271 results about "Dc circuit breaker" patented technology

The invention provides a control method and system for an energy storage PCS with an AC / DC circuit breaker and a storage medium, and the method comprises the steps: firstly, synchronously collecting the electrical parameters of a DC side and an AC side, and carrying out the preprocessing of the collected data, so as to form a standardized electrical matrix; then, all parameters in the electrical matrix are cyclically compared with corresponding early warning thresholds, first-level thresholds, second-level thresholds and fusing thresholds in a multi-level threshold mapping table; if the pre-warning threshold value is exceeded, a log is recorded, if the pre-warning threshold value is exceeded, self-healing operation is executed, if the pre-warning threshold value is exceeded, turn-off operation is executed, and if the pre-warning threshold value is reached, physical fusing is triggered; meanwhile, all operation logs are recorded, and the threshold mapping table is dynamically optimized by analyzing log data; according to the method, the fault response speed and the protection precision are improved through multi-level threshold serial comparison and a cooperative protection mechanism, the stability and the reliability under different working conditions are enhanced through the adaptive learning capability, and meanwhile, the whole life cycle cost is reduced.

The invention relates to a direct current fault ride-through method, a direct current fault ride-through device, direct current fault ride-through equipment and a medium. The method comprises the following steps: switching a control mode of network-forming type energy storage into an alternating-current voltage control mode or a direct-current control strategy, carrying out coordinated control on devices in a multi-terminal direct-current collecting and sending-out system, clearing fault current, and clearing the fault current by utilizing an active step-down control strategy or the direct-current control strategy at the same time. According to the method, measures such as additional direct current circuit breakers are not needed, control is flexible and easy to achieve, the multi-terminal direct current collecting and sending-out system after fault clearing is controlled to be recovered by judging the operation state of the multi-terminal direct current collecting and sending-out system, and safe and stable operation of the multi-terminal direct current collecting and sending-out system is facilitated.

Examples described herein provide a system for controlling power flow in an energy distribution network. The system includes a plurality of inverters, each having an inverter controller associated therewith. The system further includes a utility controller associated with a utility and configured to communicate with at least a subset of the plurality of inverters. The system further includes a customer controller associated with a customer of the utility and configured to communicate with at least the utility controller. The system further includes a direct current (DC) breaker associated with a battery of the customer. The system further includes a DC meter of the customer, the DC meter and the DC breaker each configured to communicate with the utility controller and the customer controller. The utility controller is configured to determine a current operational scenario of the energy distribution network and to control power routing within the energy distribution network.

The invention discloses a flexible direct-current power transmission system and a fault ride-through method and system thereof. The flexible direct-current power transmission system comprises a main control module, and a new energy sending-out system, an alternating-current energy consumption device, a sending-end converter, a direct-current circuit breaker, a receiving-end converter and a receiving-end alternating-current power grid which are connected in sequence, the direct current circuit breaker is deployed on a direct current power transmission line between the sending end converter and the receiving end converter, and the receiving end converter is a modular multi-level converter formed by cascading a plurality of half-bridge sub-modules with damping branches; the main control module is in communication connection with the half-bridge sub-modules, the direct-current circuit breaker and the alternating-current energy consumption device and used for controlling the damping branches of the half-bridge sub-modules in the running state, the direct-current circuit breaker and the alternating-current energy consumption device to act when a direct-current fault occurs so as to restrain direct current and adjust direct-current voltage to be within a set voltage range. Therefore, no-locking fault ride-through is completed. According to the invention, high-reliability and low-cost DC fault ride-through can be realized.

This invention relates to the field of energy storage technology and discloses a synchronous testing platform for multiple energy storage converters and its control method. The testing platform of this invention includes: an incoming line switch, a pre-charge circuit, a transformer, an auxiliary power supply switch, an AC circuit breaker, a DC circuit breaker, and a unit controller. The power grid is connected to the high-voltage side of the transformer sequentially through the incoming line switch and the pre-charge circuit. One side of the AC circuit breaker is connected to the windings on the low-voltage side of the transformer, and the other side is connected to the AC side of the energy storage converter. The DC side of the first group of energy storage converters is connected to the DC side of the second group of energy storage converters through DC circuit breakers. The first group of energy storage converters is connected to the auxiliary power supply. In this invention, after the first group of PCS (Power Storage Converters) is pre-charged, the pre-charge circuit is bypassed. Then, the first group of PCS is unlocked and controlled in DC voltage mode, and the second group of PCS is started sequentially, thereby achieving synchronous charging and discharging testing of 2N PCS, greatly improving the charging and discharging testing efficiency of the energy storage converter.

The invention discloses an online detection method for a medium and low voltage direct current circuit breaker, and relates to the technical field of power system protection control, and the method comprises the following steps: S001, building a radiation echo spectrum distribution model during the switching operation of the direct current circuit breaker, calculating an interference intensity estimated value through collecting a current drop rate and a fracture voltage climbing rate, and calculating the interference intensity estimated value according to the current drop rate and the fracture voltage climbing rate; and extracting a disturbance frequency band with concentrated interference energy and generating a characteristic signal set for representing an interference propagation path. According to the method, a closed-loop anti-interference mechanism is constructed through feature modeling, interference recognition, signal correction and parameter optimization, the stability and accuracy of state judgment are improved, misjudgment and response failure caused by high-frequency interference are prevented, the method is particularly suitable for a complex parallel system and a frequent on-off scene, and the safety and the intelligent level of a direct-current system are effectively enhanced.

The invention provides a direct-current circuit breaker and a control method thereof, and belongs to the technical field of direct-current middle-high voltage power system fault protection. The short circuit turn-off branch comprises a first capacitor and a first thyristor; the coupling commutation branch comprises a first inductor, a second inductor, a second thyristor and a third capacitor; the rated turn-off branch comprises a first resistor and a second capacitor; the first resistor, the second capacitor, the first capacitor and the second inductor are sequentially connected in series and then are connected with the main switch branch in parallel; the first inductor, the second thyristor and the third capacitor are sequentially connected in series, and the first inductor and the second inductor form mutual inductance. By controlling the on-off of the first thyristor, the first capacitor and the second capacitor are connected in series, the capacitance value is reduced, large-capacitance-value operation of a single group of capacitors is realized, and the problem that the on-off time of rated and lower low-current breaking is relatively long can be solved.

The invention provides a medium-voltage direct-hanging multi-level energy storage grid-connected direct-current fault isolation method and device. The method comprises the following steps of: establishing corresponding protection partitions on a phase arm, a bus section and a battery cluster, configuring a polarity controllable blocking sub-module capable of being inserted with reverse voltage on the phase arm, and respectively configuring direct-current circuit breakers on the bus section and the battery cluster; generating a criterion set based on the measured value, and performing consistency voting on the criterion set to obtain a direct current fault determination result and a partition positioning result; when a fault is determined, issuing modulation and zero setting, and calculating a reverse equivalent voltage according to the change rate of the phase arm current and the target current to trigger the insertion of a polarity controllable blocking sub-module; selectively driving a corresponding direct current circuit breaker to be switched on and off according to a partition positioning result, or splitting a fault phase arm; and after selective switching-off is completed, outputting an isolation state to a grid-connected control unit of the energy storage grid-connected system. According to the invention, millisecond-level robust fault discrimination, partition selective isolation, cooperation of current limiting and on-off can be realized, and the removal range is narrowed.

The invention relates to a coupled inductor current-limiting type hybrid direct-current circuit breaker topology and a working method. The coupled inductor current-limiting type hybrid direct-current circuit breaker comprises a current-carrying part and a breaking part, the current-carrying part is formed by connecting an ultra-fast mechanical switch UFD and a load change-over switch LCS in series, the breaking part comprises a bridge circuit, a first branch circuit, a second branch circuit, a third branch circuit, a fourth branch circuit, a fifth branch circuit and a sixth branch circuit, the fourth branch circuit is formed by connecting a thyristor, a coupling inductor and a primary side inductor in series to form a current-limiting branch circuit, and the fifth branch circuit is formed by connecting a secondary side inductor and a secondary side inductor. The sixth branch is formed by connecting a secondary side inductor of a coupling inductor with a thyristor in series and then connecting the secondary side inductor with a capacitor in parallel; the current limiting of the fault current is realized through the fourth branch, the fault breaking of the primary side inductor of the coupling inductor of the fourth branch is completed through the coupling effect of the secondary side inductor of the coupling inductor of the sixth branch, the peak value of the fault current is obviously reduced, and the breaking time is obviously shortened; the circuit breaker can quickly respond to faults of three working modes of current limiting breaking, reclosing and small current breaking; and the breaking part of the circuit breaker adopts the thyristors instead of the IGBTs, so that the cost of the circuit breaker is reduced.

The utility model provides a DC switch cabinet edge monitoring device comprising a DC circuit breaker, the DC circuit breaker comprises a plurality of auxiliary contacts, and the plurality of auxiliary contacts are arranged at a plurality of positions of a control loop; the monitoring module comprises a current monitoring assembly, an auxiliary position contact monitoring assembly and a distance monitoring assembly, and the monitoring module is connected with the direct current circuit breaker; the edge calculation module is used for receiving a current signal, monitored by the current monitoring assembly, of the direct-current circuit breaker, a state signal of the auxiliary contact and a numerical value signal, monitored by the current monitoring assembly, of the contact connecting rod mechanism, the edge calculation module is provided with a fault triggering threshold value, and when the received signal numerical value is larger than or smaller than the fault triggering threshold value, the fault is triggered. According to the device, the problem that core components in the direct current switch cabinet are not analyzed is solved, and the comprehensiveness and reliability of monitoring of key nodes in the direct current switch cabinet are improved.

According to the mechanical direct-current circuit breaker based on the variable inductor and the method, in the circuit breaker, a switch branch comprises a vacuum switch VB and a current sensor which are connected in series; the reverse injection branch is connected in parallel to the two ends of the vacuum switch VB, comprises a pre-charging capacitor, a discharging thyristor, a multi-stage series inductor and a parallel thyristor module, and is selectively connected in series with the multi-stage series inductor according to the detected fault current so as to realize variable inductance; a reverse injection current is formed to realize current zero passage and arc quenching of the VB fracture of the vacuum switch; the energy consumption branch is connected in parallel to two ends of the vacuum switch VB and is used for dissipating residual energy in the loop after the mechanical direct current circuit breaker is switched off; the controller is connected with the current sensor and the thyristors and used for judging the number of inductors needing to be input according to the rise rate and amplitude of fault current and controlling the corresponding thyristors to be switched on, and graded inductor series-in and reverse current injection of the multi-stage series inductors of the variable inductor are achieved.

The invention discloses a bidirectional direct current circuit breaker which comprises an electronic branch assembly, a voltage limiting branch assembly and an energy consumption branch assembly. The electronic branch assembly is used for transferring current; the voltage limiting branch assembly is electrically connected with the electronic branch assembly in parallel so as to reduce the turn-off overvoltage of the circuit breaker; and the energy consumption branch assembly is electrically connected with the electronic branch assembly in parallel so as to be used for absorbing the energy of the circuit. According to the hybrid DC circuit breaker, the current transfer function of the hybrid DC circuit breaker can be realized through the electronic branch assembly, the voltage limiting branch assembly and the energy consumption branch assembly. Compared with a bidirectional direct-current circuit breaker based on a power electronic device in the related technology, the bidirectional direct-current circuit breaker is compact in structure, low in connection inductance and high in universality, and functional units can be configured. The problems that in the related technology, connection is complex, redesign is needed under different working conditions, and functional units are inconvenient to adjust are solved.

This invention relates to the field of DC circuit breakers, and discloses a thyristor-type DC circuit breaker and its control method. The DC circuit breaker structure is a thyristor T... m1 Anode-connected thyristor T m2 The cathode forms the A terminal of the circuit breaker, T m1 Cathode connection T m2 The anode of the thyristor forms the B terminal of the circuit breaker; the thyristor T p1 anode, thyristor T p2 The cathode is connected to terminal A; T p1 Cathode connection T p2 After anode, it passes through resistor R in sequence. g Switch RCB g Grounding; T p1 Cathode connection T p2 After the anode, it also passes through inductor L p Capacitor C is connected to terminal B; one end of the surge arrester MOV is connected to terminal T. p1 The cathode is connected to the first terminal, and the other end is connected to the B terminal. This invention has a simple structure and significant cost advantages; under normal operating conditions, only a single thyristor is conducting, resulting in extremely low losses and extremely high circuit breaker efficiency. Combined with control methods, it can actively and reliably connect or disconnect bidirectional operating current or bidirectional fault current; it can also achieve fast reclosing functionality.

The utility model provides a testing device for a direct-current circuit breaker handcart, which comprises an equipment mounting rack, a computer and communication equipment, and is characterized in that the equipment mounting rack is provided with testing equipment used for being connected with a direct-current circuit breaker, and the testing equipment is connected with the computer through the communication equipment; the equipment mounting frame comprises a vertically-arranged perforated plate and supporting frames correspondingly arranged on the left side and the right side of the perforated plate, rotatable supporting blocks are arranged below the supporting frames, connecting pieces are arranged at the ends, facing the supporting frames, of the supporting blocks, telescopic rods are arranged at the other ends of the supporting blocks, one ends of the connecting pieces are arranged on the supporting blocks, and the other ends of the connecting pieces are arranged on the telescopic rods. And the other end is detachably connected with the support frame. The testing device for the direct-current circuit breaker handcart can be used for testing and simulating a direct-current source circuit breaker, and has the advantages of being simple in structure and easy to store and use.

The application provides a non-unit two-section protection method for a high-voltage direct current power grid direct current transmission line, comprising the following steps: (1) in a normal state, real-time detection of current and voltage at the installation position of the non-unit protection is performed, and line mode voltage and zero mode voltage are obtained; when the current rate of change is greater than a threshold value, step (2) is performed; (2) fault polar selection is performed, and a pre-action instruction is then issued to a circuit breaker on a potential fault pole to perform first commutation; meanwhile, step (3) is performed; (3) a section I protection time window is started; if the voltage rate of change at the installation position of the non-unit protection meets section I protection criteria, a second commutation instruction is issued to a direct current circuit breaker to perform second commutation; otherwise, step (4) is performed; (4) a section II protection time window is started after a delay; if the line mode voltage rate of change at the installation position of the non-unit protection meets section II protection criteria, a second commutation instruction is issued to a direct current circuit breaker to perform second commutation; otherwise, a pre-action return instruction is issued to the direct current circuit breaker.

The invention provides a pulse power module for discharging a super capacitor, which is applied to the field of fusion. The module adopts a double-layer discrete structure and comprises a converter box and a high-voltage box which are arranged on a primary side and are mutually independent, and the high-voltage box is positioned above the converter box and is electrically connected with the converter box to form a main circuit. A water-cooling heat dissipation H-bridge converter unit and a direct-current support capacitor are integrated in the converter box; and an air-cooled radiating direct current circuit breaker and a smoothing reactor are integrated in the high-voltage box. The module is further provided with a double-loop redundant power supply system which adapts to the fusion pulse discharge working condition, electricity is taken from the input side of the high-voltage box and the direct-current bus side of the converter box respectively, and power is reliably supplied to the control unit through a high-voltage optimization strategy. The problems of complex heat dissipation management, unstable power supply, inconvenient maintenance and the like in fusion high-power pulse application are effectively solved, and the reliability and the safety of the system are improved.

The invention provides a thyristor-based complementary commutation type solid-state DC circuit breaker and a control method thereof. The thyristor-based complementary commutation type solid-state DC circuit breaker comprises a main branch and an auxiliary branch, the main branch comprises a thyristor and a thyristor which are reversely connected in series, the anodes of the thyristors in the auxiliary branch are connected, the cathodes of the thyristors in the auxiliary branch are connected with the anodes of the thyristors through resistors, the anodes of the thyristors in the auxiliary branch are connected with the cathodes of the thyristors in the auxiliary branch, the cathodes of the thyristors in the auxiliary branch are connected with the anodes of the thyristors through the resistors, and the cathodes of the thyristors are grounded through the resistors; the other ends of the positive electrodes are respectively connected with the positive electrodes, the negative electrodes are connected with the positive electrodes, and the negative electrodes are connected with the negative electrodes; the anodes of the diodes are connected, the cathodes of the diodes are connected with the other end of the capacitor C through the resistor, the anodes of the diodes are connected with the cathodes of the diodes, the cathodes of the diodes are connected with the other end of the capacitor C through the resistor, and the lightning arrester MOV is connected with the capacitor C in parallel. The device is low in conduction loss, is high in operation efficiency, can interrupt bidirectional operation current and fault current, is high in controllability and reliability, and has a reclosing function.

The invention belongs to the technical field of power electronics, and particularly relates to a solid-state direct-current circuit breaker module based on IGCTs, an upper pressing plate and a lower pressing plate are connected through a first screw rod, the number of first radiators is one more than that of the IGCTs, and the first radiators and the IGCTs are arranged in an overlapping mode; the number of the second radiators is one more than that of the first fast recovery diodes, and the second radiators and the first fast recovery diodes are arranged in an overlapping mode. First insulating cushion blocks are arranged between the first radiators and the lower pressing plate and between the second radiators and the lower pressing plate. Insulating cushion blocks II are arranged between the radiator I and the upper pressing plate as well as between the radiator II and the upper pressing plate and correspondingly abut against the radiator I and the radiator II through two force application mechanisms positioned on the inner side of the upper pressing plate; the piezoresistor is installed on the side, away from the first radiator, of the second radiator, the RCD protection unit is installed on the insulating plate, and the insulating plate is installed on the upper pressing plate and the lower pressing plate and located on one side of the first radiator and one side of the second radiator. The structure is compact, maintenance is easy, pressure is uniform, stray inductance is reduced, and overall stability and response speed are improved.

The application discloses a stable direct-current circuit breaker oscillation characteristic measuring device, which comprises a main body composed of a shell, an operation panel arranged on one side of the shell and a measuring mechanism arranged in the shell, a wire passing support is movably connected to the side of the shell and close to the operation panel, and the wire passing support is arranged in one-to-one correspondence with the interfaces on the operation panel; the interfaces of the wire passing support and the operation panel are horizontally arranged, and the measuring cable between the interfaces of the wire passing support and the operation panel has a movement allowance. The stable direct-current circuit breaker oscillation characteristic measuring device with the above structure can make the wiring more stable and does not affect the normal use of the operation panel by arranging the wire passing support, winding a part of the measuring cable on the wire passing support and then inserting the remaining part into the corresponding interface position of the operation panel.

The invention relates to the technical field of distribution boxes, and discloses an AC / DC intelligent distribution box, which comprises a box body, an upper flip cover hinged to the front side of the box body and an AC distribution module arranged in the box body, and also comprises a DC distribution module comprising a rectifier module and a main transformer arranged in the box body, the main transformer is respectively connected with a plurality of direct-current circuit breakers arranged in the box body through direct-current power transmission lines, branch transformers corresponding to the direct-current circuit breakers are arranged in the box body, alternating current is converted into direct current through a rectifier module after passing through a main power switch of the alternating-current power distribution module, and then voltage regulation is carried out through the main transformer; a temperature control heat dissipation module and a self-soot-blowing top cover; the self-soot-blowing top cover is arranged at the top of the box body, and soot blowing cleaning is carried out through the temperature control heat dissipation module; compared with the prior art, the power connection socket has the advantages that an alternating current power supply and a direct current power supply are provided for the power connection socket at the same time, and dust falling on the top can be automatically cleaned.

The invention provides a low-conduction-loss direct-current circuit breaker with a fault type judgment function and a judgment method, and belongs to the field of circuit fault detection. In order to solve the problems that in an existing hybrid high-voltage direct-current circuit breaker, the conduction loss of a load commutation switch is high, and a circuit device does not have the fault type discrimination capability, the direct-current circuit breaker comprises a load branch, a multifunctional branch, a main breaking branch and an energy absorption branch. The discrimination method comprises the following steps: in a normal operation mode, a load branch is conducted; the capacitor pre-charging mode operates in parallel to charge the capacitor C; when the circuit is short-circuited, a thyristor turn-off mode is entered, and the T1 is turned off; and entering a load commutation mode, converting the fault current to a main breaking branch, introducing an energy absorption branch, and entering an energy absorption mode. And injecting a controlled RLC oscillation current, analyzing current waveform characteristics to judge a direct current fault type, and performing reclosing or maintenance of the circuit breaker according to the analyzed direct current fault type.

The invention relates to the technical field of direct current circuit breaker fault diagnosis, and discloses a fault detection system based on a direct current circuit breaker. The system comprises a signal acquisition module, a signal preprocessing module, a waveform distortion feature extraction module, a feature interval division module, a border crossing evaluation module, a map construction module and a fault identification module. The method comprises the following steps: synchronously collecting multi-channel time domain signals, and carrying out time mark alignment and noise filtering; matching the current signal with a standard template by using a dynamic time warping algorithm to generate a waveform distortion feature vector; dividing feature intervals according to jump edges of the state signals, extracting distortion feature sub-vectors of the state intervals, and performing multi-dimensional space distance operation on the distortion feature sub-vectors to generate interval border-crossing descriptors; integrating and constructing a fault characteristic spectrum representing a complete action process; and matching the fault mode library through an atlas comparison engine to output a recognition result and confidence. According to the invention, accurate quantification of tiny distortion of the action waveform of the DC circuit breaker and accurate positioning of staged faults are realized.

The invention provides an equivalent test circuit and test method of a hybrid multi-port direct current circuit breaker, and an equivalent transfer branch, an equivalent energy consumption branch, a first equivalent switch branch and a second equivalent switch branch of the equivalent test circuit are connected in parallel and are all connected between a first port and a second port. A hybrid multi-port direct current circuit breaker is simplified into an equivalent test circuit with only two ports, functions of all transfer branches and energy consumption branches in the multi-port direct current circuit breaker are integrated through the equivalent transfer branch and the equivalent energy consumption branch, all ports and branches do not need to be re-etched, hardware investment and occupied area of a test platform are greatly reduced, and the test efficiency is improved. Meanwhile, only the first equivalent switch branch and the second equivalent switch branch which are directly related to the fault port are reserved, complex logic of multi-port cooperative control is avoided, the building difficulty and the operation and maintenance cost of the test system are remarkably reduced, and the test period is shortened.

The invention discloses a hybrid direct current circuit breaker based on series voltage injection and parallel current injection, which comprises a main circuit, a series injection module, a parallel injection module and a main power electronic module, and is characterized in that when a main loop generates a fault current, the series injection module injects a reverse voltage to the main loop by utilizing the coupling effect of a transformer; reducing the fault current of the main loop and inhibiting the rising rate; the parallel injection module enables a main loop to inject oscillation current in parallel through high-frequency on-off operation, so that mechanical switch current in the main loop oscillates around 0 at high frequency and low amplitude, and arc-free breaking of a mechanical switch MS is guaranteed; and the main power electronic module is turned off after the MS contact is completely separated, and fault current is absorbed through a capacitor in the main power electronic module to finish circuit breaking. According to the circuit breaker disclosed by the invention, under the condition of ensuring low on-state loss during normal operation of a line, no-arc breaking of a mechanical switch is ensured, the pressure of a power electronic device is greatly reduced, and particularly, the pressure of a current device needing to be turned on and turned off at high frequency is reduced.

Solid-state circuit breakers (SSCBs) have been witnessing an impressive progress with the aid of wide bandgap (WBG) devices such as silicon carbide (SiC) MOSFETs. Along with obtaining high efficiency as the result of low on-state resistance, response times have been gaining remarkable achievements in microseconds range. Not only that, the reported successes in control and gate drivers design and incorporating fault detection / location techniques in SSCBs are promising. A MOV-resistive capacitive switch (MOV-RCS) snubber for solid state circuit breakers addresses the following: 1) the MOV degradation issue in DCCBs is solved, 2) the maximum allowable DC bus voltage on DCCBs is extended. The solid state circuit breaker and an active clamping snubber includes a first circuit including a fault current bypass based solid state breaker for low voltage direct current systems.

The invention provides a DC circuit breaker and a control method thereof, and relates to the technical field of power electronics. The direct current circuit breaker comprises a reverse connection detection unit, a control unit, an execution unit, an electric drive clutch mechanism and a contact unit. The output end of the execution unit is connected with the control end of the electric drive clutch mechanism. One end of the electrically-driven clutch mechanism is connected with the output end of the execution unit, and the other end of the electrically-driven clutch mechanism is connected with the driving end of the contact unit; the reverse connection detection unit is used for generating and outputting a reverse connection signal when detecting that the direct current circuit breaker is in a reverse connection state, and transmitting the reverse connection signal to the control unit; the control unit is used for generating an opening locking instruction according to the reverse connection signal and sending the opening locking instruction to the execution unit; and the execution unit is used for driving the electrically-driven clutch mechanism to move to the clutch disconnection position according to the opening locking instruction and keeping the clutch disconnection position so as to prevent the contact unit from connecting the main loop and improve the system safety.

The invention discloses a pre-current-limiting hybrid direct current circuit breaker based on an inductive coupling principle and a control method. The pre-current-limiting hybrid direct current circuit breaker comprises a main branch and an auxiliary branch which are connected in parallel, the auxiliary branch comprises a bridge type reversing branch composed of thyristors and diode valve groups Q1-Q4, a current transfer branch, a bypass branch, a current limiting part, a self-charging part and an energy consumption branch are arranged in the bridge type reversing branch, and energy release branches composed of common mechanical switches and resistors are arranged at the two ends of a capacitor C1 and the two ends of a capacitor C2 respectively. The energy release branch is used for discharging the corresponding capacitor after the circuit breaker acts; the bypass branch, the current limiting part and the self-charging part are connected in parallel and then are connected in series with the energy consumption branch to form a series unit; the MMC flexible DC power grid circuit is small in on-state loss, low in cost, high in reliability, capable of being flexibly adapted to different abnormal scenes of a DC system, and suitable for the fields of MMC flexible DC power grids and the like.

The application provides a thyristor-based multi-port hybrid DC circuit breaker and a control method, comprising: a plurality of main branches and a shared branch; all the main branches are connected to the shared branch; the shared branch comprises a first thyristor branch, a power supply side circuit breaker unit and a fault side circuit breaker unit, the thyristor branch is used for bearing fault current in the process of breaking of a fast mechanical switch in the main branch; the fault side circuit breaker unit is composed of a first capacitor, a first discharge resistor and a first lightning arrester element in parallel connection; the power supply side circuit breaker unit is composed of a second thyristor branch, a current limiting resistor, a second capacitor, a second discharge resistor and a second lightning arrester, wherein the second capacitor, the second discharge resistor and the second lightning arrester are connected in parallel to form a second branch, the thyristor branch and the current limiting resistor are connected in series to form a first branch, and the first branch is connected in series to the second branch.

The present application relates to a kind of medium voltage DC hybrid circuit breaker in vacuum mechanical switch high arc voltage implementation method, based on the basic principle of natural commutation of DC breaking, form arc voltage promotion method, propose the overall technical scheme based on high arc voltage vacuum fast mechanical switch, provide theory and technical basis for the research and development of natural commutation type medium voltage DC circuit breaker, engineering application.Through external transverse magnetic field (external transverse magnetic field, ETMF) to make up for the shortage of its own magnetic field.When vacuum switch is directly used for low voltage DC breaking, external transverse magnetic field control plays a crucial role.The effect of transverse magnetic field on vacuum arc is to improve the voltage of vacuum arc, force the current of DC loop to zero, thereby realizing the DC breaking of vacuum switch.Improve the rapidity and reliability of current transfer, expand the application scenario of natural commutation mode, improve the arc voltage of fast mechanical switch, improve commutation and breaking performance.