291 results about "Traction power supply" patented technology

The invention discloses an energy storage rapid compensation method and system based on track overhead line system voltage fluctuation feature recognition, and relates to the technical field of track traffic traction power supply. The method comprises the following steps: synchronously acquiring voltage and current signals of the overhead line system, and extracting a composite feature vector containing disturbance root attributes and transient change rate; on the basis of the vector, a transient energy vacancy sequence covering the ultra-short-term future is output in real time through a prediction model fusing dynamic phasor analysis and a feedforward neural network; according to the sequence, a cooperative control strategy fusing overshoot and active damping is generated in combination with a proximity compensation principle and a voltage recovery state so as to drive an along-line energy storage unit; the strategy is executed in advance, compensation energy is injected, and finally double closed-loop correction is conducted based on the voltage residual error. According to the method, the problems of response lag, unclear disturbance identification, poor collaboration and lack of adaptive ability in the prior art are solved, and advanced, accurate, collaborative and self-optimized rapid suppression of the voltage fluctuation of the overhead line system is realized.

The invention discloses a simulation method of a full-system coupled railway traction power supply system, which comprises the following steps: taking a traction power supply system and a train group as integrated simulation objects, and respectively constructing traction power supply network models including equivalent models of traction transformer, traction network, AT station and public power grid parameters; a multi-train operation simulator is constructed, and the multi-train operation simulator comprises various parameters such as trains, lines, signal systems, operation organizations and the like. Traversing all on-line trains through a multi-train operation simulator, substituting the on-line trains into a traction power supply network model, and dynamically calculating operation parameters and traction loads of a train group, including calculating locomotive initial current according to train initialization voltage, solving a traction power supply network node voltage equation and updating locomotive terminal voltage; and correcting the traction and braking characteristics of the train based on the updated locomotive terminal voltage. The method overcomes the defects of a traditional calculation method using a traction power supply system as an isolated network, reveals the dynamic state of train operation and the distribution characteristics of the traction network, and finally can obtain various parameters of each train.

The invention discloses a source load impact and system bearing life evaluation method and system, equipment and a medium, and relates to the technical field of traction power supply, and the method comprises the steps: collecting data to recognize impact, building a source load model, analyzing an impact diffusion path, evaluating system bearing, fusing multi-dimensional damage, calculating the residual life of the equipment, and automatically updating parameters. And generating a closed-loop regulation and control strategy. The system comprises a data analysis and dynamic modeling module, a bearing evaluation and conduction analysis module, a damage coupling and life prediction module and a parameter correction and strategy generation module. The traction impact time domain-frequency domain-topology integrated quantization is realized, and the problem of impact time-space diffusion assessment is solved. A life model is constructed, and multi-dimensional stress damage is accurately mapped. The micro-simulation and on-line filtering technology is utilized to ensure that model parameters are adaptively updated along with working conditions, and the problem of disjunction between evaluation and actual conditions is solved. The method supports side cloud cooperation and closed-loop pre-control, effectively improves the safety margin of the power grid, and delays the aging of equipment.

The invention discloses a distributed cooperative voltage control method for a hybrid flexible traction substation group, and aims at solving the problems of output voltage cooperation, no-load circulating current suppression and multi-substation load distribution during networking operation of a plurality of hybrid flexible traction substations (HFTSS). Rapid synchronization of output voltage phases of the substations is achieved by introducing an average consistency algorithm, and nearby distribution of train loads among the traction substations is achieved by combining self-adaptive virtual impedance. According to the method, the capacity of the hybrid flexible traction substation for coping with the dynamic change of the external power grid voltage phase can be effectively enhanced, the loss of a contact network is reduced, the regenerative braking energy utilization efficiency is improved, and a feasible path is provided for large-scale application of a low-cost hybrid flexible traction power supply system and improvement of a cooperative control technology system.

The invention relates to an electrified railway traction power supply system which is low in investment, is smooth for obtaining a current and is convenient to maintain. Rail webs outside two steel rails of a rail are respectively provided with one insulating strip; then a power supply strip is respectively arranged outside each insulating strip; each vibration inductive switch is connected in series with a sound inductive switch and a light-operated inductive switch; one ends of the connected switches are connected to the power supply strips at one sides; the other ends of the connected switches are connected with feed lines; the power supply strips at the other sides are connected with return wires. Power receiving frames at a headstock side and a tailstock side of a train are in contact with the power supply strips; when the train passes through a zone, the vibration inductive switches are closed, the sound inductive switches are closed, the light-operated inductive switches are closed, the power supply strips in the zone supply power, the power receiving frames of the train obtain a current and the train runs; when the train runs into a next power supply zone, the next power supply section is powered on, and power supply is stopped in the power supply zone. The aims of low investment, smoothness for obtaining the current and convenience for maintenance are fulfilled.

The method is applied to the fields of train regenerative braking energy utilization, stray current and rail potential treatment and the like in electrified rail transit, especially urban rail transit. The invention provides a direct-current traction power supply system capable of reducing the energy storage capacity of a super capacitor of urban rail transit, which is combined with a super capacitor energy storage device of the urban rail transit and supplies power to a power electronic device for treating stray current and rail potential by utilizing regenerative braking energy of a train. The super-capacitor energy storage device has the following advantages that on one hand, the energy storage capacity of the super-capacitor bank in the super-capacitor energy storage device between train braking and traction can be reduced, and the utilization efficiency of regenerative braking energy stored by the super-capacitor bank is improved; on the other hand, the problems of stray current, rail potential and the like in the system can be solved from the source, and the power supply distance of a traction substation is remarkably increased. Therefore, the direct-current traction power supply system is of great significance to green and safe operation of urban rail transit.

The invention discloses an urban rail energy consumption scheduling method based on artificial intelligence multi-objective optimization, and the method comprises the steps: effectively solving a problem of scheduling decision limitation caused by a single optimization objective in the prior art through comprehensive real-time data processing, multi-objective collaborative optimization and intelligent algorithm iteration solution; the optimal control of the overall operation energy consumption of the rail transit system is realized; the train operation energy efficiency, the regenerated energy utilization rate and the operation punctuality rate are effectively improved, meanwhile, the peak load of a traction power supply system is reduced, the overall energy utilization efficiency and the operation performance of rail transit are remarkably improved, and the dual purposes of energy conservation, consumption reduction and efficient operation of the system are achieved.

The invention discloses a network fault flexible reconstruction control method and system for a through traction power supply system, and the method comprises the steps: achieving the physical comprehension of a fault traction station and a traction network, and constructing a local fault isolation region based on the disconnection operation of a control electric split phase when an output or input port of a two-phase-single-phase conversion unit breaks down; the power supply system realizes self-adaptive reconstruction of a power supply path of the fault traction station through switching of a control strategy or adjustment of a power instruction, and local island operation of the traction network is completed; after the fault port is repaired, the power supply system further executes a fault recovery process, and finally, a system operation structure is recovered to a conventional mode before the fault; the system comprises a fault judgment module, an output port fault adjustment module and an input port fault adjustment module, and is used for realizing the method.

The invention discloses a two-phase input coordination control method and system for a hybrid through traction power supply device. The method comprises the following steps: acquiring alternating-current side voltage and current and direct-current side voltage of each group of two-phase input ports in the device in real time; obtaining an active reference instruction of each output port according to the DC side voltage; performing single-phase dq conversion based on a virtual axis according to the alternating current side voltage and current to obtain dq axis current components of each group of two-phase input ports; obtaining active and reactive current reference instructions of each group of two-phase input ports according to the active reference instruction and a first condition; pWM modulation is carried out according to the dq-axis current component and the active and reactive current reference instruction, and PWM instructions of each group of two-phase input ports are obtained; and continuously obtaining a PWM instruction and driving the device according to the PWM instruction.

The application discloses a kind of based on distributed control's rail transit traction power supply optimization method, comprising: obtaining environmental parameter and correcting insulation and carrying capacity, obtain correction result;According to main substation, section, catenary section and backflow node position constructs distributed control unit and graph structure;The correction result, traction load and graph structure are input into graph attention network, and output voltage, temperature rise and insulation risk;Based on prediction and constraint, execute power supply system evaluation, generate power supply topology;Power supply topology is issued to distributed control unit, and local control parameter is generated;Distributed control unit communication cooperates to generate consistent control parameter;According to consistent control parameter, section switch, power supply arm switching and backflow path adjustment are executed.The application realizes the accurate prediction and collaborative control of traction power supply system, improves power supply stability and operation safety, has the advantages of high power safety, strong power supply reliability.

The invention discloses a harmonic suppression method and system of a rail transit electric traction system. The system comprises a traction unit harmonic response acquisition module, a traction group construction and intra-group influence analysis module, a traction group collaborative behavior analysis module, a collaborative suppression strategy generation module and a suppression resource regulation and control module. The method comprises the following steps: dividing a plurality of traction units on the same train into traction groups, analyzing harmonic response information of the traction units on a traction group level to generate comprehensive harmonic influence characteristics, analyzing action results of the plurality of traction groups on a traction power supply section level, and judging whether a harmonic collaborative amplification or collaborative instability trend exists or not; and thus, a collaborative harmonic suppression strategy for the traction group or the traction unit is generated. Through differential regulation and control on harmonic suppression resources and in combination with feedback correction, dynamic adjustment of a harmonic suppression process is realized, and pertinence of harmonic suppression under a complex operation condition and operation stability of a traction power supply system are improved.

The utility model discloses an electric split-phase protection device for a contact network, and relates to the field of electrified railway traction power supply systems. The system is composed of a signal acquisition unit, an interphase fault identification unit, a fault removal unit, a power supply unit, a man-machine interface unit and an information interaction unit. An analog quantity acquisition circuit of the signal acquisition unit is connected with the interphase fault identification unit through a high-speed PCIE bus. The switching value acquisition circuit, the electric split-phase fault identification unit, the fault removal unit, the information interaction unit and the man-machine interface unit of the signal acquisition unit are connected together through the CAN bus, and the power supply unit supplies power to each unit through a device backboard power supply loop. The device is used for identifying and removing the phase-to-phase fault of the overhead line system, can improve the identification rate of the phase-to-phase fault, shortens the fault removal time, and achieves the quick removal of the fault, thereby avoiding the large-area power failure of a traction power supply system, and guaranteeing the normal operation of an electric locomotive.

The multipurpose unmanned aerial vehicle comprises a transmission unmanned aerial vehicle body, floating blocks are fixedly connected to the two sides of the bottom of the transmission unmanned aerial vehicle body, a storage battery is fixedly installed on one side of each floating block, a pesticide storage box is fixedly installed on the surface of a supporting plate, and a booster pump is fixedly installed on the top of the pesticide storage box. A connecting pipe is rotatably installed at a water outlet of the booster pump, a spraying head is rotatably installed at the top of the transmission unmanned aerial vehicle, a cleaning unmanned aerial vehicle is fixedly connected to the tail end of the traction power line, a first transmission motor is fixedly installed at the bottom of the positioning rod, and a cutting blade is fixedly connected to a transmission shaft of the first transmission motor. The cleaning unmanned aerial vehicle has the advantages that algicide in the pesticide storage box is automatically sprayed to the water surface through the booster pump in the transmission unmanned aerial vehicle, pesticide cleaning of algae on the water surface is achieved, the cleaning unmanned aerial vehicle moves in the water, the algae in the water body are cut and cleaned through the cutting blades, manpower is saved, and meanwhile the cleaning efficiency is improved. And the cleaning efficiency of the algae in the water environment is greatly improved.

The invention provides an urban rail transit traction power supply flywheel energy storage and medium-voltage energy feedback collaborative optimization configuration method, and the method comprises the steps: introducing a flywheel energy storage unit FESE and an inversion energy feedback unit IEFE into an urban rail transit power supply system at the same time, and constructing an urban rail transit AC-DC hybrid power flow analysis model; taking the daily total cost and the static recovery period as targets to construct a comprehensive cost index; the number of FESEs and the number of IEFEs are used as discrete variables, a charging voltage threshold value and a discharging voltage threshold value of the FESEs and an action voltage threshold value of an inversion energy feedback unit are used as continuous variables, a hierarchical swarm intelligent optimization method is adopted, the purpose of minimizing a comprehensive cost index is taken as a target, and on the premise that the operation constraint of a power supply system is met, the power supply system is optimized. And outputting a collaborative optimization configuration scheme including the FESE number, the IEFE number and the sum of the FESE number and the IEFE number of the traction substations.

The invention discloses an intelligent traction power supply system power adjusting method and system. Comprising the following steps: calculating real-time transfer power, and calculating compensation current in real time by combining a power transfer error and negative sequence current; calculating a current tracking value based on the current inner loop instruction value and the voltage synchronization signal; designing a feedforward-feedback composite controller, and respectively calculating a feedforward compensation quantity and a feedback control quantity; based on the feedback control quantity and the feedforward compensation quantity, the total duty ratio of the PWM modulation signal is calculated, and a railway power regulator is driven to output an actual current value; the control method and system provided by the invention are low in engineering implementation cost, adaptive to the RPC application scene of the traction substation, and easy to popularize.

The invention relates to the technical field of rail transit traction power supply, and provides an MMC-RPC power supply system optimization control method based on new energy consumption and traction load matching. Comprising the following steps: step 1, collecting a power output fluctuation characteristic Pn (t) of a new energy power generation end, a dynamic change characteristic P1 (t) of a traction load and an operation state parameter S (t) of a power supply system in real time through a distributed sensor network; step 2, constructing a multi-dimensional dynamic prediction model fpred based on the acquired Pn (t) and P1 (t) data; step 3, calculating a power difference value of the two power sources in a time dimension according to the power difference value obtained by prediction; and step 4, aiming at the delta Ph (t) and the delta Pq (t), designing a corresponding sub-module switch sequence urpc (t) through a multi-level topological structure of MMC-RPC so as to realize real-time harmonic suppression and reactive compensation of the traction load. According to the invention, cooperative control of the MMC-RPC and the energy storage system is realized through the hierarchical coordination controller, control conflicts and redundancy adjustment during independent operation of multiple devices are avoided, and the overall energy consumption of the system is reduced.

The utility model relates to an autonomous controllable traction power supply feeder protection measurement and control device, which comprises a CPU (central processing unit) plug-in unit, an alternating current plug-in unit, an input plug-in unit, an output plug-in unit, an operation plug-in unit, a power supply plug-in unit, a panel plug-in unit and a mother board plug-in unit which are connected through plug-in terminals. The panel plug-in and the mother board plug-in are connected through the flat wire harness. The CPU plug-in comprises a domestic CPU chip and a domestic FPGA chip, the domestic CPU chip and the domestic FPGA chip are in data communication through an LIO bus and a high-speed PCIE, and the CPU plug-in communicates with the panel plug-in through an Ethernet interface to achieve a man-machine interface function. Input quantity acquisition and switch control output are realized through interaction information of the input and output bus, the input plug-in and the output plug-in; the device provided by the utility model has strong practical value and application prospect.

The invention relates to a multi-level wide-modulation-ratio energy balance cycle control method and device for a high-speed flywheel, and the method is applied to the recycling of regenerative braking energy of a metro traction power supply system, and the capacitor voltage balance of a sub-module is maintained by selectively adopting a bubble sorting-carrier phase-shifting modulation method. When the difference value of the capacitor voltage of the sub-module is large, the capacitor voltage balance of the sub-module can be maintained, a PWM signal is generated to control the on and off of a switching device of the sub-module, and the problem of voltage balance control of the sub-module of the modular multilevel converter under high-frequency fundamental waves is solved. The device can be mounted on a direct-current traction network side of a subway traction power supply system, is used for recycling regenerative braking energy of a subway, and can perfectly meet the instantaneous energy requirement of frequent start and stop of the subway. Compared with the prior art, the wide-modulation-ratio energy balance cycle control method is utilized, the electric energy and kinetic energy conversion efficiency can reach 90%-95%, and the electric energy and kinetic energy conversion efficiency is far higher than that of a traditional energy storage system.

The invention provides a reactive power optimization method, system and device for a flexible direct-current traction converter. The reactive power optimization method comprises the steps of obtaining operation parameters of a power distribution network and a rail transit traction power grid; generating a comprehensive voltage regulation and control capability evaluation index of the flexible direct-current traction converter based on the operation parameters; constructing a leader optimization model by taking the minimization of the total cost of the power distribution network as a target; constructing a follower optimization model by taking profit maximization of the rail transit traction power grid as a target; combining the leader optimization model and the follower optimization model into a master-slave game model, and solving an equilibrium solution of the master-slave game model; and taking the comprehensive voltage regulation and control capability evaluation index of the direct traction converter as a pricing strategy basis, and obtaining an optimal reactive power compensation pricing strategy of the leader and an optimal reactive power output response strategy of the follower based on the equilibrium solution. According to the method, the traction power supply system is effectively excited to actively participate in voltage regulation and control of the power distribution network, so that optimal configuration of resources and safe and stable operation of the system are realized in a complex power grid environment.

The application discloses a fault ranging method in a 1-2 mode of a traction power supply system feeder breaker, relates to the technical field of electrified railway traction power supply, and converts the uplink and downlink feeder currents of a traction substation by means of the cross-link current of an AT substation and a partition substation, so that the first fault interval from the traction substation to the AT substation can also be subjected to fault ranging by the fault ranging principle of the cross-link current ratio method. The method simultaneously considers the difference between type I and type II substation, and the fault ranging precision of the first fault interval can be improved by using the method, the ranging error is controlled within a range of 250 meters, the fault point can be quickly positioned by operation and maintenance personnel when a fault occurs, the fault is timely disposed and the line is recovered to normal operation, and the method has important significance for guaranteeing the safe, stable and efficient operation of a railway transportation system.

The application discloses a kind of traction network impedance simulation system and control method based on voltage source converter, and main substation is simulated by three-phase transformer, and traction substation is simulated by single-phase transformer.Three-phase transformer steps down power supply voltage, and the voltage on the high-voltage side of the single-phase transformer of the traction substation group comes from the same two-phase voltage of the three-phase transformer, which supplies the traction network after stepping down the voltage. Among them, for the impedance simulation of the traction network, the movement of the train is equivalent to the change of the line impedance, and the VSC is used to simulate the impedance of the traction network. The VSC is used to realize the change of the impedance of the traction network on both sides of the train during the train operation. The VSC device is used to simulate the impedance of the traction network on both sides of the train during the train operation, and relevant researchers can use the invention to carry out experimental verification of the related theory of the new type of substation group bilateral traction power supply system, and promote the development of the new type of substation group bilateral traction power supply technology.

The invention relates to an on-line ice preventing / melting method for a railway overhead line system powered by a star-delta transformer. The method comprises the following steps that the star-delta transformer is transformed; calculating corresponding required phase differences under different ice melting current values; the phase difference is used for judging the required transformer ice melting gear K at the moment; selecting a proper number of windings according to the K value in the third step; adjusting the number of turns of the corresponding winding of the transformer according to the winding turn value in the fourth step; and switching on the isolation switch of the partition post to melt ice. The method has the beneficial effects that the phase shifting function of the adjusted transformer is utilized, so that the traction power supply system forms circulating current to melt ice, normal operation of a train in extremely cold weather such as freezing rain is ensured, and large-area train shutdown caused by icing of a contact network is avoided.

The invention discloses a multi-source collaborative traction power supply system adaptive protection method and system, multi-source data of each end of a traction power supply system is synchronously collected, and the multi-source data comprises SVG data of a power supply side, PMU data of a traction network and TCMS data of a locomotive end; performing data cleaning and space-time alignment on the multi-source data to obtain multi-source heterogeneous data; performing nonlinear feature decoupling extraction on the multi-source heterogeneous data to obtain mixed features; constructing a cooperative control model for cooperative work of the LSTM-RF hybrid model and the quantum particle swarm optimization model, and inputting the hybrid features into the cooperative control model to obtain predicted fixed values corresponding to various faults; and cooperatively controlling compensation of the SVG at the power supply side, action of the circuit breaker of the traction network and locking of the locomotive according to the predicted fixed value.

The invention relates to the technical field of safety monitoring of rail transit traction power supply systems, in particular to an overhead line system anomaly detection method based on a generative adversarial network and LSTM coding and decoding, which comprises the following steps: S1, synchronously acquiring multi-physics field data; s2, obtaining a mixed feature vector; s3, obtaining a single frame anomaly score; s4, obtaining a robust anomaly score; s5, obtaining a comprehensive risk score of a single node in all the nodes; step S6, obtaining a verified risk score Rv of the single node; step S7, obtaining the residual life RL of a single node; step S8, carrying out continuous evolution on the residual life of the single node; and step S9, ending the current frame flow, sliding the clock window, and continuing the next frame. According to the method, the data quality of the contact network is improved, fault samples are enriched, the zero sample detection capability of the model on unknown faults is improved, residual life prediction is carried out on progressive degradation, and the operation and maintenance cost of the contact network is reduced.

The utility model relates to the technical field of electrified railway traction power supply, and particularly discloses a standby-considered uplink and downlink ground automatic neutral section passing commutation device, which is based on a standby commutation process, can timely respond and control a standby neutral section passing device to replace commutation action to continue to complete commutation when the neutral section passing device breaks down, so that the standby neutral section passing device is prevented from being damaged. The tight connection of the standby neutral section passing device in the uplink and downlink ground automatic neutral section passing commutation considering standby is realized, and the stability of train commutation entering the neutral section area is improved.

The utility model relates to the technical field of railway in-phase traction power supply, in particular to an in-phase traction network fault current online detection device based on dynamic compensation, which comprises an analog differential sampling circuit, a signal conditioning filter circuit and a threshold comparison output circuit. And a photoelectric isolation output interface, a shielding metal shell and a bipolar auxiliary power supply module are also arranged. The analog differential sampling circuit is connected in parallel to two ends of the direct current bus capacitor, converts voltage fluctuation into analog voltage signals, inputs the analog voltage signals into the threshold comparison output circuit to be compared with reference voltage after clutter and direct current components are filtered out through the signal conditioning filter circuit, and outputs signals to the converter controller fault interruption interface through the photoelectric isolation output interface. The shielding metal shell guarantees the anti-interference performance, and the bipolar auxiliary power supply module provides stable power supply. According to the device, fault current online detection is realized through a hardware circuit, the problem of software algorithm delay is effectively avoided, and the real-time performance and reliability of in-phase traction network fault identification are remarkably improved.

This invention relates to a method and apparatus for high-speed flywheel multi-level wide-modulation specific energy balance cyclic control. The method is applied to the recycling of regenerative braking energy in subway traction power supply systems. By selectively employing a bubble sorting-carrier phase-shift modulation method to maintain the voltage balance of sub-module capacitors, it can maintain voltage balance even when the voltage difference between sub-module capacitors is large, and generate PWM signals to control the switching on and off of sub-module switching devices, thus solving the problem of voltage balance control for modular multi-level converter sub-modules under high-frequency fundamental frequencies. This apparatus can be installed on the DC traction network side of the subway traction power supply system to recycle the subway's regenerative braking energy, perfectly matching the instantaneous energy demands of frequent subway starts and stops. Compared with existing technologies, this invention, utilizing a wide-modulation specific energy balance cyclic control method, achieves an energy-to-kinetic energy conversion efficiency of 90%-95%, far exceeding traditional energy storage systems.

The application relates to the technical field of electrified railway traction power supply, and particularly provides a train uninterrupted power supply system and method applied to a main line and a branch line, which comprises a first substation connected to a main line catenary, a second substation connected to a branch line catenary, and a switch station arranged on the branch line catenary and located on one side of the second substation close to the main line catenary; the switch station comprises an electric section and a section feeder circuit breaker, wherein the electric section is arranged in series on the branch line catenary, and the section feeder circuit breaker is arranged in parallel at both ends of the electric section. The application realizes dynamic connection of the branch line and the main line power supply system through the cooperative power supply of the first substation, the second substation and the switch station, supports cross-zone power supply by the first substation when the switch station is turned on, and can be taken over by the local second substation after the switch station is turned off, so that the main line catenary can be safely isolated in the car collection and maintenance stage.

A grounding circulating current sensor installation device used for a railway traction power supply system cable comprises a clamping plate set placed on the railway traction power supply system cable, an outer folding displacement assembly used for carrying out folding motion on the clamping plate set, and an installation assembly arranged on the outer folding displacement assembly. According to the invention, the expansion area friction connection of the peripheral side surface of the railway traction power supply system cable is realized, the inward contraction of the clamping plate group is realized through the outer folding displacement assembly, and the installation of the grounding circulating current sensor is realized through the installation assembly. According to the utility model, jaw connection with the railway traction power supply system cable and seat body connection with the grounding circulating current sensor are realized, and the technical problem of connection with the railway traction power supply system cable in a binding mode is solved, so that the installation effect of the grounding circulating current sensor is improved.

The invention provides a subway steel rail insulation degradation positioning method and device, computing equipment and a storage system.The subway steel rail insulation degradation positioning method comprises the steps that a simulation model is established based on a topological structure of a target subway line, and a training data set is established based on the established training data set; a first steel rail potential distribution model is generated, a first steel rail potential gradient characteristic quantity reflecting the insulation state is extracted, and an optimal steel rail insulation defect detection threshold value is determined through an optimization algorithm; on-site potential data is obtained, a second steel rail potential distribution model is constructed according to the on-site potential data, a second steel rail potential gradient characteristic quantity is extracted through multi-resolution spatial derivative analysis, the second steel rail potential gradient characteristic quantity is compared with the optimal detection threshold value, and a potential steel rail insulation defect section is identified; and performing time sequence frequency statistics on the position information of the potential steel rail insulation defect section, and determining the final high-confidence steel rail insulation degradation position. And automatic positioning and intelligent operation and maintenance of the insulation degradation area of the subway steel rail backflow type direct-current traction power supply system are realized.