DC bus monitoring system of DC charging pile

Abstract

The invention relates to the technical field of direct current charging piles, in particular to a direct current bus monitoring system of a direct current charging pile, which comprises a monitoring module, a data processing module, a power factor correction module, a circuit diagnosis module based on topology analysis and a communication and early warning module, the monitoring module monitors operation parameters of a direct-current bus of the direct-current charging pile in real time. The data processing module collects and processes the monitored operation parameters of the DC bus. The power factor correction module monitors and adjusts the power factor of the DC bus in real time. The circuit diagnosis module based on topology analysis performs real-time structure analysis on the direct-current bus and detects topology change and faults in a circuit; the communication and early warning module sends out an early warning signal when an abnormal condition is detected. According to the invention, the system can find and process abnormal conditions in time, and the operation efficiency and stability of the system are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of direct current charging piles, and in particular to a direct current bus monitoring system for a direct current charging pile. Background Art

[0002] As an important part of electric vehicle charging infrastructure, the performance and reliability of DC charging piles directly affect the user experience and charging safety of electric vehicles. Traditional DC charging pile monitoring systems usually rely on the monitoring of a single parameter and cannot fully and real-time grasp the operating status of the DC bus. In addition, the existing monitoring system lacks efficient fault diagnosis and early warning mechanisms, making it difficult to detect and handle abnormal situations in a timely manner, thus affecting the safety and stability of the system.

[0003] In order to improve the operating efficiency and safety of DC charging piles, there is an urgent need for a system that can comprehensively and real-time monitor the operating parameters of the DC bus, and combine topological analysis and dynamic programming models to achieve efficient fault diagnosis and correction. At the same time, the system needs to have a reliable communication and early warning mechanism, which can promptly issue early warning signals when abnormal situations are detected and take corresponding emergency measures.

[0004] In view of the above problems, the present invention proposes a DC bus monitoring system for a DC charging pile, which can realize comprehensive and real-time monitoring of the DC bus and has efficient fault diagnosis and early warning capabilities, thereby improving the safety, reliability and operation efficiency of the system. Summary of the invention

[0005] Based on the above purpose, the present invention provides a DC bus monitoring system for a DC charging pile.

[0006] A DC bus monitoring system for a DC charging pile includes a monitoring module, a data processing module, a power factor correction module, a circuit diagnosis module based on topology analysis, and a communication and early warning module, wherein;

[0007] The monitoring module monitors the operating parameters of the DC bus of the DC charging pile in real time, and the operating parameters include the voltage value, the current value flowing through the DC bus and the temperature of the surrounding environment;

[0008] The data processing module collects and processes the monitored operating parameters of the DC bus;

[0009] The power factor correction module monitors and adjusts the power factor of the DC bus in real time;

[0010] The circuit diagnosis module based on topology analysis performs real-time structural analysis on the DC bus through a topology algorithm to detect topological changes and faults in the circuit;

[0011] The communication and warning module transmits the processed operating parameters and the results of the structural analysis to the remote monitoring center, and sends out a warning signal when an abnormal situation is detected.

[0012] Furthermore, the monitoring module includes:

[0013] Voltage monitoring: Install a voltage sensor on the DC bus, which collects the voltage value at each point of the DC bus in real time;

[0014] Current monitoring: Install a current sensor on the DC bus, which monitors the current value flowing through the DC bus in real time;

[0015] Temperature monitoring: Temperature sensors are arranged on the DC bus and its surrounding environment to collect temperature data of the DC bus surface and the environment in real time.

[0016] Furthermore, the data processing module includes:

[0017] Data acquisition: receiving the operating parameters of the DC bus monitored by the monitoring module;

[0018] Data preprocessing: preprocess the received operating parameters, including data filtering, noise and interference signal removal, and normalization processing;

[0019] Real-time analysis and processing: Analyze the real-time operating parameters, including calculating the power factor, detecting current and voltage anomalies, and evaluating the temperature status. Generate a real-time monitoring report based on the analysis results to display the operating status of the DC bus and the changes in various operating parameters.

[0020] Furthermore, the real-time analysis and processing includes:

[0021] Power factor calculation: collect the real-time voltage value V and the current value I flowing through the DC bus, and calculate the power factor (PF). The calculation formula is:

[0022]

[0023] P = V × I × cos(θ);

[0024] Q = V × I × sin (θ);

[0025] Where θ is the phase angle between voltage and current;

[0026] Current and voltage anomaly detection: Set the normal working range thresholds of the DC bus voltage and current, monitor the voltage value and the current value flowing through the DC bus in real time, determine whether they exceed the set range, and identify mutations by calculating the difference. If the difference exceeds the preset mutation threshold, it is considered abnormal. The calculation formula is:

[0027] ΔV=V current -V previous ;

[0028] ΔI=I current -I previous ;

[0029] Among them, V current is the voltage value at the current moment, V pervious is the voltage value at the previous moment, I current is the current value at the current moment, I previous is the current value at the previous moment;

[0030] Temperature status assessment: Set the temperature safety working range, collect temperature data in real time, smooth the temperature data using the moving average method, and determine whether the smoothed temperature data exceeds the set temperature safety working range. If it exceeds, it is identified as abnormal temperature data. The calculation formula of the moving average method is:

[0031]

[0032] Among them, T i is the collected temperature data, n is the number of sampling times;

[0033] Generate real-time monitoring report: Based on the power factor calculation results, current and voltage anomaly detection results, and temperature status assessment results, a real-time monitoring report is generated to display the current operating status of the DC bus, including voltage value, current value, power factor, and temperature changes, display detected anomalies, and provide parameter change charts.

[0034] Furthermore, the power factor correction module includes:

[0035] Abnormality detection: Real-time analysis of the monitored power factor to detect whether there is any abnormality. If the power factor deviates from the normal value, the data processing module sends an abnormal signal to trigger the power factor correction operation;

[0036] Correction operation: When an abnormal power factor is detected, the normal power factor is restored by adjusting the load of the DC bus or the compensation equipment inside the charging pile. The control algorithm is used to calculate the compensation amount based on the real-time DC bus voltage value and the current value flowing through the DC bus, and the adjustment is made through the corresponding power electronic equipment;

[0037] Feedback adjustment: After the power factor correction operation is completed, continue to monitor the voltage value and the current value flowing through the DC bus to confirm that the power factor has returned to normal. If the power factor fails to return to the normal range, continue to adjust the compensation equipment until the expected effect is achieved, and record the process and results of the power factor correction operation.

[0038] Further, the correction operation includes:

[0039] Calculate the compensation amount: Calculate the capacitance compensation value through the real-time voltage value V and the current value I flowing through the DC bus. The calculation formula of the capacitance compensation value is:

[0040]

[0041] Among them, Q cap is the required reactive power capacitor compensation, V is the real-time voltage, X c is the capacitive reactance;

[0042]

[0043] Where, f is the grid frequency, C is the required compensation capacitance value;

[0044] Adjust compensation equipment: According to the calculated capacitance compensation value, the compensation equipment of the DC bus is dynamically adjusted through power electronic equipment (such as thyristor switch or IGBT), and the corresponding capacitor is automatically connected or disconnected to perform reactive power compensation and restore normal power factor;

[0045] Feedback and verification: Continuously monitor the corrected voltage value and the current value flowing through the DC bus, calculate the new power factor, and verify whether the power factor has returned to the normal range (for example, close to 1). If the expected effect is not achieved, repeat the correction operation until the power factor returns to normal.

[0046] Furthermore, the circuit diagnosis module based on topology analysis includes:

[0047] Topological modeling: Based on the collected voltage values ​​and the current values ​​flowing through the DC bus, a topological model of the circuit is established. Each node in the circuit is represented as a node in the topological model, and the wires and components in the circuit are represented as edges in the topological model. By calculating the conduction state of each edge and the connection relationship of each node, the initial topological diagram of the circuit is generated;

[0048] Continuous monitoring and topology change detection: Continuously collect voltage values ​​and current values ​​flowing through the DC bus, update the circuit topology map in real time, track the state changes of each node and edge, compare the real-time updated topology map with the initial topology map, identify changes in the topology structure, and detect topology changes in the circuit by calculating the voltage and current changes of each node. The calculation formula is:

[0049] ΔV n =V n,current -V n,initial ;

[0050] ΔI e =I e,current -I e,initial ;

[0051] Where, ΔV n is the voltage change at node n, ΔI e is the change in current at edge e, V n,current and I e,current are the current voltage and current values, V n,initial and I e,initial are the initial voltage and current values ​​respectively;

[0052] Fault diagnosis: Based on the topology change detection results, the fault point in the circuit is identified, and the fault type is classified based on the real-time collected voltage value and the current value flowing through the DC bus, and a fault diagnosis report is generated.

[0053] Furthermore, the fault diagnosis includes:

[0054] Fault point identification: Use dynamic programming model (Bellman equation) to identify the fault point in the circuit;

[0055] Fault classification: Combine the real-time collected voltage value and the current value flowing through the DC bus to classify the fault type, including short circuit, open circuit or component failure;

[0056] Generate fault diagnosis report: Organize the fault diagnosis results and generate a fault diagnosis report. The report content includes the location, type and cause of the fault point, and describes the circuit status and topology changes.

[0057] Furthermore, the dynamic programming model (Bellman equation) includes:

[0058] State definition: define the state of each node and edge in the circuit, expressed as s, including voltage V, current I and connection status;

[0059] Action definition: defines adjustment and repair actions, denoted as a, including voltage adjustment, component replacement, and load balancing;

[0060] Instant reward: Define the instant reward R(s,a) for taking action a in state s, expressed as the performance improvement after the circuit is repaired, and the calculation formula is:

[0061] R(s,a)=-C(a)+B(s′);

[0062] Where C(a) is the cost of action a, and B(s′) is the benefit of reaching the new state s′ (e.g., system stability after the voltage and current return to normal);

[0063] State transition probability: defines the probability P(s′|s,a) of transitioning from state s to state s′ by taking action a. It is updated based on the historical and real-time voltage values ​​and the current value flowing through the DC bus. The calculation formula is:

[0064]

[0065] Where count(s,a,s′) is the number of times action a is taken from state s to state s′, ∑ s″ count(s, a, s″) is the total number of times action a is taken from state s to all states;

[0066] Value function: Calculate the value V(s) of taking the best action a in state s by iterating the Bellman equation. The calculation formula is:

[0067] V(s)=max a [R(s,a)+γ∑ s′ P(s′|s,a)V(s′)];

[0068] Among them, γ is the discount factor;

[0069] Dynamic adjustment: Continuously monitor the circuit status, update the state transition probability P(s′|s,a) and immediate reward R(s,a) in real time, and determine the best adjustment and repair action a based on the latest value function V(s);

[0070] Fault diagnosis: Identify the fault points in the circuit and the best repair strategy based on the results of the dynamic programming model.

[0071] Furthermore, the communication and warning module includes:

[0072] Data collection: Collect processing results from the data processing module and the circuit diagnosis module based on topology analysis;

[0073] Data transmission: The collected processing results are packaged and encrypted using standard communication protocols (such as HTTP / HTTPS, MQTT or other applicable protocols);

[0074] Abnormal detection and marking: Real-time monitoring of the processed operating parameters and structural analysis results. When the operating parameters are detected to be beyond the set normal range (such as voltage is too high or too low, current fluctuates abnormally, temperature is too high, etc.) or a circuit fault is identified, it is marked as an abnormal situation.

[0075] Warning signal issuance: According to the marked abnormal situation, the abnormal situation is transmitted to the remote monitoring center through the communication and warning module, triggering the warning mechanism to issue a warning signal (such as SMS notification, email alarm, sound alarm, etc.);

[0076] Remote response and processing: After receiving abnormal reports and warning signals, the remote monitoring center will take corresponding emergency measures according to the severity of the warning signals, including remotely shutting down DC charging piles, adjusting operating parameters, and dispatching maintenance personnel for on-site inspections.

[0077] Beneficial effects of the present invention:

[0078] The present invention monitors the operating parameters of the DC bus in real time, including the voltage value, the current value flowing through the DC bus and the temperature of the surrounding environment, through a monitoring module. The accuracy and reliability of the data are ensured through real-time data collection and processing by a high-precision sensor. The data processing module pre-processes and performs real-time analysis on the collected operating parameters, generates a real-time monitoring report, and displays the operating status of the DC bus and changes in various operating parameters, thereby realizing comprehensive and real-time monitoring and intelligent analysis of the operating status of the DC bus, and greatly improving the safety and reliability of the system.

[0079] The present invention performs real-time structural analysis of the DC bus through a topological algorithm to detect topological changes and potential faults in the circuit. Combined with a dynamic programming model, the system can accurately identify the fault point in the circuit and classify the fault type according to the voltage value and the current value flowing through the DC bus collected in real time, including short circuit, open circuit or component failure. The power factor correction module can monitor and adjust the power factor of the DC bus in real time, restore the normal power factor by adjusting the load or compensating the equipment, ensure the efficient operation of the system, and reduce the power loss. Through the coordinated work of the above modules, the system can timely discover and handle abnormal situations, thereby improving the operation efficiency and stability of the system.

[0080] The present invention collects and integrates the processing results of the data processing module and the circuit diagnosis module, and transmits them to the remote monitoring center in real time. When it is detected that the operating parameters exceed the set normal range or a circuit fault is identified, the communication and early warning module can promptly issue an early warning signal, including SMS notification, email alarm and sound alarm, etc., to ensure that relevant personnel can take emergency measures in time. After receiving the abnormal report and early warning signal, the remote monitoring center can take corresponding emergency measures according to the severity of the early warning signal, including remotely shutting down the DC charging pile, adjusting the operating parameters and dispatching maintenance personnel for on-site inspection. Through this mechanism, the system can respond quickly when an abnormal situation occurs to ensure the safety and reliability of the system. BRIEF DESCRIPTION OF THE DRAWINGS

[0081] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings in the following description are only for the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0082] Figure 1 A schematic diagram of system function modules according to an embodiment of the present invention;

[0083] Figure 2Schematic diagram of a circuit diagnosis module based on topology analysis according to an embodiment of the present invention. DETAILED DESCRIPTION

[0084] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with specific embodiments.

[0085] It should be noted that, unless otherwise defined, the technical terms or scientific terms used in the present invention should be understood by people with ordinary skills in the field to which the present invention belongs. The "first", "second" and similar words used in the present invention do not indicate any order, quantity or importance, but are only used to distinguish different components. "Include" or "comprise" and similar words mean that the elements or objects appearing before the word include the elements or objects listed after the word and their equivalents, without excluding other elements or objects. "Connect" or "connected" and similar words are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. "Up", "down", "left", "right" and the like are only used to indicate relative positional relationships. When the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0086] like Figure 1-Figure 2 As shown, a DC bus monitoring system for a DC charging pile includes a monitoring module, a data processing module, a power factor correction module, a circuit diagnosis module based on topology analysis, and a communication and early warning module, wherein;

[0087] The monitoring module monitors the operating parameters of the DC bus of the DC charging pile in real time, including the voltage value, the current value flowing through the DC bus and the temperature of the surrounding environment;

[0088] The data processing module collects and processes the monitored operating parameters of the DC bus;

[0089] The power factor correction module monitors and adjusts the power factor of the DC bus in real time to ensure efficient operation of the system and reduce power loss;

[0090] The circuit diagnosis module based on topology analysis performs real-time structural analysis on the DC bus through topological algorithms to detect topological changes and faults in the circuit;

[0091] The communication and warning module transmits the processed operating parameters and the results of the structural analysis to the remote monitoring center and issues a warning signal when an abnormal situation is detected;

[0092] Through the unified management and coordination of the above modules, it is ensured that the various parts of the system can work together efficiently, thereby achieving comprehensive and real-time monitoring of the DC bus and improving the safety, reliability and operating efficiency of the system.

[0093] The monitoring modules include:

[0094] Voltage monitoring: Install a voltage sensor on the DC bus, which collects the voltage value at each point of the DC bus in real time;

[0095] Current monitoring: Install a current sensor on the DC bus, which monitors the current value flowing through the DC bus in real time;

[0096] Temperature monitoring: Temperature sensors are placed on the DC bus and its surrounding environment to collect temperature data of the DC bus surface and the environment in real time;

[0097] Through the above content, comprehensive and real-time monitoring of the voltage and current values ​​of the DC bus of the DC charging pile and the surrounding ambient temperature is achieved. The high-precision sensors ensure the accuracy and reliability of the data, while the multi-point layout and continuous collection ensure the comprehensiveness and timeliness of the monitoring.

[0098] The data processing module includes:

[0099] Data acquisition: receiving the operating parameters of the DC bus monitored by the monitoring module;

[0100] Data preprocessing: preprocess the received operating parameters, including data filtering, noise and interference signal removal, and normalization, to ensure that the values ​​of different data sources are within a unified range for subsequent analysis;

[0101] Real-time analysis and processing: Analyze real-time operating parameters, including calculating power factor, detecting current and voltage anomalies, and evaluating temperature status. Generate a real-time monitoring report based on the analysis results to display the operating status of the DC bus and changes in various operating parameters.

[0102] Through the above steps, the operating parameters collected by the monitoring module are comprehensively collected and processed, realizing real-time monitoring and intelligent analysis of the DC bus operating status, and improving the safety and reliability of the system.

[0103] Real-time analysis and processing include:

[0104] Power factor calculation: collect the real-time voltage value V and the current value I flowing through the DC bus, and calculate the power factor (PF). The calculation formula is:

[0105]

[0106] P = V × I × cos(θ);

[0107] Q = V × I × sin (θ);

[0108] Where θ is the phase angle between voltage and current;

[0109] Current and voltage anomaly detection: Set the normal working range thresholds of the DC bus voltage and current, monitor the voltage value and the current value flowing through the DC bus in real time, determine whether they exceed the set range, and identify mutations by calculating the difference. If the difference exceeds the preset mutation threshold, it is considered abnormal. The calculation formula is:

[0110] ΔV=V current -V previous ;

[0111] ΔI=I current -I previous ;

[0112] Among them, V current is the voltage value at the current moment, V previous is the voltage value at the previous moment, I current is the current value at the current moment, I previous is the current value at the previous moment;

[0113] Temperature status assessment: Set the temperature safety working range, collect temperature data in real time, smooth the temperature data using the moving average method, and determine whether the smoothed temperature data exceeds the set temperature safety working range. If it exceeds, it is identified as abnormal temperature data. The calculation formula of the moving average method is:

[0114]

[0115] Among them, T i is the collected temperature data, n is the number of sampling times;

[0116] Generate real-time monitoring report: Based on the power factor calculation results, current and voltage anomaly detection results, and temperature status evaluation results, generate a real-time monitoring report that displays the current operating status of the DC bus, including voltage value, current value, power factor, and temperature changes, displays detected anomalies, and provides parameter change charts;

[0117] Through the above steps, the real-time operating parameters are comprehensively analyzed to ensure the safe and efficient operation of the DC bus, and abnormal situations are discovered and handled in time, thereby improving the reliability and stability of the system.

[0118] Set the normal operating range thresholds for the DC bus voltage and current:

[0119] Voltage range threshold setting: Determine the rated voltage value V of the DC bus according to the design specifications of the DC charging pile and the manufacturer's recommendations. rated , set the normal operating range of the voltage to the upper and lower limits of the rated voltage, such as V min =0.9×Vrated and V max =1.1×V rated , if the rated voltage of the DC bus is 400V, the normal working voltage range is 360V to 440V;

[0120] Current range threshold setting: Determine the rated current value I of the DC bus according to the design specifications of the DC charging pile and the manufacturer's recommendations. rated , set the normal operating range of the current to the upper and lower limits of the rated current, such as I min =0.9×I rated and I max =1.1×I rated , if the rated current of the DC bus is 100A, the normal working range of the current is 90A to 110;

[0121] To set the safe operating temperature range:

[0122] Temperature range setting: According to the design specifications of the DC charging pile and the manufacturer's recommendations, determine the temperature range for safe operation of the system and set the normal operating range of the temperature, such as T min and T max If the system design requires safe operation in an ambient temperature range of -20℃ to 60℃, the set temperature normal operating range is -20℃ to 60℃.

[0123] The power factor correction module includes:

[0124] Abnormality detection: Real-time analysis of the monitored power factor to detect abnormal conditions, such as when the power factor is lower than a preset threshold (indicating abnormal power consumption or a fault). If the power factor deviates from the normal value, the data processing module sends an abnormal signal to trigger a power factor correction operation.

[0125] Correction operation: When an abnormal power factor is detected, the normal power factor is restored by adjusting the load of the DC bus or the compensation equipment inside the charging pile. The control algorithm is used to calculate the compensation amount based on the real-time DC bus voltage value and the current value flowing through the DC bus, and the corresponding power electronic equipment is used to adjust it to ensure that the power factor is restored to 1;

[0126] Feedback adjustment: After the power factor correction operation is completed, continue to monitor the voltage value and the current value flowing through the DC bus to confirm that the power factor has returned to normal. If the power factor fails to return to the normal range, continue to adjust the compensation equipment until the expected effect is achieved, and record the process and results of the power factor correction operation for subsequent analysis and improvement;

[0127] Through the above steps, it is ensured that the power factor of the DC bus remains within the normal range, thereby improving the operating efficiency of the system, reducing power loss, and promptly handling possible abnormal situations.

[0128] Corrective actions include:

[0129] Calculate the compensation amount: Calculate the capacitance compensation value through the real-time voltage value V and the current value I flowing through the DC bus. The calculation formula of the capacitance compensation value is:

[0130]

[0131] Among them, Q cap is the required reactive power capacitor compensation, V is the real-time voltage, X c is the capacitive reactance;

[0132]

[0133] Where, f is the grid frequency, C is the required compensation capacitance value;

[0134] Adjust compensation equipment: According to the calculated capacitance compensation value, the compensation equipment of the DC bus is dynamically adjusted through power electronic equipment (such as thyristor switch or IGBT), and the corresponding capacitor is automatically connected or disconnected to perform reactive power compensation and restore normal power factor;

[0135] Feedback and verification: Continuously monitor the corrected voltage value and the current value flowing through the DC bus, calculate the new power factor, and verify whether the power factor has returned to the normal range (for example, close to 1). If the expected effect is not achieved, repeat the correction operation until the power factor returns to normal. Record all data and operation steps during the compensation and correction process for subsequent analysis and optimization.

[0136] Through the above correction steps, it is ensured that when an abnormal power factor is detected, the normal power factor can be restored in a timely and accurate manner by adjusting the load of the DC bus or the compensation equipment inside the charging pile, thereby improving the operating efficiency of the system, reducing energy loss, and maintaining the stability and safety of the system.

[0137] The circuit diagnosis module based on topology analysis includes:

[0138] Topological modeling: Based on the collected voltage values ​​and the current values ​​flowing through the DC bus, a topological model of the circuit is established. Each node in the circuit is represented as a node in the topological model, and the wires and components in the circuit are represented as edges in the topological model. By calculating the conduction state of each edge and the connection relationship of each node, the initial topological diagram of the circuit is generated;

[0139] Continuous monitoring and topology change detection: Continuously collect voltage values ​​and current values ​​flowing through the DC bus, update the circuit topology map in real time, track the state changes of each node and edge, compare the real-time updated topology map with the initial topology map, identify changes in the topology structure, and detect topology changes in the circuit by calculating the voltage and current changes of each node. The calculation formula is:

[0140] ΔV n =V n,current -V n,initial ;

[0141] ΔI e =I e,current -I e,initial ;

[0142] Where, ΔV n is the voltage change at node n, ΔI e is the change in current at edge e, V n,current and I e,current are the current voltage and current values, V n,initial and I e,initial are the initial voltage and current values ​​respectively;

[0143] Fault diagnosis: Based on the topology change detection results, the fault point in the circuit is identified, and the fault type is classified based on the real-time collected voltage value and the current value flowing through the DC bus, and a fault diagnosis report is generated;

[0144] Through the above steps, the circuit diagnosis module based on topology analysis can monitor the structural changes of the DC bus and its associated circuits in real time, detect and diagnose potential circuit faults in time, and ensure the safe and stable operation of the system.

[0145] Calculate the conduction state of each edge: The edge e represents the wire or component in the circuit. The conduction state is determined by measuring the voltage drop and current value. The calculation formula is:

[0146]

[0147] Among them, R e is the resistance of side e, V e,drop is the voltage drop on edge e, I e is the current on edge e

[0148] According to the resistance R e The value of is used to determine the conduction state:

[0149] If R e Close to 0, it means that edge e is in the conducting state;

[0150] If R e Infinity means that edge e is disconnected.

[0151] Calculate the connection relationship of each node: Node n represents the connection point in the circuit. The connection relationship is determined by measuring the voltage value of the connection point. The calculation formula is:

[0152] ΔV nm =V n -V m ;

[0153] Where, ΔV nm is the voltage difference between node n and node m, V n and V m are the voltage values ​​of node n and node m respectively;

[0154] According to the voltage difference ΔV nm Determine the connection relationship:

[0155] If ΔV nm Close to 0, it means that node n and node m are directly connected;

[0156] If ΔV nm If it is not 0, it means that node n and node m are connected through other components or wires.

[0157] Troubleshooting includes:

[0158] Fault point identification: Use dynamic programming model (Bellman equation) to identify the fault point in the circuit;

[0159] Fault classification: Combine the real-time collected voltage value and the current value flowing through the DC bus to classify the fault type, including short circuit, open circuit or component failure;

[0160] Fault classification criteria:

[0161] Short circuit fault: ΔV n Significant decrease, ΔI e Significant increase;

[0162] Open circuit fault: ΔV n Significant increase, ΔI e Significantly decreased or zero;

[0163] Component failure: The voltage and current changes of a node or edge do not conform to normal operating rules;

[0164] Generate fault diagnosis report: Organize the fault diagnosis results and generate a fault diagnosis report. The report includes the location, type and cause of the fault point, and describes the circuit status and topology changes.

[0165] Through the above steps, the dynamic programming model can be used to identify the fault point in the circuit according to the topology change detection result, and the fault type can be classified in combination with the real-time collected data to generate a detailed fault diagnosis report, thereby improving the safety and stability of the system.

[0166] The dynamic programming model (Bellman equation) includes:

[0167] State definition: define the state of each node and edge in the circuit, expressed as s, including voltage V, current I and connection status;

[0168] Action definition: defines adjustment and repair actions, denoted as a, including voltage adjustment, component replacement, and load balancing;

[0169] Instant reward: Define the instant reward R(s,a) for taking action a in state s, expressed as the performance improvement after the circuit is repaired, and the calculation formula is:

[0170] R(s,a)=-C(a)+B(s′);

[0171] Where C(a) is the cost of action a, and B(s′) is the benefit of reaching the new state s′ (e.g., system stability after the voltage and current return to normal);

[0172] State transition probability: defines the probability P(s′|s,a) of transitioning from state s to state s′ by taking action a. It is updated based on the historical and real-time voltage values ​​and the current value flowing through the DC bus. The calculation formula is:

[0173]

[0174] Where count(s,a,s′) is the number of times action a is taken from state s to state s′, ∑ s″ count(s, a, s″) is the total number of times action a is taken from state s to all states;

[0175] Value function: Calculate the value V(s) of taking the best action a in state s by iterating the Bellman equation. The calculation formula is:

[0176] V(s)=max a [R(s,a)+γ∑ s′ P(s′|s,a)V(s′)];

[0177] Among them, γ is the discount factor, which represents the current value of future earnings;

[0178] Dynamic adjustment: Continuously monitor the circuit status, update the state transition probability P(s′|s,a) and immediate reward R(s,a) in real time, and determine the best adjustment and repair action a based on the latest value function V(s);

[0179] Fault diagnosis: Identify the fault point in the circuit and the best repair strategy based on the results of the dynamic programming model;

[0180] Through the above content, real-time monitoring data is used to continuously update the state transition probability, improve the model's sensitivity to circuit state changes, consider action costs and system performance, optimize the immediate reward function, ensure the effectiveness of the repair strategy, and iterate the Bellman equation to calculate the long-term value of each state, determine the best repair action, and improve the overall stability and reliability of the system. The dynamic programming model can realize real-time and efficient circuit topology analysis and fault detection in DC charging pile applications, ensuring the safe and stable operation of the system.

[0181] The communication and warning module includes:

[0182] Data collection: Collect processing results from the data processing module and the circuit diagnosis module based on topology analysis;

[0183] Data transmission: Use standard communication protocols (such as HTTP / HTTPS, MQTT or other applicable protocols) to package and encrypt the collected processing results to ensure the security and integrity of the data during transmission;

[0184] Abnormal detection and marking: Real-time monitoring of the processed operating parameters and structural analysis results. When the operating parameters are detected to be beyond the set normal range (such as voltage is too high or too low, current fluctuates abnormally, temperature is too high, etc.) or a circuit fault is identified, it is marked as an abnormal situation.

[0185] Warning signal issuance: According to the marked abnormal situation, the abnormal situation is transmitted to the remote monitoring center through the communication and warning module, triggering the warning mechanism to issue a warning signal (such as SMS notification, email alarm, sound alarm, etc.) to ensure that relevant personnel receive the warning information in time;

[0186] Remote response and processing: After receiving abnormal reports and warning signals, the remote monitoring center will take corresponding emergency measures according to the severity of the warning signals, including remotely shutting down DC charging piles, adjusting operating parameters, and dispatching maintenance personnel for on-site inspections;

[0187] Through the above steps, the communication and early warning module can effectively transmit the processed operating parameters and structural analysis results to the remote monitoring center, and issue an early warning signal when an abnormal situation is detected (including abnormal operating parameters and abnormal analysis results of the circuit diagnosis module), thereby ensuring the safety and reliability of the system.

[0188] Those skilled in the art should understand that the discussion of any of the above embodiments is merely illustrative and is not intended to imply that the scope of the present invention is limited to these examples. Under the concept of the present invention, the technical features in the above embodiments or different embodiments may be combined, the steps may be implemented in any order, and there are many other variations of the different aspects of the present invention as described above, which are not provided in detail for the sake of simplicity.

[0189] The present invention is intended to cover all such substitutions, modifications and variations that fall within the broad scope of the claims. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A DC bus monitoring system for a DC charging pile, characterized in that: It includes a monitoring module, a data processing module, a power factor correction module, a circuit diagnosis module based on topology analysis, and a communication and early warning module, among which; The monitoring module monitors the operating parameters of the DC bus of the DC charging pile in real time, and the operating parameters include the voltage value, the current value flowing through the DC bus and the temperature of the surrounding environment; The data processing module collects and processes the monitored operating parameters of the DC bus; The power factor correction module monitors and adjusts the power factor of the DC bus in real time; The circuit diagnosis module based on topology analysis performs real-time structural analysis on the DC bus through a topology algorithm to detect topological changes and faults in the circuit; The communication and warning module transmits the processed operating parameters and the results of the structural analysis to the remote monitoring center, and sends out a warning signal when an abnormal situation is detected.

2. A DC bus monitoring system for a DC charging pile according to claim 1, characterized in that: The monitoring module comprises: Voltage monitoring: Install a voltage sensor on the DC bus, which collects the voltage value at each point of the DC bus in real time; Current monitoring: Install a current sensor on the DC bus, which monitors the current value flowing through the DC bus in real time; Temperature monitoring: Temperature sensors are arranged on the DC bus and its surrounding environment to collect temperature data of the DC bus surface and the environment in real time.

3. A DC bus monitoring system for a DC charging pile according to claim 1, characterized in that: The data processing module comprises: Data acquisition: receiving the operating parameters of the DC bus monitored by the monitoring module; Data preprocessing: preprocess the received operating parameters, including data filtering, noise and interference signal removal, and normalization processing; Real-time analysis and processing: Analyze the real-time operating parameters, including calculating the power factor, detecting current and voltage anomalies, and evaluating the temperature status. Generate a real-time monitoring report based on the analysis results to display the operating status of the DC bus and the changes in various operating parameters.

4. A DC bus monitoring system for a DC charging pile according to claim 3, characterized in that: The real-time analysis and processing includes: Power factor calculation: collect the real-time voltage value V and the current value I flowing through the DC bus, and calculate the power factor. The calculation formula is: P = V × I × cos(θ); Q = V × I × sin (θ); Where θ is the phase angle between voltage and current; Current and voltage anomaly detection: Set the normal working range thresholds of the DC bus voltage and current, monitor the voltage value and the current value flowing through the DC bus in real time, determine whether they exceed the set range, and identify mutations by calculating the difference. If the difference exceeds the preset mutation threshold, it is considered abnormal. The calculation formula is: ΔV=V current -V previous ; ΔI=I current -I previous ; Among them, V current is the voltage value at the current moment, V previous is the voltage value at the previous moment, I current is the current value at the current moment, I previous is the current value at the previous moment; Temperature status assessment: Set the temperature safety working range, collect temperature data in real time, smooth the temperature data using the moving average method, and determine whether the smoothed temperature data exceeds the set temperature safety working range. If it exceeds, it is identified as abnormal temperature data. The calculation formula of the moving average method is: Among them, T i is the collected temperature data, n is the number of sampling times; Generate real-time monitoring report: Based on the power factor calculation results, current and voltage anomaly detection results, and temperature status assessment results, a real-time monitoring report is generated to display the current operating status of the DC bus, including voltage value, current value, power factor, and temperature changes, display detected anomalies, and provide parameter change charts.

5. A DC bus monitoring system for a DC charging pile according to claim 4, characterized in that: The power factor correction module comprises: Abnormality detection: Real-time analysis of the monitored power factor to detect whether there is any abnormality. If the power factor deviates from the normal value, the data processing module sends an abnormal signal to trigger the power factor correction operation; Correction operation: When an abnormal power factor is detected, the normal power factor is restored by adjusting the load of the DC bus or the compensation equipment inside the charging pile. The control algorithm is used to calculate the compensation amount based on the real-time DC bus voltage value and the current value flowing through the DC bus, and the adjustment is made through the corresponding power electronic equipment; Feedback adjustment: After the power factor correction operation is completed, continue to monitor the voltage value and the current value flowing through the DC bus to confirm that the power factor has returned to normal. If the power factor fails to return to the normal range, continue to adjust the compensation equipment until the expected effect is achieved, and record the process and results of the power factor correction operation.

6. A DC bus monitoring system for a DC charging pile according to claim 5, characterized in that: The correction operation includes: Calculate the compensation amount: Calculate the capacitance compensation value through the real-time voltage value V and the current value I flowing through the DC bus. The calculation formula of the capacitance compensation value is: Among them, Q cap is the required reactive power capacitor compensation, V is the real-time voltage, X c is the capacitive reactance; Where, f is the grid frequency, C is the required compensation capacitance value; Adjust compensation equipment: According to the calculated capacitance compensation value, the DC bus compensation equipment is dynamically adjusted through power electronic equipment, and the corresponding capacitor is automatically connected or disconnected to perform reactive power compensation and restore normal power factor; Feedback and verification: Continuously monitor the corrected voltage value and the current value flowing through the DC bus, calculate the new power factor, and verify whether the power factor has returned to the normal range. If the expected effect is not achieved, repeat the correction operation until the power factor returns to normal.

7. A DC bus monitoring system for a DC charging pile according to claim 1, characterized in that: The circuit diagnosis module based on topology analysis includes: Topological modeling: Based on the collected voltage values ​​and the current values ​​flowing through the DC bus, a topological model of the circuit is established. Each node in the circuit is represented as a node in the topological model, and the wires and components in the circuit are represented as edges in the topological model. By calculating the conduction state of each edge and the connection relationship of each node, the initial topological diagram of the circuit is generated; Continuous monitoring and topology change detection: Continuously collect voltage values ​​and current values ​​flowing through the DC bus, update the circuit topology map in real time, track the state changes of each node and edge, compare the real-time updated topology map with the initial topology map, identify changes in the topology structure, and detect topology changes in the circuit by calculating the voltage and current changes of each node. The calculation formula is: ΔV n =V n,current -V n,initial ; ΔI e =I e,current -I e,initial ; Where, ΔV n is the voltage change at node n, ΔI e is the change in current at edge e, V n,current and I e,current are the current voltage and current values, V n,initial and I e,initial are the initial voltage and current values ​​respectively; Fault diagnosis: Based on the topology change detection results, the fault point in the circuit is identified, and the fault type is classified based on the real-time collected voltage value and the current value flowing through the DC bus, and a fault diagnosis report is generated.

8. A DC bus monitoring system for a DC charging pile according to claim 7, characterized in that: The fault diagnosis includes: Fault point identification: Use dynamic programming models to identify fault points in the circuit; Fault classification: Combine the real-time collected voltage value and the current value flowing through the DC bus to classify the fault type, including short circuit, open circuit or component failure; Generate fault diagnosis report: Organize the fault diagnosis results and generate a fault diagnosis report. The report content includes the location, type and cause of the fault point, and describes the circuit status and topology changes.

9. A DC bus monitoring system for a DC charging pile according to claim 8, characterized in that: The dynamic programming model includes: State definition: define the state of each node and edge in the circuit, expressed as s, including voltage V, current I and connection status; Action definition: defines adjustment and repair actions, denoted as a, including voltage adjustment, component replacement, and load balancing; Instant reward: Define the instant reward R(s,a) for taking action a in state s, expressed as the performance improvement after the circuit is repaired, and the calculation formula is: R(s,a)=-C(a)+B(s′); Where C(a) is the cost of action a, and B(s′) is the benefit of reaching the new state s′; State transition probability: defines the probability P(s′|s,a) of transitioning from state s to state s′ by taking action a. It is updated based on the historical and real-time voltage values ​​and the current value flowing through the DC bus. The calculation formula is: Where count(s,a,s′) is the number of times action a is taken from state s to state s′, ∑ s″ count(s, a, s″) is the total number of times action a is taken from state s to all states; Value function: Calculate the value V(s) of taking the best action a in state s by iterating the Bellman equation. The calculation formula is: V(s)=max a [R(s,a)+γ∑ s′ P(s′|s,a)V(s′)]; Among them, γ is the discount factor; Dynamic adjustment: Continuously monitor the circuit status, update the state transition probability P(s′|s,a) and immediate reward R(s,a) in real time, and determine the best adjustment and repair action a based on the latest value function V(s); Fault diagnosis: Identify the fault points in the circuit and the best repair strategy based on the results of the dynamic programming model.

10. A DC bus monitoring system for a DC charging pile according to claim 9, characterized in that: The communication and warning module includes: Data collection: Collect processing results from the data processing module and the circuit diagnosis module based on topology analysis; Data transmission: The collected processing results are packaged and encrypted using standard communication protocols; Abnormal detection and marking: Real-time monitoring of the processed operating parameters and structural analysis results. When the operating parameters are detected to be beyond the set normal range or a circuit fault is identified, it is marked as an abnormal situation. Warning signal issuance: According to the marked abnormal situation, the abnormal situation is transmitted to the remote monitoring center through the communication and warning module, triggering the warning mechanism to issue a warning signal; Remote response and processing: After receiving abnormal reports and warning signals, the remote monitoring center will take corresponding emergency measures according to the severity of the warning signals, including remotely shutting down DC charging piles, adjusting operating parameters, and dispatching maintenance personnel for on-site inspections.

Images