阅读说明：本技术 一种直流开关设备 (DC switch equipment ) 是由 吴小钊 张�杰 纪江辉 王小丽 李俊豪 白维正 李树昆 姜亚军 孙广涛 于 2019-09-12 设计创作，主要内容包括：本发明涉及一种直流开关设备,属于电开关技术领域,包括主流通支路,用于转移主流通支路中电流的第一转移支路,以及用于吸收第一转移支路中能量的第一能量吸收支路,主流通支路上设置有至少两个机械开关,其中一个机械开关并联有第二转移支路,该第二转移支路中设置有半导体功率模块。本发明的直流开关设备通过两个阶段转移主流通支路上的电流,先通过第二转移支路旁路与其并联的机械开关,实现第一阶段的电流转移,再通过第一转移支路旁路主流通支路,使主流通之路中的电流快速转移至第一转移支路,实现第二阶段的电流转移。由于主流通支路上不存在大功率电力电子器件,因此主流通支路上的输电损失较小、输电成本较低。(The invention relates to direct current switch equipment, which belongs to the technical field of electric switches and comprises a main flow branch, a transfer branch for transferring current in the main flow branch and a energy absorption branch for absorbing energy in the transfer branch, wherein the main flow branch is provided with at least two mechanical switches, wherein mechanical switches are connected with a second transfer branch in parallel, and a semiconductor power module is arranged in the second transfer branch.)

A DC switchgear device of the kind 1, , comprising a main flow branch, a th transfer branch for transferring current in the main flow branch, and a th energy absorption branch for absorbing energy in the th transfer branch,

at least two mechanical switches are arranged on the main flow branch, wherein mechanical switches are connected in parallel with a second transfer branch, and a semiconductor power module is arranged in the second transfer branch.

2. The dc switching apparatus of claim 1, wherein the semiconductor power module of the second transfer branch comprises more than fully-controlled semiconductor devices.

3. The dc switch apparatus of claim 1, wherein the th branch comprises a capacitor and a semiconductor power unit connected in series, and the semiconductor power unit comprises or more fully-controlled semiconductor devices or semi-controlled semiconductor devices.

4. The dc switching apparatus of claim 1, wherein the -th branch is provided with a capacitor and a mechanical switch in series.

5. The direct current switch device of claim 1, wherein the th branch is provided with a series capacitor and a mechanical switch, and or more fully-controlled semiconductor devices or semi-controlled semiconductor devices.

6. The dc switching apparatus of claim 1, wherein the semiconductor power module is connected in parallel with a second energy absorbing branch.

7. The dc switching apparatus of claim 1, wherein the mechanical switch in the main flow branch is a high speed disconnector or a vacuum switch.

8. The direct current switching device according to claim 3, 4 or 5, wherein the capacitor is connected in parallel with a discharge branch, the discharge branch comprising a resistor and a contactor connected in series.

Technical Field

The invention belongs to the technical field of electric switches, and particularly relates to direct-current switch devices.

Background

For example, the chinese patent application publication No. CN109066611A discloses dc circuit breakers, which include a branch circuit on which a mechanical switch and a high-power electronic device are disposed, a second branch circuit on which a capacitor and a mechanical switch are disposed, and a third branch circuit on which a lightning arrester is disposed, and since the branch circuit of the dc circuit breaker is a main circuit and a high-power electronic device is present, power transmission loss is large, and power transmission cost is high.

Disclosure of Invention

The invention aims to provide kinds of direct-current switch equipment, which is used for solving the problems of large transmission power loss and high transmission cost caused by high-power electronic devices in a main loop of the conventional hybrid circuit breaker.

Based on the above purpose, the present invention proposes kinds of dc switch devices, which have the following technical solutions:

the power module comprises a main flow branch, an th transfer branch for transferring current in the main flow branch, and an th energy absorption branch for absorbing energy in the th transfer branch, wherein at least two mechanical switches are arranged on the main flow branch, wherein mechanical switches are connected in parallel with a second transfer branch, and a semiconductor power module is arranged in the second transfer branch.

The beneficial effects of the above technical scheme are:

the direct current switch equipment transfers the current on the main flow branch in two stages, firstly transfers the current in stage through the second transfer branch bypass and the mechanical switch connected in parallel with the second transfer branch bypass, and then transfers the current in the main flow path to the transfer branch quickly through the transfer branch bypass main flow branch, so as to transfer the current in the second stage.

Further , in order to realize the on/off function of the semiconductor power module in the second branch, the semiconductor power module includes more than fully-controlled semiconductor devices.

, in order to realize the current diversion and on-off function of th diversion branch, th diversion branch comprises a capacitor and a semiconductor power unit which are connected in series, wherein the semiconductor power unit comprises or more fully-controlled semiconductor devices or semi-controlled semiconductor devices, as other embodiments, the th diversion branch is provided with the capacitor and a mechanical switch which are connected in series, and as other embodiments, the th diversion branch is provided with or more fully-controlled semiconductor devices or semi-controlled semiconductor devices besides the capacitor and the mechanical switch which are connected in series.

Further , in order to protect the semiconductor power module on the second transfer branch, the semiconductor power module is connected in parallel with the second energy absorption branch.

And , the mechanical switch in the main flow branch is a high-speed isolating switch or a vacuum switch, and the arc resistance is realized.

And , the capacitor is connected in parallel with a discharge branch, and the discharge branch comprises a resistor and a contactor which are connected in series, so that the capacitor is discharged through the resistor.

Drawings

FIG. 1 is a schematic diagram of a DC switchgear of a switching embodiment of the present invention;

FIG. 2 is a schematic diagram of a DC switchgear of a second embodiment of the switch of the present invention;

fig. 3 is a schematic diagram of a dc switchgear of a third embodiment of the switch of the present invention;

FIG. 4 is a schematic diagram of a DC switchgear of a fourth embodiment of the switch of the present invention;

FIG. 5 is a schematic diagram of a DC switchgear of switch embodiment five of the present invention;

the reference numerals are explained as follows:

1- th mechanical switch, 2-second mechanical switch, 3-semiconductor power module, 4-semiconductor power unit, 5, 9, 10-lightning arrester, 6-resistor, 7-capacitor, 8-contactor, 11-third mechanical switch, 12-fourth mechanical switch.

Detailed Description

The dc switch device of the present invention is intended to be used in series in a high voltage dc transmission line or a medium or low voltage dc distribution line, and to be used as a circuit breaker or a load switch, which functions to protect the line and isolate a fault, and the following describes an embodiment of the present invention in reference to the accompanying drawings at step .

Switch embodiment :

the embodiment provides dc switch devices, which include a main flow branch, a th branch, a second branch, a th branch and a second branch, as shown in fig. 1, a th mechanical switch 1 and a second mechanical switch 2 are disposed on the main flow branch, both of which are high-speed isolating switches or vacuum switches, and have arc-resistant capability, and the main flow branch is not equipped with high-power electronic devices.

An th transfer branch is connected in parallel with the main flow branch, a capacitor 7 and a semiconductor power unit 4 are arranged on the th transfer branch and used for transferring current in the main flow branch, the semiconductor power unit is composed of thyristors connected in anti-parallel, a th energy absorption branch and a discharge branch are connected in parallel at two ends of the capacitor 7, the th energy absorption branch comprises a lightning arrester 5 and used for absorbing current (energy) in the capacitor 7 on the th transfer branch, and the discharge branch comprises a resistor 6 and a contactor 8 which are connected in series.

A second transfer branch is connected in parallel with two ends of the second mechanical switch 2, a semiconductor power module 3 is arranged on the second transfer branch, the semiconductor power module comprises two full-control power electronic devices which are connected in series in a reverse direction, and each full-control power electronic device is connected with a diode in a reverse parallel mode; two ends of the two fully-controlled power electronic devices are connected in parallel with a second energy absorption branch, and a lightning arrester 9 is arranged on the second energy absorption branch and used for absorbing current on the second transfer branch.

The operation processes of the above-mentioned dc switch device include a closing operation, an opening operation, and a reclosing operation, and the following describes the respective operation processes:

the switching-on operation process is as follows:

when the direct current switching equipment is currently in an opening state and needs to be switched on, the second mechanical switch 2 is firstly switched on, and then the th mechanical switch 1 is switched on, so that the main flow branch is conducted, and the switching-on operation is completed.

The switching-off operation process comprises:

when the direct current switch equipment is in a closing state ( th mechanical switch 1 and second mechanical switch 2 are closed and bear rated current) currently, if the switching-off operation is needed, a controller of the direct current switch equipment sends a command to simultaneously switch off the th mechanical switch 1 and the second mechanical switch 2, when a fracture between the th mechanical switch 1 and the second mechanical switch 2 has constant insulation capacity ( constant insulation capacity can be determined through set time), the controller triggers the semiconductor power module 3 and the semiconductor power unit 4 to be switched on, an electric arc is generated between the fractures of the second mechanical switch 2, the electric arc voltage is larger than threshold voltage of the semiconductor power module 3, the current of the second mechanical switch 2 is transferred to the semiconductor power module 3, and the current transfer in the stage is realized.

And after the second mechanical switch 2 is extinguished, the semiconductor power module 3 is turned off, so that the current of the main flow branch is transferred to a th transfer branch capacitor 7, and the current passes through the semiconductor power unit 4 to realize current transfer at a second stage, after the current of the main flow branch is completely transferred to a th transfer branch, a fracture arc of the th mechanical switch 1 is extinguished, the current on the th transfer branch rapidly charges the capacitor 7, the voltage of the capacitor 7 rapidly rises, an arrester 5 on a th energy absorption branch is triggered to act, the arrester 5 absorbs residual energy, when the terminal voltage of the capacitor 7 of the th transfer branch is balanced with the system voltage of the direct-current switching equipment, no current passes through the th transfer branch, the semiconductor power unit 4 is turned off to complete the breaking of the direct-current switching equipment, and after the breaking, the contactor 8 is closed to discharge the capacitor 7 through the parallel resistor 6, so that the condition of reclosing in a short time is provided for preparing for next reclosing.

As another embodiment, the timing for controlling the opening of each mechanical switch during the opening operation may be that the second mechanical switch 2 is controlled to open and then the th mechanical switch 1 is controlled to open, the opening speed in the control timing is slower than the speed for simultaneously controlling the opening of the two mechanical switches, and the timing for triggering the semiconductor power module 3 and controlling the opening of the th mechanical switch 1 may be performed simultaneously, or the timing for triggering the semiconductor power module 3 and then controlling the opening of the th mechanical switch 1 may be performed first.

The reclosing operation process comprises the following steps:

after the direct current switch device is disconnected, the capacitor 7 discharges in a short time, a controller of the direct current switch device sends a closing instruction to close the -th mechanical switch 1 and the second mechanical switch 2, the main flow branch is conducted, and if the direct current switch device is closed to a fault loop, the opening operation process is repeated.

The direct current switch equipment transfers the current on the main flow branch in two stages, firstly transfers the current on the th stage through the second transfer branch bypass and the mechanical switch connected in parallel with the second transfer branch bypass, and then transfers the current on the main flow path to the th transfer branch quickly through the second transfer branch bypass, so that the current transfer on the second stage is realized.

Switch embodiment two:

the present embodiment proposes dc switch devices, which include a main flow branch, a th branch, a second branch, a th branch and a second branch, as shown in fig. 2, a th mechanical switch 1 and a second mechanical switch 2 are disposed on the main flow branch, and the main flow branch is not equipped with high power electronic devices.

An th transfer branch is provided with a capacitor 7 and a semiconductor power unit 4, the semiconductor power unit comprises two full-control type power electronic devices which are connected in series in an opposite direction, each full-control type power electronic device is connected with a diode in an anti-parallel mode, two ends of each full-control type power electronic device are connected with an arrester in parallel, the th energy absorption branch comprises the arresters (5 and 10), the arresters (5) are connected with the capacitor 7 in parallel, the arresters (10) are connected with the semiconductor power unit 4 in parallel, the capacitor 7 is connected with a discharge branch in parallel, and a resistor 6 is arranged on the discharge branch.

The semiconductor power module 3 is disposed on the second transfer branch, and the structure of the semiconductor power module 3 is the same as that of the semiconductor power unit 4. The second energy absorption branch is connected with the second transfer branch in parallel, and an arrester 9 is arranged on the second energy absorption branch.

The operation process of the dc switch device in this embodiment includes a closing operation, a breaking operation, and a reclosing operation, and it should be noted that, referring to switch embodiment , in comparison with switch embodiment , in , the semiconductor power unit 4 in the th diversion branch of this embodiment is replaced with a turn-off device, and in the breaking operation, the th diversion branch has the capability of turning off a small current, secondly, since the lightning arrester 10 is connected in parallel to both ends of the semiconductor power unit 4 on the th energy absorption branch, the lightning arrester 10 can divert part of current on the th diversion branch to perform an energy absorption function, and thirdly, since the resistor 6 of this embodiment is directly connected in parallel to the capacitor 7, the capacitor 7 can be directly discharged through the resistor 6, except that other operation timings are the same as those described in switch embodiment , and are not described herein again.

Switch embodiment three:

in this embodiment, dc switch devices are proposed, as shown in fig. 3, including a main flow branch, a th transfer branch, a second transfer branch, a th energy absorption branch, a second energy absorption branch, and a discharge branch, where the main flow branch, the second transfer branch, the th energy absorption branch, the second energy absorption branch, and the discharge branch are all the same as those described in switch embodiment , and are not described herein again, except that the th transfer branch of this embodiment includes a capacitor 7, a third mechanical switch 11, and a fourth mechanical switch 12, which are arranged in series, and the following respectively describes each operation process of the dc switch device:

the switching-on operation process is as follows:

when the direct current switching device needs to be switched on, the th mechanical switch 1, the second mechanical switch 2, the third mechanical switch 11 and the fourth mechanical switch 12 and the contactor 8 are switched on simultaneously (structural dispersity cannot be too large), and after a main flow through branch is switched on, a th transfer branch capacitor 7 is bypassed by the th mechanical switch 1 and the second mechanical switch 2, so that switching on operation is completed.

The switching-off operation process comprises:

when the direct current switchgear is currently in a closing state (the third mechanical switch 11 and the fourth mechanical switch 12 are in a closing state, and the th mechanical switch 1 and the second mechanical switch 2 are closed), and opening is required, the controller sends a command to open the th mechanical switch 1 and the second mechanical switch 2, when a fracture between the th mechanical switch 1 and the second mechanical switch 2 has fixed insulation capacity, the controller triggers the semiconductor power module 3 to be switched on, an arc is generated between the fractures of the second mechanical switch 2, the current of the main flow branch is transferred to the second transfer branch by the arc voltage, the second mechanical switch 2 is switched off, then the semiconductor power module 3 is switched off, and the current of the main flow branch is transferred to the capacitor 7 of the th transfer branch.

After the current of the main flow branch is completely transferred to the th transfer branch, the arc of a fracture of the th mechanical switch 1 is extinguished, the current quickly charges the capacitor 7, the terminal voltage of the capacitor 7 is quickly increased to trigger the lightning arrester 5 of the second absorption branch to act, the lightning arrester 5 absorbs the residual energy, when the terminal voltage of the capacitor 7 in the th transfer branch is balanced with the system voltage of the direct current switching equipment, no current passes through the th transfer branch, the residual current is cut off by the third mechanical switch 11 and the fourth mechanical switch 12, and the cut-off of the direct current switching equipment is completed.

The reclosing operation process comprises the following steps:

after the direct current switch equipment is disconnected, the capacitor 7 discharges in a short time, the controller sends a closing instruction to close the th mechanical switch 1 and the second mechanical switch 2, the main flow branch is conducted, and if the direct current switch equipment is closed to a fault loop, the opening operation process is repeated.

Switch embodiment four:

in this embodiment, dc switch devices are proposed, as shown in fig. 4, including a main flow branch, a th transfer branch, a second transfer branch, a th energy absorption branch, a second energy absorption branch and a discharge branch, where the main flow branch, the second transfer branch, the th energy absorption branch, the second energy absorption branch and the discharge branch are the same as those described in the third embodiment of the switch, and are not repeated here, except that the th transfer branch of this embodiment includes a capacitor 7, a third mechanical switch 11, a fourth mechanical switch 12 and a semiconductor power unit 4, which are arranged in series.

For a specific operation process of the dc switch device in this embodiment, reference is made to the third switch embodiment, and it should be noted that, compared with the third switch embodiment, in the opening operation process of this embodiment, the controller is required to trigger the semiconductor power module 3 and the semiconductor power unit 4 to be turned on, so as to implement the current transfer at the second stage after implementing the current transfer at the th stage, and finally implement the breaking of the dc switch device by turning off the semiconductor power unit 4, and other operation timings are the same as those described in the third switch embodiment, and are not described again here.

Switch embodiment five:

in this embodiment, dc switchgear devices are proposed, as shown in fig. 5, including a main flow path branch, a th transfer branch, a second transfer branch, a energy absorption branch, a second energy absorption branch, and a discharge branch, where the main flow path branch, the th transfer branch, the second energy absorption branch, and the discharge branch are all the same as those in switching embodiment , and are not described herein again.

The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention, and various modifications and changes may be made by those skilled in the art.

For example, in the switching embodiments to the fifth embodiment, the number of the mechanical switches arranged in the main flow path may be set as required, or may be three or more, at least mechanical switches are ensured to be connected in parallel with the semiconductor power module, and the current transfer in the stage is implemented.

For another example, in switching embodiments to fifth embodiment, the capacitor disposed in the th branch may be implemented by using energy storage elements with other structures, such as a capacitor and an inductor.

For another example, in switching embodiments to fifth embodiment, the number of the arresters in the /second energy absorption branch may be , or more than two arresters may be connected in series, so the present invention does not limit how to implement the energy absorption branch, and the energy absorption in the /second transfer branch can be implemented.

For another example, in switch embodiments to fifth embodiment, the discharge branch may include only a resistor, multiple resistors may be disposed in parallel with a capacitor, or the discharge branch may not be disposed.

For another example, in switch embodiments to fifth embodiment, the form of the semiconductor power module of the second transfer branch may be selected according to requirements, and the semiconductor power module, as an electronic switch, may be implemented by only a single fully controlled power electronic device (e.g., IGBT, IEGT, GTO, etc.) if it needs to have a unidirectional on/off function, or may be implemented by two fully controlled power electronic devices connected in series in reverse direction if it needs to have a bidirectional on/off function.

For another example, in switch embodiments to fifth embodiments, the semiconductor power unit of the th branch can be selected according to requirements, and the semiconductor power unit is used as an electronic switch, and can be implemented by a single full-control or half-control power electronic device (such as a thyristor) if a unidirectional on-off function is required, or by two full-control power electronic devices connected in series in reverse direction or by two half-control power electronic devices connected in series in reverse direction if a bidirectional on function is required.

Therefore, any modification, equivalent replacement, improvement or the like made within the spirit and principle of the present invention should be included in the scope of the claims of the present invention.