Vehicle-mounted fast-charging charger circuit detection system and method

Abstract

The invention relates to the technical field of vehicle-mounted fast-charging chargers, and particularly discloses a vehicle-mounted fast-charging charger circuit detection system and method. The protocol analysis module is used for being connected with a communication interface in the circuit and is used for synchronously analyzing communication protocol data between the circuit and external equipment; the electromagnetic compatibility detection module is used for being connected with a power input end and a signal output end in the circuit; the chip detection module is used for being connected with a chip in the circuit; a data analysis and processing module; through cooperation of the signal acquisition module, the protocol analysis module, the electromagnetic compatibility detection module, the chip detection module and the data analysis and processing module, comprehensive and deep detection can be carried out on the vehicle-mounted fast-charging charger circuit, basic performance parameters and communication protocols can be detected, and the detection precision is improved. And hidden faults and complex electromagnetic compatibility problems in the chip can be accurately found, and the accuracy and reliability of detection are improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of in-vehicle fast chargers, and particularly relates to an in-vehicle fast charger circuit detection system and method. Background Technique

[0002] The in-vehicle fast charger circuit is an in-vehicle charging device for electric vehicles or hybrid vehicles, which mainly shortens the charging time through fast charging technology to improve the user experience. At present, the detection method of the in-vehicle fast charger circuit usually requires the use of special automated test equipment for comprehensive performance testing and fault detection;

[0003] For example, Chinese Patent Document with the application number 201310522070.9 discloses a detection device for an in-vehicle charger. The detection device is that the BMS host computer is respectively connected to the in-vehicle charger through an electronic power meter and a PCAN; the low-voltage output terminal of the in-vehicle charger is connected to a low-voltage electronic load, and the high-voltage output terminal of the in-vehicle charger is connected to a high-voltage electronic load and an oscilloscope to simulate the real vehicle CAN communication state and send and receive commands; the in-vehicle charger is comprehensively detected through the detection software on the BMS host computer and the oscilloscope. The advantages of this invention are: 1. It can conveniently and quickly conduct a comprehensive detection of the in-vehicle charger; 2. The cost of the electrical components used is relatively low, which maximally reduces the production cost; 3. Using an electronic load instead of a real vehicle makes the detection convenient and fast;

[0004] However, although the above detection device can conduct a comprehensive detection, it mainly focuses on the detection of the basic performance and communication aspects of the charger circuit. For some complex and deep-seated circuit faults, such as hidden faults inside the chip and complex electromagnetic compatibility problems, it may not be able to accurately detect and locate, thus affecting the accuracy of the detection. Therefore, we need to propose an in-vehicle fast charger circuit detection system and method to solve the above existing problems, so that it can conduct a comprehensive and in-depth detection of the in-vehicle fast charger circuit, improving the accuracy and reliability of the detection. Summary of the Invention

[0005] The purpose of the present invention is to provide an in-vehicle fast charger circuit detection system and method, which can conduct a comprehensive and in-depth detection of the in-vehicle fast charger circuit, not only detecting basic performance parameters and communication protocols, but also accurately discovering hidden faults inside the chip and complex electromagnetic compatibility problems, improving the accuracy and reliability of the detection, so as to solve the problems raised in the above background technique.

[0006] To achieve the above purpose, the present invention adopts the following technical solutions:

[0007] In-vehicle fast charging charger circuit detection system, comprising: a signal acquisition module, which collects basic parameter electrical signals of voltage, current and frequency in the circuit in real time through a sensor group;

[0008] A protocol analysis module connected to the communication interface in the circuit, which is used to synchronously analyze the communication protocol data between the circuit and external devices;

[0009] An electromagnetic compatibility detection module connected to the power input end and signal output end in the circuit, which is used to perform EMI detection and EMS detection on the circuit respectively;

[0010] A chip detection module connected to the chip in the circuit, which is used to perform functional tests and electrical characteristic tests on the chips in the circuit;

[0011] A data analysis and processing module, which receives all the data from each module and performs comprehensive analysis and processing, identifies potential faults and abnormal conditions in the circuit, then generates a diagnostic report according to the identification results, and gives fault information and maintenance suggestions;

[0012] The data analysis and processing module is electrically connected to the signal acquisition module, the protocol analysis module, the electromagnetic compatibility detection module and the chip detection module respectively.

[0013] Preferably, the signal acquisition module includes a sensor group and a signal conditioning unit, the sensor group includes a voltage sensor, a current sensor and a frequency counter, and the voltage sensor, the current sensor and the frequency counter are all connected to the signal conditioning unit.

[0014] Preferably, the protocol analysis module includes a signal receiving unit, a signal decoding unit and a protocol verification unit, the signal receiving unit is electrically connected to the signal decoding unit, the signal decoding unit is electrically connected to the protocol verification unit, and the signal receiving unit receives the communication signal between the in-vehicle fast charging charger and external devices through a communication interface circuit.

[0015] Preferably, the process of the signal decoding unit synchronously analyzing the communication protocol data is as follows:

[0016] A1. According to the data frame format specified by the fast charging protocol, find the start bit, end bit, frame header and frame tail flags in the signal, and split the continuous signal into individual data frames;

[0017] A2. Extract information such as instruction code, data format, and transmission rate from the data frame according to the field order and length specified by the protocol;

[0018] A3. Use a decoding algorithm to convert the extracted information into the original binary data.

[0019] Preferably, the protocol verification unit detects whether there is an error or abnormality through the following process:

[0020] B1. Check whether the format of the decoded data frame conforms to the protocol standard. The data frame format includes the order, length, and value range of fields;

[0021] B2. According to the checksum algorithm specified in the protocol, calculate certain fields in the data frame to obtain the calculated checksum value, and then compare the calculated checksum value with the checksum value carried in the data frame. If the checksum values are not equal, it indicates that an error occurred during data transmission;

[0022] B3. Construct a state machine based on the state transition diagram of the fast charging protocol. According to the received instructions and data, determine whether the current protocol is converted as expected. If the state transition does not conform to the protocol regulations, it indicates that there is a protocol abnormality.

[0023] Preferably, the electromagnetic compatibility detection module includes an EMI detection unit for measuring the electromagnetic radiation and conducted interference signals generated when the in-vehicle fast charging charger circuit operates, and an EMS detection unit for evaluating the anti-interference ability of the in-vehicle fast charging charger circuit. Both the EMI detection unit and the EMS detection unit are connected to the data analysis and processing module.

[0024] Preferably, the process of the EMI detection unit measuring electromagnetic radiation and conducted interference signals is as follows:

[0025] C1. Place the in-vehicle fast charging charger in an electromagnetic shielding chamber, and use a near-field probe to approach various parts of the in-vehicle fast charging charger circuit to collect electromagnetic radiation signals;

[0026] C2. Connect a conducted interference measurement device to the power line of the in-vehicle fast charging charger circuit to measure the electromagnetic interference signals transmitted by the in-vehicle fast charging charger circuit to the power grid through the power line;

[0027] C3. Perform frequency-domain signal conversion on the collected electromagnetic radiation signals and electromagnetic interference signals. The frequency-domain signal conversion formula is:

[0028] k = 0, 1, …, N - 1, where X(k) is the k-th component of the frequency-domain signal, x(m) is the m-th sampling point of the time-domain signal, N is the number of sampling points, k is the frequency-domain index used to represent different frequency points, k takes values from 0 to N - 1, m is the time-domain index used to traverse all sampling points, and j is the imaginary unit;

[0029] C4. Compare the electromagnetic radiation intensity or conducted interference intensity at different frequency points with the limits specified in the relevant standards to determine whether the standards are met. If the electromagnetic radiation or conducted interference intensity at this frequency point meets the standards, there is no electromagnetic interference problem in the in-vehicle fast charger circuit. If the electromagnetic radiation or conducted interference signal at this frequency point does not meet the standards, there is an electromagnetic interference problem in the in-vehicle fast charger circuit.

[0030] Preferably, the chip detection module includes a boundary scan unit for testing the internal logic circuit function of the chip and a chip detection unit for testing the electrical characteristics of the chip. Both the boundary scan unit and the chip detection unit are connected to the data analysis and processing module.

[0031] Preferably, the data analysis and processing module performs comprehensive analysis and processing through an embedded processor. The analysis and processing process is as follows:

[0032] H1. Convert the data output by different modules received into a unified format;

[0033] H2. Extract features for each module according to the converted data;

[0034] H3. Compare the extracted data features with the features in the normal mode to confirm whether there are potential faults. If there are no potential faults, repeat steps H1 - H3; if there are potential faults, determine the fault location and enter H4;

[0035] H4. After identifying potential faults, use a positioning algorithm to determine the location of the faults;

[0036] H5. Generate a detailed diagnostic report based on the analysis results and give maintenance suggestions; the diagnostic report contains information such as the type of fault, the location where the fault occurred, and the severity assessment of the fault.

[0037] Based on the in-vehicle fast charger circuit detection system described above, the present invention also provides an in-vehicle fast charger circuit detection method, including the following steps:

[0038] S1. Connect the in-vehicle fast charger circuit to the signal acquisition module, protocol analysis module, electromagnetic compatibility detection module, and chip detection module;

[0039] S2. Start the in-vehicle fast charger circuit for charging work, and perform initialization settings on the signal acquisition module, protocol analysis module, electromagnetic compatibility detection module, and chip detection module to enable each module to work properly;

[0040] S3. Real-time collect the basic parameter electrical signals of voltage, current, and frequency in the in-vehicle fast charger circuit through the signal acquisition module, and transmit the basic parameter electrical signals to the data analysis and processing module;

[0041] S4. The protocol parsing module synchronously parses the communication protocol data between the in-vehicle fast charging charger circuit and the external device, and transmits the parsed protocol data to the data analysis and processing module;

[0042] S5. The electromagnetic compatibility detection module performs EMI detection and EMS detection on the in-vehicle fast charging charger circuit respectively, obtains the electromagnetic radiation and conduction interference capabilities and anti-interference capabilities generated by the in-vehicle fast charging charger circuit, and transmits the detection results to the data analysis and processing module;

[0043] S6. The chip detection module performs functional tests and electrical characteristic tests on the chips in the in-vehicle fast charging charger circuit, obtains chip-related data and transmits it to the data analysis and processing module;

[0044] S7. The data analysis and processing module performs comprehensive analysis and processing based on all the received data, identifies potential faults and abnormal conditions in the in-vehicle fast charging charger circuit, generates a diagnostic report according to the identification results, and gives fault information and repair suggestions.

[0045] The in-vehicle fast charging charger circuit detection system and method proposed by the present invention have the following advantages compared with the prior art:

[0046] 1. Through the coordinated cooperation of the signal acquisition module, protocol parsing module, electromagnetic compatibility detection module, chip detection module and data analysis and processing module, the present invention can comprehensively and deeply detect the in-vehicle fast charging charger circuit, not only can detect basic performance parameters and communication protocols, but also can accurately discover hidden faults inside the chips and complex electromagnetic compatibility problems, improving the accuracy and reliability of detection.

[0047] 2. By comprehensively analyzing and processing the basic parameters of the in-vehicle fast charging charger circuit, the communication protocol data with external devices, the electromagnetic radiation and conduction interference signals generated by the in-vehicle fast charging charger circuit, the anti-interference capabilities and chip-related data, the present invention can achieve comprehensive and accurate detection of the in-vehicle fast charging charger circuit, timely discover various potential faults and problems, improve the accuracy and efficiency of fault detection, and reduce errors and missed detections in manual detection. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] Figure 1 Shows a system block diagram of the detection system according to an embodiment of the present invention;

[0049] Figure 2 Shows a flow block diagram of the signal decoding unit synchronously parsing the communication protocol data according to an embodiment of the present invention;

[0050] Figure 3The flowchart showing the measurement of electromagnetic radiation and conducted interference signals by the EMI detection unit according to an embodiment of the present invention is presented;

[0051] Figure 4 The flowchart showing the comprehensive analysis and processing by the data analysis and processing module through an embedded processor according to an embodiment of the present invention is presented;

[0052] Figure 5 The flowchart showing the circuit detection method according to an embodiment of the present invention is presented. Detailed implementation manners

[0053] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. The specific embodiments described herein are only used to explain the present invention, and are not used to limit the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0054] The present invention provides a vehicle-mounted fast charging charger circuit detection system as Figures 1-4 shown, which includes a signal acquisition module, a protocol analysis module for connecting to a communication interface in the vehicle-mounted fast charging charger circuit, an electromagnetic compatibility detection module for connecting to a power input end and a signal output end in the vehicle-mounted fast charging charger circuit, a chip detection module for connecting to a chip in the vehicle-mounted fast charging charger circuit, and a data analysis and processing module. The data analysis and processing module is electrically connected to the signal acquisition module, the protocol analysis module, the electromagnetic compatibility detection module, and the chip detection module respectively;

[0055] The signal acquisition module real-time collects basic parameter electrical signals of voltage, current, and frequency in the vehicle-mounted fast charging charger circuit through a sensor group, and transmits the basic parameter electrical signals to the data analysis and processing module. The voltage and current signals output by the signal acquisition module are analog signal sampling data, and the frequency signal is digital counting data;

[0056] The signal acquisition module includes a sensor group and a signal conditioning unit. The sensor group includes a voltage sensor, a current sensor, and a frequency counter. The voltage sensor, the current sensor, and the frequency counter are all connected to the signal conditioning unit. The voltage and current signals in the circuit are collected through the voltage sensor and the current sensor, and the frequency signal is collected using the frequency counter. Then, the signal output by the sensor group is amplified and filtered by the signal conditioning unit to improve the signal quality, and the processed signal is transmitted to the data analysis and processing module.

[0057] The protocol parsing module is used to synchronously parse the communication protocol data between the in-vehicle fast charger circuit and external devices, and transmit the parsed protocol data to the data analysis and processing module. The character instruction data output by the protocol parsing module is the parsed communication protocol instruction, such as a charging instruction, a data transmission instruction, etc.

[0058] The protocol parsing module includes a signal receiving unit, a signal decoding unit, and a protocol verification unit. The signal receiving unit is electrically connected to the signal decoding unit, and the signal decoding unit is electrically connected to the protocol verification unit. The signal receiving unit receives the communication signal between the in-vehicle fast charger and external devices through a communication interface circuit; the signal decoding unit decodes the received signal according to the standard specifications of the fast charging protocol, and extracts information on instruction codes, data formats, and transmission rates; the protocol verification unit compares the decoded information with the protocol standard to judge the correctness and integrity of the protocol, and detects whether there are errors or abnormalities. The protocol verification unit mainly detects errors or abnormalities in the communication protocol itself, such as data frame format errors, checksum errors, protocol state transition abnormalities, etc.

[0059] The signal receiving unit is connected to the communication lines of the in-vehicle fast charger and external devices through a USB or CAN communication interface, sets the working mode and baud rate parameters of the interface circuit to match the format of the communication signal, and then starts the receiving program to continuously monitor the signals on the communication line.

[0060] The process of the signal decoding unit synchronously parsing the communication protocol data is as follows:

[0061] A1. According to the data frame format specified by the fast charging protocol, find the start bit, end bit, and frame header and frame tail flags in the signal, and divide the continuous signal into individual data frames;

[0062] A2. Extract the information on instruction codes, data formats, and transmission rates from the data frames according to the field order and length specified by the protocol;

[0063] A3. Use a decoding algorithm to convert the extracted information into the original binary data. The formula of the decoding algorithm is:

[0064] If V(0.5T) - V(0) > 0, the bit is 0; if V(0.5T) - V(0) < 0, the bit is 1, where V(0) is the level at the start time of the bit period, T is the bit period, and V(0.5T) is the level at the middle time of the bit period;

[0065] The process of the protocol verification unit detecting whether there are errors or abnormalities is as follows:

[0066] B1. Check whether the format of the decoded data frame conforms to the protocol standard. The data frame format includes the order, length, and value range of the fields.

[0067] B2. According to the checksum algorithm specified in the protocol, calculate certain fields in the data frame to obtain the calculated checksum value, and then compare the calculated checksum value with the checksum value carried in the data frame. If the checksum value is not equal to the checksum value carried in the data frame, it indicates that an error occurred during data transmission. The formula for the checksum algorithm is:

[0068] where C is the checksum, d i represents the i-th byte in the data, and n is the total number of bytes in the data.

[0069] Among them, the calculated checksum value is obtained by calculating the specified fields in the data frame according to the algorithm specified in the protocol, and is used to verify the correctness of data transmission. The checksum value carried in the data frame is obtained by the sender when constructing the data frame. According to the requirements of the protocol (such as the fast charging protocol), key fields in the data frame (such as instruction codes, data contents, etc.) are selected, and a conventional checksum algorithm (such as cumulative sum, CRC cyclic redundancy check, etc.) is used for calculation to obtain a checksum value. This value will be added to a specific position in the data frame (such as the frame tail) as the basis for data integrity verification.

[0070] B3. Construct a state machine based on the state transition diagram of the fast charging protocol. According to the received instructions and data, judge whether the current protocol is converted as expected. If the state transition does not conform to the protocol regulations, it indicates that there is a protocol anomaly.

[0071] Among them, the state machine is a mathematical model used to describe the state transition process of the protocol under different input conditions. The state machine consists of a state set, an input set, a state transition function, and an output function. According to the state transition diagram of the fast charging protocol, various states of the protocol (such as standby state, handshake state, charging state, etc.) and the transition conditions and transition methods between states are defined. Through this state machine, it is monitored whether the execution of the protocol meets the expectations.

[0072] The electromagnetic compatibility detection module performs EMI detection and EMS detection on the in-vehicle fast charging charger circuit respectively, obtains the electromagnetic radiation and conduction interference capabilities and anti-interference capabilities generated by the in-vehicle fast charging charger circuit, and transmits the detection results to the data analysis and processing module.

[0073] The electromagnetic compatibility detection module includes an EMI detection unit for measuring the electromagnetic radiation and conducted interference signals generated during the operation of the in-vehicle fast charger circuit, and an EMS detection unit for evaluating the anti-interference ability of the in-vehicle fast charger circuit. Both the EMI detection unit and the EMS detection unit are connected to the data analysis and processing module. The unit of the electromagnetic radiation intensity data output by the EMI detection unit is dBμV / m, the unit of the conducted interference voltage data is dBμV, and the unit of the conducted interference current data is dBμA. The anti-interference ability detection results output by the EMS detection unit include the operating status and performance indicators of the charger under different interference intensities. The unit of the chip pin resistance data output by the chip detection module is Ω, the unit of the capacitance data is F, and the unit of the leakage current data is A. In addition, it also includes chip test instructions and corresponding response data. The EMI detection unit and the EMS detection unit mainly detect problems in electromagnetic compatibility, such as excessive electromagnetic radiation and insufficient anti-interference ability.

[0074] The process of the EMI detection unit for measuring electromagnetic radiation and conducted interference signals is as follows:

[0075] C1. Place the in-vehicle fast charger in an electromagnetic shielding chamber, and use a near-field probe to approach various parts of the in-vehicle fast charger circuit to collect electromagnetic radiation signals. The near-field probe is placed at the input / output interfaces, power conversion modules, and key parts of the control circuit board of the in-vehicle charger for scanning according to the actual electromagnetic radiation collection requirements, which can effectively locate the electromagnetic radiation source.

[0076] C2. Connect a conducted interference measurement device to the power line of the in-vehicle fast charger circuit to measure the electromagnetic interference signals transmitted by the in-vehicle fast charger circuit to the power grid through the power line.

[0077] C3. Perform frequency-domain signal conversion on the collected electromagnetic radiation signals and electromagnetic interference signals. The frequency-domain signal conversion formula is:

[0078] k = 0, 1, …, N - 1, where X(k) is the k-th component of the frequency-domain signal, x(m) is the m-th sampling point of the time-domain signal, N is the number of sampling points, k is the frequency-domain index used to represent different frequency points, k takes values from 0 to N - 1, m is the time-domain index used to traverse all sampling points, j is the imaginary unit, and e is the base of the natural logarithm, which is used to convert the time-domain signal x(m) to the frequency-domain representation X(k).

[0079] C4. Compare the electromagnetic radiation intensity or conducted interference intensity at different frequency points with the limits specified in the relevant standards to determine compliance. If the electromagnetic radiation or conducted interference intensity at this frequency point meets the standard, that is, the measured electromagnetic radiation intensity or conducted interference intensity is less than or equal to the standard electromagnetic radiation intensity or conducted interference intensity value, then there is no electromagnetic interference problem in the in-vehicle fast charger circuit. If the electromagnetic radiation or conducted interference signal at this frequency point does not meet the standard, that is, the measured electromagnetic radiation intensity or conducted interference intensity is greater than the standard electromagnetic radiation intensity or conducted interference intensity value, then there is an electromagnetic interference problem in the in-vehicle fast charger circuit. The relevant standards are set as CISPR or RN series standards.

[0080] The process for the EMS detection unit to perform anti-interference ability detection is as follows:

[0081] D1. Use an electromagnetic interference generator to generate electromagnetic interference signals of different types and intensities;

[0082] The formula for the electromagnetic interference generator to generate electromagnetic interference signals is:

[0083] Among them, V(k) is the voltage signal that changes with time, V g is the peak voltage of the signal, that is, the maximum voltage value that the signal can reach, which determines the intensity of the interference signal, ω is the angular frequency used to determine the frequency characteristics of the signal, t is the time used in the signal change process, is the initial phase that determines the phase state of the signal at the starting moment;

[0084] D2. Apply the generated electromagnetic interference signal to the in-vehicle fast charger through a discharge gun. When applying the electromagnetic interference signal, it is necessary to operate in accordance with the relevant specified methods and positions to ensure the consistency and reliability of the interference;

[0085] D3. When applying the electromagnetic interference signal, use an oscilloscope and a logic analyzer to monitor the output signal and control signal of the in-vehicle fast charger in real time;

[0086] D4. Evaluate the anti-interference ability of the in-vehicle fast charger according to the monitoring results. If the in-vehicle fast charger can maintain normal operation under the specified interference intensity and all performance indicators are within the allowable range, then it is considered that the charger has passed this EMS test; otherwise, if there is a performance degradation, malfunction or failure, it is necessary to further analyze the reasons and take corresponding improvement measures, such as optimizing the circuit design, strengthening electromagnetic shielding, etc., and then conduct the test again until the charger meets the requirements.

[0087] The chip detection module performs functional tests and electrical characteristic tests on the chips in the in-vehicle fast charger circuit, and transmits the chip-related data to the data analysis and processing module;

[0088] The chip detection module includes a boundary scan unit for testing the functions of the internal logic circuit of the chip and a chip detection unit for testing the electrical characteristics of the chip. Both the boundary scan unit and the chip detection unit are connected to the data analysis and processing module.

[0089] The process of the boundary scan unit testing the functions of the internal logic circuit of the chip is as follows:

[0090] E1. Connect the JTAG controller to the JTAG interface of the chip, and initialize the communication link to ensure that signals can be correctly transmitted between the JTAG controller and the chip;

[0091] E2. According to the format and timing specified by the JTAG protocol, the JTAG controller sends control instructions for testing the internal logic circuit and pin states to the chip, and uses the control instructions to control the boundary scan unit inside the chip to perform different types of tests;

[0092] E3. The boundary scan unit performs corresponding operations according to the received control instructions, and the test results are returned to the JTAG controller through the JTAG interface;

[0093] E4. The JTAG controller reads the data scanned by the boundary scan unit, and compares the read data with the pre-set expected results. By checking the data consistency, it can be judged whether the internal logic circuit of the chip is working properly. If data mismatch is found, it means that there are problems such as logic errors, short circuits or open circuits in the chip. The pre-set expected results are set based on industry test standards and specifications. When performing boundary scan tests, according to the standard regulations, for a specific test instruction sequence, the chip should return data in a specific format and content. These standard-specified data are the expected results.

[0094] The process of the chip detection unit testing the electrical characteristics of the chip is as follows;

[0095] F1. Place the chip on the probe station, align the probes with the pins of the chip accurately and make contact, so as to establish an electrical connection between the probes and the chip pins;

[0096] F2. Using the electrical connection provided by the probe station, apply test signals including voltage signals and current signals from an external signal source to the chip pins;

[0097] F3. While applying the test signal, measure the resistance values of each pin, and compare the measured resistance values with the standard values in the chip's specification sheet. If the measured resistance value exceeds the normal range of the standard value, it is determined that there is an abnormality in the electrical performance of the chip. That is, if the resistance value is infinite, there is an open-circuit phenomenon in the chip's pins; if the resistance value approaches 0, there is a short-circuit phenomenon in the chip. If the measured resistance value is within the normal range of the standard value, it is determined that there is no abnormality in the electrical performance of the chip.

[0098] The data analysis and processing module performs comprehensive analysis and processing based on all the received data, identifies potential faults and abnormal conditions existing in the in-vehicle fast charger circuit, generates a diagnostic report according to the identification results, and gives fault information and repair suggestions.

[0099] The data analysis and processing module performs comprehensive analysis and processing through an embedded processor, and the analysis and processing process is as follows:

[0100] H1. Convert the data output by different modules into a unified format; specifically: for the analog signal sampling data (voltage, current) of the signal acquisition module, convert it from its original binary format to a floating-point format. The conversion formula is: floating-point number = binary value × resolution + offset, where the resolution and offset are determined according to the range of the sensor; the digital count data of the frequency signal is directly converted to a floating-point format;

[0101] For the character-type instruction data output by the protocol parsing module, convert it to ASCII encoding format for storage;

[0102] For the electromagnetic radiation intensity data (dBμV / m), conducted interference voltage data (dBμV), and conducted interference current data (dBμA) output by the electromagnetic compatibility detection module, first perform conversion according to the range and resolution of the sensor, convert the dB value to the actual physical quantity value (such as converting the electromagnetic radiation intensity from dBμV / m to μV / m), and the conversion formula is: physical quantity value = 10 ^ (dB value / 20), and add a timestamp (in the format of YYYY-MM-DD HH:MM:SS.ms) to each detected data. Then, organize the converted electromagnetic radiation intensity and conducted interference data into a structured data format including information such as timestamp, physical quantity value, and detection location;

[0103] For the electrical parameter data such as the pin resistance (Ω), capacitance (F), leakage current (A), etc. obtained by the chip detection module, perform conversion according to the range and resolution of the measuring instrument (such as converting the ADC sampling value into the actual resistance value, and the conversion formula is: resistance value = reference resistance × (2^n - sampling value) / sampling value, where n is the number of bits of the ADC and the reference resistance is a known standard resistance), and add labels to the electrical parameter data of each pin (such as "resistance of pin 1 of chip U1"), indicating the chip to which the pin belongs and the pin number. At the same time, associate the chip test instructions and the corresponding response data, and organize them into a structured data format including information such as instructions, responses, and test time;

[0104] H2. Extract features for each module based on the converted data. The specific operations for feature extraction are as follows: For the data of the signal acquisition module, use the Fast Fourier Transform (FFT) algorithm to convert the voltage and current signals in the time domain into frequency domain signals, and extract their frequency features (such as fundamental frequency, harmonic frequency, and their amplitudes, etc.). Through this Fast Fourier Transform (FFT) algorithm, the spectral distribution of the signal can be obtained to analyze whether there are abnormal frequency components; For the frequency signals, directly extract their numerical features (such as frequency value, frequency stability, etc.), and compare them with the normal working frequency range to determine whether there is frequency abnormality.

[0105] For the data of the protocol parsing module, extract the key information in the communication protocol by parsing specific fields of the protocol data packet, such as the version number of the charging protocol and the charging power negotiation value as features.

[0106] For the data of the electromagnetic compatibility detection module, calculate the mean and variance of the electromagnetic radiation intensity to statistically characterize, as well as features such as the threshold of electromagnetic sensitivity;

[0107] For the data of the chip detection module, perform bit operations on the chip register data to obtain the values of specific function bits and determine whether the working mode of the chip is normal.

[0108] H3. Compare the extracted data features with the features in the normal mode to confirm whether there are potential faults. If there are no potential faults, repeat steps H1 - H3; If there are potential faults, determine the fault location and enter H4;

[0109] Specifically: for the voltage data characteristics of the signal acquisition module, if it exceeds the threshold of the normal operating voltage range, an overvoltage fault may be determined; for the charging power negotiation value of the protocol parsing module, if it does not match the power value specified in the charger specification and exceeds the allowable error range, a charging protocol fault may be determined; for the average value of the electromagnetic radiation intensity of the electromagnetic compatibility detection module, if it exceeds the limit specified by the relevant standard, an excessive electromagnetic radiation fault can be determined; for the error code of the chip detection module, if a specific error code appears, it indicates that the chip may have a certain type of fault, such as a communication fault, a logic error, etc.

[0110] H4. After identifying potential faults, use the location algorithm to determine the location of the faults; specifically: for the faults of the signal acquisition module, the location algorithm determines the specific location of the fault point in the charger circuit through the sensor number or location information; for the faults of the protocol parsing module, the location algorithm analyzes through the communication link status matrix to determine which communication interface or protocol processing unit has problems; the communication link status matrix formula is:

[0111] where h is the total number of horizontal nodes in the communication link, c is the total number of vertical nodes in the communication link, M is the communication link status matrix, when M ch = 1, it indicates that the communication from node c to node h is normal, when M ch = 0, it indicates that the communication from node c to node h is abnormal;

[0112] For the faults of the electromagnetic compatibility detection module, the location algorithm locates the faults based on the electromagnetic radiation gradient, calculates the gradient in the x direction in space, and determines the fault source location by finding the maximum value point. The calculation formula is:

[0113]

[0114]

[0115]

[0116] where and are the gradient components of the electromagnetic radiation intensity in the x, y, and z directions respectively, I(x, y, z) is the electromagnetic radiation intensity measured at the coordinate (x, y, z), and Δx, Δy, and Δz are the small displacement increments in the x, y, and z directions respectively;

[0117] For the faults of the chip detection module, the location algorithm locates based on the logic gate circuit fault analysis. The logic gate circuit output formula is:

[0118] Among them, Y is the output of the logic gate, l is the number of inputs of the logic gate, and X b is the b-th input variable of the logic gate. When X b = 1, the logic gate works normally, indicating no fault. When X b = 0, the logic gate cannot work, indicating a fault exists.

[0119] H5. Generate a detailed diagnostic report based on the analysis results and give maintenance suggestions; the diagnostic report includes information such as the type of fault, the location where the fault occurred, and the assessment of the severity of the fault.

[0120] The maintenance suggestions include: for the faulty chip, it is recommended to replace the chip with a specific model; for the problem of excessive electromagnetic radiation, it is recommended to take shielding measures or replace components with better electromagnetic compatibility; the maintenance suggestions should be operable so that maintenance personnel can perform effective maintenance and debugging according to the report.

[0121] The data analysis and processing module compares the extracted data features with the features in the normal mode. It is a comprehensive fault detection and potential fault identification from the overall system level. It not only includes the types of faults detected by each module separately, but also can detect abnormal situations that occur in the association between modules and some potential faults that are hidden and require comprehensive data from multiple aspects to judge. The specific association methods are as follows:

[0122] The protocol errors or abnormal data detected by the protocol parsing module will be transmitted as the output data of the protocol parsing module to the data analysis and processing module. When the data analysis and processing module performs feature extraction, it will compare these protocol-related features (such as protocol version number, charging power negotiation value, etc.) with the features in the normal mode. If the protocol parsing module has determined that there are protocol errors or abnormalities, the data analysis and processing module will further analyze the impact of this abnormality on the operation of the entire system and whether there are other associated faults;

[0123] The data of excessive electromagnetic radiation or insufficient anti-interference ability detected by the electromagnetic compatibility detection module will be transmitted as the output data of the electromagnetic compatibility detection module to the data analysis and processing module. When the data analysis and processing module performs feature extraction, it will compare the statistical features of the mean and variance of the electromagnetic radiation intensity and the features of the threshold of electromagnetic sensitivity with the features in the normal mode. If the electromagnetic compatibility detection module has determined that there are electromagnetic interference problems, the data analysis and processing module will combine the data of other modules (such as voltage and current data of the signal acquisition module, chip working state data of the chip detection module, etc.) and comprehensively analyze the impact of this electromagnetic interference problem on other parts of the circuit and whether there are other potential faults caused by electromagnetic interference;

[0124] In addition to the faults detected by each module individually, the data analysis and processing module can also discover some potential faults that cannot be detected by individual modules through comprehensive analysis of the data characteristics of each module. For example, when the voltage and current data of the signal acquisition module show abnormal fluctuations, while the protocol parsing module and the electromagnetic compatibility detection module do not detect obvious abnormalities, the data analysis and processing module may discover potential faults such as component aging and poor contact in the circuit by comparing these data characteristics with those in the normal mode.

[0125] Through the data analysis and processing module, it is possible to quickly locate the fault location based on the data provided by each module and give a detailed diagnosis result, helping the maintenance personnel to repair in a timely and accurate manner, reducing the fault troubleshooting time and maintenance cost.

[0126] Through the coordinated cooperation of the signal acquisition module, the protocol parsing module, the electromagnetic compatibility detection module, the chip detection module, and the data analysis and processing module, it is possible to conduct a comprehensive and in-depth detection of the in-vehicle fast charger circuit. It can not only detect basic performance parameters and communication protocols, but also accurately discover hidden faults inside the chip and complex electromagnetic compatibility problems, improving the accuracy and reliability of the detection.

[0127] Based on the in-vehicle fast charger circuit detection system described above, the present invention also provides an in-vehicle fast charger circuit detection method, as Figure 5 shown, including the following steps:

[0128] S1. Connect the in-vehicle fast charger circuit to the signal acquisition module, the protocol parsing module, the electromagnetic compatibility detection module, and the chip detection module;

[0129] S2. Start the in-vehicle fast charger circuit to perform the charging operation, and perform initialization settings on the signal acquisition module, the protocol parsing module, the electromagnetic compatibility detection module, and the chip detection module to enable each module to work properly;

[0130] S3. Through the signal acquisition module, real-time collect the basic parameter electrical signals of voltage, current, and frequency in the in-vehicle fast charger circuit, and transmit the basic parameter electrical signals to the data analysis and processing module;

[0131] S4. Through the protocol parsing module, synchronously parse the communication protocol data between the in-vehicle fast charger circuit and external devices, and transmit the parsed protocol data to the data analysis and processing module;

[0132] S5. Through the electromagnetic compatibility detection module, perform EMI detection and EMS detection on the in-vehicle fast charger circuit respectively to obtain the electromagnetic radiation and conducted interference capabilities and anti-interference capabilities generated by the in-vehicle fast charger circuit, and transmit the detection results to the data analysis and processing module;

[0133] S6. The chip detection module performs functional tests and electrical characteristic tests on the chips in the in-vehicle fast charger circuit, and transmits the chip-related data to the data analysis and processing module;

[0134] S7. The data analysis and processing module performs comprehensive analysis and processing based on all the received data, identifies potential faults and abnormal conditions existing in the in-vehicle fast charger circuit, generates a diagnostic report according to the identification results, and gives fault information and repair suggestions.

[0135] By comprehensively analyzing and processing the basic parameters of the in-vehicle fast charger circuit, the communication protocol data with external devices, the electromagnetic radiation and conducted interference signals generated by the in-vehicle fast charger circuit, the anti-interference ability, and the chip-related data, it is possible to achieve a comprehensive and accurate detection of the in-vehicle fast charger circuit, timely discover various potential faults and problems, improve the accuracy and efficiency of fault detection, and reduce the errors and missed detections of manual detection.

[0136] It should be noted that the in-vehicle fast charger circuit used in the present invention is a well-known common sense technology in the art. For example, the Chinese patent document with the application number 202021333432.1 discloses a fast charging in-vehicle charger circuit, including a capacitor C1, a capacitor C2, a buck chip U1 of model IP6520, an inductor L1, a capacitor C3, a capacitor C4, and an output port (20). The positive electrode of the capacitor C1 is respectively connected to one end of the vehicle battery (10), one end of the capacitor C2, and the pin 2 of the buck chip U1. The negative electrode of the capacitor C1 is respectively connected to the other end of the vehicle battery (10), the other end of the capacitor C2, and the ground terminal. One end of the inductor L1 is respectively connected to one end of the capacitor C3, the pin 3 of the buck chip U1, and the ground terminal. The other end of the capacitor C3 is connected to the pin 4 of the buck chip U1. The other end of the inductor L1 is respectively connected to the pin 1 of the buck chip U1, the positive electrode of the capacitor C4, and the input end of the output port (20). The negative electrode of the capacitor C4 is respectively connected to the ground terminal and the input end of the output port (20).

[0137] The connection method of each module in the in-vehicle fast charger circuit detection system of the present invention to the fast charging in-vehicle charger circuit is as follows: One end of the voltage sensor is connected to the line where the positive electrode of the capacitor C1 is connected to the vehicle battery 10, for collecting the input DC voltage signal; the other end is connected to the line where the pin 1 of the buck chip U1 is connected to the inductor L1, the capacitor C4, and the output port 20, for collecting the output DC voltage signal.

[0138] The current sensor is connected in series to the line where the vehicle battery 10 is connected to the positive electrode of the capacitor C1, for collecting the charging input current; or connected in series to the line where the inductor L1 is connected to the output port 20, for collecting the output charging current;

[0139] If the fast - charging vehicle charger has a dedicated communication interface (such as a CAN interface, a USB interface, etc.) for communicating with external devices, the protocol parsing module is connected to this communication interface through the corresponding interface circuit. For example, if it is a CAN interface, the CAN transceiver of the protocol parsing module is connected to the CAN interface pins of the vehicle charger to receive and send the fast - charging protocol signals transmitted on the CAN bus.

[0140] EMI detection unit: The near - field probe can be moved around the charger circuit board, close to components such as capacitors C1, C2, C3, C4, inductor L1, and buck chip U1, to collect the electromagnetic radiation signals generated when these components work. The conducted interference measuring device is connected in series on the power line connecting the automotive battery 10 and the charger, and is used to measure the electromagnetic interference signals transmitted by the charger to the power grid through the power line.

[0141] EMS detection unit: The charger is placed in the test area of the electromagnetic compatibility test system. The interference signals generated by the electromagnetic interference generator are applied to the power line (the line connected to the automotive battery 10) and the signal line (if there are communication signal lines, etc.) of the charger through the coupling device, while monitoring the working state and output signals of the charger.

[0142] Boundary - scan technology (JTAG): It is connected to the buck chip U1 through the JTAG interface. The pins of the JTAG interface are connected to the corresponding JTAG pins on the buck chip U1, generally including pins such as test data input (TDI), test data output (TDO), test clock (TCK), test mode selection (TMS), etc., to realize communication with the internal boundary - scan unit of the chip for chip testing.

[0143] Finally, it should be noted that the above - mentioned are only the preferred embodiments of the present invention and are not used to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, for those skilled in the art, they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements for some of the technical features. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. Vehicle fast charging charger circuit detection system, characterized in that: Including: A signal acquisition module that collects basic parameter electrical signals of voltage, current, and frequency in the circuit in real time through a sensor group; A protocol analysis module connected to the communication interface in the circuit, which is used to synchronously analyze the communication protocol data between the circuit and external devices; An electromagnetic compatibility detection module connected to the power input terminal and signal output terminal in the circuit, which is used to perform EMI detection and EMS detection on the circuit respectively; A chip detection module connected to the chip in the circuit, which is used to perform functional tests and electrical characteristic tests on the chips in the circuit; A data analysis and processing module that receives all data from each module and performs comprehensive analysis and processing, identifies potential faults and abnormal conditions in the circuit, then generates a diagnostic report based on the identification results, and gives fault information and repair suggestions; The data analysis and processing module is electrically connected to the signal acquisition module, the protocol analysis module, the electromagnetic compatibility detection module, and the chip detection module respectively.

2. The in-vehicle fast charging charger circuit detection system according to claim 1, characterized in that: The signal acquisition module includes a sensor group and a signal conditioning unit. The sensor group includes a voltage sensor, a current sensor, and a frequency counter, and the voltage sensor, the current sensor, and the frequency counter are all connected to the signal conditioning unit.

3. The in-vehicle fast charging charger circuit detection system according to claim 2, characterized in that: The protocol analysis module includes a signal receiving unit, a signal decoding unit, and a protocol verification unit. The signal receiving unit is electrically connected to the signal decoding unit, the signal decoding unit is electrically connected to the protocol verification unit, and the signal receiving unit receives the communication signal between the in-vehicle fast charger and external devices through a communication interface circuit.

4. The in-vehicle fast charging charger circuit detection system according to claim 3, wherein: The process of the signal decoding unit synchronously analyzing the communication protocol data is as follows: A1. According to the data frame format specified by the fast charging protocol, find the start bit, end bit, and frame header and frame tail flags in the signal, and split the continuous signal into individual data frames; A2. Extract the information of the instruction code, data format, and transmission rate from the data frame according to the field order and length specified by the protocol; A3. Use a decoding algorithm to convert the extracted information into the original binary data.

5. The in-vehicle fast charging charger circuit detection system according to claim 4, wherein: The process of the protocol verification unit detecting whether there are errors or abnormalities is as follows: B1. Check whether the decoded data frame format conforms to the protocol standard. The data frame format includes the order, length, and value range of the fields; B2. According to the checksum algorithm specified by the protocol, calculate some fields in the data frame to obtain the calculated checksum value, and then compare the calculated checksum value with the checksum value carried in the data frame. If the checksum value is not equal to the checksum value carried in the data frame, it means that an error occurred during data transmission; B3. Construct a state machine based on the state transition diagram of the fast charging protocol, and judge whether the current protocol is converted as expected according to the received instructions and data. If the state transition does not conform to the protocol regulations, it means that there is a protocol anomaly.

6. The in-vehicle fast charging charger circuit detection system according to claim 1, characterized in that: The electromagnetic compatibility detection module includes an EMI detection unit for measuring the electromagnetic radiation and conducted interference signals generated during the operation of the in-vehicle fast charger circuit, and an EMS detection unit for evaluating the anti-interference ability of the in-vehicle fast charger circuit. Both the EMI detection unit and the EMS detection unit are connected to the data analysis and processing module.

7. The in-vehicle fast charging charger circuit detection system according to claim 6, characterized in that: The process of the EMI detection unit measuring the electromagnetic radiation and conducted interference signals is as follows: C1. Place the in-vehicle fast charger in an electromagnetic shielding room, and use a near-field probe to approach each part of the in-vehicle fast charger circuit to collect electromagnetic radiation signals. C2. Connect a conducted interference measurement device to the power line of the in-vehicle fast charger circuit to measure the electromagnetic interference signal transmitted by the in-vehicle fast charger circuit to the power grid through the power line. C3. Perform frequency-domain signal conversion on the collected electromagnetic radiation signals and electromagnetic interference signals. The frequency-domain signal conversion formula is: Wherein, X(k) is the k-th component of the frequency-domain signal, x(m) is the m-th sampling point of the time-domain signal, N is the number of sampling points, k is the frequency-domain index used to represent different frequency points, k ranges from 0 to N-1, m is the time-domain index used to traverse all sampling points, and j is the imaginary unit; C4. Compare the electromagnetic radiation intensity or conducted interference intensity at different frequency points with the limit values specified by relevant standards to determine whether it meets the standards. If the electromagnetic radiation or conducted interference intensity at this frequency point meets the standards, there is no electromagnetic interference problem in the in-vehicle fast charger circuit. If the electromagnetic radiation or conducted interference signal at this frequency point does not meet the standards, there is an electromagnetic interference problem in the in-vehicle fast charger circuit.

8. The in-vehicle fast charging charger circuit detection system according to claim 7, wherein: The chip detection module includes a boundary scan unit for testing the functions of the internal logic circuit of the chip and a chip detection unit for testing the electrical characteristics of the chip. Both the boundary scan unit and the chip detection unit are connected to the data analysis and processing module.

9. The in-vehicle fast charging charger circuit detection system according to claim 8, characterized in that: The data analysis and processing module performs comprehensive analysis and processing through an embedded processor. The analysis and processing process is as follows: H1. Convert the data output by different modules received into a unified format. H2. Extract features for each module based on the converted data. H3. Compare the data features extracted with the features in the normal mode to confirm whether there are potential faults. If there are no potential faults, repeat steps H1 - H3; if there are potential faults, determine the fault location and enter H4. H4. After identifying the potential faults, use a positioning algorithm to determine the location of the faults. H5. Generate a detailed diagnostic report based on the analysis results and give maintenance suggestions; the diagnostic report contains information such as the type of the fault, the location where the fault occurred, and the evaluation of the severity of the fault.

10. A method for detecting a vehicle-mounted fast charging charger circuit, based on the vehicle-mounted fast charging charger circuit detection system according to any one of claims 1-9, characterized in that: It includes the following steps: S1. Connect the in-vehicle fast charger circuit to the signal acquisition module, protocol analysis module, electromagnetic compatibility detection module, and chip detection module. S2. Start the in-vehicle fast charger circuit to perform the charging operation, and perform initialization settings on the signal acquisition module, protocol analysis module, electromagnetic compatibility detection module, and chip detection module to enable each module to work properly. S3. Through the signal acquisition module, collect the basic parameter electrical signals of voltage, current, and frequency in the in-vehicle fast charger circuit in real time, and transmit the basic parameter electrical signals to the data analysis and processing module. S4. The protocol parsing module synchronously parses the communication protocol data between the in-vehicle fast charging charger circuit and external devices, and transmits the parsed protocol data to the data analysis and processing module; S5. The electromagnetic compatibility detection module conducts EMI detection and EMS detection on the in-vehicle fast charging charger circuit respectively, obtains the electromagnetic radiation and conducted interference capabilities and anti-interference capabilities generated by the in-vehicle fast charging charger circuit, and transmits the detection results to the data analysis and processing module; S6. The chip detection module conducts functional tests and electrical characteristic tests on the chips in the in-vehicle fast charging charger circuit, obtains chip-related data and transmits it to the data analysis and processing module; S7. The data analysis and processing module conducts comprehensive analysis and processing based on all the received data, identifies potential faults and abnormal conditions existing in the in-vehicle fast charging charger circuit, generates a diagnostic report according to the identification results, and gives fault information and repair suggestions.

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