of the difference between the requested voltage of the charging pile and the voltage at the vehicle battery terminal is compared with the preset voltage synchronization dead zone threshold; when the absolute value of the difference is less than the synchronization dead zone threshold, voltage synchronization is determined to be complete, and the current collection stage begins.

[0067] Step S3, Current Deviation Calculation: Calculate the current deviation between the actual output current value and the preset target current. Specifically, collect the actual output current of the charging pile in real time, calculate the difference between the actual output current of the charging pile and the preset target current, and obtain the current deviation.

[0068] Step S4, Current Deviation Range Judgment and Voltage Regulation Control: Compare the calculated current deviation with the preset tolerance range to determine whether the current deviation exceeds the preset tolerance range.

[0069] If the current deviation exceeds the preset tolerance range, the output voltage adjustment increment is calculated by the PI regulator based on the current deviation, and the charging pile request voltage is adjusted according to the adjustment increment so that the actual output current converges to the preset target current.

[0070] If the current deviation does not exceed the preset tolerance range, the current requested voltage of the charging pile will remain unchanged, and the voltage adjustment operation will not be performed.

[0071] This method first performs synchronous verification of the charging pile's requested voltage and the battery terminal voltage, and then performs closed-loop current regulation. This eliminates the instantaneous inrush current caused by the voltage difference at the initial charging start-up, reducing the impact losses of on-board high-voltage components and charging pile power devices. In the scenario of pulse heating synchronous charging, by collecting the actual output current in real time and comparing it with the preset target current deviation, the charging pile's requested voltage is dynamically corrected using a PI regulator. This can quickly suppress large current fluctuations caused by pulse heating, stabilizing the actual output current of the charging pile to the target range, avoiding abnormal current fluctuations that trigger charging pile protection and cause charging interruptions, and ensuring stable synchronous operation of low-temperature pulse heating and DC charging. When the current deviation is within the allowable tolerance range, the charging pile's requested voltage remains unchanged, eliminating the need for continuous adjustment, reducing the controller's computational load, and avoiding current oscillations caused by frequent voltage adjustments.

[0072] The entire control logic relies solely on software algorithms to adjust and issue voltage commands, requiring no modifications to the charging pile hardware. It is compatible with various DC charging devices, offering strong versatility. Simultaneously, the consistently stable current with minimal fluctuations reduces the voltage difference between charging and discharging battery cells, improves individual cell consistency, slows battery aging, and enhances low-temperature charging efficiency and user experience.

[0073] As an optional implementation of this application, the charging current control method based on PI regulation provided in this application embodiment further includes a battery voltage pre-synchronization control step: after the vehicle charging process starts and before entering PI regulation control, an open-loop control mode is adopted to request voltage from the charging pile with a preset adjustment slope. Perform gradual, continuous adjustments until... , This refers to the vehicle battery terminal voltage. This is the preset voltage synchronization dead zone threshold.

[0074] This implementation adds an open-loop progressive voltage pre-synchronization control before the PI current closed-loop regulation. It gradually adjusts the charging pile's requested voltage at a fixed slope until the absolute value of the difference between the requested voltage and the battery terminal voltage falls into the synchronization dead zone. This eliminates the spike inrush current generated by the voltage difference at the moment of charging, reducing instantaneous electrical stress on the charging pile's power devices and the vehicle's high-voltage circuit, and extending the lifespan of the charging system hardware. Employing open-loop uniform voltage regulation logic, the adjustment rate is controllable, preventing sudden voltage rises and falls. This provides a stable initial operating condition for subsequent PI current closed-loop regulation, significantly reducing the initial adjustment deviation of the PI controller and minimizing current overshoot and oscillation. This pre-synchronization logic is implemented solely through software timing control, requiring no additional hardware, and is adaptable to various DC charging scenarios. Combined with the back-end current closed-loop control, it further enhances the overall operational stability under pulse heating charging conditions.

[0075] Furthermore, the open-loop control method for gradually adjusting the requested voltage of the charging pile with a preset adjustment slope specifically includes the following steps:

[0076] Step 1: Calculate the maximum allowable voltage regulation in a single control cycle. Where K is the preset adjustment slope, in units of V / s, representing the maximum allowable rate of change of the charging pile's requested voltage per unit time. It is calibrated according to the vehicle charging system and the power characteristics of the charging pile. The smaller the slope value, the smoother the voltage adjustment and the smaller the power-on inrush current; the larger the slope value, the faster the voltage synchronization speed, which can be flexibly matched according to the needs of low-temperature charging scenarios.

[0077] The sampling period, measured in seconds, is the time it takes for the battery management system to perform voltage acquisition and regulation calculations in a single cycle. It is determined by the underlying scheduling cycle of the vehicle controller hardware and its value remains fixed.

[0078] Step two: Perform directional adjustment based on the polarity of the voltage deviation.

[0079] when At that time, within each control cycle, Increasing ;

[0080] when At that time, within each control cycle, Decreasing ;

[0081] Step 3: Request voltage from the adjusted charging station. Limit the amplitude to ensure ,in This is the minimum output voltage limit for the charging station. This is the maximum output voltage limit.

[0082] This implementation quantifies the maximum voltage regulation step size per cycle by preset adjustment slope K and sampling period t. It adjusts the voltage at a uniform speed based on the polarity of the deviation between the charging pile's requested voltage and the vehicle battery's terminal voltage, ensuring a smooth and controllable voltage regulation process and effectively avoiding inrush currents caused by voltage surges. Simultaneously, it sets hard limits on the charging pile's output voltage (upper and lower limits) to prevent the commanded voltage from exceeding the equipment's rated operating range during voltage regulation, thus mitigating the risk of overvoltage damage to the charging pile's power unit.

[0083] As an optional embodiment of this application, the PI regulator adopts a continuous-time PI control algorithm, and the output voltage adjustment increment of the PI regulator is composed of the superposition of the battery terminal voltage, the proportional adjustment component, and the integral adjustment component; the proportional adjustment component is the product of the current error signal and the proportional gain coefficient; the integral adjustment component is the product of the integral value of the current error signal in the time domain and the integral gain coefficient.

[0084] The current error signal is formed by adding the negative value of the preset current value to the negative value of the current deviation value. The current deviation value is the difference between the actual output current of the charging pile and the requested current of the charging pile. The preset current value is used to determine the preset target current, which is equal to the requested current of the charging pile minus the preset current value.

[0085] Specifically, the output voltage adjustment increment of the PI regulator The formula for calculation is:

[0086] ;

[0087] , ,

[0088] in, This refers to the vehicle battery terminal voltage. For proportional adjustment components, To adjust the integral component, For the preset current value, This is the current deviation value. This represents the actual output current of the charging pile. Request current for the charging station.

[0089] A continuous-time PI control algorithm is adopted, which obtains the voltage regulation increment by superimposing proportional and integral components. The proportional component can quickly respond to current deviations and achieve dynamic correction, while the integral component can eliminate steady-state current error and improve steady-state current control accuracy. This scheme reconstructs the current error signal and constrains the target current range with a preset current value, stabilizing the charging current within a safe range below the charging pile's requested current. This effectively offsets the current disturbance caused by pulse heating and avoids triggering the charging pile's protection shutdown due to current over-limit. This error construction method can accurately limit the upper limit of the charging current, achieving smooth current convergence in conjunction with PI regulation. At the same time, the algorithm has simple operation logic, low computational power consumption of the vehicle controller, and requires no modification to the charging pile hardware. It can be adapted to low-temperature pulse heating charging scenarios, balancing charging stability and equipment versatility.

[0090] As an optional embodiment of this application, after adjusting the charging pile request voltage according to the adjustment increment, the charging pile request voltage is... Limit the amplitude to ensure ,in This is the minimum output voltage limit for the charging station. This is the maximum output voltage limit. Setting upper and lower limits on the requested voltage of the regulated charging pile can prevent the issuance of voltage commands exceeding the rated operating range of the charging pile, thus protecting the charging pile's power conversion unit from failure due to overvoltage or undervoltage.

[0091] When the requested voltage of the charging pile reaches the limiting boundary, the integral term of the PI regulator is frozen, and integral accumulation is stopped to achieve anti-integral saturation control and eliminate the current overshoot and regulation lag problems caused by continuous integral accumulation during the voltage limiting stage. After leaving the limiting range, the integral can resume normal operation, taking into account both dynamic adjustment response speed and steady-state current control accuracy, further improving the stability of current output under pulse heating charging conditions.

[0092] As an optional implementation of this application, after the PI regulator calculates the output voltage adjustment increment, the output voltage adjustment increment is compared with the maximum allowable voltage adjustment amount per single control cycle, and the smaller absolute value of the two is taken as the actual adjustment amount to adjust the charging pile's requested voltage; wherein, the maximum allowable voltage adjustment amount per single control cycle... K is the preset adjustment slope. The sampling period.

[0093] This implementation compares the voltage regulation increment calculated by PI with the maximum allowable voltage regulation in a single cycle, taking the smaller absolute value as the actual regulation. This limits the voltage variation within a single control cycle, preventing excessive voltage regulation in a single operation from causing drastic current fluctuations and reducing the risk of current oscillations under pulse heating conditions. By quantifying the upper limit of voltage regulation in a single cycle using a preset regulation slope and sampling period, the voltage regulation rate is stable and controllable, allowing the charging current to converge smoothly to the target range.

[0094] As an optional implementation of this application, an abnormal state reset mechanism is also included. When a vehicle charging process termination signal is received or the actual output current of the charging pile is less than or equal to zero, the internal state variable of the PI regulator is immediately reset, and the charging pile requested voltage is reset to the vehicle battery terminal voltage currently collected in real time.

[0095] By setting up a charging anomaly reset mechanism, all internal state variables of the PI regulator are cleared the instant the charging process ends or the charging pile output current returns to zero. This eliminates historical integral accumulated errors and prevents residual adjustment parameters from the previous charging cycle from interfering with the current charging. Simultaneously, the requested voltage from the charging pile is directly reset to the real-time vehicle battery terminal voltage, resulting in a smaller initial voltage deviation upon the next charging start. This reduces the inrush current, lowers the initial adjustment pressure on the PI regulator, improves the reliability of the control logic under pulse heating charging conditions, and prevents current runaway and charging interruption issues caused by accumulated errors from multiple charging cycles.

[0096] As an optional implementation of this application, when the actual charging current of the charging pile is greater than the preset target current, the PI regulator is activated to calculate the negative adjustment increment and the charging pile request voltage is lowered to reduce the actual charging current of the charging pile.

[0097] When the actual charging current of the charging pile is less than the preset target current, the PI regulator is activated to calculate the positive adjustment increment and increase the requested voltage of the charging pile to increase the actual charging current.

[0098] This implementation method can specifically eliminate current deviation and achieve bidirectional closed-loop correction of charging current. It can quickly offset the bidirectional current disturbance caused by pulse heating and continuously keep the output current stably constrained within the preset safe range. This avoids the charging pile from being triggered to shut down due to excessive current or the charging efficiency being affected by excessively low current. The control logic is clear and the response is direct. Combined with the PI algorithm, it can accelerate the current convergence speed and improve the current stability throughout the low-temperature pulse heating charging process.

[0099] In one embodiment, this application provides a charging current control device based on PI regulation, see [link to relevant documentation]. Figure 2As shown, the control device 10 includes a voltage monitoring module 11, a current acquisition module 12, a deviation calculation module 13, and a PI regulation control module 14. The voltage monitoring module 11 monitors the absolute value of the difference between the charging pile's requested voltage and the vehicle's battery terminal voltage in real time, responding to the vehicle charging process start signal and the pulse heating function activation signal. The current acquisition module 12 acquires the actual output current of the charging pile when the absolute value of the difference is less than a preset voltage synchronization dead zone threshold. The deviation calculation module 13 calculates the current deviation between the actual output current value and a preset target current. The PI regulation control module 14 determines whether the current deviation exceeds a preset tolerance range. If it does, it calculates the output voltage adjustment increment based on the current deviation using a PI regulator, adjusts the charging pile's requested voltage according to the adjustment increment, and brings the actual output current to the preset target current; if it does not exceed the tolerance range, it maintains the current charging pile's requested voltage unchanged.

[0100] As an optional implementation of this application, see [link to relevant documentation]. Figure 4 As shown, the PI regulation control module 14 includes a proportional regulation unit 141, an integral regulation unit 142, a voltage synthesis unit 143, and a limiting control unit 144. The proportional regulation unit 141 generates the product of the current error signal and the proportional gain coefficient as the proportional regulation component. The integral regulation unit 142 generates the integral value of the current error signal in the time domain and the product of the integral gain coefficient as the integral regulation component. The voltage synthesis unit 143 superimposes the battery terminal voltage, the proportional regulation component, and the integral regulation component to form the output voltage regulation increment. The limiting control unit 144 limits the amplitude of the regulated charging pile request voltage and freezes the integral term of the PI regulator when the limiting boundary is reached, stopping integral accumulation to achieve anti-integral saturation control.

[0101] As an optional implementation of this application, see [link to relevant documentation]. Figure 3 As shown, the charging current control device based on PI regulation provided in this application also includes an abnormal reset module, which is used to immediately reset the internal state variables of the PI regulation control module and reset the charging pile requested voltage to the currently collected vehicle battery terminal voltage when a vehicle charging process termination signal is received or the actual output current of the charging pile is detected to be less than or equal to zero.

[0102] In one embodiment, this application provides a vehicle, see [link to relevant documentation]. Figure 5 As shown, the vehicle 20 includes a memory 21 and a processor 22. The memory 21 is used to store computer programs. The processor 22 is coupled to the memory 21 and is configured to execute the computer programs to implement the PI-based charging current control method provided in any of the above embodiments.

[0103] In one embodiment, this application provides a vehicle, see [link to relevant documentation]. Figure 6 As shown, the vehicle 20 includes a PI-based charging current control device 10 provided in any of the above embodiments.

[0104] It should be noted that the vehicle 20 provided in this application may be, but is not limited to, a pure electric vehicle (PEV / BEV), a hybrid electric vehicle (HEV), a range-extended electric vehicle (REEV), a plug-in hybrid electric vehicle (PHEV), or a new energy vehicle.

[0105] The above embodiments are merely preferred embodiments provided to fully illustrate the present invention, and the scope of protection of the present invention is not limited thereto. Equivalent substitutions or modifications made by those skilled in the art based on the present invention are all within the scope of protection of the present invention.

Claims

1. A PI regulation based charging current control method, characterized by, include: In response to receiving the vehicle charging process start signal and the pulse heating function start signal, the absolute value of the difference between the charging pile requested voltage and the vehicle battery terminal voltage is monitored in real time. When the absolute value of the difference is less than the preset voltage synchronization dead zone threshold, the actual output current of the charging pile is collected. Calculate the current deviation between the actual output current value and the preset target current; Determine whether the current deviation exceeds the preset tolerance range: If the current deviation is exceeded, the output voltage adjustment increment is calculated by the PI regulator based on the current deviation, and the charging pile request voltage is adjusted according to the adjustment increment so that the actual output current converges to the preset target current. If the voltage does not exceed the limit, the current requested voltage for the charging station will remain unchanged.

2. The PI regulation based charging current control method of claim 1, wherein, It also includes a battery voltage pre-synchronization control step: after the vehicle charging process starts but before entering PI regulation control, an open-loop control mode is used to request voltage from the charging pile with a preset adjustment slope. Make gradual adjustments until... , This refers to the vehicle battery terminal voltage. This is the preset voltage synchronization dead zone threshold.

3. The PI regulation based charging current control method of claim 2, wherein, The open-loop control method, using a preset adjustment slope, progressively adjusts the requested voltage of the charging pile, specifically including: Calculate the maximum allowable voltage regulation in a single control cycle. K is the preset adjustment slope. The sampling period; Targeted adjustment is performed based on the polarity of the voltage deviation: When is incremented by one in each control cycle ; When the value of the counter is decreased ; Request voltage for the adjusted charging station Limit the amplitude to ensure ,in This is the minimum output voltage limit for the charging station. This is the maximum output voltage limit.

4. The charging current control method based on PI regulation according to claim 1, characterized in that: The PI regulator adopts a continuous-time PI control algorithm. The output voltage adjustment increment of the PI regulator is composed of the superposition of the battery terminal voltage, the proportional adjustment component, and the integral adjustment component. The proportional adjustment component is the product of the current error signal and the proportional gain coefficient. The integral adjustment component is the product of the integral value of the current error signal in the time domain and the integral gain coefficient. The current error signal is formed by adding the negative value of the preset current value to the negative value of the current deviation value. The current deviation value is the difference between the actual output current of the charging pile and the requested current of the charging pile. The preset current value is used to determine the preset target current, which is equal to the requested current of the charging pile minus the preset current value.

5. The charging current control method based on PI regulation according to claim 1, characterized in that: After adjusting the charging pile's requested voltage according to the aforementioned adjustment increment, the charging pile's requested voltage... Apply amplitude limits to ensure ,in This is the minimum output voltage limit for the charging station. This is the maximum output voltage limit. When the requested voltage of the charging pile reaches the limit boundary, the integral term of the PI regulator is frozen, and integral accumulation is stopped to achieve anti-integral saturation control.

6. The PI regulation based charging current control method of claim 1, wherein: After the PI regulator calculates the output voltage adjustment increment, it compares the output voltage adjustment increment with the maximum allowable voltage adjustment amount in a single control cycle, and takes the smaller absolute value of the two as the actual adjustment amount to adjust the charging pile's requested voltage. Wherein, the maximum allowed voltage adjustment amount of a single control period K is a preset adjustment slope, and t is a sampling period.

7. The PI regulation based charging current control method of claim 1, wherein: It also includes an abnormal state reset mechanism. When a vehicle charging process termination signal is received or the actual output current of the charging pile is less than or equal to zero, the internal state variables of the PI regulator are immediately reset, and the charging pile requested voltage is reset to the vehicle battery terminal voltage collected in real time.

8. The PI regulation based charging current control method of claim 1, wherein: When the actual charging current of the charging pile is greater than the preset target current, the PI regulator is activated to calculate the negative adjustment increment and lower the charging pile's requested voltage to reduce the actual charging current of the charging pile. When the actual charging current of the charging pile is less than the preset target current, the PI regulator is activated to calculate the positive adjustment increment and increase the requested voltage of the charging pile to increase the actual charging current.

9. A PI regulation based charging current control device, characterized by, include: The voltage monitoring module is used to monitor the absolute value of the difference between the charging pile's requested voltage and the vehicle's battery terminal voltage in real time in response to the vehicle charging process start signal and the pulse heating function turn-on signal. The current acquisition module is used to acquire the actual output current of the charging pile when the absolute value of the difference is less than the preset voltage synchronization dead zone threshold. The deviation calculation module is used to calculate the current deviation between the actual output current value and the preset target current. The PI regulation control module is used to determine whether the current deviation exceeds the preset tolerance range, and when it does, calculate the output voltage adjustment increment based on the current deviation through the PI regulator, and adjust the charging pile request voltage according to the adjustment increment so that the actual output current converges to the preset target current. If the voltage is not exceeded, maintain the current requested voltage of the charging station.

10. The PI regulation based charging current control device of claim 9, wherein, The PI regulation control module includes: The proportional adjustment unit is used to generate the product of the current error signal and the proportional gain coefficient as the proportional adjustment component. An integral adjustment unit is used to generate the product of the integral value of the current error signal in the time domain and the integral gain coefficient as the integral adjustment component. The voltage synthesis unit is used to superimpose the battery terminal voltage, the proportional regulation component, and the integral regulation component to form the output voltage regulation increment. The amplitude limiting control unit is used to limit the amplitude of the regulated charging pile request voltage and freeze the integral term of the PI regulator when the amplitude limiting boundary is reached, stopping integral accumulation to achieve anti-integral saturation control.

11. The PI regulation based charging current control device of claim 9, wherein, It also includes an abnormal reset module, which is used to immediately reset the internal state variables of the PI regulation control module when a vehicle charging process termination signal is received or the actual output current of the charging pile is detected to be less than or equal to zero, and reset the charging pile request voltage to the vehicle battery terminal voltage currently collected in real time.

12. A vehicle characterized by: The system includes a memory and a processor, the memory being used to store a computer program; the processor is coupled to the memory and configured to execute the computer program to implement the PI-based charging current control method as described in any one of claims 1 to 8. Alternatively, it may include the PI-based charging current control device as described in any one of claims 9 to 11.

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