37 results about "HVDC converter station" patented technology

The invention discloses a network construction type and network following type control seamless switching method and device oriented to an MMC-HVDC converter station, relates to the technical field of power system control, and aims at realizing seamless switching of network construction type and network following type control by constructing unified initialization setting of outer ring reference current and phase angle and voltage amplitude on the premise of not changing inner ring current control. And the continuity of the power angle and the amplitude of the output voltage in the control mode switching process is ensured. The technology can quickly respond to changes of power grid conditions, and system disturbance and instability caused by mode switching are avoided. Simulation results show that the technology effectively reduces the impact of control switching on the system, significantly improves the stability and reliability of the system, is suitable for flexible direct current transmission systems under various power grid conditions, and especially has significant advantages in weak power grid access and frequency support scenes.

The invention discloses a coordination control method and related equipment for a network-construction-type flexible direct current converter station. The method comprises the following steps: firstly, determining the maximum capacitive reactive power capacity of the network-construction-type flexible direct current converter station; simulating a fault through time domain simulation, and calculating dynamic reactive power required for guaranteeing the stability of the transient voltage of the hub bus; selecting a parallel capacitor bank close to a grid-connected point to form a collaborative resource set, and initializing and distributing the input capacity of the collaborative resource set; taking the flexible direct current reference voltage, the active power and the capacitor input capacity as boundaries, taking maximization of a static voltage stability index as a target, executing continuous power flow optimization, calculating reactive power reserve capacity, and sending a control target after conditions are met. According to the invention, excessive consumption of flexible direct-current reactive power reserve is avoided by determining the capacity reference, and the dynamic reactive power demand is accurately calculated to ensure fault support; the cooperative capacitor bank supplements insufficient static resources and reduces flexible DC burden; through continuous power flow optimization, overall planning of steady-state and transient-state voltage stability is achieved, and the comprehensive supporting capacity of the network-constructing flexible direct current power supply to the voltage stability of the power grid is effectively improved.

The invention provides an extra-high voltage direct current converter station high-voltage isolation switch redundant mechanism case, which comprises a frame body, a first driving assembly, a second driving assembly and a transmission assembly, and is characterized in that the first driving assembly and the second driving assembly are detachably connected in the frame body; the transmission assembly comprises a driver, a first input shaft, a first clutch, a second input shaft, a second clutch and an output shaft, the driver is fixedly connected into the frame body, the first input shaft is connected to the driver and connected with the output end of the first driving assembly through the first clutch, and the second input shaft is connected to the driver and connected with the output end of the second driving assembly through the second clutch. The second input shaft is connected with the output end of the second driving assembly through the second clutch, the output shaft is connected to the driver, and the end, away from the driver, of the output shaft extends out of the frame body. When the first driving assembly is stuck, the second driving assembly timely replaces the first driving assembly to work, and it is guaranteed that the disconnecting switch can be smoothly switched on and switched off.

A seamless switching method and device for network-oriented MMC-HVDC converter station construction and network following control, relates to the field of power system control technology, without changing the inner loop current control, by constructing a unified outer loop reference current and initializing the setting of phase angle and voltage amplitude, the continuity of output voltage power angle and amplitude in the control mode switching process is ensured. The technology can quickly respond to changes in grid conditions, avoiding system disturbance and instability caused by mode switching. Simulation results show that this technology effectively reduces the impact of control switching on the system, significantly improves the stability and reliability of the system, and is suitable for flexible HVDC transmission systems under various grid conditions, especially in weak grid access and frequency support scenarios.

The invention relates to the technical field of power systems, and discloses a multi-level direct current sending end small disturbance stability assessment method, device and equipment and a medium. Carrying out frequency domain impedance modeling on the following network type new energy converter, the constructed network type energy storage converter, the following network type load converter and the modularized multi-level high-voltage direct current converter station, and constructing a frequency domain impedance network of the all-electric system based on an equivalent impedance model of each device; and performing small disturbance stability analysis on the frequency domain impedance network by using a generalized Nyquist stability criterion, and determining the small disturbance stability of the all-electric system in an alternating current and direct current hybrid scene through a Nyquist diagram of impedance ratios of two sides of a voltage source and a current source in the frequency domain impedance network. Therefore, an effective evaluation means is provided for stable operation of the alternating-current and direct-current series-parallel all-electric system.

The invention relates to the technical field of high-voltage direct-current transmission, and particularly provides an LCC-full-bridge MMC series light HVDC converter station control method, which comprises the following steps: a rectification side of a power grid commutation converter adjusts direct-current power through an outer ring and an inner ring adopts linear trigger angle control to generate a trigger pulse; transformer tap adjustment is supplemented; on the basis of the established stable direct current system, an inversion side selects a minimum trigger angle as a control signal by coordinating three control rings of a turn-off angle, direct current voltage and direct current to form a control system; the full-bridge modularized multi-level converter is switched to a power grid following and network construction control mode according to power grid conditions; and when a direct current fault is detected, setting the trigger angle of the commutation converter of the power grid to be 90 degrees and switching the full-bridge modular multi-level converter to an STATCOM mode, thereby realizing direct current fault ride-through without locking the converter. According to the invention, direct-current fault rapid ride-through of the non-locking converter is realized.

The invention provides a balance testing method and a leveling method for an extra-high voltage direct current converter station capacitor bank, and belongs to the technical field of alternating current filter capacitor bank maintenance. The balance test method comprises the following steps: removing a low-voltage side lead of the capacitor bank and a lead of a current transformer in the capacitor bank; an AC filter high-voltage end grounding knife switch to which the capacitor bank belongs is closed, so that the high-voltage side of the capacitor bank is grounded; applying a test voltage between the low-voltage side of the capacitor bank and the grounding grid, and obtaining a test current value between an upper bridge arm middle connection point and a lower bridge arm middle connection point of the capacitor bank; obtaining an unbalance value of the capacitor bank according to the test voltage value, the test current value and an unbalance protection constant value of the capacitor bank; and if the unbalance value is smaller than the qualified value, the balance test of the capacitor bank passes. A high-voltage side lead of the capacitor bank does not need to be dismounted, a high-voltage side test wire does not need to be hooked during test, and the requirements of operation on special vehicles and the strength and danger of climbing operation are greatly reduced.

The invention relates to the technical field of electrical measurement, in particular to an intelligent cable management system and method for a high-voltage direct-current converter station, and the system comprises a data analysis module, a path evaluation module, a current shunting module, an anomaly detection module and a load mapping module. According to the method, on the basis of collecting node temperature, current and current-carrying capacity data, the heat capacity utilization rate and the redundancy rate are jointly calculated to improve the margin quantification precision, path endpoint deviations are dynamically compared based on the margin, path states are sorted in combination with the current-carrying capacity, and the problem of uneven heat capacity distribution is solved; a shunting instruction is generated according to a path current-carrying ratio and a redundancy rate to improve load balance, abnormal nodes are identified through sudden change of a temperature rise rate and a current change rate, loads are remapped in combination with the redundancy rate and the shunting instruction, thermal capacity evaluation, path sorting, shunting control and abnormal reconstruction closed-loop control are performed, and thermal safety management and response sensitivity are enhanced.

The invention discloses a high-voltage direct-current power transmission system simulation model and a construction method, and relates to the technical field of system-level model construction, and the model comprises a primary topology module and a secondary control module. The primary topology module comprises a first power supply module and a rectifier station module at a rectifier side, a direct current power transmission module, and an inverter station module and a second power supply module at an inverter side; the input end of the rectifier station module is electrically connected with the first power supply module, the input end of the DC power transmission module is electrically connected with the output end of the rectifier station module, the output end is connected with the input end of the inverter station module, and the output end of the inverter station module is electrically connected with the second power supply module; and the secondary control module is used for controlling the current, voltage and power of the rectification side and the inversion side based on PID control logic. The primary topology adopts symmetrical single pole wiring, the HVDC is embedded into an alternating current power grid, and the influence of a transformer substation of the alternating current power grid on an HVDC converter station is researched.

The application discloses a kind of power grid grid interval maintenance state judging method, device, equipment and medium.The method comprises: obtaining the position information of circuit breaker in target ac field, string internal isolator and string external line switch, and sending position information to ac section loss discrimination device;According to position information and preset judging logic, the maintenance state of each device in target ac field is determined by ac section loss discrimination device, wherein the maintenance state includes circuit breaker maintenance state, converter unit maintenance state and line maintenance state.Through the method of the application, the maintenance state of electrical interval in flexible HVDC converter station can be judged in real time and accurately, avoiding the time difference and misoperation risk caused by manual operation, improving the reliability and accuracy of ac section loss discrimination device.In addition, the method does not depend on manual intervention, reduces the influence of human factors on system stability, improves the safety and stability of power grid operation.

The invention belongs to the technical field of electrical equipment testing devices, and particularly relates to a mobile off-line testing device for an extra / high-voltage direct-current converter station protection device, which comprises a testing platform car shell, a mobile controllable power supply assembly, a control unit and an inverter assembly are arranged at the lower part in the testing platform car shell, and a testing tool storage cabinet is arranged in the middle of the testing platform car shell. An operation panel is arranged on the upper portion of the testing device, a power strip and a terminal strip are arranged on the side face of the operation panel, the terminal strip comprises a direct-current power supply terminal and a signal terminal, and the terminal strip is connected with a protection device through an adaptive cable. The protection device off-line test platform solves the problems that an original debugging system needs to additionally add multiple power supplies and more power lines, and the site is disordered and complex, can ensure that test and verification are easily promoted, is an external power supply system, is light and convenient to move at any time, and can meet different debugging working conditions.

A bipolar short-circuit test device for an HVDC converter station on an island, comprising an outdoor DC yard inside the station and a short-circuit test yard outside the station. The original positive and negative line outlets of the HVDC converter station on the island are led to the short-circuit test yard outside the station through the outdoor DC yard for bipolar short-circuit tests. The outdoor DC yard inside the station mainly includes smoothing reactors, resistor-capacitor voltage dividers, DC line arresters, a first cable terminal connected to the indoor DC yard through a submarine cable, and a second cable terminal connected to the short-circuit test yard outside the station. The short-circuit test yard outside the station mainly includes post insulators, aluminum-magnesium alloy pipes, and a third cable terminal connected to the outdoor DC yard inside the station through a submarine cable. The post insulators support the aluminum-magnesium alloy pipes and are arranged in two columns at the middle position of the short-circuit test yard outside the station, forming the positive and negative poles of the short-circuit test. Third cable terminals are respectively arranged corresponding to the east side and the south side of the post insulators. A non-metallic fence is arranged in a circle around the short-circuit test yard outside the station.

The present application relates to the technical field of power system, discloses a kind of multi-level DC sending end small signal stability evaluation method, device, equipment and medium, the present application considers the coupling influence between different heterogeneous devices, to network type new energy converter, network type energy storage converter, network type load converter and modular multi-level high voltage direct current converter station are carried out frequency domain impedance modeling, and based on the equivalent impedance model of each device, the frequency domain impedance network of all-electric system is constructed, the small signal stability of frequency domain impedance network is analyzed using generalized Nyquist stability criterion, the Nyquist diagram of impedance ratio on the two sides of voltage source and current source in frequency domain impedance network is determined The small signal stability of all-electric system under AC / DC hybrid scene, so as to provide an effective evaluation means for the stable operation of AC / DC hybrid all-electric system.

The invention provides an electrical system of an extra-high voltage direct current converter station knife switch redundancy mechanism box. The electrical system comprises an A system motor loop, a B system motor loop, a system control loop connected with the A system motor loop and the B system motor loop, and an electromagnetic clutch loop connected with the system control loop. The system control loop comprises a change-over switch, a system selection switch, an A system control branch and a B system control branch, wherein the A system control branch and the B system control branch are connected with the change-over switch and the system selection switch. When the system A breaks down, the change-over switch is switched to a near control gear, the system selection switch is switched to the system B, the system B is controlled by the system B control branch in a short-range or remote mode to switch on the high-voltage isolation switch through the electromagnetic clutch loop, and the high-voltage isolation switch is controlled to be switched on or switched off. The safety, reliability and automation degree of the high-voltage isolating switch can be improved, and the problem of direct-current locking generated when a secondary signal loop of the high-voltage isolating switch is not in place can be effectively prevented.

The present disclosure relates to a direct current switchyard configured for a bipolar high voltage direct current system, the direct-current switching station comprises a common bus which is a positive electrode, a negative electrode and a neutral part, a plurality of sub-buses of the positive electrode, a plurality of sub-buses of the negative electrode, a plurality of sub-buses of the neutral part, a plurality of high-speed direct-current circuit breakers with high-current interruption capability, and a plurality of direct-current switches with non-current interruption capability, each sub-bus of the anode and the cathode is connected to its respective common bus via a respective high-speed DC circuit breaker of a number of high-speed DC circuit breakers, and wherein each sub-bus of the anode and the cathode is connected to at least one high-voltage DC power transmission medium via a respective DC switch of a number of DC switches, and each high-voltage direct-current power transmission medium is also connected to a high-voltage direct-current converter

The invention relates to an extra-high voltage direct current converter station six-split conductor clamp fitting, which comprises a bus clamp, a sub-wire clamp and a locking assembly, and is characterized in that the bus clamp is provided with two semicircular cylinders which can be in butt joint to form a mother conductor clamping cavity, and the head ends of the semicircular cylinders are provided with semicircular check rings. The number of the sub-wire clamps is six, the sub-wire clamps are distributed on the outer side face of the check ring of the bus clamp, and each sub-wire clamp comprises a wire penetrating cylinder, an arc-shaped clamping plate and a puller bolt. The locking assembly comprises a front thread head, a rear thread head, a locking cylinder and a locking rod. The locking rod comprises a rod body and an anti-disengaging head. Through the closed-loop anti-loosening structural design of the locking rod and the locking cylinder, the problem that a traditional wire clamp bolt is prone to loosening is effectively solved, the locking rod penetrates through the check ring and the puller bolt to limit the rotation freedom degree of the bolt, the locking cylinder abuts against the anti-loosening head after being screwed, double anti-loosening is formed, dynamic loads such as wind loads and electromagnetic vibration are resisted, it is guaranteed that a wire is clamped stably, and the service life of the wire clamp is prolonged. And the falling risk is avoided.

1. The name of the design product: flexible HVDC converter station monitoring system graphical user interface for computer. 2. The use of the design product: the design product is applied to computer, used for running program. 3. The design points of the design product: the content of the graphical user interface in the screen of the product, wherein the computer is the existing design. 4. The picture or photo best indicating the design points: front view. 5. The display screen panel is the conventional design, and the rear view, left view, right view, top view, bottom view and perspective view are omitted. 6. The use of the graphical user interface: the graphical user interface of the product is the software interface of the flexible HVDC converter station monitoring system. 7. The change state description of the graphical user interface: the front view is the "three-terminal system diagram" displayed by the system; the interface change state diagram is the interface displayed after clicking "station main wiring" in the front view interface.

The invention discloses a firewall of an extra-high voltage converter station and a construction process thereof, the firewall comprises a reinforced concrete shear wall, and the construction process comprises construction section division, scaffold installation, template installation, concrete pouring, firewall maintenance and post-cast strip construction. On the basis of structural mechanics analysis and BIM simulation, the firewall is divided into construction sections, and the transportation capacity of the tower crane is matched; the combined steel frame-wood formwork, the keel and the split bolts are adopted to construct the form of the formwork, and the overall rigidity and the formwork mounting and dismounting efficiency are both improved; through full-chain innovation of the construction technology, collaborative optimization of efficiency, cost, environmental protection and safety is achieved on the premise that the safety of the firewall structure is guaranteed, and reliable technical support is provided for construction of the extra-high-voltage direct-current converter station.

The invention relates to the technical field of flexible direct-current power transmission, in particular to an insulation coordination method of an extra-high voltage flexible direct-current converter station connected to a new energy base, which comprises the following steps of: S1, analyzing a lightning arrester configuration scheme and selecting parameters according to a system main wiring form and an overvoltage characteristic of the converter station; s2, establishing an electromagnetic transient simulation model of the internal overvoltage of the large-scale new energy delivery system, establishing an actual control protection strategy, and establishing a high-frequency transient model of the lightning overvoltage of the extra-high voltage flexible DC converter station connected to the new energy base; s3, internal overvoltage simulation is carried out, and an insulation cooperation scheme is adjusted according to a simulation result; and S4, carrying out lightning verification based on the alternating current side intrusion wave and the direct current side lightning intrusion wave. Through reasonable lightning arrester configuration and parameter optimization, insulation cooperation of the system is realized, influence of transient overvoltage on equipment is effectively reduced, efficient and stable operation of the system is ensured, and equipment cost and engineering construction cost are reduced at the same time.

The invention relates to a power control method and device for a high-voltage direct-current converter station, computer equipment, a computer readable storage medium and a computer program product, relates to the field of power control, and can improve the power control efficiency of the high-voltage direct-current converter station. The method comprises the following steps: receiving first direct current power plan data sent by a scheduling end to a centralized control end through a first communication channel; the scheduling end also sends second direct-current power plan data to the execution end through a second communication channel; determining a centralized control end control instruction of the current power according to the first power control mode and the first direct current power plan data; and sending the centralized control end control instruction to an execution end, so that the execution end performs first power control according to the centralized control end control instruction based on the current control authority after receiving the centralized control end control instruction, or performs second power control according to the second power control mode and the second direct current power plan data.

The invention discloses a high-voltage direct-current converter station whole-station video nano-management method, and relates to the technical field of intelligent operation and maintenance of power systems. According to the method, a video management server is locally deployed in a converter station, so that unified access, management and service provision of multi-source heterogeneous video equipment are realized. The system supports standard and private protocol adaptation, provides a standardized northbound interface, and realizes acquisition, transmission, storage, calling and security control of video data. The method solves the problems of discretization, non-uniform interfaces and high operation and maintenance cost of a converter station video system, improves the integration, safety and expandability of the video system, and is suitable for intelligent operation and maintenance management of the high-voltage direct-current converter station.

The present disclosure relates to a method of energizing a voltage source converter (VSC) of a high voltage direct current (HVDC) converter station. The present disclosure specifically discloses a method comprising, by operating an AC circuit breaker, performing the following steps in order to energize a VSC: electrically connecting a first main side phase of a converter transformer to a first phase A of an AC power source; electrically connecting a second primary side phase of the converter transformer to a second phase B of the AC power source; and electrically connecting a third primary side phase of the converter transformer to a third phase C of the AC power source. According to the invention, at least one secondary side of the converter transformer is set as the D wiring, and the three-phase AC circuit breakers are sequentially closed according to a certain sequence, so that only one phase or two phases of the converter transformer are connected with the pre-inserted starting resistor PIR and the bypass circuit breaker, compared with a conventionally used three-phase starting resistor, the starting resistor is optimized, and the starting efficiency is improved. Therefore, the occupied area is reduced and the cost is reduced.

The application discloses a kind of half indoor arrangement's back-to-back hvdc converter station starting loop, comprising: several groups of bridge arm reactor, the bridge arm reactor includes juxtaposition operation's first bridge arm reactor and second bridge arm reactor;The side of first bridge arm reactor is connected to bypass disconnecting switch;The side of second bridge arm reactor is connected to starting resistance by support insulator;Starting resistance and branch current measuring device are connected in series, and the starting resistance is connected in parallel with the bypass disconnecting switch and then connected in series with loop current measuring device;The loop current measuring device is connected in series with voltage measuring device, HGIS and starting loop lightning arrester in turn.This application can reduce the noise influence of equipment, avoid the solarization aging of reactor, slow down the aging of protective layer on the surface of reactor, effectively reduce the dirt of external insulation of equipment, reduce the influence of dust and external environment on equipment, and is conducive to the operation and maintenance of equipment.

The invention provides a method and device for evaluating the local inertia supporting capacity of a new energy delivery type AC / DC power system, and relates to the technical field of power system operation and control, and the method comprises the steps: building a parameterized differential-algebraic equation model; deriving an inertia distribution matrix of the power system by using a generalized energy framework, and calculating a local inertia supporting capability index of each network node based on the inertia distribution matrix; determining the network region of which the index value is lower than a preset index threshold value as an inertia weak region, and predicting the dynamic evolution trend of the inertia weak region based on a hybrid automaton model to obtain a prediction result; and establishing a mapping relation between the inertia supporting capability of the inertia weak area and the commutation failure risk of the high-voltage direct-current converter station, and evaluating the stability margin of the system. According to the method provided by the invention, the problem that the inertia space-time heterogeneity cannot be identified and evaluated by a traditional method can be solved, and accurate identification and risk evaluation of a region with weak local inertia supporting capability can be realized.

The utility model provides a redundant mechanism case for a high-voltage isolating switch of an extra-high-voltage direct-current converter station, which comprises a frame body, a first driving assembly, a second driving assembly and a transmission assembly, and is characterized in that the first driving assembly and the second driving assembly are detachably connected in the frame body; the transmission assembly comprises a driver, a first input shaft, a first clutch, a second input shaft, a second clutch and an output shaft, the driver is fixedly connected into the frame body, the first input shaft is connected to the driver and connected with the output end of the first driving assembly through the first clutch, and the second input shaft is connected to the driver and connected with the output end of the second driving assembly through the second clutch. The second input shaft is connected with the output end of the second driving assembly through the second clutch, the output shaft is connected to the driver, and the end, away from the driver, of the output shaft extends out of the frame body. When the first driving assembly is stuck, the second driving assembly timely replaces the first driving assembly to work, and it is guaranteed that the disconnecting switch can be smoothly switched on and switched off.

The embodiment of the invention provides a high-voltage direct-current converter station overvoltage suppression method cooperatively driven by a data mechanism, and the method comprises the steps: detecting converter valve side data of a high-voltage direct-current converter station; parameters of a converter valve arrester of the high-voltage direct-current converter station are optimized; optimizing a converter valve control strategy of the high-voltage direct-current converter station; based on lightning arrester parameters and a control strategy, cooperatively inhibiting converter valve operation overvoltage of the high-voltage direct-current converter station; according to the invention, based on the SAC maximum entropy deep reinforcement learning algorithm, in combination with optimized parameters of the lightning arrester, multiple working conditions are simulated to cover a complex operation overvoltage scene, core data such as voltage, current and control signals are collected, and a self-adaptive converter valve control strategy is trained; and compared with a traditional fixed strategy, the strategy can respond to the state change of the system in real time.

A method for controlling a high voltage direct current (HVDC) converter station is provided, wherein the converter station includes a first voltage source converter (VSC) associated with a first power controller and a second VSC associated with a second power controller. The first VSC and the second VSC are connected in series between a first DC terminal and a second DC terminal of the converter station. According to an embodiment, the method includes: determining a common DC reference voltage based on any one of a first DC voltage measured across the first VSC and a second DC voltage measured across the second VSC. The method further includes: determining a first reference DC voltage for the first VSC based on the determined common DC reference voltage and a first DC voltage contribution from the first power controller, and determining a second reference DC voltage for the second VSC based on the determined common DC reference voltage and a second DC voltage contribution from the second power controller. The operation of the first VSC and the second VSC can then be controlled, respectively, based at least in part on the first reference DC voltage and the second reference DC voltage.

The application discloses a low-residual-voltage converter valve lightning arrester, which is developed by using a low-residual-voltage resistor disc, improving a charge rate, increasing the number of parallel columns, increasing the diameter of the resistor disc, improving the gradient of the resistor disc and the like, so as to reduce the insulation level, manufacturing difficulty and cost of the converter valve of an extra-high voltage direct-current converter station in a high-altitude area.

The present application relates to the technical field of noise identification, and particularly relates to a main sound source noise identification method and system for a flexible direct current converter station. Current of the converter station and audio time sequence data of each monitoring point are acquired; time-frequency diagrams are obtained by processing the audio time sequence data, amplitude variation differences of different monitoring points under the same frequency point are analyzed, amplitude variation of the target point frequency point is adjusted accordingly, an amplitude variation index is obtained, and whether the noise is from the converter transformer is analyzed conveniently; for the noise caused by the magnetostriction of the converter transformer core, the vibration frequency is stable, and the amplitude varies synchronously with the current, so in the target point time-frequency diagram, the correlation between the amplitude variation index and the current time sequence data and the difference of the time sequence characteristics under each frequency are analyzed, a multi-frequency synchronization index is determined, and the possibility that the frequency component is from the magnetostriction effect of the core is reflected; finally, the amplitude variation and the multi-frequency synchronization index are fused, noise characteristics are comprehensively analyzed, and noise source identification accuracy is improved.

The application discloses a kind of capacitive capacity monitoring method and system of flexible direct current converter station bushing, it is related to the field of flexible direct current transmission equipment on-line monitoring and electrical parameter identification technique, including in the bushing of flexible direct current converter station bushing end screen and ground setting capacitor voltage divider and constructing series capacitor measurement structure, acquisition bushing primary voltage signal and end screen current.Primary voltage signal and end screen current are carried out synchronous signal preprocessing, using wavelet transform and filtering strategy to remove noise and extract frequency domain features.Capacitive capacity coupling relationship of bushing structure parameter is calculated based on frequency domain features, and abnormal point is judged by establishing capacitive capacity change identification model and combining temperature and humidity data.The method described in the application effectively overcomes the problems of static analysis lag, single variable misjudgment and insufficient frequency spectrum resolution, realizes real-time monitoring of flexible direct current bushing capacitive capacity, abnormal dynamic early warning and system improvement of model adaptability, and significantly enhances the safety operation guarantee capability of equipment throughout its life cycle.