Charging system of new energy locomotive

Abstract

The invention discloses a charging system of a new energy locomotive. The charging system comprises a power grid side data acquisition module, a cable state acquisition module, a battery side data acquisition module, a cable dynamic impedance calculation unit, a polarization voltage correction unit, a closed-loop power control unit and a three-terminal data interaction bus. Each acquisition module establishes a two-way transmission link with the calculation unit, the correction unit and the control unit through a bus, and generates a charging control instruction through coupling operation and correction operation; according to the system, the problem that multi-dimensional state coupling is not considered in the prior art is solved, accurate control over the charging process is achieved, and the charging stability and safety are guaranteed.

Description

Technical Field

[0001] This invention relates to the field of electric vehicle power unit technology, specifically a charging system for a new energy vehicle. Background Technology

[0002] In the charging process of new energy locomotives, the charging cable, as a key carrier of energy transmission, directly affects charging efficiency and safety. In existing technologies, the control logic of charging systems is mostly designed based on a single dimension of grid input parameters or battery state parameters, without fully considering the dynamic changes of the charging cable in actual use. During charging of new energy locomotives, the charging cable often experiences varying degrees of bending due to changes in its orientation. Simultaneously, high current transmission leads to increased core wire temperature and altered current density distribution. These factors collectively cause dynamic fluctuations in cable impedance. This dynamic impedance change interacts with the battery polarization voltage, thereby altering the matching relationship between actual charging power and voltage. Existing systems lack a multi-factor coupled calculation model, relying solely on fixed impedance parameters or simple linear correction methods. This results in deviations between charging control commands and actual operating conditions, easily leading to unstable charging voltage, decreased charging efficiency, and even the risk of battery overcharging, severely impacting the reliability of the charging system and the battery life of the new energy locomotive.

[0003] Therefore, there is an urgent need for a charging system that can accurately capture the dynamic state coupling relationship of multiple terminals and realize dynamic adaptive control of the charging process. Summary of the Invention

[0004] The purpose of this invention is to address the shortcomings of existing technologies by proposing a charging system for new energy vehicles. The system includes a grid-side data acquisition module, a cable status acquisition module, a battery-side data acquisition module, a cable dynamic impedance calculation unit, a polarization voltage correction unit, a closed-loop power control unit, and a three-terminal data interaction bus. The grid-side data acquisition module, the cable status acquisition module, and the battery-side data acquisition module establish bidirectional data transmission links with the cable dynamic impedance calculation unit, the polarization voltage correction unit, and the closed-loop power control unit, respectively, through the three-terminal data interaction bus. The cable dynamic impedance calculation unit receives multi-dimensional status data transmitted from the cable status acquisition module and performs coupling calculations. The polarization voltage correction unit receives the calculation results output by the cable dynamic impedance calculation unit and battery-related data transmitted by the battery-side data acquisition module and performs correction calculations. The closed-loop power control unit receives the correction results output by the polarization voltage correction unit and grid-related data transmitted by the grid-side data acquisition module and generates charging control commands. These charging control commands are fed back to the charging execution module through the three-terminal data interaction bus to adjust the charging process.

[0005] Preferably, the power grid-side data acquisition module includes a voltage sensor, a current sensor, and a harmonic detection submodule. The voltage sensor acquires the power grid input voltage signal, the current sensor acquires the power grid input current signal, and the harmonic detection submodule performs spectral analysis on the power grid input voltage signal and the power grid input current signal to obtain power grid harmonic distortion rate data. The power grid input voltage signal, the power grid input current signal, and the power grid harmonic distortion rate data are all transmitted through the three-terminal data interaction bus.

[0006] Preferably, the cable status acquisition module includes an angle sensor, a temperature sensor, and a current density calculation submodule. The angle sensor acquires the bending angle signal of the charging cable, the temperature sensor acquires the core wire temperature signal of the charging cable, and the current density calculation submodule calculates the current density data based on the grid input current signal and the cross-sectional area parameter of the charging cable. The bending angle signal, the core wire temperature signal, and the current density data are all transmitted through the three-terminal data interaction bus.

[0007] Preferably, the battery-side data acquisition module includes a remaining power detection submodule, a terminal voltage sensor, and a magnetic field strength sensor. The remaining power detection submodule acquires the remaining power data of the new energy vehicle's power battery, the terminal voltage sensor acquires the terminal voltage signal of the power battery, and the magnetic field strength sensor acquires the ambient magnetic field strength data around the power battery. The remaining power data, the terminal voltage signal, and the ambient magnetic field strength data are all transmitted through the three-terminal data interaction bus.

[0008] Preferably, the cable dynamic impedance calculation unit executes the cable dynamic impedance calculation model to obtain cable dynamic impedance data, and the cable dynamic impedance calculation model is as follows:

[0009] in, This refers to the dynamic impedance data of the cable, in ohms. This is the reference impedance under standard cable conditions, with dimensions in ohms; The angle value corresponding to the bending angle signal of the charging cable, in degrees; This is the temperature value corresponding to the core wire temperature signal of the charging cable, in degrees Celsius. The current density data output by the current density calculation submodule is in the dimension of amperes per square millimeter; The coupling coefficient between the bending angle and temperature is expressed in units of (degrees Celsius). The coupling coefficient between the bending angle and the current density is expressed in units of degree-ampere-millimeter. The coupling coefficient between temperature and current density is expressed in units of (degrees Celsius·amperes per square millimeter). The three-dimensional coupling coefficient of bending angle, temperature and current density is expressed in units of (degrees Celsius amperes per square millimeter). The temperature sensitivity coefficient of the cable impedance, measured in degrees Celsius; This is the reference temperature under standard cable conditions, measured in degrees Celsius.

[0010] Preferably, the polarization voltage correction unit executes a polarization voltage correction model to obtain corrected battery polarization voltage data, wherein the polarization voltage correction model is: ; in, The corrected battery polarization voltage data is expressed in volts. This is the reference polarization voltage under standard battery conditions, measured in volts. The output of the cable dynamic impedance calculation unit is the cable dynamic impedance data, with the dimension in ohms; The remaining battery power data output by the remaining battery power detection submodule is expressed as a percentage. The data represents the ambient magnetic field strength collected by a magnetic field strength sensor, with the dimension millitalas. The coupling coefficient between dynamic impedance and residual charge is expressed in units of ohms per percentage. denoted as the coupling coefficient between dynamic impedance and ambient magnetic field strength, with dimensions per (ohm·mtesa). The coupling coefficient between the remaining electric charge and the ambient magnetic field strength is expressed in units of per (percentage millitalas). The polarization voltage increment caused by dynamic impedance, in volts; This represents the polarization voltage increment caused by the ambient magnetic field strength, with dimensions in volts.

[0011] Preferably, the three-terminal data interaction bus includes a grid-side data transmission channel, a cable-side data transmission channel, and a battery-side data transmission channel. The grid-side data transmission channel is dedicated to transmitting bidirectional data between the grid-side data acquisition module and the closed-loop power control unit. The cable-side data transmission channel is dedicated to transmitting bidirectional data between the cable status acquisition module and the cable dynamic impedance calculation unit. The battery-side data transmission channel is dedicated to transmitting bidirectional data between the battery-side data acquisition module and the polarization voltage correction unit. The three data transmission channels operate in parallel and data timestamp alignment is achieved through a data synchronizer.

[0012] Preferably, the data synchronizer has a built-in timestamp generation submodule and a data alignment submodule. The timestamp generation submodule adds a high-precision timestamp to each transmitted data, and the data alignment submodule matches the data in the power grid side data transmission channel, the cable side data transmission channel, and the battery side data transmission channel according to the same time node based on the high-precision timestamp, so as to ensure that the cable dynamic impedance calculation unit, the polarization voltage correction unit, and the closed-loop power control unit receive multi-source data at the same time.

[0013] Preferably, the closed-loop power control unit includes a data preprocessing submodule, a control command generation submodule, and a command output submodule. The data preprocessing submodule filters and normalizes the received corrected battery polarization voltage data, grid input voltage signal, grid input current signal, and grid harmonic distortion rate data. The control command generation submodule generates charging voltage adjustment commands and charging current adjustment commands based on the preprocessed data and a preset charging control strategy. The command output submodule converts the charging voltage adjustment commands and the charging current adjustment commands into control signals recognizable by the charging execution module and outputs them.

[0014] Preferably, the control command generation submodule generates the target power values ​​corresponding to the charging voltage adjustment command and the charging current adjustment command through a charging power closed-loop control model. The charging power closed-loop control model is as follows: ; in, The target power value is expressed in kilowatts. The preset charging target power is expressed in kilowatts. The voltage value corresponding to the power grid input voltage signal, with the dimension of volts; The polarization voltage increment caused by dynamic impedance, in volts; The corrected battery polarization voltage data is expressed in volts. This is data on the harmonic distortion rate of the power grid, expressed as a percentage. The harmonic distortion rate influence coefficient is expressed as a percentage. The coupling coefficient between dynamic impedance and harmonic distortion rate is expressed in units of ohms per percentage. The control command generation submodule generates the charging voltage adjustment command and the charging current adjustment command based on the target power value and the rated voltage and rated current of the power battery.

[0015] Technical Effects: The core inventive technology of this invention lies in constructing a closed-loop control architecture for multi-terminal data acquisition and coupled computation. It achieves synchronous transmission of data from the power grid, cable, and battery through a three-terminal data interaction bus. Combined with a cable dynamic impedance calculation model, a polarization voltage correction model, and a charging power closed-loop control model, it accurately captures the coupling relationships of multi-dimensional states. This technical solution effectively solves the problem of insufficient control accuracy caused by existing technologies that do not consider the coupling of cable dynamic states with other parameters, achieving dynamic adaptive adjustment during the charging process, ensuring charging voltage stability, and improving charging efficiency and safety. Attached Figure Description

[0016] Figure 1 This is a block diagram showing the connection between the multi-source data acquisition and core computing unit in this application; Figure 2 This is a block diagram showing the connection between data synchronization and power control execution in this application. Detailed Implementation

[0017] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0018] Traditional charging systems have the following technical problems: During the charging process, the bending angle, core temperature, and current density of the charging cable will change dynamically and couple to affect the cable impedance. This impedance change interacts with the battery polarization voltage and grid parameters, causing the actual charging conditions to deviate from the control expectations. However, the existing system has not established a multi-factor coupling calculation mechanism and only relies on single parameter regulation, resulting in insufficient control accuracy.

[0019] Based on this, please refer to Figure 1 and Figure 2This embodiment provides a charging system for a new energy vehicle, including a grid-side data acquisition module, a cable status acquisition module, a battery-side data acquisition module, a cable dynamic impedance calculation unit, a polarization voltage correction unit, a closed-loop power control unit, and a three-terminal data interaction bus. The grid-side data acquisition module, cable status acquisition module, and battery-side data acquisition module establish bidirectional data transmission links with the cable dynamic impedance calculation unit, polarization voltage correction unit, and closed-loop power control unit, respectively, through the three-terminal data interaction bus. The cable dynamic impedance calculation unit receives multi-dimensional status data transmitted by the cable status acquisition module and performs coupling calculations. The polarization voltage correction unit receives the calculation results output by the cable dynamic impedance calculation unit and battery-related data transmitted by the battery-side data acquisition module and performs correction calculations. The closed-loop power control unit receives the correction results output by the polarization voltage correction unit and grid-related data transmitted by the grid-side data acquisition module and generates charging control commands. The charging control commands are fed back to the charging execution module through the three-terminal data interaction bus to adjust the charging process.

[0020] The core of this technical solution lies in constructing a multi-terminal collaborative closed-loop control architecture. Each module achieves bidirectional data transmission through a three-terminal data interaction bus, ensuring real-time interaction of multi-source data. The grid-side data acquisition module is responsible for capturing the voltage, current, and harmonic characteristics of the grid input, providing basic grid-side data for subsequent power control. The cable status acquisition module focuses on the dynamic state of the charging cable, acquiring key parameters such as bending angle, core wire temperature, and current density. These parameters are the core basis for reflecting changes in cable impedance. The battery-side data acquisition module collects the remaining battery charge, terminal voltage, and surrounding magnetic field strength, providing battery-side data support for polarization voltage correction. The cable dynamic impedance calculation unit performs coupled calculations on the multi-dimensional state data of the cable to accurately obtain the dynamic impedance value. The polarization voltage correction unit combines the dynamic impedance data with relevant battery data to correct the polarization voltage to reflect the actual battery state. The closed-loop power control unit integrates the corrected polarization voltage data with grid data to generate charging control commands adapted to the current operating conditions, and finally adjusts the charging process through the charging execution module. All modules form a complete closed loop of data acquisition, coupled calculation, correction optimization, and control output, ensuring a high degree of matching between control commands and actual operating conditions.

[0021] The technical effects achieved by this solution include: accurately capturing the coupling relationship between multiple states, realizing dynamic adaptive control of the charging process, ensuring charging stability and safety, and avoiding charging efficiency reduction or battery damage caused by parameter mismatch.

[0022] Traditional grid-side data acquisition has the following technical problems: it only collects the basic values ​​of grid input voltage and current, without considering the impact of grid harmonic distortion on the charging process, resulting in insufficient grid-side data dimensions and affecting the accuracy of subsequent power control.

[0023] Based on this, the power grid side data acquisition module includes a voltage sensor, a current sensor, and a harmonic detection submodule. The voltage sensor acquires the power grid input voltage signal, the current sensor acquires the power grid input current signal, and the harmonic detection submodule performs spectrum analysis on the power grid input voltage signal and the power grid input current signal to obtain power grid harmonic distortion rate data. The power grid input voltage signal, the power grid input current signal, and the power grid harmonic distortion rate data are all transmitted through a three-terminal data interaction bus.

[0024] In this technical solution, the voltage sensor employs a Hall voltage sensor, capable of acquiring the AC voltage signal input from the power grid in real time. Its working principle is based on the Hall effect, converting the voltage signal into a corresponding electrical signal output. The current sensor uses a Rogowski coil current sensor, acquiring the power grid input current signal through electromagnetic induction, featuring a wide measurement range and high precision. The harmonic detection submodule incorporates a spectrum analysis algorithm to perform a fast Fourier transform on the acquired power grid input voltage and current signals, decomposing each harmonic component and then calculating the power grid harmonic distortion rate data. The three data acquisition components have clearly defined roles: the voltage and current sensors provide basic electrical parameters, while the harmonic detection submodule supplements harmonic characteristic parameters, enriching the dimensions of the power grid data. The acquired three types of data are transmitted in real time to the closed-loop power control unit via a three-terminal data interaction bus power grid-side data transmission channel, providing comprehensive power grid-side input data for subsequent power control models.

[0025] The technical effects achieved by this solution include: improving the dimensions of grid-side data acquisition, providing accurate grid status information for charging power control, and enhancing the adaptability of charging control under grid harmonic conditions.

[0026] Traditional cable condition acquisition has the following technical problems: it does not comprehensively collect data on the bending angle, core temperature and current density of the charging cable, and only relies on fixed parameters or single condition parameters to judge the cable condition, which cannot reflect the dynamic changes of the cable and leads to inaccurate cable impedance calculation.

[0027] Based on this, the cable status acquisition module includes an angle sensor, a temperature sensor, and a current density calculation submodule. The angle sensor acquires the bending angle signal of the charging cable, the temperature sensor acquires the core wire temperature signal of the charging cable, and the current density calculation submodule calculates the current density data based on the grid input current signal and the cross-sectional area parameter of the charging cable. The bending angle signal, core wire temperature signal, and current density data are all transmitted through a three-terminal data interaction bus.

[0028] In this technical solution, the angle sensor is a microelectromechanical system (MEMS) angle sensor, installed at key bending points of the charging cable. It can detect the bending angle of the cable in real time, and its measurement range covers the bending angle range that the cable may experience during charging, outputting the corresponding angle electrical signal. The temperature sensor is a PT100 platinum resistance temperature sensor, embedded inside the core wire of the charging cable, directly measuring the core wire temperature. Utilizing the characteristic that the resistance value of the platinum resistance changes with temperature, the temperature signal is converted into an acquireable electrical signal. The current density calculation submodule has built-in calculation logic, receives the grid input current signal transmitted by the current sensor, and, combined with the preset charging cable cross-sectional area parameters, obtains the current density data by dividing the current by the cross-sectional area. These three types of data reflect the mechanical state, thermal state, and electrical load state of the cable, respectively, comprehensively covering the key factors affecting cable impedance. The acquired bending angle signal, core wire temperature signal, and current density data are transmitted to the cable dynamic impedance calculation unit through the cable-side data transmission channel of the three-terminal data interaction bus, providing complete input data for the coupled calculation of cable dynamic impedance.

[0029] The technical effects achieved by this solution include: comprehensively capturing the multi-dimensional dynamic state of charging cables, providing accurate data support for the calculation of cable dynamic impedance, and ensuring the comprehensiveness and accuracy of cable condition assessment.

[0030] Traditional battery-side data acquisition has the following technical problems: it only collects the remaining battery capacity and terminal voltage data, without considering the influence of the ambient magnetic field strength on the battery polarization voltage, resulting in incomplete battery-side data acquisition and affecting the accuracy of polarization voltage correction.

[0031] Based on this, the battery-side data acquisition module includes a remaining power detection submodule, a terminal voltage sensor, and a magnetic field strength sensor. The remaining power detection submodule collects the remaining power data of the new energy vehicle's power battery, the terminal voltage sensor collects the terminal voltage signal of the power battery, and the magnetic field strength sensor collects the ambient magnetic field strength data around the power battery. The remaining power data, terminal voltage signal, and ambient magnetic field strength data are all transmitted through a three-terminal data interaction bus.

[0032] In this technical solution, the remaining power detection submodule employs an ampere-hour integration method combined with open-circuit voltage calibration. It collects and integrates the battery's charging and discharging current, while simultaneously using the correlation between open-circuit voltage and remaining power for calibration, obtaining accurate remaining power data. The terminal voltage sensor uses a differential voltage sensor to directly acquire the terminal voltage signal between the positive and negative terminals of the power battery. It features high input impedance and low measurement error, ensuring the accuracy of the terminal voltage signal acquisition. The magnetic field strength sensor uses a Hall effect magnetic field sensor, installed around the power battery pack, capable of detecting the surrounding magnetic field strength in real time and converting the magnetic field strength signal into a corresponding electrical signal output. The remaining power data reflects the battery's energy state, the terminal voltage signal reflects the battery's immediate electrical state, and the ambient magnetic field strength data reflects the external electromagnetic environment in which the battery is located. These three types of data together constitute complete state information on the battery side. The collected remaining power data, terminal voltage signal, and ambient magnetic field strength data are transmitted to the polarization voltage correction unit through the battery-side data transmission channel of the three-terminal data interaction bus, providing comprehensive battery-side data for accurate polarization voltage correction.

[0033] The technical effects achieved by this solution include: enriching the dimensions of battery-side data acquisition, considering the influence of environmental magnetic field strength on battery status, providing a complete data foundation for polarization voltage correction, and improving the accuracy of battery status assessment.

[0034] Traditional cable impedance calculation has the following technical problems: it uses a fixed impedance value or only considers a single factor for linear correction, without taking into account the coupling effects of bending angle, temperature and current density, resulting in a large deviation between the impedance calculation and the actual situation, which affects the accuracy of subsequent charging control.

[0035] Based on this, the cable dynamic impedance calculation unit executes the cable dynamic impedance calculation model to obtain the cable dynamic impedance data. The cable dynamic impedance calculation model is as follows: ; in, This refers to the dynamic impedance data of the cable, in ohms. This is the reference impedance under standard cable conditions, with dimensions in ohms; The angle value corresponding to the bending angle signal of the charging cable, in degrees; This is the temperature value corresponding to the core wire temperature signal of the charging cable, in degrees Celsius. The current density data output by the current density calculation submodule is in the dimension of amperes per square millimeter; The coupling coefficient between the bending angle and temperature is expressed in units of (degrees Celsius). The coupling coefficient between the bending angle and the current density is expressed in units of degree-ampere-millimeter. The coupling coefficient between temperature and current density is expressed in units of (degrees Celsius·amperes per square millimeter). The three-dimensional coupling coefficient of bending angle, temperature and current density is expressed in units of (degrees Celsius amperes per square millimeter). The temperature sensitivity coefficient of the cable impedance, measured in degrees Celsius; This is the reference temperature under standard cable conditions, measured in degrees Celsius.

[0036] The core of this technical solution is the construction of a dynamic impedance calculation model for cables, whose theoretical design is based on the principles of electromagnetics and materials mechanics. Changes in cable impedance essentially reflect changes in the physical state of the conductor. Changes in bending angle alter the stress distribution within the conductor, thus affecting its conductivity; increased temperature intensifies the thermal motion of free electrons within the conductor, increasing resistance; changes in current density produce the skin effect, affecting current distribution and thus altering impedance. Furthermore, these factors do not act independently; an increased bending angle may exacerbate the effect of temperature rise on impedance, and an increase in current density further amplifies the coupling effect between temperature and bending angle. Therefore, the model introduces pairwise coupling terms and three-dimensional coupling terms. The logical derivation process of the model is as follows: First, the reference impedance under standard cable conditions is used... Based on this, the standard state is defined as the reference temperature. The impedance value under no bending angle and rated current density; then considering the single effect of temperature, through the exponential term. This describes the exponential relationship between temperature and impedance, based on the classic theory of the temperature characteristics of conductor resistance. It then introduces a coupling effect term involving bending angle, temperature, and current density, through... , , Describe the pairwise coupling effects separately, by The three-dimensional coupling effect of the three factors is described, and each coupling coefficient is obtained by fitting a large amount of experimental data, which can accurately reflect the coupling effect under different combinations of factors. Finally, the single influence term of temperature is multiplied by the multi-factor coupling influence term to obtain the final dynamic impedance data of the cable. The cable dynamic impedance calculation unit receives the bending angle value transmitted by the cable status acquisition module. Core wire temperature value Current density data Substitute the data into the model for calculation to obtain real-time and accurate dynamic impedance data of the cable.

[0037] The technical effects achieved by this solution include: accurately calculating the dynamic impedance of the charging cable, fully considering the coupling effects of multiple factors, avoiding impedance calculation deviations caused by traditional single-parameter correction, and providing accurate cable status parameters for subsequent polarization voltage correction and power control.

[0038] Traditional battery polarization voltage calculation has the following technical problems: it does not consider the coupling effect of cable dynamic impedance, remaining charge and ambient magnetic field strength, and only uses a fixed reference value or simple linear correction, which leads to inaccurate polarization voltage calculation and affects the accuracy of charging power matching.

[0039] Based on this, the polarization voltage correction unit executes the polarization voltage correction model to obtain the corrected battery polarization voltage data. The polarization voltage correction model is as follows: ; in, The corrected battery polarization voltage data is expressed in volts. This is the reference polarization voltage under standard battery conditions, measured in volts. The output of the cable dynamic impedance calculation unit is the cable dynamic impedance data, with the dimension in ohms; The remaining battery power data output by the remaining battery power detection submodule is expressed as a percentage. The data represents the ambient magnetic field strength collected by a magnetic field strength sensor, with the dimension millitalas. The coupling coefficient between dynamic impedance and residual charge is expressed in units of ohms per percentage. denoted as the coupling coefficient between dynamic impedance and ambient magnetic field strength, with dimensions per (ohm·mtesa). The coupling coefficient between the remaining electric charge and the ambient magnetic field strength is expressed in units of per (percentage millitalas). The polarization voltage increment caused by dynamic impedance, in volts; This represents the polarization voltage increment caused by the ambient magnetic field strength, with dimensions in volts.

[0040] The theoretical design of this technical solution is based on the principles of battery electrochemistry and electromagnetic induction. Battery polarization voltage is the voltage generated during charging and discharging due to electrochemical and concentration polarization. Its magnitude is affected by the remaining battery charge; the lower the remaining charge, the more pronounced the polarization effect. Simultaneously, changes in the dynamic impedance of the cable alter the voltage distribution in the charging circuit, indirectly affecting the battery's polarization process. Changes in the ambient magnetic field strength induce an electromotive force within the battery, which is superimposed on the polarization voltage, affecting its actual measurement. These factors are interconnected; an increase in dynamic impedance may exacerbate the impact of remaining charge on the polarization voltage, and changes in the ambient magnetic field strength alter the coupling effect between dynamic impedance and remaining charge. The logical derivation of the model is as follows: First, the reference polarization voltage under standard battery conditions is used... Based on this, the standard state is defined as the polarization voltage value under rated remaining charge, standard ambient magnetic field strength, and standard cable impedance; then, considering the coupling effects of dynamic impedance, remaining charge, and ambient magnetic field strength, through... , , The pairwise coupling effects among the three factors are described separately. Each coupling coefficient is obtained by fitting extensive battery charge-discharge experimental data, accurately reflecting the coupling effect under different combinations of factors. Next, the direct influence of dynamic impedance and ambient magnetic field strength on polarization voltage is considered. and The polarization voltage increments caused by dynamic impedance and ambient magnetic field strength are described separately. These two increments are obtained through experimental calibration and show a linear relationship with dynamic impedance and ambient magnetic field strength, respectively. Finally, the reference polarization voltage is added to the coupling effect term and the direct increment term to obtain the corrected battery polarization voltage data. The polarization voltage correction unit receives dynamic impedance data of the cable. Remaining battery power data Environmental magnetic field strength data Substitute the values ​​into the model for calculation to obtain accurate corrected polarization voltage data.

[0041] The technical effects achieved by this solution include: accurately correcting the battery polarization voltage, fully considering the coupling and direct effects of multiple factors, avoiding the polarization voltage calculation deviation caused by traditional simple correction, and providing accurate battery state parameters for charging power control.

[0042] Traditional data transmission buses have the following technical problems: they use a single channel to transmit data from multiple ends, which leads to mutual interference in data transmission and cannot guarantee the synchronization of data from multiple sources. This results in the data received by subsequent computing units being out of sync, affecting the accuracy of calculations.

[0043] Based on this, the three-terminal data interaction bus includes a power grid-side data transmission channel, a cable-side data transmission channel, and a battery-side data transmission channel. The power grid-side data transmission channel is dedicated to transmitting bidirectional data between the power grid-side data acquisition module and the closed-loop power control unit. The cable-side data transmission channel is dedicated to transmitting bidirectional data between the cable status acquisition module and the cable dynamic impedance calculation unit. The battery-side data transmission channel is dedicated to transmitting bidirectional data between the battery-side data acquisition module and the polarization voltage correction unit. The three data transmission channels work in parallel and achieve data timestamp alignment through a data synchronizer.

[0044] In this technical solution, the three-terminal data interaction bus adopts a three-line parallel architecture, with three independent data transmission channels corresponding to the data transmission needs of the power grid side, cable side, and battery side, respectively. The power grid side data transmission channel uses differential signal transmission to specifically transmit power grid input voltage signals, power grid input current signals, power grid harmonic distortion rate data, and power grid side control signals fed back from the closed-loop power control unit. Differential transmission effectively suppresses electromagnetic interference, ensuring the stability of power grid data transmission. The cable side data transmission channel uses high-speed serial transmission to specifically transmit bending angle signals, core wire temperature signals, current density data, and acquisition control signals fed back from the cable dynamic impedance calculation unit. High-speed serial transmission meets the real-time transmission requirements of cable status data. The battery side data transmission channel uses an anti-interference transmission line to specifically transmit remaining power data, terminal voltage signals, ambient magnetic field strength data, and battery side control signals fed back from the polarization voltage correction unit, adapting to the electromagnetic environment around the battery. The three channels operate in parallel to avoid mutual interference in data transmission. Simultaneously, a data synchronizer timestamps the transmitted data of the three channels, ensuring that each calculation unit receives multi-source data at the same time, providing a synchronous data foundation for subsequent coupled calculations.

[0045] The technical effects achieved by this solution include: enabling independent parallel transmission of data from multiple terminals, avoiding data interference, ensuring the time synchronization of data from multiple sources, providing accurate synchronous data support for coupled operations, and improving the overall computational accuracy of the system.

[0046] Traditional data synchronization suffers from the following technical problems: lack of a dedicated data synchronization mechanism; inconsistent timestamps of multi-source data, causing each computing unit to perform calculations based on data from different times, affecting the accuracy of the calculation results.

[0047] Based on this, the data synchronizer has a built-in timestamp generation submodule and a data alignment submodule. The timestamp generation submodule adds a high-precision timestamp to each transmitted data, and the data alignment submodule matches the data in the power grid side data transmission channel, cable side data transmission channel and battery side data transmission channel according to the same time node based on the high-precision timestamp, so as to ensure that the cable dynamic impedance calculation unit, polarization voltage correction unit and closed-loop power control unit receive multi-source data at the same time.

[0048] In this technical solution, the data synchronizer uses a high-precision clock chip to provide a reference clock signal, with clock accuracy reaching the microsecond level, ensuring the accuracy of the timestamps. The timestamp generation submodule is connected to the transmitting end of the three data transmission channels. When each piece of data is output from the acquisition module, the timestamp generation submodule immediately adds a corresponding high-precision timestamp to the data. The timestamp contains year, month, day, hour, minute, second, and microsecond information, which can uniquely identify the acquisition time of the data. The data alignment submodule is connected to the receiving end of the three data transmission channels, receiving the timestamped data transmitted from each channel. Through a timestamp comparison algorithm, data with the same timestamp or a deviation within a preset threshold in the three channels are determined to be data from the same time and are matched and integrated. For data with a timestamp deviation exceeding the threshold, the data alignment submodule will trigger a retransmission command, requiring the acquisition module to resend the data at the corresponding time. Through this mechanism, the cable dynamic impedance calculation unit can receive bending angle signals, core wire temperature signals, and current density data at the same time. The polarization voltage correction unit can receive cable dynamic impedance data, remaining charge data, and ambient magnetic field strength data at the same time. The closed-loop power control unit can receive corrected polarization voltage data, grid input voltage signal, grid input current signal, and grid harmonic distortion rate data at the same time.

[0049] The technical effects achieved by this solution include: achieving precise time alignment of multi-source data, ensuring that each computing unit performs calculations based on data from the same moment, avoiding calculation errors caused by time deviations, and improving the accuracy of coupled calculations.

[0050] Traditional power control units have the following technical problems: insufficient data preprocessing, simple control command generation logic, inability to perform precise control based on multi-source data, resulting in a large deviation between charging control commands and actual needs.

[0051] Based on this, the closed-loop power control unit includes a data preprocessing submodule, a control command generation submodule, and a command output submodule. The data preprocessing submodule filters and normalizes the received corrected battery polarization voltage data, grid input voltage signal, grid input current signal, and grid harmonic distortion rate data. The control command generation submodule generates charging voltage adjustment commands and charging current adjustment commands based on the preprocessed data and the preset charging control strategy. The command output submodule converts the charging voltage adjustment commands and charging current adjustment commands into control signals that can be recognized by the charging execution module and outputs them.

[0052] In this technical solution, the closed-loop power control unit adopts a three-level processing architecture. The data preprocessing submodule first processes the received multi-source data. The filtering process uses a moving average filtering algorithm to remove random noise from the data and ensure data smoothness. The sliding window size is dynamically adjusted according to the data transmission rate, balancing real-time performance and filtering effect. The normalization process converts data with different dimensions to the same numerical range, eliminating the influence of dimensional differences on subsequent calculations. The normalization method uses the maximum-minimum normalization method to map the data to the range of 0 to 1. The control command generation submodule has a built-in preset charging control strategy. This strategy is formulated based on the charging characteristic curve of the power battery. Based on the preprocessed corrected polarization voltage data, grid input voltage signal, grid input current signal, and grid harmonic distortion rate data, combined with the charging power closed-loop control model, the target charging voltage and current values ​​are calculated, and then charging voltage adjustment commands and charging current adjustment commands are generated. The command output submodule converts the generated digital control commands into analog control signals that the charging execution module can recognize. A digital-to-analog converter chip is used to realize the signal conversion. The conversion accuracy meets the control requirements of the charging execution module, ensuring accurate transmission of control signals.

[0053] The technical effects achieved by this solution include: fully preprocessing multi-source data to eliminate noise and dimensional effects; generating precise control commands through logic to output control signals adapted to actual working conditions, thereby improving the accuracy of charging control.

[0054] Traditional charging power control has the following technical problems: it does not consider the coupling effects of dynamic impedance, polarization voltage, and harmonic distortion rate, and the power calculation is based only on fixed parameters, resulting in a large deviation between the target power value and the actual adapted power, which affects charging efficiency and safety.

[0055] Based on this, the control command generation submodule generates target power values ​​corresponding to the charging voltage adjustment command and the charging current adjustment command through the charging power closed-loop control model. The charging power closed-loop control model is as follows:

[0056] in, The target power value is expressed in kilowatts. The preset charging target power is expressed in kilowatts. The voltage value corresponding to the power grid input voltage signal, with the dimension of volts; The polarization voltage increment caused by dynamic impedance, in volts; The corrected battery polarization voltage data is expressed in volts. This is data on the harmonic distortion rate of the power grid, expressed as a percentage. The harmonic distortion rate influence coefficient is expressed as a percentage. The coupling coefficient between dynamic impedance and harmonic distortion rate is expressed in units of per (ohm·percentage). The control command generation submodule generates charging voltage adjustment commands and charging current adjustment commands based on the target power value and the rated voltage and rated current of the power battery.

[0057] The theoretical design of this technical solution is based on the principle of circuit power balance and the theory of grid harmonic effects. The target power of the charging system needs to be adapted to the grid power supply capacity, cable transmission capacity, and battery receiving capacity simultaneously. Changes in the grid input voltage directly affect the upper limit of the charging power. The polarization voltage increment caused by dynamic impedance and the corrected battery polarization voltage will occupy part of the grid voltage, resulting in a reduction in the effective voltage actually available for charging. The grid harmonic distortion rate affects the power supply quality of the grid. The higher the harmonic content, the lower the effective power supply. At the same time, dynamic impedance will exacerbate the impact of harmonic distortion rate on power. The logical derivation process of the model is as follows: First, with a preset target charging power... Based on this, the value is set according to the rated capacity and charging requirements of the power battery; then, the influence of the grid input voltage, the polarization voltage increment caused by dynamic impedance, and the corrected battery polarization voltage on the effective voltage are considered. The effective voltage percentage is calculated, reflecting the actual voltage share available for charging. A decrease in effective voltage directly leads to a decrease in charging power. Next, the grid harmonic distortion rate and its coupling effect with dynamic impedance are considered. Calculate the harmonic influence factor, which reflects the effect of harmonic distortion rate on the attenuation of charging power. This is the single influence coefficient of harmonic distortion rate. The coupling influence coefficient between dynamic impedance and harmonic distortion rate is given, both of which are obtained by fitting experimental data. Finally, the preset charging target power, effective voltage ratio, and harmonic influence coefficient are multiplied to obtain the final target power value. The control command generation submodule receives... , , , , Substituting parameters into the model, the calculation is obtained. Then, combining the rated voltage and rated current of the power battery, the power formula is used. The target charging voltage and current values ​​are derived, and then charging voltage adjustment commands and charging current adjustment commands are generated. The technical effects achieved by this solution include: accurately calculating the target charging power adapted to the current operating conditions, fully considering the coupling effects of multiple factors such as the power grid, cables, and batteries, ensuring a high degree of matching between the target power and the actual operating conditions, and improving charging efficiency and safety.

[0058] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention in any other way. Any person skilled in the art may make changes or modifications to the above-disclosed technical content to create equivalent embodiments that can be applied to other fields. However, any simple modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the protection scope of the present invention.

Claims

1. A charging system for a new energy locomotive, comprising a grid-side data acquisition module, a cable status acquisition module, a battery-side data acquisition module, a cable dynamic impedance calculation unit, a polarization voltage correction unit, a closed-loop power control unit, and a three-terminal data interaction bus, characterized in that, The grid-side data acquisition module, the cable status acquisition module, and the battery-side data acquisition module establish bidirectional data transmission links with the cable dynamic impedance calculation unit, the polarization voltage correction unit, and the closed-loop power control unit respectively through the three-terminal data interaction bus. The cable dynamic impedance calculation unit receives multi-dimensional status data transmitted by the cable status acquisition module and performs coupling calculations. The polarization voltage correction unit receives the calculation results output by the cable dynamic impedance calculation unit and the battery-related data transmitted by the battery-side data acquisition module and performs correction calculations. The closed-loop power control unit receives the correction results output by the polarization voltage correction unit and the grid-related data transmitted by the grid-side data acquisition module and generates charging control commands. The charging control commands are fed back to the charging execution module through the three-terminal data interaction bus to adjust the charging process.

2. The charging system for new energy locomotives according to claim 1, characterized in that, The power grid-side data acquisition module includes a voltage sensor, a current sensor, and a harmonic detection submodule. The voltage sensor acquires the power grid input voltage signal, the current sensor acquires the power grid input current signal, and the harmonic detection submodule performs spectral analysis on the power grid input voltage signal and the power grid input current signal to obtain power grid harmonic distortion rate data. The power grid input voltage signal, the power grid input current signal, and the power grid harmonic distortion rate data are all transmitted through the three-terminal data interaction bus.

3. The charging system for new energy locomotives according to claim 1, characterized in that, The cable status acquisition module includes an angle sensor, a temperature sensor, and a current density calculation submodule. The angle sensor acquires the bending angle signal of the charging cable, the temperature sensor acquires the core wire temperature signal of the charging cable, and the current density calculation submodule calculates the current density data based on the grid input current signal and the cross-sectional area parameter of the charging cable. The bending angle signal, the core wire temperature signal, and the current density data are all transmitted through the three-terminal data interaction bus.

4. The charging system for new energy locomotives according to claim 1, characterized in that, The battery-side data acquisition module includes a remaining power detection submodule, a terminal voltage sensor, and a magnetic field strength sensor. The remaining power detection submodule acquires the remaining power data of the new energy vehicle's power battery, the terminal voltage sensor acquires the terminal voltage signal of the power battery, and the magnetic field strength sensor acquires the ambient magnetic field strength data around the power battery. The remaining power data, the terminal voltage signal, and the ambient magnetic field strength data are all transmitted through the three-terminal data interaction bus.

5. The charging system for new energy locomotives according to claim 1, characterized in that, The cable dynamic impedance calculation unit executes the cable dynamic impedance calculation model to obtain cable dynamic impedance data. The cable dynamic impedance calculation model is as follows: ； in, This refers to the dynamic impedance data of the cable, in ohms. This is the reference impedance under standard cable conditions, with dimensions in ohms; The angle value corresponding to the bending angle signal of the charging cable, in degrees; This is the temperature value corresponding to the core wire temperature signal of the charging cable, in degrees Celsius. The current density data output by the current density calculation submodule is in the dimension of amperes per square millimeter; The coupling coefficient between the bending angle and temperature is expressed in units of (degrees Celsius). The coupling coefficient between the bending angle and the current density is expressed in units of degree-ampere-millimeter. The coupling coefficient between temperature and current density is expressed in units of (degrees Celsius·amperes per square millimeter). The three-dimensional coupling coefficient of bending angle, temperature and current density is expressed in units of (degrees Celsius amperes per square millimeter). The temperature sensitivity coefficient of the cable impedance, measured in degrees Celsius; This is the reference temperature under standard cable conditions, measured in degrees Celsius.

6. The charging system for new energy locomotives according to claim 5, characterized in that, The polarization voltage correction unit executes the polarization voltage correction model to obtain the corrected battery polarization voltage data. The polarization voltage correction model is as follows: ； in, The corrected battery polarization voltage data is expressed in volts. This is the reference polarization voltage under standard battery conditions, measured in volts. The output of the cable dynamic impedance calculation unit is the cable dynamic impedance data, with the dimension in ohms; The remaining battery power data output by the remaining battery power detection submodule is expressed as a percentage. The data represents the ambient magnetic field strength collected by a magnetic field strength sensor, with the dimension millitalas. The coupling coefficient between dynamic impedance and residual charge is expressed in units of ohms per percentage. denoted as the coupling coefficient between dynamic impedance and ambient magnetic field strength, with dimensions per (ohm·mtesa). The coupling coefficient between the remaining electric charge and the ambient magnetic field strength is expressed in units of per (percentage millitalas). The polarization voltage increment caused by dynamic impedance, in volts; This represents the polarization voltage increment caused by the ambient magnetic field strength, with dimensions in volts.

7. The charging system for new energy locomotives according to claim 6, characterized in that, The three-terminal data interaction bus includes a power grid-side data transmission channel, a cable-side data transmission channel, and a battery-side data transmission channel. The power grid-side data transmission channel is dedicated to transmitting bidirectional data between the power grid-side data acquisition module and the closed-loop power control unit. The cable-side data transmission channel is dedicated to transmitting bidirectional data between the cable status acquisition module and the cable dynamic impedance calculation unit. The battery-side data transmission channel is dedicated to transmitting bidirectional data between the battery-side data acquisition module and the polarization voltage correction unit. The three data transmission channels work in parallel and are aligned with data timestamps through a data synchronizer.

8. The charging system for new energy locomotives according to claim 7, characterized in that, The data synchronizer has a built-in timestamp generation submodule and a data alignment submodule. The timestamp generation submodule adds a high-precision timestamp to each transmitted data. The data alignment submodule matches the data in the power grid side data transmission channel, the cable side data transmission channel, and the battery side data transmission channel according to the same time node based on the high-precision timestamp, ensuring that the cable dynamic impedance calculation unit, the polarization voltage correction unit, and the closed-loop power control unit receive multi-source data at the same time.

9. The charging system for new energy locomotives according to claim 8, characterized in that, The closed-loop power control unit includes a data preprocessing submodule, a control command generation submodule, and a command output submodule. The data preprocessing submodule filters and normalizes the received corrected battery polarization voltage data, grid input voltage signal, grid input current signal, and grid harmonic distortion rate data. The control command generation submodule generates charging voltage adjustment commands and charging current adjustment commands based on the preprocessed data and a preset charging control strategy. The command output submodule converts the charging voltage adjustment commands and the charging current adjustment commands into control signals that can be recognized by the charging execution module and outputs them.

10. The charging system for new energy locomotives according to claim 9, characterized in that, The control command generation submodule generates the target power values ​​corresponding to the charging voltage adjustment command and the charging current adjustment command through a charging power closed-loop control model. The charging power closed-loop control model is as follows: ； in, The target power value is expressed in kilowatts. The preset charging target power is expressed in kilowatts. The voltage value corresponding to the power grid input voltage signal, with the dimension of volts; The polarization voltage increment caused by dynamic impedance, in volts; The corrected battery polarization voltage data is expressed in volts. This is data on the harmonic distortion rate of the power grid, expressed as a percentage. The harmonic distortion rate influence coefficient is expressed as a percentage. The coupling coefficient between dynamic impedance and harmonic distortion rate is expressed in units of ohms per percentage. The control command generation submodule generates the charging voltage adjustment command and the charging current adjustment command based on the target power value and the rated voltage and rated current of the power battery.

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