CN210297244U

CN210297244U - Fast DC switch

Info

Publication number: CN210297244U
Application number: CN201920436711.1U
Authority: CN
Inventors: 任蔚
Original assignee: Shaanxi Qinyu Electrical Appliances Co ltd
Current assignee: Shaanxi Qinyu Electrical Appliances Co ltd
Priority date: 2019-04-02
Filing date: 2019-04-02
Publication date: 2020-04-10
Anticipated expiration: 2029-04-02

Abstract

The utility model provides a quick direct current switch, belongs to the power switch field, its characterized in that: the system comprises a main current branch, an oscillation transfer branch and an energy consumption branch; the main current branch, the oscillation transfer branch and the energy consumption branch are connected in parallel and then led out through the wire outlet ends A1 and A2. The capacitance value adjustment of the pre-charging capacitor of the oscillation transfer branch is realized by controlling the action of the oscillation transfer branch switching switch K1. Under the condition of small current switching-on and switching-off, the small current transfer is completed through the small capacitor, so that the switching-on and switching-off time is effectively shortened, the fracture can be prevented from being punctured, and the switching-on and switching-off reliability is improved; under the heavy current breaking working condition, the breaking is realized through the large capacitance transfer current, the breaking capacity is improved, the breaking speed is high, and the reliability is high. The utility model provides a switching scheme has that rated through-flow loss is low, and the fracture insulation is recovered well, the reliability of opening and shutting is high, and full current range advantage such as fast of opening and shutting can satisfy the requirement of present direct current system to switch security, reliability, economic nature.

Description

Fast DC switch

Technical Field

The utility model belongs to the power switch field especially relates to a quick direct current switch.

Background

The direct current power transmission and distribution system is an important development direction of a future power grid, has the advantages of flexible operation mode, high electric energy quality, stable system, convenience for efficient access of distributed energy and the like, and the direct current switch is a core device for ensuring safe and reliable operation of the direct current power distribution network. The mechanical direct current switch based on pre-charging capacitor transfer has the advantages of large on-off current, low cost, small loss and the like, and has wide application prospect in future direct current systems. However, the mechanical scheme is very difficult to break small currents due to the presence of the pre-charged transfer capacitor, with the current range being less than 1000 amps for small currents and greater than 1000 amps for large currents. On the one hand, the large reverse injection current generated by the pre-charging capacitor under the condition of low current switching-on and switching-off may cause breakdown of a mechanical fracture, so that switching-on and switching-off failure is caused, and on the other hand, in the low current switching-on and switching-off process, the current is transferred from the mechanical fracture to the capacitor, and then the capacitor needs a long charging time to charge to establish switching-on and switching-off voltage, so that the low current switching-on and switching-off time is long.

Disclosure of Invention

The utility model aims at solving the above problem, a mechanical type direct current switch of transfer capacitance appearance value adjustable is provided.

The utility model discloses a fast direct current switch, which comprises a main current branch, an oscillation transfer branch and an energy consumption branch; the main current branch, the oscillation transfer branch and the energy consumption branch are connected in parallel and then led out through the wire outlet ends A1 and A2.

Quick direct current switch, its characterized in that: the oscillation transfer branch circuit comprises a capacitance value adjustable circuit, an inductor and a power electronic device which are connected in series; the capacitance value adjustable circuit comprises a switch K1, a pre-charge capacitor C1 and C2; the C2 and the K1 are connected in series and then are connected with the C1 in parallel; the capacitance value of the pre-charging capacitor C1 is smaller than that of the capacitor C2.

Quick direct current switch, its characterized in that: the main current branch includes either a mechanical switch S1 or a mechanical switch S1 in series-parallel and combination with the power electronics.

Quick direct current switch, its characterized in that: the switch K1 includes but is not limited to the following devices singly or in any combination: trigger gap, thyristor, mechanical switch.

Quick direct current switch, its characterized in that: the inductor is a common hollow inductor or an inductor with an iron core or a coupling transformer.

Quick direct current switch, its characterized in that: the power electronic devices include, but are not limited to, the following, either alone or in any combination: thyristors, diodes.

The utility model discloses a control method of quick direct current switch: the capacitance value adjustment of the pre-charging capacitor of the oscillation transfer branch is realized by controlling the action of a change-over switch K1 on the oscillation transfer branch; the specific process is as follows: when the large current is switched on and switched off, the capacitor C2 and the capacitor C1 which are connected in parallel on the oscillation transfer branch participate in current transfer and switching off simultaneously; when a small current is cut off, the capacitor C2 of the oscillation transfer branch is cut off by opening the switch K1, and only the capacitor C1 is reserved for transferring and cutting off the current.

The utility model discloses a control method of quick direct current switch: the method comprises the following steps: when small current is cut off, the mechanical switch S1 and the change-over switch K1 are simultaneously opened, the small current is transferred to the oscillation transfer branch C1 from the main current branch, the current of the main current branch is reduced to zero, and the electric arc is extinguished; the small current continuously charges the transfer branch capacitor C1, and when the voltage of C1 exceeds the system voltage, the current rapidly drops to zero to complete the disconnection; when the large current is cut off, the mechanical switch S1 is opened, the change-over switch K1 is kept closed, the large current is transferred to the oscillation transfer branch from the main current branch, the current of the main current branch is reduced to zero, and the electric arc is extinguished; and large current continuously charges the capacitors C1 and C2, and when the capacitor voltage reaches the breakover voltage of the lightning arrester, the current is transferred to the energy consumption branch circuit to complete the disconnection of the large current.

Quick direct current switch shifts branch circuit change over switch K1 action through the control oscillation, realizes that the oscillation shifts the branch circuit and adjusts the appearance value of charging capacitor in advance. Under the condition of small current switching-on and switching-off, the small current transfer is completed through the small capacitor, so that the switching-on and switching-off time is effectively shortened, the fracture can be prevented from being punctured, and the switching-on and switching-off reliability is improved; under the heavy current breaking working condition, the breaking is realized through the large capacitance transfer current, the breaking capacity is improved, the breaking speed is high, and the reliability is high. The utility model provides a switching scheme has that rated through-flow loss is low, and the fracture insulation is recovered well, the reliability of opening and shutting is high, and full current range advantage such as fast of opening and shutting can satisfy the requirement of present direct current system to switch security, reliability, economic nature.

Drawings

Fig. 1 is a schematic structural diagram of a dc switch according to the present invention;

fig. 2 is a schematic circuit structure diagram of the dc switch of the present invention according to embodiment 1;

fig. 3 is a schematic circuit diagram of the circuit for switching off a small current according to embodiment 1 of the present invention;

fig. 3 (a) is a schematic circuit diagram of a normal through-current state when the dc switch according to embodiment 1 is turned on and off with a small current;

fig. 3 (b) is a schematic circuit diagram of the dc switch according to embodiment 1 when a rated open signal is received when the dc switch is opened to a low current;

fig. 3 (c) is a schematic diagram of a circuit for triggering a conducting state of a transfer branch when a dc switch turns off a small current according to embodiment 1;

FIG. 3 (d) is a schematic circuit diagram of the capacitor voltage reaching the system voltage when the DC switch described in embodiment 1 is turned on and off with a small current;

fig. 4 is a schematic circuit diagram of the circuit for breaking a large current according to embodiment 1 of the present invention;

fig. 4 (a) is a schematic circuit diagram of a normal current flowing state when the dc switch of embodiment 1 switches off a large current;

fig. 4 (b) is a schematic circuit diagram of the dc switch according to embodiment 1 when a rated open signal is received when a large current is opened;

fig. 4 (c) is a schematic circuit diagram of the on-state circuit of the trigger transfer branch when the dc switch turns off the large current according to embodiment 1;

fig. 4 (d) is a circuit diagram illustrating the circuit of the dc switch according to embodiment 1, which turns on/off the large current capacitor voltage to reach the lightning arrester conducting voltage;

fig. 4 (e) is a schematic circuit diagram of a state of current transfer to the energy-consuming branch when the dc switch turns on or off a large current according to embodiment 1;

fig. 5 is a schematic circuit diagram of the dc switch according to embodiment 2 of the present invention;

fig. 6 is a schematic circuit diagram of the circuit for switching off a small current according to embodiment 2 of the present invention;

fig. 6 (a) is a schematic circuit diagram of a normal through-current state when the dc switch according to embodiment 2 is turned on and off with a small current;

fig. 6 (b) is a schematic circuit diagram of the dc switch according to embodiment 2 when a rated open signal is received when the dc switch is turned on and off at a low current;

fig. 6 (c) is a schematic diagram of a circuit for triggering a conducting state of a transfer branch when a dc switch turns off a small current according to embodiment 2;

FIG. 6 (d) is a schematic circuit diagram of the capacitor voltage reaching the system voltage when the DC switch described in embodiment 2 is turned on and off with a small current;

fig. 7 is a schematic circuit diagram of the circuit for breaking a large current according to embodiment 2 of the present invention;

fig. 7 (a) is a circuit diagram illustrating a normal current flowing state when the dc switch according to embodiment 2 switches off a large current;

fig. 7 (b) is a schematic circuit diagram of the dc switch according to embodiment 2 when a rated open signal is received when the dc switch opens a large current;

fig. 7 (c) is a schematic circuit diagram of the on-state circuit of the trigger transfer branch when the dc switch turns off the large current according to embodiment 2;

fig. 7 (d) is a circuit diagram illustrating the circuit of embodiment 2, wherein the dc switch turns on/off the large current capacitor voltage to reach the lightning arrester conducting voltage;

fig. 7 (e) is a circuit diagram illustrating a state of current transition to the energy-consuming branch when the dc switch turns on/off a large current according to embodiment 2;

fig. 8 is a schematic circuit diagram of the dc switch according to the embodiment 3 of the present invention;

fig. 9 is a schematic circuit diagram of the circuit for switching off a small current according to embodiment 3 of the present invention;

fig. 9 (a) is a schematic circuit diagram of a normal through-current state when the dc switch according to embodiment 3 is turned on and off with a small current;

fig. 9 (b) is a schematic circuit diagram of the dc switch according to embodiment 3 when a rated open signal is received when the dc switch is turned on and off at a low current;

fig. 9 (c) is a schematic diagram of a circuit for triggering a conducting state of a transfer branch when a dc switch turns off a small current according to embodiment 3;

FIG. 9 (d) is a schematic circuit diagram illustrating a capacitor voltage reaching a system voltage when the DC switch described in embodiment 3 is turned on and off with a small current;

fig. 10 is a schematic circuit diagram of the circuit for breaking a large current according to embodiment 3 of the present invention;

fig. 10 (a) is a circuit diagram illustrating a normal current flowing state when the dc switch according to embodiment 3 switches off a large current;

fig. 10 (b) is a schematic circuit diagram of the dc switch according to embodiment 3 when receiving a rated open signal when opening a large current;

fig. 10 (c) is a circuit diagram illustrating the on-state of the trigger transfer branch when the dc switch turns off the large current according to embodiment 3;

fig. 10 (d) is a circuit diagram illustrating the circuit of embodiment 3, wherein the dc switch disconnects the large current capacitor voltage to reach the lightning arrester conducting voltage;

fig. 10 (e) is a circuit diagram illustrating a state of current transition to the energy-consuming branch when the dc switch turns off a large current according to embodiment 3;

fig. 11 is a schematic circuit diagram of the dc switch according to embodiment 4 of the present invention;

fig. 12 is a schematic circuit diagram of the circuit for switching off a small current according to embodiment 4 of the present invention;

fig. 12 (a) is a schematic circuit diagram of a normal current flowing state when the dc switch described in embodiment 4 switches off a small current;

fig. 12 (b) is a schematic circuit diagram of the dc switch according to embodiment 4 when a rated open signal is received when the dc switch is turned on and off at a low current;

fig. 12 (c) is a schematic diagram of the circuit for triggering the conducting state of the transfer branch when the dc switch turns off a small current according to embodiment 4;

FIG. 12 (d) is a circuit diagram illustrating a capacitor voltage reaching a system voltage when the DC switch described in embodiment 4 is turned on and off with a small current;

fig. 13 is a schematic circuit diagram of the circuit for breaking a large current according to embodiment 4 of the present invention;

fig. 13 (a) is a circuit diagram illustrating a normal current flowing state when the dc switch according to embodiment 4 switches off a large current;

fig. 13 (b) is a schematic circuit diagram of the dc switch according to embodiment 4 when a rated open signal is received when the dc switch opens a large current;

fig. 13 (c) is a schematic diagram of the circuit for triggering the conducting state of the transfer branch when the dc switch turns off the large current according to embodiment 4;

fig. 13 (d) is a circuit diagram illustrating the circuit of embodiment 4, in which the dc switch turns on/off the large current capacitor voltage to reach the lightning arrester conducting voltage;

fig. 13 (e) is a circuit diagram illustrating a state of current transition to the energy-consuming branch when the dc switch turns off a large current according to embodiment 4;

fig. 14 is a schematic circuit diagram of the dc switch according to the embodiment 5 of the present invention;

fig. 15 is a schematic circuit diagram of the circuit for switching off a small current according to embodiment 5 of the present invention;

fig. 15 (a) is a schematic circuit diagram of a normal current flowing state when the dc switch according to embodiment 5 is turned on and off with a small current;

fig. 15 (b) is a schematic circuit diagram of the dc switch according to embodiment 5 when a rated open signal is received when the dc switch is turned on and off at a low current;

fig. 15 (c) is a schematic diagram of the circuit for triggering the conducting state of the transfer branch when the dc switch turns off a small current according to embodiment 5;

FIG. 15 (d) is a schematic circuit diagram of the capacitor voltage reaching the system voltage when the DC switch described in embodiment 5 switches off a small current;

fig. 16 is a schematic circuit diagram of the circuit for breaking a large current according to embodiment 5 of the present invention;

fig. 16 (a) is a circuit diagram illustrating a normal current flowing state when the dc switch according to embodiment 5 switches off a large current;

fig. 16 (b) is a schematic circuit diagram of the dc switch according to embodiment 5 when receiving a rated open signal when opening a large current;

fig. 16 (c) is a circuit diagram illustrating the on-state of the trigger transfer branch when the dc switch turns off the large current according to embodiment 5;

fig. 16 (d) is a circuit diagram illustrating the circuit of the dc switch according to embodiment 5 for switching off the large current capacitor voltage to the arrester conducting voltage;

fig. 16 (e) is a circuit diagram illustrating a state of current transition to the energy consuming branch when the dc switch turns on/off a large current according to embodiment 5.

Detailed Description

The following describes the fast dc switch according to the present invention in detail with reference to the accompanying drawings and embodiments.

Example 1

As shown in fig. 1, the fast dc switch of this embodiment includes a main current circuit, an oscillation transfer branch, and an energy consumption branch.

The circuit of the fast dc switch according to this embodiment is shown in fig. 2;

the specific process of switching off the small current is shown in fig. 3:

(1) in the normal through-current state shown in fig. 3 (a), the system current flows in from the outlet terminal a1, passes through the mechanical switch S1, and then flows out from the outlet terminal a 2;

(2) when the control system receives a rated cut-off signal, a high-speed mechanical switch S1 is opened to start arcing, as shown in (b) of FIG. 3; the changeover switch K1 is opened;

(3) as shown in fig. 3 (c), after a period of time delay, triggering the transfer branch circuit to conduct, and transferring the current to the transfer branch circuit; when the current of the main loop is reduced to zero, the electric arc is extinguished, and follow current is carried out through the follow current branch;

(4) as shown in fig. 3 (d), the small current continuously charges the transfer capacitor, and when the capacitor voltage reaches the system voltage, the current drops to zero, completing the small current cut-off;

(5) when the current flows to the opposite direction, the oscillation transfer branch circuit firstly carries out primary oscillation discharge through the high-speed mechanical switch to realize the voltage reversal of the pre-charging capacitor, and then carries out the switching-off action. The current transfer process and the forward current switching-off process have the same current transfer mode and time sequence;

as shown in fig. 4, a specific process of turning on/off a large current by the fast dc switch in this embodiment includes:

(1) in the normal through-current state shown in fig. 4 (a), the system current flows in from the outlet terminal a1, passes through the mechanical switch S1, and then flows out from the outlet terminal a 2;

(2) when the control system receives a rated on-off signal, a high-speed mechanical switch S1 is opened to start arcing as shown in FIG. 4 (b); the diverter switch K1 remains closed;

(3) as shown in fig. 4 (c), after a period of time delay, triggering the transfer branch circuit to conduct, and transferring the current to the transfer branch circuit; when the current of the main loop is reduced to zero, the electric arc is extinguished, and follow current is carried out through a follow current thyristor;

(4) as shown in (d) - (e) of fig. 4, the large current continuously charges the transfer capacitor, when the capacitor voltage reaches the lightning arrester conducting voltage, the energy consumption branch is conducted, the current is transferred to the energy consumption branch, and the large current is cut off;

(5) when the current direction is opposite, the oscillation transfer branch circuit firstly carries out primary oscillation discharge through the high-speed mechanical switch to realize the voltage reversal of the pre-charging capacitor, and then carries out the switching-off action. The current transfer process is the same as the current transfer mode and time sequence in the forward current breaking process.

Example 2

The structure of the fast dc switch according to this embodiment is shown in fig. 5;

example 2 a specific process for switching off a small current is shown in fig. 6;

(1) in the normal through-current state shown in fig. 6 (a), the system current flows in from the outlet terminal a1, passes through the mechanical switch S1, and then flows out from the outlet terminal a 2;

(2) when the control system receives a rated on-off signal, a high-speed mechanical switch S1 is opened to start arcing, as shown in FIG. 6 (b); the changeover switch K1 is opened;

(3) as shown in fig. 6 (c), after a period of time delay, triggering the transfer branch and the freewheeling branch to conduct, and transferring the current to the transfer branch; when the current of the main loop is reduced to zero, the electric arc is extinguished, and follow current is carried out through the follow current branch;

(4) as shown in fig. 6 (d), the small current continuously charges the transfer capacitor, and when the capacitor voltage reaches the system voltage, the current drops to zero, completing the small current cut-off;

example 2 a specific process for switching off a large current is shown in fig. 7;

(1) in the normal through-current state shown in fig. 7 (a), the system current flows in from the outlet terminal a1, passes through the mechanical switch S1, and then flows out from the outlet terminal a 2;

(2) when the control system receives a rated on-off signal, a high-speed mechanical switch S1 is opened to start arcing, as shown in FIG. 7 (b); the diverter switch K1 remains closed;

(3) as shown in fig. 7 (c), after a period of time delay, triggering the transfer branch and the freewheeling branch to conduct, and transferring the current to the transfer branch; when the current of the main loop is reduced to zero, the electric arc is extinguished, and follow current is carried out through a follow current thyristor;

(4) as shown in (d) - (e) of fig. 7, the large current is continuously charged to the transfer capacitor, when the capacitor voltage reaches the lightning arrester conducting voltage, the energy consumption branch is conducted, the current is transferred to the energy consumption branch, and the large current is cut off.

Example 3

The structure of the fast dc switch according to this embodiment is shown in fig. 8;

example 3 a specific process for switching off a small current is shown in fig. 9;

(1) in the normal through-current state shown in fig. 9 (a), the system current flows in from the outlet terminal a1, passes through the mechanical switch S1, and then flows out from the outlet terminal a 2;

(2) when the control system receives a rated on-off signal, as shown in fig. 9 (b), the high-speed mechanical switch S1 is opened to start arcing; the changeover switch K1 is opened;

(3) as shown in fig. 9 (c), after a period of time delay, triggering the transfer branch circuit to conduct, and transferring the current to the transfer branch circuit; when the current of the main loop is reduced to zero, the electric arc is extinguished;

(4) as shown in fig. 9 (d), the small current continuously charges the transfer capacitor, and when the capacitor voltage reaches the system voltage, the current drops to zero, completing the small current cut-off;

example 3 a specific process for switching off a large current is shown in fig. 10;

(1) in the normal through-current state shown in fig. 10 (a), the system current flows in from the outlet terminal a1, passes through the mechanical switch S1, and then flows out from the outlet terminal a 2;

(2) as shown in fig. 10 (b), when the control system receives the rated on/off signal, the high-speed mechanical switch S1 is opened to start arcing; the diverter switch K1 remains closed;

(3) as shown in fig. 10 (c), after a period of time delay, triggering the transfer branch circuit to conduct, and transferring the current to the transfer branch circuit; when the current of the main loop is reduced to zero, the electric arc is extinguished;

(4) as shown in (d) - (e) of fig. 10, the large current is continuously charged to the transfer capacitor, when the capacitor voltage reaches the lightning arrester conducting voltage, the energy consumption branch is conducted, the current is transferred to the energy consumption branch, and the large current is turned on and off.

Example 4

The structure of the fast dc switch according to this embodiment is shown in fig. 11;

example 4 a specific procedure for switching off a small current is shown in fig. 12:

(1) in the normal through-current state shown in fig. 12 (a), the system current flows in from the outlet terminal a1, passes through the mechanical switch S1, and then flows out from the outlet terminal a 2;

(2) as shown in fig. 12 (b), when the control system receives the rated on/off signal, the high-speed mechanical switch S1 is opened to start arcing; the changeover switch K1 is opened;

(3) as shown in fig. 12 (c), after a period of time delay, triggering the transfer branch circuit to conduct, and transferring the current to the transfer branch circuit; when the current of the main loop is reduced to zero, the electric arc is extinguished;

(4) as shown in fig. 12 (d), the small current continuously charges the transfer capacitor, and when the capacitor voltage reaches the system voltage, the current drops to zero, completing the small current cut-off;

example 4 a specific procedure for switching off a large current is shown in fig. 13;

(1) in the normal through-current state shown in fig. 13 (a), the system current flows in from the outlet terminal a1, passes through the mechanical switch S1, and then flows out from the outlet terminal a 2;

(2) as shown in fig. 13 (b), when the control system receives the rated on/off signal, the high-speed mechanical switch S1 is opened to start arcing; the diverter switch K1 remains closed;

(3) as shown in fig. 13 (c), after a period of time delay, triggering the transfer branch circuit to conduct, and transferring the current to the transfer branch circuit; when the current of the main loop is reduced to zero, the electric arc is extinguished;

(4) as shown in (d) - (e) of fig. 13, the large current continuously charges the transfer capacitor, when the capacitor voltage reaches the lightning arrester conducting voltage, the energy consumption branch is conducted, the current is transferred to the energy consumption branch, and the large current is cut off;

example 5

The structure of the fast dc switch according to this embodiment is shown in fig. 14;

example 5 a specific procedure for switching off a small current is shown in fig. 15;

(1) in the normal through-current state shown in fig. 15 (a), the system current flows in from the outlet terminal a1, passes through the mechanical switch S1, and then flows out from the outlet terminal a 2;

(2) as shown in fig. 15 (b), when the control system receives the rated on/off signal, the high-speed mechanical switch S1 is opened to start arcing; the changeover switch K1 is opened;

(3) as shown in fig. 15 (c), after a period of time delay, triggering the transfer branch circuit to conduct, and transferring the current to the transfer branch circuit under the action of the magnetic coupling transformer; when the current of the main loop is reduced to zero, the electric arc is extinguished;

(4) as shown in fig. 15 (d), the small current continuously charges the transfer capacitor, and when the capacitor voltage reaches the system voltage, the current drops to zero, completing the small current cut-off;

example 5 a specific process for switching off a large current is shown in fig. 16;

(1) in the normal through-current state shown in fig. 16 (a), the system current flows from the outlet terminal a1, passes through the mechanical switch S1, and then flows out from the outlet terminal a 2;

(2) when the control system receives a rated on/off signal, as shown in fig. 16 (b), the high-speed mechanical switch S1 is opened to start arcing; the diverter switch K1 remains closed;

(3) as shown in fig. 16 (c), after a period of time delay, triggering the transfer branch circuit to conduct, and transferring the current to the transfer branch circuit under the action of the magnetic coupling transformer; when the current of the main loop is reduced to zero, the electric arc is extinguished;

(4) as shown in (d) - (e) of fig. 16, the large current is continuously charged to the transfer capacitor, when the capacitor voltage reaches the lightning arrester conducting voltage, the energy consumption branch is conducted, the current is transferred to the energy consumption branch, and the large current is turned on and off.

Claims

1. A fast direct current switch comprises a main current branch, an oscillation transfer branch and an energy consumption branch; the main current branch, the oscillation transfer branch and the energy consumption branch are connected in parallel and then led out through outlet ends A1 and A2; the method is characterized in that: the oscillation transfer branch circuit comprises a capacitance value adjustable circuit, an inductor and a power electronic device which are connected in series; the capacitance value adjustable circuit comprises a switch K1, a pre-charge capacitor C1 and C2; the C2 and the K1 are connected in series and then are connected with the C1 in parallel; the capacitance value of the pre-charging capacitor C1 is smaller than that of the capacitor C2.

2. The fast dc switch according to claim 1, wherein: the main current branch includes either a mechanical switch S1 or a mechanical switch S1 in series-parallel and combination with the power electronics.

3. The fast dc switch according to claim 1 or 2, wherein: the switch K1 includes but is not limited to the following devices singly or in any combination: trigger gap, thyristor, mechanical switch.

4. The fast dc switch according to claim 3, wherein: the inductor is a common hollow inductor or an inductor with an iron core or a coupling transformer.

5. The fast dc switch according to claim 4, wherein: the power electronic devices include, but are not limited to, the following, either alone or in any combination: thyristors, diodes.