Network voltage fluctuation fault diagnosis method based on data analysis

Abstract

The invention discloses a network voltage fluctuation fault diagnosis method based on data analysis, and relates to the technical field of power supply systems, fault diagnosis and rail transit, and the method comprises the steps: constructing a line power supply relation graph of a rail transit power supply system; and the line power supply relation diagram and the collected real-time state data of the equipment are input into a fault judgment module, and the fault judgment module judges a network voltage fluctuation fault by using a fault judgment logic diagram and judges a fault influence range. According to the invention, the line power supply relation graph is matched with the fault judgment method, so that the fault influence range can be quickly and accurately judged. According to the method, the equipment operation state is matched in the form of the line power supply relation graph, multidirectional analysis can be ensured, and the accuracy of fault judgment is ensured. According to the line power supply relation diagram and the equipment operation state, the fault influence range can be quickly and directly judged based on the fault judgment logic diagram.

Description

Technical Field

[0001] The present invention relates to the technical fields of power supply systems, fault diagnosis, and rail transit technology. More specifically, it relates to a method for diagnosing network voltage fluctuation faults based on data analysis. Background Art

[0002] In the prior art, for the diagnosis of network voltage fluctuation faults in rail transit power supply systems, it mainly includes a fault diagnosis method based on oscillogram analysis, a fault diagnosis method based on harmonic analysis, and a fault diagnosis method based on state estimation. Specifically as follows: (1) Fault diagnosis method based on oscillogram analysis Currently, this method analyzes signals such as voltage and current during the occurrence of a fault based on fault oscillogram information to determine the fault type and location. The oscillogram analysis method is mainly applicable to the diagnosis of local faults, such as single-phase grounding, resonance, etc. This method mainly realizes fault diagnosis through the following steps: 1. Data acquisition: Use devices such as voltage monitoring devices or oscillographs to collect real-time data of the grid voltage.

[0003] 2. Data processing: Process the collected data, including filtering, noise reduction, data conversion, etc., to extract useful information.

[0004] 3. Feature extraction: Extract features related to voltage fluctuations from the processed data, such as waveform, peak value, duration, etc.

[0005] 4. Event detection: Detect the occurrence of voltage fluctuation events according to the extracted features.

[0006] 5. Event analysis: Analyze the detected voltage fluctuation events, including cause analysis, impact assessment, etc.

[0007] 6. Decision making: Make corresponding decisions according to the analysis results, such as adjusting the grid operation mode, taking compensation measures, etc.

[0008] The advantages of the network voltage fluctuation oscillogram analysis method include: 1. It can monitor the network voltage fluctuation situation in real time, and discover and solve problems in a timely manner.

[0009] 2. It can provide detailed voltage fluctuation data and analysis results, which helps to understand the operation status of the grid and optimization measures.

[0010] 3. It can provide a reference basis for grid planning and transformation, and improve the stability and reliability of the grid.

[0011] Defects: This method also has some limitations. For example, it requires the configuration of professional voltage monitoring devices and oscillographs, the complexity of data processing is relatively high, and the technical requirements for personnel are relatively high, etc.

[0012] (2)Harmonic analysis fault diagnosis method The main steps of the network voltage fluctuation harmonic analysis method include: Data acquisition: Use equipment such as voltage transformers or power quality analyzers to collect voltage signals in the power system.

[0013] Signal processing: Preprocess the collected voltage signals, such as filtering and denoising operations, to improve the signal quality.

[0014] Harmonic analysis: Use harmonic analysis tools, such as spectrum analyzers or Fourier transforms, to perform harmonic analysis on the processed voltage signals. This can determine the various frequency components and their amplitudes in the voltage signals.

[0015] Evaluation and diagnosis: According to the results of harmonic analysis, evaluate the stability of the power system and the power quality. If voltage fluctuations or harmonic problems are found to exceed the allowable range, further diagnosis is required to determine the cause of the problem and the solution.

[0016] Solution: According to the diagnosis results, take corresponding measures to solve voltage fluctuations and harmonic problems. This may include improving the power supply structure of the power system, adding reactive power compensation devices, replacing equipment, etc.

[0017] Verification and monitoring: After implementing the solution, it is necessary to verify and monitor the voltage fluctuations and harmonic problems in the power system to ensure that the problems are effectively solved. This can be achieved by regularly collecting and analyzing voltage signals.

[0018] Defects: This method also has some limitations, such as the need to configure professional monitoring equipment and analysis equipment, the high complexity of data processing, and the high technical requirements for personnel, etc.

[0019] (3)State estimation method fault diagnosis method The main steps of the state estimation method fault diagnosis method include: Collect data: First, it is necessary to collect voltage data during the operation of the power grid, including voltage fluctuation conditions, duration, frequency, etc. These data can be obtained through means such as the monitoring systems of power companies, measuring equipment, and sensors.

[0020] Data processing and analysis: Process and analyze the collected voltage data to extract features and indicators related to network voltage fluctuations. These features and indicators may include voltage fluctuation amplitude, fluctuation frequency, duration, occurrence time, etc.

[0021] Formulate evaluation criteria: According to the actual situation and operation requirements of the power grid, formulate corresponding network voltage fluctuation state evaluation criteria. These criteria can include the maximum range of voltage fluctuations, allowable fluctuation frequencies, and durations, etc.

[0022] Evaluate the grid voltage fluctuation status: According to the characteristics and indicators of the voltage data obtained through processing and analysis, and in comparison with the evaluation criteria, evaluate the grid voltage fluctuation status. The evaluation results can be divided into different levels such as stable, basically stable, and unstable.

[0023] Formulate countermeasures: According to the evaluation results, formulate corresponding countermeasures for different levels of grid voltage fluctuation status. For example, for the unstable status, it may be necessary to start the standby power supply, adjust the grid operation mode, or perform equipment maintenance, etc.

[0024] Continuously monitor and adjust: After implementing the countermeasures, it is necessary to continuously monitor the voltage fluctuation of the power grid and make necessary adjustments according to the actual situation. This helps to ensure the stable operation and reliability of the power grid.

[0025] Defects: High data requirements: The grid voltage fluctuation status evaluation method requires a large amount of grid voltage data as support, which requires power companies, grid operators and other institutions to establish a perfect monitoring system and data acquisition system.

[0026] High technical difficulty: The techniques and algorithms involved in the grid voltage fluctuation status evaluation method are relatively complex and require professional personnel for development and maintenance.

[0027] High sensitivity and accuracy requirements: The grid voltage fluctuation is affected by various factors, and its changes are random and uncertain. Therefore, an evaluation method with high sensitivity and accuracy is required to accurately reflect the operation status of the power grid.

[0028] Requires continuous monitoring and maintenance: The grid voltage fluctuation status evaluation method requires continuous monitoring of the operation status of the power grid and timely taking corresponding measures for maintenance and adjustment, which requires a large amount of manpower, material resources and financial resources. Summary of the Invention

[0029] In order to overcome the defects existing in the above-mentioned prior art, the present invention discloses a grid voltage fluctuation fault diagnosis method based on data analysis. The purpose of the present invention is to solve the problems existing in the fault diagnosis methods of oscillogram analysis, harmonic analysis, and state estimation method in the prior art. The present invention is a fault diagnosis method that combines a fault judgment logic diagram and a line power supply relationship diagram and relies on the equipment status, and integrates to obtain a grid voltage fluctuation fault judgment method, which can accurately find the influence range of the grid voltage fluctuation fault.

[0030] In order to achieve the above purpose, the technical solution adopted by the present invention: A grid voltage fluctuation fault diagnosis method based on data analysis, comprising the following steps: I. Construct a line power supply relationship diagram S1. Construct the line power supply relationship diagram of the rail transit power supply system; In the present invention, the function of the line power supply relationship diagram is to assist in judging the electrical connection relationship between electrical equipment and the fault influence range. The relationship between the line power supply relationship diagram and the subsequent steps is: check the electrical connection between faulty equipment (whether it is in the same power supply circuit and the fault influence range).

[0031] II. Data Input S2. Input the line power supply relationship diagram and the collected real-time status data of the equipment into the fault judgment module; Preferably, in step S2, use the data acquisition module to collect the real-time status data of the equipment; a fault judgment logic diagram is set in the fault judgment module.

[0032] In the present invention, with the real-time status of the equipment and the line power supply relationship diagram as the input, input into the fault judgment module, and the fault judgment module combines the fault judgment logic diagram to perform fault diagnosis and analysis.

[0033] III. Start the Network Voltage Fluctuation Analysis Process S3. Analyze and judge the input data. When the circuit breaker of the high-voltage busbar equipment in the input data is closed, or a voltage transient event occurs in the high-voltage incoming switchgear cabinet, start the network voltage fluctuation analysis process and enter the next step; Preferably, step S3 includes: when the circuit breaker of the high-voltage busbar equipment in the switchgear of the adjacent power supply sub-region allows operation, or a voltage transient event occurs in the high-voltage incoming switchgear cabinets of all substations in the power supply sub-region, start the network voltage fluctuation analysis process.

[0034] Preferably, in step S3, the high-voltage busbar equipment is 35kV busbar equipment, and the high-voltage incoming switchgear cabinet is 35kV incoming switchgear cabinet.

[0035] Preferably, in step S3, the voltage transient event includes voltage swell, voltage sag and interruption.

[0036] In the above steps, when the circuit breaker of the 35kV busbar equipment in the switchgear of the adjacent power supply sub-region allows operation, or a voltage transient event (including voltage swell, voltage sag, interruption) occurs in the 35kV incoming switchgear cabinets of all substations in the power supply sub-region, start the network voltage fluctuation analysis process.

[0037] Among them, the function of the 35kV busbar equipment is: when one of the two 35kV incoming switch cabinets of the switchgear fails, connect the other 35kV incoming switch cabinet for power supply; the function of the circuit breaker is to disconnect and connect the circuit; the function of the 35kV incoming switchgear cabinet is to access electrical energy from other power supply links.

[0038] When the circuit breaker closing of the 35kV bus equipment in the adjacent power supply sub - area occurs and is allowed to operate, it indicates that one of the two 35kV incoming line cabinets in the switching station has a fault. At this time, the circuit breaker closing of the 35kV bus equipment in the switching station is required to occur, and the other 35kV incoming line cabinet is connected for power supply.

[0039] When voltage transient events occur in the 35kV incoming switchgear of all substations in the power supply sub - area, it indicates that the voltage of the 35kV incoming switchgear of all substations in the power supply sub - area fluctuates. At this time, relevant electrical equipment needs to be checked according to the line power supply relationship diagram.

[0040] IV. SVG device judgment S4. Use the input data to judge whether the dynamic reactive power compensation device has stopped operating. If so, enter the next step; if not, troubleshoot the stop. Preferably, step S4 includes: judging whether the dynamic reactive power compensation device in the switching station has stopped operating within the entire power supply sub - area; if it has not stopped operating, troubleshoot the stop; if it has stopped operating, proceed to the next analysis.

[0041] In the above steps, the function of the dynamic reactive power compensation device (SVG) is to adjust the phase and amplitude of the AC - side output voltage of the bridge circuit, or directly control the AC - side current of the circuit, so that the circuit absorbs or emits reactive power that meets the requirements, achieving the purpose of dynamic reactive power compensation.

[0042] When the SVG device in the switching station has not stopped operating, it indicates that the SVG is in a normal working state; when it has stopped operating, it indicates that the SVG is not in a working state.

[0043] V. Judgment of the pilot differential protection action of the differential protection device S5. Use the input data to judge whether the differential protection device has a pilot differential protection action. If so, judge it as an external power supply tripping fault and troubleshoot the stop; if not, enter the next step. Preferably, step S5 includes: judging whether the pilot differential protection action of the differential protection device occurs in the high - voltage incoming switchgear of the switching station within the entire power supply sub - area; if the pilot differential protection action of the differential protection device occurs, judge it as an external power supply tripping fault and troubleshoot the stop; if the pilot differential protection action of the differential protection device has not occurred, proceed to the next judgment.

[0044] Preferably, in step S5, the high - voltage incoming switchgear is the 35kV incoming switchgear.

[0045] In the above steps, the function of the differential protection device is as follows: when the vector difference of the CT currents at both ends of the input reaches the set operating value, the operating element is activated to protect the equipment between the CTs at both ends of the input. When the pilot differential protection of the differential protection device operates, it indicates that the vector difference of the CT currents at both ends of the input reaches the set operating value; when it does not occur, it indicates that the vector difference of the CT currents at both ends of the input does not reach the set operating value.

[0046] VI. Judgment of Circuit Breaker in Open Position or Bus-coupler Cabinet in Closed Position S6. Use the input data to judge whether the circuit breaker in the high-voltage switchgear cabinet is in the open position or the bus-coupler cabinet is in the closed position. If so, proceed to the next step; if not, stop the troubleshooting. Preferably, step S6 includes: judging whether the circuit breaker in the high-voltage switchgear cabinets of all substations in the entire power supply area is in the open position or the bus-coupler cabinet is in the closed position; if an action occurs, proceed to the next judgment; if no action occurs, stop the troubleshooting.

[0047] Preferably, in step S6, the high-voltage switchgear cabinet is a 35kV switchgear cabinet.

[0048] Preferably, in step S6, the switchgear cabinet includes an incoming line cabinet, an outgoing line cabinet, a feeder cabinet, and a bus-coupler cabinet.

[0049] In the above steps, judge whether the circuit breaker in the 35kV switchgear cabinets (incoming line cabinet, outgoing line cabinet, feeder cabinet, bus-coupler cabinet) of all substations in the entire power supply area is in the open position or the bus-coupler cabinet is in the closed position. If an action occurs, proceed to the next judgment; if no action occurs, stop the troubleshooting. When the circuit breaker is in the open position, it indicates that the equipment of the 35kV switchgear cabinet is faulty and is in a non-operating state; when the bus-coupler cabinet is in the closed position, it indicates that the incoming line cabinet of a 35kV circuit is faulty and is in a non-operating state. When neither the circuit breaker in the open position nor the bus-coupler cabinet in the closed position occurs, it indicates that all electrical equipment in the substation is in a normal operating state.

[0050] VII. Judgment of Four Conditions S7. Analyze the change in the equipment operation status within T seconds and judge whether the circuit breaker in the low-voltage switchgear cabinet is in the open position or the bus-coupler cabinet is in the closed position, whether the regenerative energy feeding device is abnormal, whether the working mode of the DC panel has changed, and whether the operating flag of the active power filter device has stopped operating. (1) Judgment of Low-voltage Switchgear Cabinet Preferably, in step S7, judging whether the circuit breaker in the low-voltage switchgear cabinet is in the open position or the bus-coupler cabinet is in the closed position includes: judging whether the circuit breaker in the low-voltage incoming line switchgear cabinet or the low-voltage bus-coupler switchgear cabinet of all substations in the entire power supply area is in the open position or the bus-coupler cabinet is in the closed position. If so, the judgment condition is met.

[0051] In the above steps, it is determined whether the circuit breakers of the incoming line switch cabinets, the bus coupler switch cabinets, and the incoming line switch cabinets of the 2# 400V in all substations within the entire power supply area have tripped or the bus coupler switch cabinet is closed.

[0052] In the above steps, when the circuit breaker trips, it indicates that the 400V switch cabinet has a fault and is in a non-operating state; when the bus coupler switch cabinet is closed, it indicates that the incoming line switch cabinet of the 400V in the same power supply circuit has a fault and is in a non-operating state. When neither the circuit breaker trip nor the bus coupler switch cabinet closing occurs, it indicates that all electrical equipment in the substation is in normal operating condition.

[0053] (2)Regenerative energy feed device judgment Preferably, in step S7, judging whether the regenerative energy feed device is abnormal includes: judging whether the inverter-type regenerative energy feed device in the traction and rectifier substation within the entire power supply area has been put into or withdrawn, whether the resistor-type regenerative energy feed device is operating or on standby, or whether the operating mode of the flywheel-type regenerative energy feed device has exited; if the inverter-type regenerative energy feed device has exited, the resistor-type regenerative energy feed device is on standby, or the operating mode of the flywheel-type regenerative energy feed device has exited, then the judgment condition is met.

[0054] In the above steps, it is determined whether the inverter-type regenerative energy feed device in the traction and rectifier substation within the entire power supply area has been put into / withdrawn, whether the resistor-type regenerative energy feed device is operating / on standby, and whether the flywheel-type regenerative energy feed device has exited its operating mode.

[0055] In the above steps, for the inverter-type regenerative energy feed device, its DC side is connected to the DC bus of the traction grid, and its AC side is connected to the AC grid. When the braking energy of the train causes the DC voltage of the traction grid to exceed the set value, the inverter-type regenerative energy feed device starts and absorbs electrical energy from the traction grid and feeds the electrical energy back to the AC grid for other loads to use, and achieves the purpose of stabilizing the DC bus voltage. When the device is put into operation, it indicates that the inverter-type regenerative energy feed device starts and absorbs electrical energy from the traction grid; when it exits, it indicates that the inverter-type regenerative energy feed device has stopped operating and is in an abnormal working state.

[0056] For the resistor-type regenerative energy feed device, its DC side is connected to the DC bus of the traction grid, and its AC side is connected to the AC grid. When the braking energy of the train causes the DC voltage of the traction grid to exceed the set value, the resistor-type regenerative energy feed device starts and absorbs electrical energy from the traction grid and converts the electrical energy into heat; when it is operating, it indicates that the resistor-type regenerative energy feed device starts and absorbs electrical energy from the traction grid; when it is on standby, it indicates that the resistor-type regenerative energy feed device has stopped operating and is in an abnormal working state.

[0057] For a flywheel - type regenerative energy feeding device, its DC side is connected to the DC bus of the traction power grid, and its AC side is connected to the AC power grid. When the braking energy of the train causes the DC voltage of the traction power grid to exceed the set value, the flywheel - type regenerative energy feeding device starts and absorbs electric energy from the traction power grid and feeds the electric energy back to the AC power grid; when the operating mode exits, it indicates that the flywheel - type regenerative energy feeding device exits operation and is in an abnormal working state.

[0058] (3)Judgment of the working mode of the DC panel Preferably, in step S7, judging whether the working mode of the DC panel changes includes: judging whether the AC working mode of the automatic transfer switch of the DC panel in all substations within the entire power supply area changes. If so, the judgment condition is met.

[0059] In the above steps, judge whether the AC working mode of the DC panel ATS switching to 1# AC working mode / the DC panel ATS switching to 2# AC working mode in all substations within the entire power supply area changes.

[0060] Among them, ATS refers to the automatic transfer switch. The functions of the DC panel ATS switching to 1# and the DC panel ATS switching to 2# are to automatically switch two DC power supplies. When the AC working mode changes, it indicates that one of the DC power supplies exits operation and is in an abnormal working state.

[0061] (4)Judgment of the active power filter device Preferably, in step S7, judging whether the operation flag of the active power filter device stops operating includes: judging whether the operation flag of the active power filter device in all substations within the entire power supply area stops operating. If so, the judgment condition is met.

[0062] In the above steps, judge whether the operation flag of the active power filter device in all substations within the entire power supply area stops operating. Among them, the function of the active power filter device is to dynamically suppress harmonics and compensate for reactive power, and it can compensate for harmonics and reactive power whose magnitudes and frequencies are both changing. When the operation flag stops operating, it indicates that the active power filter device exits operation and is in an abnormal working state.

[0063] VIII. Network voltage fluctuation fault S8. Judge whether any three of the four judgment conditions in step S7 are met. If so, output the network voltage fluctuation fault and judge the fault - affected range according to the line power supply relationship diagram.

[0064] In the above steps, for the entire fault judgment method, only judge the state of the equipment operation status that changes within 3 seconds within the entire judgment method, and if any three conditions are met, it can be output as a network voltage fluctuation fault and the fault - affected range can be judged.

[0065] In the present invention, it is necessary to meet any three conditions because when any three conditions in S7 are met, it can be indicated that the electrical equipment in the same power supply circuit is in an abnormal working state, which is caused by network voltage fluctuation. The specific method for determining the fault influence range is as follows: According to the electrical connection relationship of the electrical equipment in the line power supply relationship diagram, when there is electrical equipment in an abnormal working state in the same power supply circuit, it is the network voltage fluctuation influence range.

[0066] In the present invention, according to the troubleshooting logic, only the abnormal conditions of the monitoring parameters of these devices are checked to accurately locate the cause of the fault, rather than checking other irrelevant devices.

[0067] Advantages of the present invention: 1. Compared with the fault analysis method using oscillograms, it mainly analyzes the current and voltage in the fault oscillogram file and is assisted by manual judgment, and the types of fault judgments are relatively few. Greatly affected by the oscillogram file and human factors, the timeliness and accuracy cannot be guaranteed, and this method cannot meet the requirements.

[0068] However, the present invention can quickly and accurately determine the fault influence range in the form of a line power supply relationship diagram in combination with the fault judgment method.

[0069] 2. Compared with the harmonic analysis fault diagnosis method, it mainly uses the voltage signal collected by the voltage transformer or the power quality analyzer as the judgment standard, which is too single and prone to misjudgment or missed judgment.

[0070] However, the present invention can ensure multi-faceted analysis and the accuracy of fault judgment in the form of a line power supply relationship diagram in combination with the operation status of the equipment.

[0071] 3. Compared with the state assessment fault diagnosis method, it mainly obtains the characteristics of network voltage fluctuation by processing and analyzing the voltage fluctuation situation, duration, and frequency during the operation process to judge the network voltage fluctuation fault.

[0072] The present invention can quickly and directly determine the fault influence range based on the line power supply relationship diagram and the equipment operation status, relying on the fault judgment logic diagram. Description of the Drawings

[0073] Figure 1 It is a schematic diagram of the fault judgment logic diagram of the present invention; Figure 2 For the present invention Figure 1 The enlarged upper part of the fault judgment logic diagram process in the present invention; Figure 3 For the present invention Figure 1 The enlarged lower left part of the fault judgment logic diagram process in the present invention; Figure 4 For the present inventionFigure 1 Enlarged view of the lower right part of the fault judgment logic diagram process in Figure 5 This is the power supply relationship diagram of the circuit of the present invention. Specific embodiments

[0074] The concept, specific structure and technical effects of the present invention will be clearly and completely described below in conjunction with the embodiments and the drawings, so as to fully understand the purpose, features and effects of the present invention.

[0075] Embodiment 1 A method for diagnosing network voltage fluctuation faults based on data analysis, as Figure 1 , Figure 2 , Figure 3 and Figure 4 shown, includes the following steps: S1. Construct a power supply relationship diagram of the lines of the rail transit power supply system; S2. Input the power supply relationship diagram of the lines and the real-time status data of the collected equipment into the fault judgment module; S3. Analyze and judge the input data. When the circuit breaker of the high-voltage busbar equipment is closed in the input data, or a voltage transient event occurs in the high-voltage incoming switchgear, start the network voltage fluctuation analysis process and enter the next step; S4. Use the input data to judge whether the dynamic reactive power compensation device stops operating. If so, enter the next step; if not, check and stop; S5. Use the input data to judge whether the pilot differential protection device has a pilot differential protection action. If so, judge it as an external power supply tripping fault and check and stop; if not, enter the next step; S6. Use the input data to judge whether the circuit breaker of the high-voltage switchgear has a tripping action or the bus-coupler cabinet has a closing action. If so, enter the next step; if not, check and stop; S7. Analyze the change of the equipment operation status within T seconds, and judge whether the circuit breaker of the low-voltage switchgear has a tripping action or the bus-coupler cabinet has a closing action, judge whether the regenerative energy feedback device is abnormal, judge whether the working mode of the DC panel has changed, and judge whether the active filter device has a running flag stop action; S8. Judge whether any three of the four judgment conditions in step S7 are satisfied. If so, output a network voltage fluctuation fault and judge the fault influence range according to the power supply relationship diagram of the lines.

[0076] Embodiment 2 On the basis of Embodiment 1, this embodiment further elaborates on step S1.

[0077] In step S1, construct a power supply relationship diagram of the lines of the rail transit power supply system, as Figure 5As shown in the figure, the function of the line power supply relationship diagram is to assist in judging the electrical connection relationship between electrical equipment and the scope of fault influence.

[0078] Embodiment 3 On the basis of Embodiment 2, this embodiment further elaborates on Step S2.

[0079] In Step S2, the data acquisition module is used to collect the real-time status data of the equipment; a fault judgment logic diagram is set in the fault judgment module. With the real-time status of the equipment and the line power supply relationship diagram as inputs, they are input into the fault judgment module, and the fault judgment module combines the fault judgment logic diagram to perform fault diagnosis and analysis.

[0080] Embodiment 4 On the basis of Embodiment 3, this embodiment further elaborates on Step S3.

[0081] In Step S3, when the circuit breaker closing permission action occurs for the 35kV busbar equipment in the adjacent power supply subzone, or a voltage transient event (including voltage rise, voltage dip, interruption) occurs in the 35kV incoming switchgear of all substations in the power supply subzone, the network voltage fluctuation analysis process is started.

[0082] Embodiment 5 On the basis of Embodiment 4, this embodiment further elaborates on Step S4.

[0083] In Step S4, it is judged whether the dynamic reactive power compensation device in the switchgear station stops operating within the entire power supply subzone; if it does not stop operating, the troubleshooting stops; if it stops operating, the next step of analysis is carried out.

[0084] Embodiment 6 On the basis of Embodiment 5, this embodiment further elaborates on Step S5.

[0085] In Step S5, it is judged whether the pilot differential protection action of the differential protection device occurs in the high-voltage incoming switchgear of the switchgear station within the entire power supply subzone; if the pilot differential protection action of the differential protection device occurs, it is judged as an external power supply tripping fault and the troubleshooting stops; if the pilot differential protection action of the differential protection device does not occur, the next step of judgment is carried out.

[0086] Embodiment 7 On the basis of Embodiment 6, this embodiment further elaborates on Step S6.

[0087] In Step S6, it is judged whether the circuit breaker opening position action or the bus coupler cabinet closing position action occurs for all 35kV switchgears (incoming cabinet, outgoing cabinet, feeder cabinet, bus coupler cabinet) in all substations within the entire power supply subzone. If the action occurs, the next step of judgment is carried out; if the action does not occur, the troubleshooting stops.

[0088] Example 8 On the basis of Example 7, this example further elaborates on step S7.

[0089] In step S7, for the low-voltage switchgear, it is judged whether the circuit breakers of the incoming line switchgear, the bus coupler switchgear, and the 2# 400V incoming line switchgear in all substations within the entire power supply area have tripped or the bus coupler switchgear has closed.

[0090] For the renewable energy feeding device, it is judged whether the inverter-type renewable energy feeding device in the traction and mixing substation within the entire power supply area has been put into / withdrawn, whether the resistor-type renewable energy feeding device has been operating / standby, and whether the flywheel-type renewable energy feeding device has changed its operating mode.

[0091] For the DC power supply panel working mode, it is judged whether the DC power supply panel ATS switching to the 1# AC working mode / DC power supply panel ATS switching to the 2# AC working mode has changed in all substations within the entire power supply area.

[0092] For the active power filter device, it is judged whether the operation flag of the active power filter device in all substations within the entire power supply area has stopped.

[0093] Example 9 On the basis of Example 8, this example further elaborates on step S8.

[0094] In step S8, for the entire fault judgment method, only the state in which the device operating state has changed within 3 seconds in the entire judgment method is judged, and if any three conditions are met, it can be output as a network voltage fluctuation fault and the fault impact range can be determined.

[0095] The above has specifically described the embodiments of the present invention. However, the present invention is not limited to the described embodiments. Those skilled in the art can make various equivalent variations or substitutions without departing from the spirit of the present invention, and these equivalents or substitutions are all included within the scope defined by the claims of the present invention.

Claims

1. A method for diagnosing network voltage fluctuation faults based on data analysis, characterized in that, It includes the following steps: S1. Construct a line power supply relationship diagram of the rail transit power supply system; S2. Input the line power supply relationship diagram and the real-time status data of the collected equipment into the fault judgment module; S3. Analyze and judge the input data. When the circuit breaker of the high-voltage busbar equipment is closed in the input data, or a voltage transient event occurs in the high-voltage incoming switchgear cabinet, start the network voltage fluctuation analysis process and proceed to the next step; S4. Use the input data to judge whether the dynamic reactive power compensation device has stopped operating. If so, proceed to the next step; if not, check and stop; S5. Use the input data to judge whether the pilot differential protection device has an action of pilot differential protection. If so, judge it as an external power supply tripping fault and check and stop; if not, proceed to the next step; S6. Use the input data to judge whether the circuit breaker of the high-voltage switchgear cabinet has a tripping action or the bus coupler cabinet has a closing action. If so, proceed to the next step; if not, check and stop; S7. Analyze the change of the equipment operation state within T seconds, and judge whether the circuit breaker of the low-voltage switchgear cabinet has a tripping action or the bus coupler cabinet has a closing action, judge whether the regenerative energy feedback device is abnormal, judge whether the working mode of the DC panel has changed, and judge whether the active filter device has a stop action of the operation flag; S8. Judge whether any three of the four judgment conditions in step S7 are satisfied. If so, output a network voltage fluctuation fault and judge the fault influence range according to the line power supply relationship diagram.

2. The method for diagnosing the network voltage fluctuation fault according to claim 1, wherein, In step S2, use the data acquisition module to collect the real-time status data of the equipment; a fault judgment logic diagram is set in the fault judgment module.

3. The method for diagnosing the network voltage fluctuation fault according to claim 1, wherein Step S3 includes: when the circuit breaker closing permission action occurs in the high-voltage busbar equipment of the switchgear in the adjacent power supply area, or a voltage transient event occurs in the high-voltage incoming switchgear cabinets of all substations in the power supply area, start the network voltage fluctuation analysis process.

4. The network voltage fluctuation fault diagnosis method according to claim 1, wherein Step S4 includes: judge whether the dynamic reactive power compensation device in the switchgear in the entire power supply area has a stopped operation state; if there is no stopped operation state, check and stop; if there is a stopped operation state, proceed to the next analysis.

5. The net pressure fluctuation fault diagnosis method according to claim 1, wherein Step S5 includes: judge whether the pilot differential protection device of the high-voltage incoming switchgear cabinets of the switchgears in the entire power supply area has an action of pilot differential protection; if there is an action of the pilot differential protection device, judge it as an external power supply tripping fault and check and stop; if there is no action of the pilot differential protection device, then make the next judgment.

6. The method for diagnosing the network voltage fluctuation fault according to claim 1, wherein Step S6 includes: judge whether the circuit breaker of the high-voltage switchgear cabinets of all substations in the entire power supply area has a tripping action or the bus coupler cabinet has a closing action; if there is an action, make the next judgment; if there is no action, check and stop.

7. The method for diagnosing the network voltage fluctuation fault according to claim 1, characterized in that, In step S7, judging whether the circuit breaker of the low-voltage switchgear cabinet has a tripping action or the bus coupler cabinet has a closing action includes: judging whether the circuit breaker of the low-voltage incoming switchgear cabinets or the low-voltage bus coupler switchgear cabinets of all substations in the entire power supply area has a tripping action or the bus coupler cabinet has a closing action. If so, the judgment condition is satisfied.

8. The method for diagnosing the network voltage fluctuation fault according to claim 1, characterized in that, In step S7, judging whether the regenerative energy feedback device is abnormal includes: judging whether the inverter-type regenerative energy feedback device in the traction and hybrid substation within the entire power supply section is put into or withdrawn, whether the resistor-type regenerative energy feedback device is operating or on standby, or whether the operating mode of the flywheel-type regenerative energy feedback device exits; if the inverter-type regenerative energy feedback device exits, the resistor-type regenerative energy feedback device is on standby, or the operating mode of the flywheel-type regenerative energy feedback device exits, then the judgment condition is met.

9. The method for diagnosing the network voltage fluctuation fault according to claim 1, wherein, In step S7, judging whether the working mode of the DC panel has changed includes: judging whether the AC working mode of the automatic transfer switch of the DC panel has changed in all substations within the entire power supply section. If so, the judgment condition is met.

10. The method for diagnosing the network voltage fluctuation fault according to claim 1, wherein In step S7, judging whether the operation flag of the active power filter device has stopped operating includes: judging whether the operation flag of the active power filter device in all substations within the entire power supply section has stopped operating. If so, the judgment condition is met.

Images