A method for monitoring the operating status of a DC charging pile charging module based on multi-parameter sensing

Abstract

The present invention discloses a method for monitoring the operating status of a charging module of a DC charging pile based on multi-parameter perception, by extracting key characterization quantities for safety characterization and setting corresponding index thresholds; determining the physical parameter set required for monitoring the status of the charging module according to the key characterization quantities; carrying out the selection of various types of sensors, and determining the location and number of measurement points; the data edge terminal collects the monitoring data of all sensors, and calculates the key characterization quantities, compares the calculation results of the key characterization quantities with the index thresholds, and gives the status evaluation results; the data edge terminal uploads the monitoring data, the calculation results of the key characterization quantities and the status evaluation results to the monitoring main station; the monitoring main station sends charging module operation and maintenance suggestions and early warning information to the operation and maintenance unit. The present invention uses multi-dimensional data of multi-parameter perception, and the data analysis is more comprehensive and accurate; at the same time, the index threshold fully considers the family characteristics and operating conditions, and the fault location is more accurate and fast.

Description

Technical Field

[0001] The present invention belongs to the technical field of electric vehicle charging pile status monitoring, and in particular relates to a method for monitoring the operating status of a charging module of a DC charging pile based on multi-parameter perception. Background Art

[0002] With the rapid growth of new energy vehicles and their charging infrastructure, inter-city and high-speed fast charging stations provide fast charging services for the majority of users, equipped with high-power DC charging piles (charging power 60kW-650kW). Due to long-term high-power operation and the influence of external environment such as light and rain, the insulation level of key equipment of DC charging piles is prone to decline, which eventually leads to equipment failure. Among them, the charging module (common specifications 15kW, 20kW, 30kW, etc.) is used for efficient conversion of AC and DC power, and is the core component of DC charging piles, which is prone to short circuit and burnout failures. However, the current DC charging pile charging module status monitoring is only displayed on the charging pile screen in the form of fault codes, which makes it difficult to warn of safety hazards and fault risks, and it is impossible to accurately locate the fault point and trace the cause of the fault, which is not conducive to the safe operation and control of DC charging piles. Therefore, how to effectively monitor the real-time operating status of the charging module and accurately predict the risk of faults is a major technical problem. Summary of the invention

[0003] In view of the above-mentioned technical difficulties and shortcomings, the present invention discloses a method for monitoring the operating status of a charging module of a DC charging pile based on multi-parameter perception, which can realize remote real-time monitoring of the charging module, early warning of safety hazards, and precise positioning of faults, effectively ensuring the safe operation of the charging module and improving the quality control level of the DC charging pile.

[0004] The purpose of the present invention can be achieved by the following technical solution: A method for monitoring the operating status of a DC charging pile charging module based on multi-parameter perception, comprising the following steps:

[0005] Step S1: Analyze the causes of safety failures in the operation of the charging module of the DC charging pile, extract key characterization quantities for safety characterization, and set corresponding indicator thresholds;

[0006] The key characterization quantities include:

[0007] Insulation aging / abnormality is characterized by temperature rise and leakage current abnormality of key components;

[0008] Phase-to-phase short circuit is characterized by overcurrent and abnormal temperature rise;

[0009] Single-phase grounding is characterized by overcurrent and leakage current abnormalities;

[0010] Abnormal heat dissipation is characterized by abnormal temperature rise of the charging module;

[0011] Enclosure leakage is characterized by abnormal leakage current;

[0012] Power supply abnormality, internal short circuit of charging module or component failure, characterized by overcurrent, overvoltage or undervoltage;

[0013] The risk of moisture and water intrusion is characterized by humidity;

[0014] When setting the indicator thresholds of key characterization quantities, except for the humidity difference threshold and humidity threshold, all other thresholds are based on the historical operation change characteristics of charging modules of the same specification, and are optimized by comprehensively considering the family characteristics of charging modules of the same batch, ambient temperature, ambient humidity, and the influence of operating load, and comprehensively determining the indicator thresholds of key characterization quantities;

[0015] Step S2: determining a set of physical parameters required for monitoring the charging module status according to key characterization quantities;

[0016] Step S3: According to the physical parameter set required for charging module status monitoring, various sensors are selected and the location and number of measurement points are determined;

[0017] Step S4: The data edge terminal collects monitoring data from all sensors and stores them locally;

[0018] Step S5: The data edge terminal extracts the monitoring data to calculate the key characterization quantity, and compares the calculation result of the key characterization quantity with the indicator threshold to give a status evaluation result;

[0019] Step S6: The data edge terminal uploads the monitoring data, key characterization quantity calculation results and status evaluation results to the monitoring main station;

[0020] Step S7: Based on the status evaluation result, the monitoring master station sends charging module operation and maintenance suggestions and early warning information to the operation and maintenance unit;

[0021] Step S8: Repeat steps S4 to S7 in a loop, the monitoring master station monitors the status of the charging module in real time, updates the status information in a timely manner, and adjusts the operation and maintenance suggestions and warning information.

[0022] Further preferably, in step S1, the corresponding indicator threshold is set as follows:

[0023] For insulation aging / abnormality, set the first threshold of temperature rise and the first threshold of leakage current;

[0024] For phase-to-phase short circuit, set the first current threshold and the second temperature rise threshold;

[0025] For single-phase grounding, a second threshold value of leakage current is set;

[0026] In view of the shell leakage, a third leakage current threshold is set;

[0027] In response to abnormal heat dissipation, set the third temperature rise threshold;

[0028] In case of power supply anomaly, internal short circuit of charging module or component failure, set the first voltage threshold, the second voltage threshold and the second current threshold;

[0029] To address the risks of moisture and water immersion, set the humidity difference threshold and humidity threshold.

[0030] Further preferably, in step S1, the formula for comprehensively determining the threshold of the key characterization quantity indicator is as follows:

[0031] ;

[0032] ;

[0033] Among them, Y is the threshold value of the key characterization indicator determined comprehensively, Refers to the threshold value of key characterization indicators of charging modules of the same specification that change with the running time, t is the running time, F is the batch, T is the ambient temperature, H is the ambient humidity, and L is the running load; , , , They refer to family characteristics, ambient temperature, ambient humidity, and operating load influencing factors respectively; The historical data of the index threshold under the characteristics of the batch F charging module family; It is the historical data of indicator threshold under ambient temperature T; is the standard data of indicator threshold under ambient temperature T; It is the historical data of indicator threshold under ambient humidity H; It is the standard data of indicator threshold under ambient humidity H; It is the historical data of the indicator threshold under the operating load L; It is the standard data of indicator threshold under operating load L.

[0034] Further preferably, in step S2, the set of physical parameters required for monitoring the status of the charging module is divided into two types: electrical parameter signals and environmental signals; wherein the electrical parameter signals include three-phase input AC voltage, AC current, output DC voltage, DC current, and ground current; and the environmental signals include the internal and external ambient temperature and humidity of the charging module, and the surface temperature and humidity of the wiring terminals.

[0035] Further preferably, in step S4, the data edge terminal adopts a classified and graded differentiated acquisition strategy; for the acquisition of electrical parameter signals, a high-frequency sampling strategy is adopted, the sampling frequency reaches above 4.0 kHz, and the sampling time interval is not greater than 0.25 ms; for the acquisition of environmental signals, a low-frequency sampling strategy is adopted, the sampling frequency is below 1.0 Hz, and the sampling time interval is not greater than 1.0 s.

[0036] Further preferably, the data edge terminal in step S5 extracts monitoring data to calculate key characterization quantities, including:

[0037] The humidity of the charging module is equal to the humidity monitoring value inside the charging module;

[0038] The ambient humidity is equal to the external ambient humidity monitoring value of the charging module;

[0039] The temperature rise at the terminal is equal to the difference between the terminal surface temperature and the ambient temperature;

[0040] The temperature rise of the charging module is equal to the difference between the internal temperature of the charging module and the ambient temperature;

[0041] The humidity difference at the terminal is equal to the difference between the surface humidity of the terminal and the ambient humidity;

[0042] The humidity difference of the charging module is equal to the difference between the humidity inside the charging module and the ambient humidity;

[0043] The input current is equal to the effective value of the three-phase input current monitoring data;

[0044] The leakage current is equal to the effective value of the ground loop current monitoring data;

[0045] The output current is equal to the effective value of the output current monitoring data;

[0046] The input voltage is equal to the effective value of the three-phase input voltage monitoring data;

[0047] The output voltage is equal to the effective value of the output voltage monitoring data.

[0048] Further preferably, the calculation result of the key characterization quantity is compared with the index threshold in step S5 to give a status evaluation result, which is divided into two situations: abnormal and normal, including:

[0049] When the temperature rise at a single or multiple terminals is greater than the first temperature rise threshold, and the leakage current monitoring value is greater than the first leakage current threshold, there is an insulation aging or abnormality problem;

[0050] When the input current and the output current are greater than the first current threshold, and the temperature rise at one or more terminals is greater than the second temperature rise threshold, there is an input or output phase short circuit problem;

[0051] When the input current and output current are greater than the first current threshold, and the leakage current monitoring value is greater than the second leakage current threshold, and the temperature rise at a single terminal is greater than the second temperature rise threshold, there is an input or output single-phase grounding problem;

[0052] When the leakage current is greater than the third threshold value of the leakage current, but there is no other obvious monitoring abnormality, there is a shell leakage problem;

[0053] When the temperature rise of the charging module is greater than the third temperature rise threshold, but there are no other obvious monitoring abnormalities, there is a heat dissipation abnormality;

[0054] When the input voltage is lower than the first voltage threshold or greater than the second voltage threshold, there is a power supply overvoltage or undervoltage problem;

[0055] When the input current is greater than the second current threshold, but there are no other obvious monitoring abnormalities, there is a power supply overcurrent problem;

[0056] When the input current is greater than the second current threshold, and the temperature rise at a single terminal is greater than the second temperature rise threshold, there is an internal short circuit problem in the charging module;

[0057] When the output voltage is lower than the first voltage threshold or higher than the second voltage threshold, there is a problem of internal component failure;

[0058] When the humidity of the charging module and the ambient humidity are greater than the humidity threshold, there is a risk of moisture and water immersion;

[0059] When the humidity difference of the charging module is greater than the humidity difference threshold, there is a risk of water ingress and condensation in the charging module;

[0060] When the humidity difference of the wiring terminals is greater than the humidity difference threshold, there is a risk of condensation or water on the wiring terminals.

[0061] Further preferably, when the calculation result of the key characterization quantity does not exceed the index threshold, the charging module status is evaluated as normal, and is further refined into two categories: low risk and high risk:

[0062] ;

[0063] in, represents the i-th key characterization quantity, represents the i-th indicator threshold, Represents the evaluation value of the charging module in normal state; when When it is greater than 2, the charging module status is further evaluated as high risk, otherwise it is low risk.

[0064] Further preferably, the data edge terminal adopts the principle of combining sparse and dense mode to upload the monitoring data. For the monitoring data when the status evaluation result is normal, the uploaded data adopts the sparse mode; for the monitoring data when the status evaluation result is abnormal, the uploaded data adopts the dense mode.

[0065] Compared with the prior art, the present invention has the following advantages:

[0066] 1. The present invention uses multi-dimensional data of multi-parameter perception, and the data analysis is more comprehensive and accurate; at the same time, the indicator threshold fully considers the family characteristics and operating conditions, and the fault location is more accurate and rapid.

[0067] 2. The present invention adopts a high- and low-frequency mixed classification and grading differentiated collection strategy and a sparse and dense data upload strategy, which can not only accurately capture and record the waveform of the fault, but also reduce the amount of data upload, reduce the communication pressure at all levels, and take into account both accurate fault positioning and reliable and fast communication. BRIEF DESCRIPTION OF THE DRAWINGS

[0068] Figure 1 It is a schematic diagram of the method flow of the present invention. DETAILED DESCRIPTION

[0069] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0070] like Figure 1 As shown, a method for monitoring the operating status of a DC charging pile charging module based on multi-parameter perception includes the following steps:

[0071] Step S1: Analyze the causes of safety failures in the operation of the charging module of the DC charging pile, extract key characterization quantities for safety characterization, and set corresponding indicator thresholds;

[0072] Step S2: determining a set of physical parameters required for monitoring the charging module status according to key characterization quantities;

[0073] Step S3: According to the physical parameter set required for charging module status monitoring, various sensors are selected and the location and number of measurement points are determined;

[0074] Step S4: The data edge terminal collects monitoring data from all sensors and stores them locally;

[0075] Step S5: The data edge terminal extracts the monitoring data to calculate the key characterization quantity, and compares the calculation result of the key characterization quantity with the indicator threshold to give a status evaluation result;

[0076] Step S6: The data edge terminal uploads the monitoring data, key characterization quantity calculation results and status evaluation results to the monitoring main station;

[0077] Step S7: Based on the status evaluation result, the monitoring master station sends charging module operation and maintenance suggestions and early warning information to the operation and maintenance unit;

[0078] Step S8: Repeat steps S4 to S7 in a loop, the monitoring master station monitors the status of the charging module in real time, updates the status information in a timely manner, and adjusts the operation and maintenance suggestions and warning information.

[0079] In this embodiment, step S1 specifically includes the following sub-steps:

[0080] S11: Extract key characterization quantities for safety characterization:

[0081] The main causes of charging module operation safety failures are local heating, burning, and cracking caused by equipment insulation aging / abnormality, phase-to-phase short circuit, single-phase grounding, and heat dissipation failures.

[0082] Among them, insulation aging / abnormality is characterized by temperature rise and leakage current abnormality of key components;

[0083] Phase-to-phase short circuit is characterized by overcurrent and abnormal temperature rise;

[0084] Single-phase grounding is characterized by overcurrent and leakage current abnormalities;

[0085] Abnormal heat dissipation is characterized by abnormal temperature rise of the charging module;

[0086] Enclosure leakage is characterized by abnormal leakage current;

[0087] Power supply abnormality, internal short circuit of the charging module or component failure is characterized by overcurrent, overvoltage or undervoltage.

[0088] In addition, excessive humidity inside and outside the charging module or water immersion in key components can also cause safety failure problems. The risk of moisture and water immersion is characterized by humidity.

[0089] S12: Set different indicator thresholds for key characterization quantities involved in operational safety failure issues:

[0090] Among them, for insulation aging / abnormality, the first temperature rise threshold and the first leakage current threshold are set;

[0091] For phase-to-phase short circuit, set the first current threshold and the second temperature rise threshold;

[0092] For single-phase grounding, a second threshold value of leakage current is set;

[0093] In view of the shell leakage, a third leakage current threshold is set;

[0094] In response to abnormal heat dissipation, set the third temperature rise threshold;

[0095] In case of power supply anomaly, internal short circuit of charging module or component failure, set the first voltage threshold, the second voltage threshold and the second current threshold;

[0096] To address the risks of moisture and water immersion, set the humidity difference threshold and humidity threshold.

[0097] Among them, when setting the indicator thresholds of key characterization quantities, except for the humidity difference threshold and humidity threshold, all are based on the historical operation change characteristics of charging modules of the same specification, and are optimized by comprehensively considering the family characteristics of charging modules of the same batch, ambient temperature, ambient humidity, operating load and other influencing factors. The general formula is as follows:

[0098] ;

[0099] ;

[0100] Among them, Y is the threshold value of the key characterization indicator determined comprehensively, Refers to the threshold value of key characterization indicators of charging modules of the same specification that change with the running time, t is the running time, F is the batch, T is the ambient temperature, H is the ambient humidity, and L is the running load; , , , They refer to family characteristics, ambient temperature, ambient humidity, and operating load influencing factors respectively; The historical data of the index threshold under the characteristics of the batch F charging module family; It is the historical data of indicator threshold under ambient temperature T; It is the standard data of indicator threshold under ambient temperature T; It is the historical data of indicator threshold under ambient humidity H; It is the standard data of indicator threshold under ambient humidity H; It is the historical data of the indicator threshold under the operating load L; It is the standard data of the index threshold under the operating load L. The corresponding index threshold of the charging modules of the same batch put into operation earlier can be obtained through monitoring or testing means.

[0101] In step S2 of this embodiment, the physical parameter set required for monitoring the status of the charging module is divided into two types: electrical parameter signals and environmental signals. The electrical parameter signals include three-phase input AC voltage, AC current, output DC voltage, DC current, and ground current; the environmental signals include the internal and external ambient temperature and humidity of the charging module, and the surface temperature and humidity of the wiring terminals.

[0102] Step S3 of this embodiment specifically includes the following steps:

[0103] S31: Selection of sensors for measuring electrical parameter signals. Among them, electrical parameter signals are divided into two categories: current and voltage. For AC and DC current measurement, fluxgate current sensors, Hall current sensors, zero flux current sensors, giant magnetoresistance current sensors, etc. can be selected; for AC and DC voltage measurement, split resistance, split capacitance voltage sensors, Hall voltage sensors, etc. can be selected.

[0104] S32: For the selection of sensors for measuring environmental signals, an integrated temperature and humidity sensor with a flexible substrate can be selected.

[0105] S33: Sensor installation location selection. Install one current sensor each at the three-phase AC input, DC output, and ground loop; install one voltage sensor each at the three-phase AC input and DC output; install one temperature and humidity integrated sensor each at the three-phase AC input and DC output terminals and inside and outside the module.

[0106] In step S4 of this embodiment, the data edge terminal adopts a classified and graded differentiated acquisition strategy. For the acquisition of electrical parameter signals, a high-frequency sampling strategy is adopted, with a sampling frequency of more than 4.0 kHz and a sampling time interval of no more than 0.25 ms; for the acquisition of environmental signals, a low-frequency sampling strategy is adopted, with a sampling frequency of less than 1.0 Hz and a sampling time interval of no more than 1.0 s.

[0107] In addition, the storage period of monitoring data is generally 7 days. In cases of continuous high temperature, rainy weather and high utilization, the storage period can be extended to 14 days or 30 days.

[0108] Step S5 of this embodiment specifically includes the following steps:

[0109] S51: The data edge terminal extracts monitoring data to calculate key characterization quantities:

[0110] The humidity of the charging module is equal to the humidity monitoring value inside the charging module;

[0111] The ambient humidity is equal to the external ambient humidity monitoring value of the charging module;

[0112] The temperature rise at the terminal is equal to the difference between the terminal surface temperature and the ambient temperature;

[0113] The temperature rise of the charging module is equal to the difference between the internal temperature of the charging module and the ambient temperature;

[0114] The humidity difference at the terminal is equal to the difference between the surface humidity of the terminal and the ambient humidity;

[0115] The humidity difference of the charging module is equal to the difference between the humidity inside the charging module and the ambient humidity;

[0116] The input current is equal to the effective value of the three-phase input current monitoring data;

[0117] The leakage current is equal to the effective value of the ground loop current monitoring data;

[0118] The output current is equal to the effective value of the output current monitoring data;

[0119] The input voltage is equal to the effective value of the three-phase input voltage monitoring data;

[0120] The output voltage is equal to the effective value of the output voltage monitoring data.

[0121] S52: Compare the calculation result of the key characterization quantity with the index threshold value and provide a state evaluation result;

[0122] In step S5, the calculation result of the key characterization quantity is compared with the index threshold, and a state evaluation result is given, which is divided into two situations: abnormal and normal, including:

[0123] When the temperature rise at a single or multiple terminals is greater than the first temperature rise threshold, and the leakage current monitoring value is greater than the first leakage current threshold, there is an insulation aging or abnormality problem;

[0124] When the input current and the output current are greater than the first current threshold, and the temperature rise at one or more terminals is greater than the second temperature rise threshold, there is an input or output phase short circuit problem;

[0125] When the input current and output current are greater than the first current threshold, and the leakage current monitoring value is greater than the second leakage current threshold, and the temperature rise at a single terminal is greater than the second temperature rise threshold, there is an input or output single-phase grounding problem;

[0126] When the leakage current is greater than the third threshold value of the leakage current, but there is no other obvious monitoring abnormality, there is a shell leakage problem;

[0127] When the temperature rise of the charging module is greater than the third temperature rise threshold, but there are no other obvious monitoring abnormalities, there is a heat dissipation abnormality;

[0128] When the input voltage is lower than the first voltage threshold or greater than the second voltage threshold, there is a power supply overvoltage or undervoltage problem;

[0129] When the input current is greater than the second current threshold, but there are no other obvious monitoring abnormalities, there is a power supply overcurrent problem;

[0130] When the input current is greater than the second current threshold, and the temperature rise at a single terminal is greater than the second temperature rise threshold, there is an internal short circuit problem in the charging module;

[0131] When the output voltage is lower than the first voltage threshold or higher than the second voltage threshold, there is a problem of internal component failure;

[0132] When the humidity of the charging module and the ambient humidity are greater than the humidity threshold, there is a risk of moisture and water immersion;

[0133] When the humidity difference of the charging module is greater than the humidity difference threshold, there is a risk of water ingress and condensation in the charging module;

[0134] When the humidity difference of the wiring terminals is greater than the humidity difference threshold, there is a risk of condensation or water on the wiring terminals.

[0135] When the calculation result of the key characterization quantity does not exceed the indicator threshold, the charging module status is evaluated as normal, and is further refined into two categories: low risk and high risk:

[0136] ;

[0137] in, represents the i-th key characterization quantity, represents the i-th indicator threshold, Represents the evaluation value of the charging module in normal state; when When it is greater than 2, the charging module status is further evaluated as high risk, otherwise it is low risk.

[0138] In step S6, there are two types of communication links between the data edge terminal and the monitoring master station:

[0139] One is data edge terminal - rail meter - collection terminal (concentrator) - monitoring main station (power consumption information system). The communication between the data edge terminal and the rail meter adopts 485 / CAN communication protocol, the communication between the rail meter and the collection terminal (concentrator) adopts power broadband carrier or low-power wireless, and the communication between the collection terminal (concentrator) and the monitoring main station (power consumption information system) adopts 4G wireless network;

[0140] The other is data edge terminal - aggregation node - monitoring main station. The communication between the data edge terminal and the aggregation node adopts 485 communication protocol or low-power wireless, and the communication between the aggregation node and the monitoring main station adopts 4G wireless network.

[0141] The data edge terminal adopts the principle of combining sparse and dense modes to upload monitoring data. For monitoring data when the status evaluation results are normal, the uploaded data adopts a sparse mode with a large time interval; for monitoring data when the status evaluation results are abnormal, the uploaded data adopts a dense mode with an extremely short time interval.

[0142] Based on the above embodiment, the actual application is as follows: select a 20kW constant power charging module (maximum output voltage 1000V) of a 120kW DC charging pile as the monitoring object. The weather is clear, the ambient temperature is 25°, and the ambient humidity is 56%. When the charging module operates normally at constant power, the input three-phase AC voltage is 380V, the three-phase AC current is 32A, and the output DC voltage is 500V and the DC current is 39A. The specific process is:

[0143] Step 1. Install one current sensor each at the three-phase AC input, DC output, neutral line, and ground line loop; install one voltage sensor each at the three-phase AC input and DC output; install one temperature and humidity integrated sensor each at the three-phase AC input and DC output terminals and inside and outside the module.

[0144] Step 2. Set different indicator thresholds: set the first current threshold to 80A, the second current threshold to 60A, the first leakage current threshold to 5mA, the second leakage current threshold to 10A, the third leakage current threshold to 10mA, the first voltage threshold to 500V, the second voltage threshold to 1200V; the first temperature rise threshold to 40°, the second temperature rise threshold to 70°, the third temperature rise threshold to 30°, the humidity difference threshold to 20%RH, and the humidity threshold to 90%RH.

[0145] Step 3. The data edge terminal collects the output data of each position sensor. Electrical quantity data: three-phase AC input voltage 381V, 380V, 379V, output DC voltage 499V, three-phase AC input current 31A, 32A, 33A, output DC current 39A, neutral current 1A, leakage current 1mA. Ambient temperature and humidity data: The temperature and humidity at the three-phase AC input terminals are: (45°, 57%RH), (46°, 58%RH), (44°, 56%RH), the temperature and humidity at the DC output terminals are: (48°, 56%RH), (49°, 58%RH), the temperature and humidity inside and outside the module are: (58°, 54%RH), (26°, 56%RH).

[0146] Step 4. Calculate the values ​​of all key characterization quantities and compare them with the indicator thresholds. It is found that the temperature rise monitoring value of the charging module reaches 32°, which is greater than the third temperature rise threshold of 30°, while other monitoring values ​​are normal. Therefore, it is suspected that the heat dissipation of the charging module is abnormal. It is recommended that the operation and maintenance unit check whether the module cooling fan is faulty or the heat dissipation port is blocked.

[0147] Step 5: The data edge terminal uploads relevant data to the monitoring main station and issues a warning to the operation and maintenance unit, suggesting that the cooling fan of the charging module be checked for failure or blockage of the cooling port.

[0148] Step 6: The operation and maintenance unit sent personnel to conduct on-site inspection and found that the cooling fan of the charging module was not rotating. After replacing the fan, the status monitoring data was normal.

[0149] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A method for monitoring the operating status of a DC charging pile charging module based on multi-parameter perception, characterized in that: The following steps are involved: Step S1: Analyze the causes of safety failures in the operation of the charging module of the DC charging pile, extract key characterization quantities for safety characterization, and set corresponding indicator thresholds; The key characterization quantities include: Insulation aging / abnormality is characterized by temperature rise and leakage current abnormality of key components; Phase-to-phase short circuit is characterized by overcurrent and abnormal temperature rise; Single-phase grounding is characterized by overcurrent and leakage current abnormalities; Abnormal heat dissipation is characterized by abnormal temperature rise of the charging module; Enclosure leakage is characterized by abnormal leakage current; Power supply abnormality, internal short circuit of charging module or component failure, characterized by overcurrent, overvoltage or undervoltage; The risk of moisture and flooding is characterized by humidity; When setting the indicator thresholds of key characterization quantities, except for the humidity difference threshold and humidity threshold, all other thresholds are based on the historical operation change characteristics of charging modules of the same specification, and are optimized by comprehensively considering the family characteristics of charging modules of the same batch, ambient temperature, ambient humidity, and the influence of operating load, and comprehensively determining the indicator thresholds of key characterization quantities; Step S2: determining a set of physical parameters required for monitoring the charging module status according to key characterization quantities; Step S3: According to the physical parameter set required for charging module status monitoring, various sensors are selected and the location and number of measurement points are determined; Step S4: The data edge terminal collects monitoring data from all sensors and stores them locally; Step S5: The data edge terminal extracts the monitoring data to calculate the key characterization quantity, and compares the calculation result of the key characterization quantity with the indicator threshold to give a status evaluation result; Step S6: The data edge terminal uploads the monitoring data, key characterization quantity calculation results and status evaluation results to the monitoring main station; Step S7: Based on the status evaluation result, the monitoring master station sends charging module operation and maintenance suggestions and early warning information to the operation and maintenance unit; Step S8: Repeat steps S4 to S7 in a loop, the monitoring master station monitors the status of the charging module in real time, updates the status information in a timely manner, and adjusts the operation and maintenance suggestions and warning information.

2. The method for monitoring the operating status of a DC charging pile charging module based on multi-parameter perception according to claim 1 is characterized in that: In step S1, the corresponding indicator thresholds are set as follows: For insulation aging / abnormality, set the first threshold of temperature rise and the first threshold of leakage current; For phase-to-phase short circuit, set the first current threshold and the second temperature rise threshold; For single-phase grounding, a second threshold value of leakage current is set; In view of the shell leakage, a third leakage current threshold is set; In response to abnormal heat dissipation, a third temperature rise threshold is set; In case of power supply anomaly, internal short circuit of charging module or component failure, set the first voltage threshold, the second voltage threshold and the second current threshold; To address the risks of moisture and water immersion, set the humidity difference threshold and humidity threshold.

3. The method for monitoring the operating status of a DC charging pile charging module based on multi-parameter perception according to claim 1 is characterized in that: In step S1, the formula for comprehensively determining the threshold of the key characterization quantity index is as follows: ； ； Among them, Y is the threshold value of the key characterization indicator determined comprehensively, Refers to the threshold value of key characterization indicators of charging modules of the same specification that change with the running time, t is the running time, F is the batch, T is the ambient temperature, H is the ambient humidity, and L is the running load; , , , They refer to family characteristics, ambient temperature, ambient humidity, and operating load influencing factors respectively; The historical data of the index threshold under the characteristics of the batch F charging module family; It is the historical data of indicator threshold under ambient temperature T; is the standard data of indicator threshold under ambient temperature T; It is the historical data of indicator threshold under ambient humidity H; It is the standard data of indicator threshold under ambient humidity H; It is the historical data of the indicator threshold under the operating load L; It is the standard data of indicator threshold under operating load L.

4. The method for monitoring the operating status of a DC charging pile charging module based on multi-parameter perception according to claim 1 is characterized in that: In step S2, the physical parameter set required for monitoring the status of the charging module is divided into two types: electrical parameter signals and environmental signals; among them, the electrical parameter signals include three-phase input AC voltage, AC current, output DC voltage, DC current, and ground current; the environmental signals include the internal and external ambient temperature and humidity of the charging module, and the surface temperature and humidity of the wiring terminals.

5. The method for monitoring the operating status of a DC charging pile charging module based on multi-parameter perception according to claim 1 is characterized in that: In step S4, the data edge terminal adopts a classified and graded differentiated acquisition strategy; for the acquisition of electrical parameter signals, a high-frequency sampling strategy is adopted, the sampling frequency reaches above 4.0 kHz, and the sampling time interval is not greater than 0.25 ms; for the acquisition of environmental signals, a low-frequency sampling strategy is adopted, the sampling frequency is below 1.0 Hz, and the sampling time interval is not greater than 1.0 s.

6. The method for monitoring the operating status of a DC charging pile charging module based on multi-parameter sensing according to claim 1 is characterized in that: In step S5, the data edge terminal extracts monitoring data to calculate key characterization quantities, including: The humidity of the charging module is equal to the humidity monitoring value inside the charging module; The ambient humidity is equal to the external ambient humidity monitoring value of the charging module; The temperature rise at the terminal is equal to the difference between the terminal surface temperature and the ambient temperature; The temperature rise of the charging module is equal to the difference between the internal temperature of the charging module and the ambient temperature; The humidity difference at the terminal is equal to the difference between the surface humidity of the terminal and the ambient humidity; The humidity difference of the charging module is equal to the difference between the humidity inside the charging module and the ambient humidity; The input current is equal to the effective value of the three-phase input current monitoring data; The leakage current is equal to the effective value of the ground loop current monitoring data; The output current is equal to the effective value of the output current monitoring data; The input voltage is equal to the effective value of the three-phase input voltage monitoring data; The output voltage is equal to the effective value of the output voltage monitoring data.

7. The method for monitoring the operating status of a DC charging pile charging module based on multi-parameter perception according to claim 6 is characterized in that: In step S5, the calculation result of the key characterization quantity is compared with the index threshold, and a state evaluation result is given, which is divided into two situations: abnormal and normal, including: When the temperature rise at a single or multiple terminals is greater than the first temperature rise threshold, and the leakage current monitoring value is greater than the first leakage current threshold, there is an insulation aging or abnormality problem; When the input current and the output current are greater than the first current threshold, and the temperature rise at one or more terminals is greater than the second temperature rise threshold, there is an input or output phase short circuit problem; When the input current and output current are greater than the first current threshold, and the leakage current monitoring value is greater than the second leakage current threshold, and the temperature rise at a single terminal is greater than the second temperature rise threshold, there is an input or output single-phase grounding problem; When the leakage current is greater than the third threshold value of the leakage current, but there is no other obvious monitoring abnormality, there is a shell leakage problem; When the temperature rise of the charging module is greater than the third temperature rise threshold, but there are no other obvious monitoring abnormalities, there is a heat dissipation abnormality; When the input voltage is lower than the first voltage threshold or greater than the second voltage threshold, there is a power supply overvoltage or undervoltage problem; When the input current is greater than the second current threshold, but there are no other obvious monitoring abnormalities, there is a power supply overcurrent problem; When the input current is greater than the second current threshold, and the temperature rise at a single terminal is greater than the second temperature rise threshold, there is an internal short circuit problem in the charging module; When the output voltage is lower than the first voltage threshold or higher than the second voltage threshold, there is a problem of internal component failure; When the humidity of the charging module and the ambient humidity are greater than the humidity threshold, there is a risk of moisture and water immersion; When the humidity difference of the charging module is greater than the humidity difference threshold, there is a risk of water ingress and condensation in the charging module; When the humidity difference of the wiring terminals is greater than the humidity difference threshold, there is a risk of condensation or water on the wiring terminals.

8. The method for monitoring the operating status of a DC charging pile charging module based on multi-parameter sensing according to claim 7 is characterized in that: When the calculation result of the key characterization quantity does not exceed the indicator threshold, the charging module status is evaluated as normal, and is further refined into two categories: low risk and high risk: ； in, represents the i-th key characterization quantity, represents the i-th indicator threshold, Represents the evaluation value of the charging module in normal state; when When it is greater than 2, the charging module status is further evaluated as high risk, otherwise it is low risk.

9. The method for monitoring the operating status of a DC charging pile charging module based on multi-parameter sensing according to claim 1, characterized in that: The data edge terminal adopts the principle of combining sparse and dense mode to upload monitoring data. For monitoring data when the status evaluation results are normal, the uploaded data adopts sparse mode; for monitoring data when the status evaluation results are abnormal, the uploaded data adopts dense mode.

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