CN215897281U - Voltage regulation and control type oscillation type direct current breaker - Google Patents
Voltage regulation and control type oscillation type direct current breaker Download PDFInfo
- Publication number
- CN215897281U CN215897281U CN202122113347.5U CN202122113347U CN215897281U CN 215897281 U CN215897281 U CN 215897281U CN 202122113347 U CN202122113347 U CN 202122113347U CN 215897281 U CN215897281 U CN 215897281U
- Authority
- CN
- China
- Prior art keywords
- branch
- current
- circuit
- voltage
- oscillating
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Images
Landscapes
- Driving Mechanisms And Operating Circuits Of Arc-Extinguishing High-Tension Switches (AREA)
Abstract
The utility model provides a voltage regulation and control type oscillation type direct current breaker, which comprises: the energy-saving power supply comprises a through-flow branch, an energy-consuming branch and a cut-off branch, wherein the through-flow branch is connected into a power line in series; a breaking branch connected in parallel with the through-flow branch; one end of the energy consumption branch is respectively connected with one end of the through-flow branch and one end of the cut-off branch, and the other end of the energy consumption branch is connected with the cut-off branch; when the power line is not faulted, the through-current branch conducts the direct-current load current. When a power line has a fault, the circuit breaker can realize continuous on-off of the maximum current for a plurality of times in a short time by controlling the on-off branch circuit to oscillate and generate the oscillating current and continuously increasing the amplitude of the oscillating current until the oscillating current which has the same amplitude with the fault current and is opposite in direction is generated, so that the flexibility and the availability of the circuit breaker are greatly improved. The dual requirements of large-scale direct-current power grid construction on the technical performance and the economical efficiency of the direct-current circuit breaker are met.
Description
Technical Field
The utility model relates to the technical field of power electronics, in particular to a voltage regulation and control type oscillation direct-current circuit breaker.
Background
The high-voltage direct-current circuit breaker is one of core devices for constructing a multi-terminal direct-current power grid, and the technical economy of the high-voltage direct-current circuit breaker directly influences the flexibility and the universality of the application of the direct-current power grid. At present, the main technical routes of the high-voltage direct-current circuit breaker are mainly two types: the circuit breaker is a hybrid direct-current circuit breaker, a mechanical switch is used for through-current in normal operation, an auxiliary current conversion branch circuit and the like are used for transferring current to a power electronic device branch circuit connected in parallel during fault, and then the power electronic device is used for breaking the current. The other type is a mechanical direct current breaker, arc quenching of a mechanical switch is realized by reversely injecting current into a pre-charging capacitor, and direct current breaking is finally completed. However, in the prior art, either a hybrid direct current breaker or a mechanical direct current breaker is adopted, so that the dual requirements of large-scale direct current power grid construction on the technical performance and the economical efficiency of the direct current breaker are difficult to meet at the same time, and the large-scale application of the high-voltage direct current breaker in a multi-terminal and direct current power grid is limited.
SUMMERY OF THE UTILITY MODEL
Therefore, the technical problem to be solved by the present invention is to overcome the defect that the dc circuit breaker in the prior art is difficult to satisfy the dual requirements of technical performance and economic performance, thereby providing a voltage-regulated oscillating dc circuit breaker.
In order to achieve the purpose, the utility model provides the following technical scheme:
an embodiment of the present invention provides a voltage-regulated oscillating dc circuit breaker, including: the energy-saving power supply comprises a through-flow branch, an energy-consuming branch and a cut-off branch, wherein the through-flow branch is connected into a power line in series; a disconnect branch connected in parallel with the through-flow branch; one end of the energy consumption branch is respectively connected with one end of the through-flow branch and one end of the cut-off branch, and the other end of the energy consumption branch is connected with the cut-off branch; when the power line is not in fault, the through-current branch circuit conducts direct-current load current; when the power line has a fault, the running state of the cut-off branch is controlled, the cut-off branch generates oscillating current which is equal to the fault current in amplitude and opposite in direction, the through-current branch is reliably cut off, and finally the energy consumption branch consumes the fault current energy.
Preferably, the disconnection branch comprises: the voltage source comprises a controlled voltage conversion circuit and an oscillating circuit, wherein one end of the controlled voltage conversion circuit is connected with one end of the through-current branch, the other end of the controlled voltage conversion circuit is connected with one end of the oscillating circuit, and the other end of the oscillating circuit is connected with the other end of the through-current branch; the controlled voltage conversion circuit is used for boosting the alternating voltage and rectifying the alternating voltage to output direct voltage; the oscillating circuit is used for receiving the direct-current voltage output by the controlled voltage conversion unit and generating oscillating current.
Preferably, the controlled voltage conversion circuit includes: the rectifier isolation circuit is connected with the square wave voltage conversion circuit in series.
Preferably, the rectifying and isolating circuit includes: the circuit comprises an isolation circuit and a rectifying circuit, wherein the isolation circuit is connected with the rectifying circuit in series.
Preferably, the square wave voltage converting circuit includes: the bridge type square wave conversion circuit or the module cascade square wave conversion circuit is characterized in that a controllable bridge arm unit of the bridge type square wave conversion circuit comprises a plurality of first sub-module units; the module cascade square wave conversion circuit comprises a plurality of cascade second sub-module units.
Preferably, the current branch comprises at least one mechanical switch.
The technical scheme of the utility model has the following advantages:
the utility model provides a voltage regulation and control type oscillation type direct current breaker, which comprises: the energy-saving power supply comprises a through-flow branch, an energy-consuming branch and a cut-off branch, wherein the through-flow branch is connected into a power line in series; a breaking branch connected in parallel with the through-flow branch; one end of the energy consumption branch is respectively connected with one end of the through-flow branch and one end of the cut-off branch, and the other end of the energy consumption branch is connected with the cut-off branch; when the power line is not in fault, the through-current branch circuit conducts the direct-current load current; when the power line has a fault, the running state of the cut-off branch is controlled, the cut-off branch generates oscillating current which has the same amplitude and the opposite direction with the fault current, so that the through-flow branch is reliably cut off, and finally the energy of the fault current is consumed by the energy consumption branch. When a power line has a fault, the circuit breaker can realize continuous on-off of the maximum current for a plurality of times in a short time by controlling the on-off branch circuit to oscillate and generate the oscillating current and continuously increasing the amplitude of the oscillating current until the oscillating current which has the same amplitude with the fault current and is opposite in direction is generated, so that the flexibility and the availability of the circuit breaker are greatly improved. The dual requirements of large-scale direct-current power grid construction on the technical performance and the economical efficiency of the direct-current circuit breaker are met.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and other drawings can be obtained by those skilled in the art without creative efforts.
Fig. 1 is a schematic block diagram of a specific example of an oscillating dc circuit breaker according to an embodiment of the present invention;
fig. 2 is a schematic block diagram of another specific example of an oscillating dc circuit breaker according to an embodiment of the present invention;
fig. 3 is a schematic block diagram of another specific example of the oscillating dc circuit breaker according to the embodiment of the present invention;
fig. 4 is a circuit configuration diagram of a specific example of a rectifying and isolating circuit provided in an embodiment of the present invention;
fig. 5 is a circuit configuration diagram of a specific example of a full-bridge square wave conversion circuit according to an embodiment of the present invention;
fig. 6 is a circuit configuration diagram of a specific example of a half-bridge type square wave conversion circuit according to an embodiment of the present invention;
fig. 7 is a circuit configuration diagram of a specific example of a first sub-module unit according to an embodiment of the present invention;
fig. 8 is a circuit configuration diagram of a specific example of a second sub-module unit according to an embodiment of the present invention;
fig. 9 is a flowchart of a specific example of a control method of an oscillating dc circuit breaker according to an embodiment of the present invention;
fig. 10 is a circuit configuration diagram of a specific example of the oscillating dc circuit breaker according to the embodiment of the present invention;
FIG. 11 is a detailed flow diagram of the load current provided by the embodiment of the present invention;
fig. 12 is a diagram illustrating an operation state of the oscillating dc circuit breaker according to an embodiment of the present invention;
FIG. 13 is another detailed flow diagram of the load current provided by the embodiment of the present invention;
FIG. 14 is a specific flow diagram of the oscillating current provided by the embodiment of the present invention;
FIG. 15 is another specific flow diagram of the oscillating current provided by the embodiment of the present invention;
FIG. 16 is another specific flow diagram of the oscillating current provided by the embodiment of the present invention;
fig. 17 is another specific flow diagram of the oscillating current provided by the embodiment of the present invention.
Detailed Description
The technical solutions of the present invention will be described clearly and completely with reference to the accompanying drawings, and it should be understood that the described embodiments are some, but not all embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, and are only for convenience of description and simplicity of description, but do not indicate or imply that the device or element being referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus, should not be construed as limiting the present invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.
In the description of the present invention, it should be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral connection; can be mechanically or electrically connected; the two elements may be directly connected or indirectly connected through an intermediate medium, or may be communicated with each other inside the two elements, or may be wirelessly connected or wired connected. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.
In addition, the technical features involved in the different embodiments of the present invention described below may be combined with each other as long as they do not conflict with each other.
The embodiment of the utility model provides a voltage regulation and control type oscillation direct-current circuit breaker which can be applied to a medium-high voltage direct-current system. As shown in fig. 1, the oscillating type dc circuit breaker includes: a through-flow branch 1, an energy consumption branch 2 and a cut-off branch 3. The current branch circuit 1 is connected in series into a power line; a breaking branch 3 connected in parallel with the through-flow branch 1; one end of the energy consumption branch 2 is respectively connected with one end of the through-flow branch 1 and one end of the cut-off branch 3, and the other end of the energy consumption branch is connected with the cut-off branch 3; when the power line is not in fault, the through-current branch circuit 1 conducts direct-current load current; when the power line has a fault, the running state of the cut-off branch 3 is controlled, the cut-off branch 3 generates oscillating current which has the same amplitude and the opposite direction with the fault current, so that the through-current branch 1 is reliably cut off, and finally the energy consumption branch 2 consumes the energy of the fault current.
In an embodiment, as shown in fig. 1, when no fault occurs on the converter side or the line side, the current branch 1 is in a conducting state, which enables the transmission of the dc load current between the converter side and the line side, and the open branch 3 is pre-charged before the dc breaker is put into operation. When a fault occurs on the converter side or the line side, for example, when a short-circuit fault occurs, the through-flow branch 1 is disconnected at the moment, the disconnected branch 3 is made to oscillate and generate an oscillating current by controlling the running state of the disconnected branch 3, the amplitude of the oscillating current is continuously increased in the process until the disconnected branch 3 generates an oscillating current which has the same amplitude and the opposite direction with the fault current, and the oscillating current which has the same amplitude and the opposite direction with the fault current is injected into the through-flow branch 1, so that the through-flow branch 1 is mechanically switched off and reliably disconnected. Further, the fault current is transferred to the cut-off branch 3, the fault current can charge the cut-off branch 3, when the charging voltage rises to the preset protection voltage threshold, the energy consumption branch 2 is conducted, the fault current is transferred to the energy consumption branch 2 and is absorbed by the energy consumption branch until the fault current crosses zero, and the system recovers to operate normally.
In the embodiment of the utility model, when a power line has a fault, the oscillating type direct current breaker can realize bidirectional and rapid switching-on and switching-off of direct current, has low running loss, does not need to be provided with a water cooling system, has strong overload capacity, can realize switching-on and switching-off current of tens of kA, and meets the application requirement of a direct current power transmission and distribution system. By controlling the on-off branch 3 to oscillate and generate the oscillating current and continuously increasing the amplitude of the oscillating current until the oscillating current which has the same amplitude and the opposite direction to the fault current is generated, the breaker can realize continuous on-off of the maximum current for a plurality of times in a short time, and the flexibility and the availability of the breaker are greatly improved.
The utility model provides a voltage regulation and control type oscillation type direct current breaker, which comprises: the energy-saving power supply comprises a through-flow branch, an energy-consuming branch and a cut-off branch, wherein the through-flow branch is connected into a power line in series; a breaking branch connected in parallel with the through-flow branch; one end of the energy consumption branch is respectively connected with one end of the through-flow branch and one end of the cut-off branch, and the other end of the energy consumption branch is connected with the cut-off branch; when the power line is not in fault, the through-current branch circuit conducts the direct-current load current; when the power line has a fault, the running state of the cut-off branch is controlled, the cut-off branch generates oscillating current which has the same amplitude and the opposite direction with the fault current, so that the through-flow branch is reliably cut off, and finally the energy of the fault current is consumed by the energy consumption branch. When a power line has a fault, the circuit breaker can realize continuous on-off of the maximum current for a plurality of times in a short time by controlling the on-off branch circuit to oscillate and generate the oscillating current and continuously increasing the amplitude of the oscillating current until the oscillating current which has the same amplitude with the fault current and is opposite in direction is generated, so that the flexibility and the availability of the circuit breaker are greatly improved. The dual requirements of large-scale direct-current power grid construction on the technical performance and the economical efficiency of the direct-current circuit breaker are met.
In one embodiment, shown in fig. 2, the opening of branch 3 comprises: a controlled voltage conversion circuit 31 and an oscillation circuit 32, wherein one end of the controlled voltage conversion circuit 31 is connected with one end of the current branch 1, the other end of the controlled voltage conversion circuit 31 is connected with one end of the oscillation circuit 32, and the other end of the oscillation circuit 32 is connected with the other end of the current branch 1; a controlled voltage conversion circuit 31 for boosting an alternating-current voltage and rectifying the output direct-current voltage; and the oscillating circuit 32 is used for receiving the direct-current voltage output by the controlled voltage conversion unit and generating oscillating current.
In one embodiment, as shown in fig. 3, the controlled voltage converting circuit 31 includes: a rectification isolation circuit 311 and a square wave voltage conversion circuit 312, wherein the rectification isolation circuit 311 and the square wave voltage conversion circuit 312 are connected in series. The rectifying and isolating circuit 311 is configured to boost the ac voltage, rectify the ac voltage, and output the dc voltage, and implement voltage isolation between a high potential on a rectification side and a ground potential; the square wave voltage converting circuit 312 functions to convert the dc current output from the rectifying/isolating circuit 311 into square wave voltages of different levels and output the square wave voltages to the oscillating circuit 32. In the embodiment of the present invention, as shown in fig. 4, the rectifying and isolating circuit 311 includes: an isolation circuit 3111 and a rectifier circuit 3112, wherein the isolation circuit 3111 is connected in series with the rectifier circuit 3112. In other embodiments, as shown in fig. 4, the rectifying and isolating circuit 311 further includes a boost circuit 3113, and the boost circuit 3113 is located between the isolating circuit 3111 and the rectifying circuit 3112.
Specifically, as shown in fig. 4, the isolation circuit 3111 is composed of an isolation transformer, and a primary side of the isolation transformer inputs 220V/380V ac voltage, and outputs the ac voltage through a secondary side after being isolated by an original secondary side. The primary side of the boost circuit 3113 inputs the ac voltage output by the isolation transformer, and the secondary side outputs the target value of the boosted ac voltage, and if the boost ratio requirement is low, the isolation circuit 3111 and the boost circuit 3113 can be integrated into a single isolation boost circuit, which is implemented by a single isolation boost transformer. The rectifier circuit 3112 may be a diode-uncontrolled rectifier bridge, and rectifies the ac voltage output from the secondary side of the booster circuit 3113 to a dc voltage target value and outputs the dc voltage target value to the square wave voltage converter circuit 312.
In the embodiment of the utility model, the voltage grade of the controlled voltage conversion circuit 31 is far lower than the rated voltage grade of the direct current circuit breaker, the cut-off current can be designed to be 2-5% of the rated voltage of the circuit breaker according to the target, the number of adopted power electronic devices can be saved by more than 80% compared with that of the hybrid direct current circuit breaker with the same voltage grade, and the economy of the direct current circuit breaker is obviously improved.
In addition, according to the requirements of specific on-off performance parameters, the controlled voltage source only needs to adopt a power electronic unit with the rated voltage level of about 2% -6%, and the cost of the circuit breaker is greatly reduced.
In one embodiment, the oscillating circuit 32 is an LC oscillating circuit, which includes an oscillating capacitor C and an oscillating inductor L.
In an embodiment, the energy consumption branch 2 is connected in parallel to two ends of the oscillation capacitor C. In the embodiment of the present invention, the energy consumption branch 2 may also be connected in parallel with two ends of the breaking branch 3.
In one embodiment, the square wave voltage converting circuit 312 includes: the bridge type square wave conversion circuit or the module cascade square wave conversion circuit is characterized in that a controllable bridge arm unit of the bridge type square wave conversion circuit comprises a plurality of first sub-module units; the module cascade square wave conversion circuit comprises a plurality of cascade second sub-module units.
In an embodiment, the square wave voltage converting circuit 312 may be a bridge type square wave converting circuit and a module cascade type square wave converting circuit according to its configuration. The bridge-type square wave conversion circuit can be divided into a full-bridge type and a half-bridge type according to the number of the controllable bridge arm units, wherein as shown in fig. 5, the full-bridge type square wave conversion circuit is composed of 4 controllable bridge arm units and 1 group of source capacitors. As shown in fig. 6, the half-bridge square wave conversion circuit is composed of 2 controllable bridge arm units and 2 sets of source capacitors. The bridge type square wave conversion circuit outputs target voltage by periodically controlling the on-off of the bridge arm units. The controllable bridge arm unit in the bridge type square wave conversion circuit can be formed by connecting a plurality of SM1 type sub-module units (i.e. a first sub-module unit) in series, and as shown in FIG. 7, the first sub-module unit comprises an IGBT module based on IGBT (IGCT), an IGBT-Diode-HB module and an IGBT-HB module. The module cascaded square wave conversion circuit is formed by cascading a plurality of SM2 type-sub module units (i.e., a second sub module unit), as shown in fig. 8, the second sub module unit includes an IGBT-FB module, an IGBT-MB module, and an IGBT-CD module based on an IGBT (igct).
In the embodiment of the utility model, the source capacitor or the sub-module capacitor in the square wave voltage conversion circuit 312 has voltage for a long time, and can provide control energy for power electronic devices and rapid mechanical switch control devices, so that an independent energy supply device is omitted, the parts of a circuit breaker group are simplified, and the equipment cost is reduced.
In an embodiment, the current branch 1 comprises at least one mechanical switch UMS.
In a specific embodiment, the current branch 1 is formed by at least one set of mechanical switches UMS. The mechanical switch UMS needs to withstand system load current and short-time overcurrent, and also needs to withstand transient overvoltage generated by breaking of the direct-current circuit breaker. According to the electrical stress, the fast mechanical switch UMS in the through-flow branch 1 can adopt a multi-fracture series connection, a multi-branch parallel connection and a multi-fracture series-parallel connection. In the embodiment of the utility model, the through-flow branch 1 has small loss and does not need water cooling, when the power line is not in fault, the quick mechanical switch is in a conducting state, and the direct-current system pre-charges the controlled oscillation unit, so that the controlled oscillation unit can self-take energy, external power supply equipment is saved, and the reliability of the direct-current circuit breaker is improved. In addition, the transmission of direct current load current and the aims of bidirectional short-circuit current on-off and quick reclosing can be realized only by using a small number of power electronic devices.
In an embodiment, the energy consumption branch 2 includes an arrester MOV, and in other embodiments, the energy consumption branch 2 may also be configured by a non-linear resistor or a series-parallel connection of arresters, which is not limited herein.
The embodiment of the utility model provides a control method of a voltage regulation and control type oscillation type direct current breaker, based on the oscillation type direct current breaker, as shown in fig. 9, the control method comprises the following steps:
step S1: and monitoring whether the power lines connected with the two ends of the through-flow branch circuit have faults or not in real time.
Step S2: when the power line connected with at least one end of the through-current branch circuit has a fault, the open-close branch circuit generates oscillating current which has the same amplitude and the opposite direction with the fault current by controlling the running state of the open-close branch circuit, so that the through-current branch circuit is reliably turned off.
In an embodiment, as shown in fig. 10, a rectification/isolation circuit based on an isolation/boost integration and a diode full-bridge rectification circuit and a module-cascaded square-wave voltage conversion circuit based on an IGBT-MB module are taken as examples for description.
The open branch is precharged before the through-current branch is turned on. Specifically, before the oscillating dc circuit breaker is put into operation, the switches K0, K1, and K2 are closed, and the transformer secondary side is rectified and then applied to the MB module capacitor CSM1And CSM2Charging, the current flows as shown in fig. 11. When MB module capacitor CSM1And CSM2After charging to the target voltage, the switches K0, K1, K2 are opened. Before the main branch rapid mechanical switch UMS is switched on, the circuit breaker is in an off state as shown in figure 12After the UMS is turned on, the load current flows through the main branch, and the circuit breaker is put into operation as shown in fig. 13.
When a fault occurs on the converter side or the line side, such as a short-circuit fault, the through-current branch is disconnected, the amplitude of the oscillating current is increased continuously in the process until the disconnected branch generates the oscillating current which has the same amplitude and the opposite direction to the fault current, and the oscillating current which has the same amplitude and the opposite direction to the fault current is injected into the through-current branch, so that the through-current unit mechanical switch is extinguished, and the through-current unit is reliably disconnected.
In one embodiment, by controlling the operation state of the open branch circuit, the open branch circuit generates an oscillating current with the same amplitude and the opposite direction to the fault current, so that the through-current branch circuit is reliably turned off, and the method comprises the following steps:
step S21: and controlling the opening of a mechanical switch of the through-current branch.
Step S22: when the mechanical switch reaches the designed open distance which can sufficiently endure the transient on-off voltage, the opening and closing of the sub-module unit of the on-off branch circuit is controlled periodically until the controlled oscillation unit generates oscillation current which has the same amplitude and the opposite direction with the short-circuit current, the current of the mechanical switch crosses zero, and the arc extinction and the opening are completed.
In an embodiment, when a fault occurs on the line side of the dc circuit breaker, the dc circuit breaker receives an open command or an overcurrent protection action, and the main branch is opened by the UMS fast mechanical switch. And when the mechanical switch UMS is opened to a sufficient opening distance, triggering an MB sub-module in the square wave voltage conversion circuit, and controlling the IGBT of the sub-module to be periodically switched on and off. Wherein, MB module capacitor CSM1And CSM2And discharging to a loop formed by the fast mechanical switch UMS, the oscillating capacitor C and the inductor L to generate oscillating current. As shown in fig. 14, at this time, T2, T4, and T6 are turned on, T1, T3, and T5 are kept turned off, the MB submodule outputs a 1-fold positive voltage (+ UCsm) to the loop clockwise, and an oscillating current with an amplitude of 1-fold in the same direction as the voltage is generated in the excitation loop.
In the next control period, T2, T4, T6 are turned off, T1, T3, T5 are turned on, the MB submodule outputs 2 times negative voltage (-2UCsm) to the loop in the counterclockwise direction, 2 times amplitude oscillation current in the same direction as the voltage is generated in the excitation loop, at this time, the oscillation current generated by excitation in the loop is reversed, and the amplitude is further increased under power supply excitation, as shown in fig. 15.
In the process of periodically outputting voltage by the square wave voltage conversion circuit, when the direction of oscillation current generated by excitation is opposite to the fault current and the amplitude is equal to the fault current, the fault current generates a zero crossing point, and the mechanical switch arc is extinguished. The fault current is transferred from the through-current branch to the cut-off branch, all IGBTs of the MB submodule are kept off at the moment, and the current respectively passes through a T6 anti-parallel diode and a capacitor CSM1T4 anti-parallel diode and capacitor CSM2And T4 flows through the anti-parallel diode, the current charges the oscillating capacitor C of the open branch, and the voltage of the oscillating capacitor C rises to the MOV operation voltage, as shown in fig. 16.
Further, when the voltage of the oscillation capacitor C of the open branch circuit reaches the MOV operating voltage, the fault current commutates to the energy consuming branch circuit, and the MOV absorbs the fault current energy and completes the fault current breaking, as shown in fig. 17.
The method and the drawings are described only by taking the case where a short-circuit fault occurs in a line-side power line and a current flows from the converter side to the line side as an example, and the operating principle of the dc circuit breaker is the same as that described above when a current flows from the line side to the converter side.
The utility model provides a control method of a voltage regulation and control type oscillation type direct current breaker, which comprises the following steps: monitoring whether the power lines connected with the two ends of the through-flow branch circuit have faults in real time; when the power line connected with at least one end of the through-current branch circuit has a fault, the open-close branch circuit generates oscillating current which has the same amplitude and the opposite direction with the fault current by controlling the running state of the open-close branch circuit, so that the through-current branch circuit is reliably turned off. When a power line has a fault, the circuit breaker can realize continuous on-off of the maximum current for a plurality of times in a short time by controlling the on-off branch circuit to oscillate and generate the oscillating current and continuously increasing the amplitude of the oscillating current until the oscillating current which has the same amplitude with the fault current and is opposite in direction is generated, so that the flexibility and the availability of the circuit breaker are greatly improved. The dual requirements of large-scale direct-current power grid construction on the technical performance and the economical efficiency of the direct-current circuit breaker are met.
It should be understood that the above examples are only for clarity of illustration and are not intended to limit the embodiments. Other variations and modifications will be apparent to persons skilled in the art in light of the above description. And are neither required nor exhaustive of all embodiments. And obvious variations or modifications of the utility model may be made without departing from the spirit or scope of the utility model.
Claims (6)
1. A voltage-regulated oscillating-type direct current circuit breaker, comprising: a through-flow branch, an energy-consuming branch and a cut-off branch, wherein,
a through-current branch connected in series to the power line;
a disconnect branch connected in parallel with the through-flow branch;
one end of the energy consumption branch is respectively connected with one end of the through-flow branch and one end of the cut-off branch, and the other end of the energy consumption branch is connected with the cut-off branch;
when the power line is not in fault, the through-current branch circuit conducts direct-current load current; when the power line has a fault, the running state of the cut-off branch is controlled, the cut-off branch generates oscillating current which is equal to the fault current in amplitude and opposite in direction, the through-current branch is reliably cut off, and finally the energy consumption branch consumes the fault current energy.
2. The voltage regulated oscillating dc circuit breaker according to claim 1, wherein said opening branch comprises: a controlled voltage conversion circuit and an oscillation circuit, wherein,
one end of the controlled voltage conversion circuit is connected with one end of the through-current branch circuit, the other end of the controlled voltage conversion circuit is connected with one end of the oscillating circuit, and the other end of the oscillating circuit is connected with the other end of the through-current branch circuit;
the controlled voltage conversion circuit is used for boosting the alternating voltage and rectifying the alternating voltage to output direct voltage;
the oscillating circuit is used for receiving the direct-current voltage output by the controlled voltage conversion unit and generating oscillating current.
3. The voltage-regulated oscillating dc circuit breaker according to claim 2, characterized in that said controlled voltage transformation circuit comprises: the rectifier isolation circuit is connected with the square wave voltage conversion circuit in series.
4. The voltage regulated oscillating dc circuit breaker according to claim 3, wherein said rectifying and isolating circuit comprises: the circuit comprises an isolation circuit and a rectifying circuit, wherein the isolation circuit is connected with the rectifying circuit in series.
5. The voltage-regulated oscillating dc circuit breaker according to claim 3, wherein said square-wave voltage conversion circuit comprises: bridge type square wave conversion circuit or module cascade square wave conversion circuit, wherein,
the controllable bridge arm unit of the bridge type square wave conversion circuit comprises a plurality of first sub-module units;
the module cascade square wave conversion circuit comprises a plurality of cascade second sub-module units.
6. The voltage regulated oscillating dc circuit breaker according to claim 5, characterized in that said through-current branch comprises at least one mechanical switch.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202122113347.5U CN215897281U (en) | 2021-09-02 | 2021-09-02 | Voltage regulation and control type oscillation type direct current breaker |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202122113347.5U CN215897281U (en) | 2021-09-02 | 2021-09-02 | Voltage regulation and control type oscillation type direct current breaker |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN215897281U true CN215897281U (en) | 2022-02-22 |
Family
ID=80564127
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202122113347.5U Active CN215897281U (en) | 2021-09-02 | 2021-09-02 | Voltage regulation and control type oscillation type direct current breaker |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN215897281U (en) |
-
2021
- 2021-09-02 CN CN202122113347.5U patent/CN215897281U/en active Active
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Shi et al. | Isolated modular multilevel DC–DC converter with DC fault current control capability based on current-fed dual active bridge for MVDC application | |
| CN202197226U (en) | Power station direct current power supply device based on super capacitor | |
| US11967859B2 (en) | Power factor correction circuit, power factor correction assembly and on-line uninterruptible power supply comprising same | |
| US10637371B2 (en) | Interface arrangement between an alternating current power system and a direct current power system with control of converter valve for fault protection | |
| US9917443B2 (en) | Photovoltaic system and method for operating a photovoltaic system for feeding electrical power into a medium-voltage network | |
| KR20180103181A (en) | DC current interrupter and control method | |
| CN107612408B (en) | Energy storage converter and energy storage system | |
| CN111404127A (en) | Natural commutation type hybrid direct current circuit breaker and current turn-off method of direct current system | |
| CN107086605B (en) | Black start method for zero start boosting of power grids | |
| CN210430911U (en) | Direct current breaker | |
| CN113422360A (en) | Direct current breaker and control method | |
| CN113839370A (en) | Voltage regulation and control type oscillation type direct current breaker and control method thereof | |
| CN205123611U (en) | Modular converter topology and transverter system | |
| CN215897281U (en) | Voltage regulation and control type oscillation type direct current breaker | |
| CN207124475U (en) | Energy-storage system | |
| Agrawal et al. | Novel bidirectional hybrid DC circuit breaker topology using current fed converter | |
| CN105991054A (en) | Converter sub module, control method and converter | |
| CN110352554A (en) | Power converter for energy system | |
| CN114336550A (en) | Self-energy-taking multi-port direct-current circuit breaker and application method | |
| CN207368676U (en) | A kind of energy accumulation current converter and energy-storage system | |
| CN206461533U (en) | Overhaul power output device | |
| CN215498254U (en) | Direct current breaker based on MMC source | |
| Mobarrez et al. | Impact of DC side fault protection on performance and operation of multi-terminal DC (MTDC) systems | |
| CN113381435B (en) | Flexible loop closing device and control method thereof | |
| CN215498253U (en) | Direct current breaker |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| GR01 | Patent grant | ||
| GR01 | Patent grant |