116 results about "Ac circuit" patented technology

The invention discloses an energy storage type SOP black-start method, system and device based on improved VSG network construction control and a medium, and relates to the field of power grid black-start, and the method comprises the steps: an energy storage type converter MMC carries out the active and reactive control based on an improved VSG network construction control strategy; a non-fault side MMC is controlled to firstly close an isolation circuit breaker and slowly charge a direct-current capacitor, and when the voltage reaches a set threshold value, a current-limiting resistor is quitted; the fault side MMC is started by the same step as the non-fault side MMC; after synchronization is completed, AC circuit breakers between the non-fault side MMC and the feeder load and between the fault side MMC and the feeder load are closed respectively; based on the collected power grid power data, MMC output parameters are adjusted to meet the power grid connection condition, the control mode is switched according to the grid connection state, and the black start process is ended. And by arranging the black start resistor for current-limiting charging and sub-module voltage balance control, the phenomena of overcurrent and voltage unbalance in the black start process are avoided.

Disclosed in the present invention is a high-voltage high-frequency SiC Mosfet novel power transformer, comprising a superordinate computer, a controller, an inverter circuit, and a signal detection circuit. The superordinate computer is connected to the controller; the inverter circuit uses a three-phase T-type inverter topology circuit to convert high-voltage power in a three-phase circuit into three-phase controllable AC power; the inverter circuit comprises a primary rectifier circuit, a primary DC-AC circuit, a three-phase winding transformer, a secondary rectifier circuit, and a secondary DC-AC circuit; a plurality of SiC Mosfets are used in the primary rectifier circuit, the primary DC-AC circuit, the secondary rectifier circuit, and the secondary DC-AC circuit; the signal detection circuit obtains detection data; and a DSP is provided in the controller, the DSP is provided with an algorithm module, the algorithm module performs an operation on the basis of the detection data to generate a specific instruction, and the controller adjusts the inverter circuit on the basis of operating parameters or the specific instruction. In the present invention, a plurality of SiC Mosfets are used, and the structure of the inverter circuit is optimized, thereby improving the working efficiency; and a detection and control feedback mechanism is additionally provided, so that effective regulation within the transformer can be realized, thereby improving the performance.

The invention discloses a voltage circuit breaker AC open circuit control method and device, and relates to the technical field of open circuit control, and the method comprises the following steps: obtaining a target waveform sequence of a target AC circuit, and obtaining a fundamental component and a higher harmonic component through frequency domain decomposition, so as to extract current waveform features; constructing a zero-crossing prediction model based on current waveform characteristics, dynamically correcting the prediction model in combination with higher harmonic components and load asymmetry characteristics, and generating a preliminary breaking moment candidate interval; determining a final on-off moment by combining the instantaneous power direction reversal point and an arc maintenance energy threshold value; and triggering the circuit breaker to act at the final breaking moment, and dynamically adjusting the contact separation speed based on the residual arc energy until the arc energy is attenuated to a safety value. According to the method, the zero-crossing prediction model is constructed by extracting the current waveform characteristics, the contact separation strategy is dynamically corrected, and the problems of arc extension and equipment damage of a traditional circuit breaker under the condition of harmonic distortion or sudden disturbance are solved.

An electric propulsion system for an aircraft, comprising: - an electrical power source (1) including a synchronous generator (11) driven by a heat engine (12), - a first synchronous electric motor (3) connected to an output of the synchronous generator by an alternating current electrical circuit (2), - a rotating propulsion unit (7), characterized in that it comprises: - a direct current electrical circuit (4) comprising, from an input connected to the alternating current electrical circuit: a first alternating / direct current converter (41), a direct current electrical link (42) and a second direct / alternating converter (43), - a second electric motor (5) connected to an output of the direct / alternating converter, - a differential gear train (6) including a first input shaft (61) connected to the first synchronous electric motor,a second input shaft (62) connected to the second electric motor and an output shaft (63) connected to the rotating propulsion unit. Figure for the abbreviation: Figure 1,

A DC:DC converter includes: a DC:AC converter circuit having DC and AC sides; an AC:DC converter circuit having DC and sides; an AC link connecting the AC side of the DC:AC circuit and the AC side of the AC:DC converter circuit, the AC link including a transformer having a first winding connected to the AC side of the DC:AC converter circuit and a second winding connected to the AC side of the AC:DC converter; a capacitor; and a switch arrangement having a first state and a second state, wherein: in the first state, the capacitor is connected in series between the AC side of the DC:AC converter circuit and the first winding of the transformer; and in the second state, there is a current path between the AC side of the DC:AC converter circuit and the first winding of the transformer that does not include the capacitor.

This invention discloses an AC circuit breaker control method and device, relating to the field of circuit breaker control technology. The method includes the following steps: acquiring the target waveform sequence of the target AC circuit and obtaining the fundamental and higher harmonic components through frequency domain decomposition to extract current waveform features; constructing a zero-crossing prediction model based on the current waveform features, and dynamically correcting the prediction model by combining the higher harmonic components and load asymmetry characteristics to generate a candidate interval for the initial breaking time; determining the final breaking time by combining the instantaneous power direction reversal point and the arc sustaining energy threshold; triggering the circuit breaker operation at the final breaking time, and dynamically adjusting the contact separation speed based on the residual arc energy until the arc energy decays to a safe value. This invention solves the problems of arc extension and equipment damage in traditional circuit breakers under harmonic distortion or sudden disturbances by extracting current waveform features to construct a zero-crossing prediction model and dynamically correcting the contact separation strategy.

The invention discloses an electric power protection system, a control method and a related product. The power protection system comprises a controller, a switch assembly and a three-phase shunt reactor, the three first ends of the switch assembly are connected with the three-phase alternating current circuits in a one-to-one correspondence mode, the three second ends of the switch assembly are connected with the first ends of the three-phase shunt reactors in a one-to-one correspondence mode, and the second ends of the three-phase shunt reactors are connected together. A controller configured to obtain a three-phase AC voltage and a three-phase AC current; obtaining three-phase interphase impedance according to the three-phase alternating voltage and the three-phase alternating current; according to the three-phase interphase impedance, judging whether the reactor has a turn-to-turn short circuit fault or not; and under the condition that the reactor has a turn-to-turn short circuit fault, the switch assembly is controlled to be switched off. According to the embodiment of the invention, whether the reactor has the turn-to-turn short circuit fault or not is judged through the three-phase interphase impedance, and the switch assembly is controlled to be switched off under the condition that the reactor has the turn-to-turn short circuit fault, so that the safety of a power grid is improved.

The invention relates to the technical field of signal switching, in particular to a signal switching structure, and solves the problems that in the prior art, a signal switching and assembling structure of an AC / DC circuit board is complex in assembling process, and assembling consistency is difficult to guarantee. The AC power terminal and the DC power terminal are installed in the socket shell, the low-voltage connector is used for collecting and leading out temperature signals, a DC cavity and an AC cavity are formed in the socket shell, the side edges of the DC cavity and the side edges of the AC cavity are communicated, and a circuit board assembly is arranged in the socket shell; the circuit board assembly comprises an AC circuit board installed in the AC cavity and a DC circuit board installed in the DC cavity, and the AC circuit board and the DC circuit board are electrically interconnected and mechanically fixed through a plug-in. The integrated circuit board assembly has the advantages that the AC circuit board and the DC circuit board are connected and fixed in advance through the plug-in to form the integrated circuit board assembly, synchronous assembly of the AC circuit board and the DC circuit board is achieved through the integrated structure, the assembly process is simplified, and deviation accumulation caused by step-by-step assembly is avoided.

The invention discloses a power converter, a charging control method, an optical storage and charging system and a storage medium. The power converter comprises a direct current bus arranged on the direct current side of the power converter; the slow start circuit is arranged on the alternating current side of the power converter, and the on-off state of the slow start circuit is used for controlling on-off between the alternating current side and the alternating current circuit; the controller is used for executing the following operations: controlling the slow start circuit to be conducted, so that the direct-current bus receives the electric energy of the alternating-current circuit; boosting the voltage on the DC bus to a target voltage according to the electric energy of the AC circuit; and providing power for the charging module by using the direct-current bus with the boosted voltage, so that the charging module charges the to-be-charged equipment. The power converter can ensure that the optical storage and charging system can work continuously, further ensure that the optical storage and charging system can charge the to-be-charged equipment at any time, and improve the user experience.

The utility model provides an energy storage power station heterogeneous energy storage unit collaborative operation simulation system, which is used for simulating collaborative grid connection of various energy storage units, and comprises a first energy storage unit, a second energy storage unit, a third energy storage unit, a fourth energy storage unit and a fourth energy storage unit, wherein the first energy storage unit is composed of a battery cluster, a first bidirectional DC / AC circuit and a three-phase boosting transformer which are sequentially connected in series; the second energy storage unit is composed of a battery cluster, a second bidirectional DC / AC circuit and a single-phase boosting transformer which are sequentially connected in series; the third energy storage unit is composed of a battery cluster, a bidirectional DC / DC conversion circuit and a first bidirectional DC / AC circuit which are sequentially connected in series; the sampling units are connected with the battery clusters of the energy storage units, and are used for acquiring single cell voltage, inter-cluster current and grid-connected voltage of the energy storage units and transmitting the voltage, the current and the grid-connected voltage to an upper computer; and a user can master the working state of each heterogeneous energy storage unit and the state of the single battery cell in real time.

A circuit breaker device protects an electric multi-phase low-voltage alternating current circuit. The device contains a housing having grid-side phase connections and load-side phase connections for phase conductors of the low-voltage alternating current circuit. Series circuits of the device each contain a mechanical phase contact and an electronic switch. Each series circuit electrically connects a grid-side phase connection to one of the load-side phase connections. The mechanical phase contacts are switched together to an open state to prevent a current flow or to a closed state for a current flow, by use of semiconductor-based switch elements. In each series circuit, the level of the current of the respective phase conductor is ascertained. If a first current threshold or current / time threshold is exceeded in a phase conductor, a prevention of the current flow is initiated, and the electronic switches are switched to a high-ohmic or low-ohmic state by a control input.

The invention provides an electromagnetic brake control device which further controls an electromagnetic brake without delay. An electromagnetic brake control device (55), which controls an electromagnetic brake (54) that brakes the rotation of an AC motor (53) when the energization of an electromagnetic brake coil (54a) is cut off, is provided with: a rectifier (81), the DC side of which is connected to the electromagnetic brake coil (54a); a switching unit (84) that controls the power to the electromagnetic brake coil (54a) by switching a rectifier circuit (RL) connecting the rectifier (81) and the electromagnetic brake coil (54a) on and off; a DC converter (82) that is connected to the motor drive AC circuit (51a) and converts AC power to a predetermined DC voltage; an electromagnetic brake release circuit unit (85) that switches the switching unit (84) to an ON state by means of the DC voltage generated by the DC converter (82); and an electromagnetic brake operation command unit (83) that switches the switching unit (84) to the OFF state when the value of the current waveform of the AC motor (53) is between a positive threshold value and a negative threshold value and lasts for a predetermined determination time or longer.

The invention discloses a distributed relay protection secondary alternating current loop abnormity diagnosis method, and relates to the technical field of power system relay protection, edge diagnosis nodes with a self-organizing network function are deployed at key nodes of a secondary alternating current loop of a distributed relay protection system, and a distributed diagnosis network is formed; the edge diagnosis node collects multi-dimensional feature data of the secondary alternating current loop in real time through a multi-mode sensing unit, wherein the multi-dimensional feature data comprises electrical quantity features, waveform distortion features, time sequence features, environment features and the like; according to the method, distributed edge diagnosis nodes are deployed, multi-dimensional feature data of a secondary alternating-current loop are collected, the multi-dimensional feature data are preprocessed by the edge nodes and then uploaded to a block chain network for consensus verification, and abnormal accurate positioning and grading are achieved in combination with an improved deep learning model; the method effectively solves the problems that a traditional centralized diagnosis method is poor in real-time performance, weak in anti-interference capability and low in data credibility.

The invention discloses an anti-surge ceramic capacitor material and a preparation method thereof, and belongs to the technical field of electronic ceramic materials. The material is prepared by taking high-purity barium titanate (BaTiO3) as a basic raw material and cooperatively doping lanthanide oxide (La2O3) and transition metal carbonate (MnCO3) as a grain boundary regulating agent through a solid phase method. The ceramic capacitor material is prepared from the following components in mol percent: 96 to 98 mol percent of BaTiO3, 1 to 2.5 mol percent of La2O3 and 0.5 to 2 mol percent of MnCO3, and the sum of the mol percent of all the components is 100 percent. According to the invention, La < 3 + > and Mn < 2 + > are synergistically segregated on a grain boundary, so that a compact grain boundary layer is formed, grains are refined, defects are inhibited, and the surge breakdown resistance (greater than or equal to 10 kV / mm) is remarkably improved. The material has a wide application prospect in surge frequency scenes such as an alternating current circuit and a power supply module.

The invention relates to the technical field of electric power, in particular to an outdoor high-voltage alternating-current circuit breaker which comprises a box body, a supporting plate is arranged on the side, away from the box body, of a current transformer, a column rod is rotationally connected to the middle of the upper surface of the supporting plate, three hemispherical wind shields are annularly installed at the upper end of the column rod at equal intervals, and a cam is installed on the column rod; the two sets of pushing plates are slidably installed on the upper surface of the box body, cylinders are installed at the two ends of the connecting plate and sleeved with cylinders, connecting rods are installed at the ends, close to the box body, of the cylinders, and the ends, away from the cylinders, of the connecting rods penetrate through the cylinders and are connected with the pushing plates. The bird nesting prevention device has the following beneficial effects that the nesting action of birds is destroyed, and the birds are prevented from nesting between the pole columns in the aspect of behavior.

The application belongs to the technical field of circuit automation detection, and specifically provides a secondary alternating current loop insulation monitoring method and system based on multi-modal machine learning, comprising: processing high-frequency pulse current signals generated by insulation defect faults of a secondary loop through multi-element variational modal decomposition to obtain time-frequency domain features of fault signals under different modes; selecting feature parameters for fault diagnosis, using a local linear embedding algorithm to reduce dimensions of feature parameters of fault time domain reconstruction signals and fault frequency domain reconstruction signals, taking the reduced historical fault time-frequency feature vectors and real-time fault time-frequency feature vectors as a training set and a test set respectively, and classifying through a support vector machine algorithm to obtain fault types and fault rates of each fault type after classification. The method and system utilize that insulation defects of a secondary loop will cause partial discharge, and the partial discharge will generate high-frequency pulse current signals, and analyze the insulation state of the secondary loop by extracting features of fault signals.

The application discloses a kind of physical simulation methods for PT / CT secondary circuit insulation anomaly monitoring, it is related to electric variable measurement technical field, including, setting two groups PT, and setting test point and the measurement system of high-precision current transformer, the insulation fault of two points ground of PT secondary side N phase is analyzed;Through distribution area to power supply simulation system and connect load, make system load operation;Load is adjusted into three-phase unbalanced mode, so that the secondary side of double-winding transformer T2 ABC three-phase current is unbalanced, and measurement and judgment are carried out;Output final judgment result.The application adopts waveform similarity analysis method based on Hausdorff distance when carrying out current measurement and data feature analysis, can accurately locate the fault branch when PT / CT secondary ac circuit occurs multiple points.

The utility model discloses an exhaust structure of an alternating current circuit breaker, which relates to the field of circuit breakers and comprises a shell and an arc extinguish chamber, the shell comprises a middle cover, a left cover and a right cover, the left cover and the right cover are mounted on two sides of the middle cover, and the middle cover is provided with a plurality of first gas guide plates for guiding gas from the arc extinguish chamber to the left side and the right side. The middle cover and the left cover are matched to form a first exhaust channel, the middle cover and the right cover are matched to form a second exhaust channel, a third exhaust channel and a fourth exhaust channel, and a first outlet communicated with the first channel and a second outlet communicated with the second exhaust channel and the fourth exhaust channel are formed in the bottom of the side wall of the shell. And a third outlet communicated with the third channel is formed in the upper surface of the shell. The utility model has the advantages of space saving and good safety.

The present invention provides an electric DC-AC power converter based on a plurality of DC-AC power modules connected with their AC output terminals connected in series. Each DC-AC power module: a circuit board (PCB or DBC) having a top side and a bottom side, a resonant DC-AC circuit comprising at least one semiconductor switch arranged for operation at a switching frequency of more than 1 MHz, and at least one capacitor connected to the semiconductor switch via conductive parts of the circuit board. At least one damping circuit with a resistor component, preferably with a resistor and capacitor in parallel, is connected in parallel with the conductive parts of the circuit board connecting the capacitor and the semiconductor switch. The damping circuit is tuned to dampen a resonance caused by parasitic behaviour of the circuit board, wherein said resonance has a frequency higher than the swithing frequency. In this way, the high frequency resonance caused by said parasitic behaviour of the circuit board can be eliminated. This high frequency resonance in each power module has been found to be critical for stability of a power converter based on series connected power modules. With the simple damping circuit, high power DC-AC conversion is possible using GaN or SiC semiconductor technology.

The invention provides a power supply for driving a liquid crystal dimming device. The haze of the liquid crystal layer is gradually changed. A power supply (20) for driving a liquid crystal dimming device is provided with: a DC / DC circuit unit (40) for transforming a DC voltage and outputting the transformed DC voltage; and a DC / AC circuit unit (60) that converts the DC voltage output from the DC / DC circuit unit (40) into an AC voltage and outputs the AC voltage to a liquid crystal dimming device (11). The DC / AC circuit unit (60) is provided with: an inverter circuit (61) that converts a DC voltage output from the DC / DC circuit unit (40) into a pseudo-sinusoidal AC voltage by switching operation of switching elements (62-65); and a DC / AC control unit (72) capable of changing the voltage value of the AC voltage by controlling the ON time of the switching elements (62-65).

The invention relates to the field of power electronic technology and electrical protection, and discloses a direct-current and alternating-current circuit breaker and an application method, and the circuit breaker comprises a power conversion stage which is configured to convert input electric energy and output the electric energy to a load; the sensing unit is configured to collect voltage and current signals of an output load of the power conversion stage; the control unit is electrically connected with the power conversion stage and the sensing unit, and is configured to control the power conversion stage to generate and apply a composite voltage containing a fundamental wave voltage and an active detection voltage to a load; obtaining response current of the load to the composite voltage through a sensing unit; based on the response current, a real-time electrical characteristic of the load is determined. By controlling the power conversion stage to generate and apply the composite voltage containing the active detection voltage and calculating the broadband complex impedance spectrum of the load based on the response current, tiny electrical characteristic changes caused by degradation of internal elements of the load can be accurately recognized in an early stage, and therefore predictive recognition of potential faults is achieved.

A method and device for reducing electrical consumption in an AC electric circuit with an AC device and at least one energy saving device that includesa) An electromagnetic induction Voigt filter, dry type;b) A harmonics Snubber / Cyber network filter;c) Linear phase FIR notch filters;d) Surge suppression device;e) A surge suppression device with EMP Faraday filters;f) Active atomic resonance filter;g) Harmonic surge filter;h) High efficiency magnetic transformer with a coil core and three distinct wire windings for creating a transformer, at least one the wires has different conductive contents from the others.

The invention relates to the technical field of protection equipment in a three-phase alternating-current power distribution or transmission system, in particular to a series-connection type hybrid circuit breaker applied to a three-phase alternating-current power system and a using method, and the series-connection type hybrid circuit breaker comprises a main alternating-current circuit and a circuit breaker unit connected with the main alternating-current circuit in series; the circuit breaker unit comprises a three-phase transformer, a power electron injection branch and a mechanical switch module; the power electron injection branch is connected with the three-phase transformer, and the mechanical switch module is arranged between the three-phase transformer and the main alternating current circuit. The beneficial effects of the invention are that the transformer is coupled in the main loop to induce the voltage with the polarity opposite to that of the power supply, and reverse voltage injection is realized, so that the fault current is rapidly suppressed in a microsecond level; the fault current is modulated into the high-frequency alternating-current ripple current close to zero by using the rapid mode switching of the power electronic branch, so that the action window of the mechanical switch is expanded, and the arc-free interruption is realized.

This utility model proposes an AC / DC operation training circuit for urban rail transit, including an AC circuit 1 and an AC circuit 2 configured with an interlocked backup relationship, a busbar connected to AC circuit 1 and AC circuit 2, an emergency lighting circuit connected to the busbar, a first simulated fault switch, and a second simulated fault switch. AC circuit 1 includes an AC circuit 1 incoming switch, an AC circuit 1 contactor, and a first contactor; AC circuit 2 includes an AC circuit 2 incoming switch, an AC circuit 2 contactor, and a second contactor. The AC circuit 1 incoming switch is connected to the three phase lines of a three-phase power supply, and the AC circuit 1 contactor coil is connected between two of the three phase lines. The AC circuit 2 incoming switch is also connected to the three phase lines of a three-phase power supply, and the AC circuit 2 contactor coil and the first normally closed contact of the AC circuit 1 contactor are connected in series between two of the three phase lines. This utility model can meet the needs of efficient and safe training in various scenarios.

The application discloses an electronic tripping device and method suitable for a three-phase alternating current circuit breaker, which comprises a power taking transformer, a sampling sensor, a power processing circuit, a sampling processing circuit, a control circuit and a tripping circuit, and the method comprises setting a rated current level I r , a long time delay protection level Class , a short time delay tripping current I sd , collecting data and transmitting the data to the control circuit to calculate the effective value of the three-phase current; determining whether a phase current is greater than a limited current value and whether the three-phase is balanced; if yes, tripping; determining whether the current is greater than I sd , starting a timer, and determining whether the current is greater than I sd ‑I r、 total heat resistance Q 0 , and controlling the tripping of the circuit breaker. The application realizes the isolation of a main circuit and a tripping controller; the three sampling modules of the application have an "or" logical relationship, and the reliability of the tripping mechanism is high; the application adopts a critical heat resistance principle to realize a inverse time limit protection algorithm, and realizes the real-time protection and high reliability requirements.

To provide a control device of a charging relay circuit for a vehicle capable of suppressing freezing of a relay without providing a dedicated component.SOLUTION: An AC circuit configured to supply power supplied from the AC charging device to the power storage device; and a DC circuit configured to supply power supplied from the DC charging device to the power storage device, wherein the AC circuit includes a transformer and an AC / DC converter, the control device is configured to control the AC-DC converter to cause a current to flow through the AC circuit (step S1) in a state in which the power storage device and the AC circuit are connected to each other by the C-contact relay when a system of the electric vehicle is stopped for a predetermined time or more under a temperature equal to or lower than a predetermined temperature (Yes in steps S6, S3, and S5).SELECTED DRAWING: Figure 3

The invention discloses a distributed photovoltaic grid-connected data processing method and device, terminal equipment and a storage medium, and belongs to the field of power systems, and the method comprises the steps: obtaining combiner box forward converter operation data, DC-DC circuit operation data and DC-AC circuit operation data of a distributed photovoltaic grid-connected system; simulation operation is carried out based on combiner box forward converter operation data and the first averaging model, simulation operation is carried out based on DC-DC circuit operation data and the second averaging model, simulation operation is carried out based on DC-AC circuit operation data and the third averaging model, and simulation operation is carried out according to the simulation operation result of each averaging model. And obtaining a state detection result of the distributed photovoltaic grid-connected system. Therefore, by implementing the method, the problem of low efficiency of state detection of the existing distributed photovoltaic grid-connected system can be solved.

The invention discloses an optical storage system and a control method thereof, the optical storage system comprises a photovoltaic string, an energy storage unit and a load device, the photovoltaic string is connected to a DC bus through a photovoltaic DC / DC circuit, the energy storage unit is connected to the DC bus through an energy storage DC / DC circuit, and the load device and a power grid are connected to the DC bus through a DC / AC circuit; the photovoltaic DC / DC circuit, the energy storage DC / DC circuit and the DC / AC circuit are used for detecting the bus voltage of the DC bus and adjusting the working state of the photovoltaic DC / DC circuit, the energy storage DC / DC circuit and the DC / AC circuit according to the voltage interval of the bus voltage; wherein the voltage interval is set according to a voltage reference value and represents the energy balance state of the optical storage system under the current bus voltage; according to the invention, energy output or input can be automatically triggered and adjusted without depending on a communication system of the optical storage system, so that the energy balance state in the optical storage system is further influenced, and stable control of the bus voltage is realized.

The application discloses a method for coordinating active energy recovery and AC energy consumption device of offshore wind power flexible direct current system, and belongs to the field of power system transmission and distribution. After the AC power grid fails, the DC voltage is first lifted, and after the capacitor energy of the onshore converter station reaches the early warning value, the capacitor energy of the offshore converter station is lifted to the preset maximum value. If the fault is cleared before the AC circuit breaker is opened, the DC voltage, the capacitor energy of the onshore and offshore converter stations are controlled to decrease to the rated value in turn; otherwise, the AC energy consumption device is put into operation, and the onshore converter station is switched to energy-AC voltage control. After the circuit breaker is reclosed, the energy consumption device is withdrawn, the onshore converter station is switched back to the initial control, and the DC voltage, the capacitor energy of the onshore and offshore converter stations are controlled to decrease to the rated value in turn. The application can reduce the waste caused by the dissipation of surplus power in heat; compared with the DC energy consumption device, the application can also greatly reduce the cost and control complexity of the energy consumption device.