DE102022210690A1 - Method for switching off currents with adaptive switching times and medium and/or high voltage switchgear for switching off currents with adaptive switching times - Google Patents

Abstract

The invention relates, inter alia, to a method for switching off currents with a medium and/or high-voltage switchgear (1) with adaptive switching times, wherein the medium and/or high-voltage switchgear (1) has:- at least one medium and/or high-voltage switch (10) with at least one vacuum interrupter (15) per phase,- at least one protective device (50) for triggering a switching operation of the medium and/or high-voltage switch(es), andat least one current sensor (100) per phase for determining the current flow in the respective phase, wherein in response to a switch-off signal (1000) or a switch-off detection of the protective device (50), the current flow through the respectively assigned vacuum interrupter(s) (15) is determined by means of the at least one current sensor (100) per phase.

Description

The present disclosure relates to a method for switching off currents with a medium and/or high voltage switchgear with adaptive switching times, to additional electronics for medium and/or high voltage switchgear for switching off currents with adaptive switching times, to a protection device for medium and/or high voltage switchgear for switching off currents with adaptive switching times and to a medium and/or high voltage switchgear for switching off currents with adaptive switching times.

Medium and/or high voltage switches, particularly circuit breakers or vacuum interrupters, or vacuum switches for short, for alternating current have the task of interrupting the flow of electrical energy quickly, reliably and repeatedly. Vacuum interrupters are often used as a switching element; the current is interrupted by opening the switching contacts of the vacuum interrupter; the arc formed between the switching contacts then extinguishes when the current next passes zero. The switching contacts of the vacuum interrupter are often one fixed contact and one moving contact per vacuum interrupter.

A distinction is made between switching off a "normal" load current for operation within the energy distribution network and switching off a fault current to protect the equipment in the energy distribution network. The causes of such faults are short circuits or earth faults in the equipment. Short-circuit currents are significantly higher than the nominal currents. Circuit breakers are dimensioned according to the nominal currents and short-circuit currents. According to their product standard, circuit breakers must be able to carry the rated short-circuit current for several seconds without being damaged.

When short-circuit currents flow, a decaying DC component will flow in the current, depending on the impedance of the power distribution network to the alternating current. This DC component often exceeds the amplitude of the alternating current, so that the total current does not cross zero and the arc between the open contacts of a vacuum interrupter is not extinguished. The energy released by the arc can then damage the switching contacts of the vacuum interrupter.

In order to ensure that the current is switched off safely in the event of a fault with a direct current component, the operating time of the circuit breaker is selected to be so long that the direct current component has decayed so far at the time the switching contacts open that a zero crossing occurs in the current flow and the arc can be extinguished. The decay of the direct current component is also described as decay behavior or decay progression. In the sense of this disclosure, the operating time of a medium and/or high-voltage switch, in particular a circuit breaker, is to be understood as the period between the triggering of the medium and/or high-voltage switch with a trigger signal and the complete separation of the switching contacts of the medium and/or high-voltage switch, during which period and distance of the switching contacts the arc can be extinguished and a sufficient separation distance between the switching contacts of the medium and/or high-voltage switch is achieved. Typical operating times for the event of a short circuit in circuit breakers with vacuum interrupters are 35 ms to 50 ms.

For the purpose of optimal operational management, it is sensible to select the operating time as short as possible for the shutdown of "normal" load currents. Desirable operating times are in the range of less than 20 ms. Due to their mechanical design, vacuum circuit breakers with spring-loaded actuators cannot be influenced in their movement sequence and thus their mechanical operating time after unlatching by, for example, an electromagnet as a trigger.

In order to achieve different operating times, especially with spring-loaded drives, different fast triggers can be used. Due to the mechanical design, a maximum of 3 different triggers can usually be installed so that a maximum of 3 different operating times can be achieved. In practice, only 2 triggers with different speeds are used because the third trigger is installed for redundancy reasons in case one of the other triggers does not work as intended.

The control of the different speed releases is usually carried out via an appropriately designed protective device, which decides on the basis of the measured currents whether a rapid shutdown should take place, e.g. for a "normal" load current, or a delayed shutdown for a short-circuit current with a direct current component.

Due to the increasingly complex network topologies of energy distribution networks with variable energy flow direction due to decentralized energy generation, different settings, parameter sets, must be active in the protection device depending on the load flow direction in order to ensure safe operation even in the event of a short circuit. Selecting the appropriate parameter set occurs dynamically in the protective device or on request by a higher-level device.

The specification and activation of the appropriate parameter set is complex and cannot always be solved satisfactorily in practice due to the limited number of possible parameter sets in the protection device and the methods for selecting the parameter set suitable for the operating case.

For safety reasons, the delay of the switching command is always selected in the parameter set of the protection device to be large enough to prevent damage to the circuit breaker even under the most unfavorable network conditions. The set delay of the switching command is therefore usually larger than necessary for safe operation and may hinder optimal operation in the energy distribution network.

The object of the invention is to provide an improved or alternative method or device.

The problem is solved by the independent claims and the claims dependent on the independent claims.

• - mindestens einen Mittel- und/oder Hochspannungsschalter mit mindestens einer Vakuumschaltröhre je Phase,
• - mindestens ein Schutzgerät zum Auslösen eines Schaltvorganges des oder der Mittel- und/oder Hochspannungsschalter, und
• - mindestens einen Stromsensor je Phase zur Bestimmung des Stromflusses in der jeweiligen Phase,

wobei

• ▪ auf ein Abschaltsignal oder eine Abschalterkennung des Schutzgerätes hin mittels des mindestens einen Stromsensors je Phase der Stromfluss durch die jeweils zugeordnete oder zugeordneten Vakuumschaltröhren bestimmt wird,
• ▪ aus den jeweiligen Stromflüssen je Phase ein Gleichstromanteil an dem jeweiligen Stromfluss je Phase und ein zeitlicher Verlauf der Gleichstromanteile bestimmt wird,
• ▪ aus den je Phase bestimmten zeitlichen Verläufen der Gleichstromanteile ein Abklingverlauf der Gleichstromanteile und ein Abschaltzeitpunkt bestimmt wird,
• ▪ aus dem Abschaltzeitpunkt eine Schaltverzögerung bestimmt wird, die ein Abschalten zum vorher bestimmten Abschaltzeitpunkt bewirkt, und
• ▪ Auslösen des Mittel- und/oder Hochspannungsschalters, mit der so bestimmten Schaltverzögerung, so dass der oder die Mittel- und/oder Hochspannungsschalter den Strom zum Abschaltzeitpunkt abschalten.

A first aspect relates to a method for switching off currents with a medium and/or high voltage switchgear with adaptive switching times, wherein the medium and/or high voltage switchgear comprises:

• - at least one medium and/or high voltage switch with at least one vacuum interrupter per phase,
• - at least one protective device for triggering a switching operation of the medium and/or high voltage switch(es), and
• - at least one current sensor per phase to determine the current flow in the respective phase,

where

• ▪ in response to a shutdown signal or shutdown detection of the protective device, the current flow through the respective assigned vacuum interrupter or tubes is determined by means of at least one current sensor per phase,
• ▪ a direct current component of the respective current flow per phase and a temporal progression of the direct current components are determined from the respective current flows per phase,
• ▪ a decay curve of the direct current components and a switch-off time are determined from the temporal profiles of the direct current components determined for each phase,
• ▪ a switching delay is determined from the switch-off time, which causes a switch-off at the previously determined switch-off time, and
• ▪ Tripping the medium and/or high voltage switch with the switching delay determined so that the medium and/or high voltage switch(es) switch off the current at the switch-off time.

The operating time of the circuit breaker is continuously extended or adjusted by electronics, for example in the protective device or by means of additional electronics, according to the actual current flowing and the decay times, thus ensuring that the current is always switched off as quickly as possible but safely, regardless of the level of the direct current component in the current.

This ensures that an incorrectly or not optimally selected parameter set in the protection device or a special network configuration that was not planned when the parameter set in the protection device was created does not lead to an overload of the vacuum interrupters in the switch, in particular the circuit breaker, due to an arc that does not extinguish.

Preferably, the currents or current flows are fault currents that are to be switched off. The currents or fault currents are switched off by opening or separating the switching contacts of one or more vacuum interrupters.

It is also preferred that it is a single-phase, three-phase or generally multi-phase medium and/or high voltage switchgear.

In a particularly preferred variant, the medium and/or high-voltage switchgear has more than one vacuum interrupter per phase, in particular two or three vacuum interrupters per phase, which enables high currents to be switched off.

The shutdown signal, in particular a fault shutdown signal, within the meaning of this application is one of several possibilities for initiating a shutdown of the medium and/or high-voltage switchgear. It is particularly preferred that, in addition to the shutdown signal, manual triggering via shutdown detection also leads to an adaptive shutdown, i.e. to a shutdown at a specific shutdown time.

It is also preferred that the switch-off time is the earliest possible switch-off time. The earliest possible switch-off time is the time at which the direct current component falls below a predetermined threshold value or falls below it for the first time, thus enabling safe switch-off, in particular by reaching a zero crossing of the current.

It is also preferred that the medium and/or high voltage switch(es) are operated by means of one or more spring-loaded actuators, and that the switching contacts of the vacuum interrupter(s) are separated by the spring-loaded actuator(s), thus interrupting the flow of current at the time of switching off. Alternatively, instead of one or more spring-loaded actuators, one or more magnetic actuators can also be provided to drive the switching contact(s).

It is further preferred that the current flows measured with the current sensor(s) are transmitted to the protective device and the determination of the switch-off time is carried out in the protective device and the protective device causes the medium and/or high voltage switch to be triggered with the determined switching delay in such a way that the medium and/or high voltage switch(es) switch off the current at the switch-off time.

It is also preferred that the current flows measured with the current sensor(s) are transmitted to the protective device and the determination of the switch-off time is carried out in the protective device and the protective device causes the medium and/or high-voltage switch to be triggered with the determined switching delay in such a way that the medium and/or high-voltage switch(es) switch off the current at the switch-off time.

It is also preferred that the current flows measured with the current sensor(s) are transmitted to additional electronics and the determination of the switch-off time is carried out in the additional electronics in response to a switch-off signal from the protective device and the additional electronics forward the switch-off signal from the protective device to the medium and/or high-voltage switch(es) with a delay of the specified switching delay and thus cause the medium and/or high-voltage switch(es) to switch off the current at the switch-off time. Such additional electronics can also be retrofitted in particular, i.e. an existing medium and/or high-voltage switchgear can be retrofitted with such additional electronics and thus form a medium and/or high-voltage switchgear with adaptive switching times, or enable a method for switching off currents with a medium and/or high-voltage switchgear with adaptive switching times.

It is also preferred that a plausibility and/or threshold check of the respective current flows per phase determined with the current sensors and/or the respective direct current components determined and/or the respective time profiles of the direct current components and/or the respective decay profiles is carried out and, in the event of a negative plausibility and/or threshold check, the medium and/or high voltage switch(es) is switched off with a predetermined switching delay. This ensures reliable switching off even if the switch-off time is incorrectly determined.

• - an einem ersten Signaleingang, zum Beispiel über zweite Signal- oder Datenleitungen, ein Abschaltsignal oder eine Abschalterkennung zu empfangen,
• - an einem oder mehr zweiten Signaleingängen, zum Beispiel über erste Signal- oder Datenleitungen, zweite Signale von Stromsensoren zu empfangen,
• - und aus dem oder den zweiten Signalen einen Gleichstromanteil an dem jeweiligen Stromfluss je Phase und einen zeitlichen Verlauf der Gleichstromanteile zu bestimmen,
• - aus den je Phase bestimmten zeitlichen Verläufen der Gleichstromanteile ein Abklingverlauf der Gleichstromanteile und einen Abschaltzeitpunkt, insbesondere einen frühestmöglichen Abschaltzeitpunkt zu bestimmen,
• - aus dem Abschaltzeitpunkt eine Schaltverzögerung zu bestimmen, und
• - nach Ablauf der bestimmten Schaltverzögerung ein Auslösesignal auf einen Auslöseausgang, beispielsweise über erste Signal- oder Datenleitungen, zu geben, das geeignet ist ein Auslösen und Abschalten eines oder mehrerer Mittel- und/oder Hochspannungsschalter zu bewirken.

Another aspect relates to additional electronics for medium and/or high voltage switchgear for switching off currents with adaptive switching times, wherein the additional electronics are designed:

• - to receive a shutdown signal or shutdown detection at a first signal input, for example via second signal or data lines,
• - to receive second signals from current sensors at one or more second signal inputs, for example via first signal or data lines,
• - and to determine from the second signal(s) a direct current component of the respective current flow per phase and a temporal progression of the direct current components,
• - to determine a decay curve of the direct current components and a switch-off time, in particular an earliest possible switch-off time, from the time curves of the direct current components determined for each phase,
• - to determine a switching delay from the switch-off time, and
• - after the specified switching delay has elapsed, to send a trigger signal to a trigger output, for example via first signal or data lines, which is suitable for triggering and switching off one or more medium and/or high voltage switches.

In particular, such additional electronics are designed to carry out the methods described above with or in a medium and/or high-voltage switchgear.

Preferably, such additional electronics can also be retrofitted, so an existing system can Medium and/or high-voltage switchgear can be retrofitted with such additional electronics to form a medium and/or high-voltage switchgear with adaptive switching times.

• ▪ an einem oder mehr zweiten Signaleingängen zweite Signale von Stromsensoren zu empfangen,
• ▪ und aus dem oder den zweiten Signalen einen Gleichstro- manteil an dem jeweiligen Stromfluss je Phase und einen zeitlichen Verlauf der Gleichstromanteile zu bestimmen,
• ▪ aus den je Phase bestimmten zeitlichen Verläufen der Gleichstromanteile ein Abklingverlauf der Gleichstromanteile und einen Abschaltzeitpunkt, insbesondere einen frühestmöglichen Abschaltzeitpunkt, zu bestimmen,
• ▪ aus dem Abschaltzeitpunkt eine Schaltverzögerung zu bestimmen, und
• ▪ nach Ablauf der bestimmten Schaltverzögerung ein Auslösesignal auf einen Auslöseausgang zu geben, das geeignet ist ein Auslösen eines oder mehrerer Mittel- und/oder Hochspannungsschalter zu bewirken.

Another aspect relates to a protection device for medium and/or high voltage switchgear for switching off currents with adaptive switching times, whereby
the protective device is designed
to receive first signals at one or more first signal inputs and second signals at one or more second signal inputs, it being determined from the first signal(s) and/or second signals whether a fault shutdown is required, and in the event of a fault shutdown being required:

• ▪ to receive second signals from current sensors at one or more second signal inputs,
• ▪ and to determine from the second signal(s) a direct current component of the respective current flow per phase and a temporal progression of the direct current components,
• ▪ to determine a decay curve of the direct current components and a switch-off time, in particular an earliest possible switch-off time, from the time curves of the direct current components determined for each phase,
• ▪ to determine a switching delay from the switch-off time, and
• ▪ to send a trigger signal to a trigger output after the specified switching delay has elapsed, which is suitable for triggering one or more medium and/or high voltage switches.

In particular, such a protective device is designed to carry out the methods described above with or in a medium and/or high-voltage switchgear.

In a special embodiment, the protective device and/or the additional electronics are constructed as a distributed system, in particular a cloud system. It is also possible that the protective device is partially or completely constructed and/or the additional electronics are partially or completely constructed as a distributed system, in particular a cloud system.

In the sense of the invention, a cloud system is possibly spatially distributed data processor and data storage devices that are connected via a data communication network such as the Internet. Software that, for example, takes on tasks of the protective device and/or the additional electronics can be executed in modules as a so-called cloud application wherever sufficient data processor and/or data storage resources are available. This ensures high scalability and availability. In addition, many companies essentially no longer need to operate, maintain and protect their own server computers or hardware on a large scale against hacker attacks.

• - mindestens einen Mittel- und/oder Hochspannungsschalter mit mindestens einer Vakuumschaltröhre je Phase,
• - mindestens ein Schutzgerät zum Auslösen eines Schaltvorganges des oder der Mittel- und/oder Hochspannungsschalter, und
• - mindestens einen Stromsensor je Phase, wobei das Schutzgerät ein Schutzgerät nach den vorstehenden Ausführungen ist und/oder die Mittel- und/oder Hochspannungsschaltanlage weiter eine Zusatzelektronik gemäß den vorstehenden Ausführungen aufweist.

Another aspect relates to a medium and/or high voltage switchgear for switching off currents with adaptive switching times,
wherein the medium and/or high voltage switchgear comprises:

• - at least one medium and/or high voltage switch with at least one vacuum interrupter per phase,
• - at least one protective device for triggering a switching operation of the medium and/or high voltage switch(es), and
• - at least one current sensor per phase, wherein the protective device is a protective device according to the above statements and/or the medium and/or high voltage switchgear further comprises additional electronics according to the above statements.

With regard to the device according to the invention, all statements made above and below regarding the method according to the invention apply and vice versa in a corresponding manner; in particular, the device according to the invention is designed to carry out the method according to the invention in any embodiment or a combination of embodiments. With regard to the advantages of the device according to the invention, reference is also made to the advantages described for the method according to the invention.

• 1: Beispielhafte schematische Darstellung einer Mittel- und/oder Hochspannungsschaltanlage;
• 2: Beispielhafte schematische Darstellung einer Seitenansicht eines dreiphasigen Mittel- und/oder Hochspannungsschalter mit Federspeicherantrieb;
• 3: Beispielhafte schematische Darstellung einer Vakuumschaltröhre im Aufriss mit Schaltkontakten;
• 4: Beispielhafte schematische Darstellung einer Mittel- und/oder Hochspannungsschaltanlage mit adaptiven Schaltzeiten;
• 5: Beispielhaftes Ablaufdiagramm eines Verfahrens zum Abschalten von Strömen mit einer Mittel- und/oder Hochspannungsschaltanlage mit adaptiven Schaltzeiten.

The invention is explained in more detail below using an exemplary embodiment. The specific design of the exemplary embodiment is in no way to be understood as limiting the general design of the method and device according to the invention; rather, individual design features of the exemplary embodiment can be freely combined with one another and with the features described above in any way.

• 1 : Example schematic representation of a medium and/or high voltage switchgear;
• 2 : Example schematic representation of a side view of a three-phase medium and/or high voltage switch with spring-loaded mechanism;
• 3 : Example schematic representation of a vacuum interrupter in elevation with switching contacts;
• 4 : Example schematic representation of a medium and/or high voltage switchgear with adaptive switching times;
• 5 : Example flow chart of a method for switching off currents with a medium and/or high voltage switchgear with adaptive switching times.

The 1 shows an exemplary schematic representation of a medium and/or high voltage switchgear 1 with optional display elements 4, a protective device 50 and optional additional electronics 60. In the example shown, the protective device 50 and the additional electronics 60 are accessible from the outside from the front. In an alternative embodiment not shown, the protective device 50 and/or the additional electronics 60 can also be arranged behind a cover or door or inside the medium and/or high voltage switchgear 1.

The 2 shows an exemplary schematic representation of a side view of a three-phase medium and/or high voltage switch 10 with vacuum interrupter 15 and spring-loaded drive 40. Furthermore, the drive 30 with the power transmission arrangement 35 between the drive 30 and the vacuum interrupter 15 is shown.

The 3 shows an exemplary schematic representation of a vacuum interrupter 15 in elevation 20 with switching contacts 16. The elevation 20 allows a view of the switching contacts 16 which are otherwise not visible inside the vacuum interrupter.

The switching contacts 16 are formed here, for example, by a fixed contact 17 and a moving contact 18. The moving contact 18 is arranged movably in the vacuum interrupter 15 by means of a bellows 19.

The 4 shows an exemplary schematic representation of a medium and/or high voltage switchgear 1 with adaptive switching times. The medium and/or high voltage switchgear 1 is divided into three areas, the low voltage compartment, in which the protective device 50 and an optional additional electronics 60 are arranged, wherein the additional electronics 60 is connected via first signal or data lines 61 both to a current sensor 100 in a power supply and current output compartment 14 and to a medium and/or high voltage switch 10, which is arranged in a switch compartment 12. Furthermore, the additional electronics 60 is connected to the protective device 50 via second signal or data lines. If the protective device 50 takes over the function of the additional electronics 60, not shown here, then the protective device is connected to the first signal or data lines.

The medium and/or high voltage switch 10 has, for example, a spring-loaded drive 40, which acts on a drive 30. The drive 30 is connected via a power transmission arrangement 35 to the moving contact 18, which is in the 3 is shown. The spring-loaded drive 40 is triggered, for example, by a magnetic release (not shown). Alternatively and not shown, a magnetic actuator can also be provided instead of a spring-loaded drive 40 with a magnetic release for driving the moving contact(s) of the vacuum interrupter 15.

The power supply and power output space 14 can alternatively and not shown also be divided into two separate areas, a power supply space and a power output space. The current sensor 100 can be arranged either on the power supply 80 or the power output 90 or also on the power supply 80 and the power output 90. In an embodiment not shown, the current sensor 100 or the current sensors 100 can also be arranged on the vacuum interrupter, in particular arranged within a pole shell of the vacuum interrupter.

In a preferred embodiment, each phase is provided with one current sensor 100 or two current sensors 100.

The 5 shows an exemplary flow chart of a method for switching off currents with a medium and/or high voltage switchgear 1 with adaptive switching times.

In response to a shutdown signal 1000 or (not shown) to a shutdown detection of a protective device 50, in a first method step 1001 a current flow in a phase through one or more assigned vacuum interrupters 15 is determined by means of at least one current sensor 100 per phase. Furthermore, a direct current component of the respective current flow per phase and a temporal progression of the direct current components are determined from the respective current flows per phase.

In a second method step 1100, a decay curve of the direct current components and a switch-off time 1200 are determined from the temporal profiles of the direct current components determined for each phase.

In a third method step 1300, a switching delay 1400 is determined from the switch-off time 1200, wherein the switching delay 1400 causes a switch-off at the previously determined switch-off time 1200.

If the optional fourth method step does not take place - i.e. is not implemented or activated - the next step, with the determined switching delay 1400, is the triggering step 1600, with the triggering of the medium and/or high voltage switch 10, with the switching delay 1400 thus determined, so that the medium and/or high voltage switch(es) 10 switch(es) off the current at the switch-off time 1200.

In an optional fourth method step 1500, a plausibility and/or threshold value check 1500 of the respective current flows per phase determined with the current sensors 100 and/or the respective direct current components determined and/or the respective time profiles of the direct current components and/or the respective decay profiles is carried out.

In the case of a positive result, i.e. in the case of plausible values for the determined current flows per phase and/or the determined respective direct current components and/or the respective time profiles of the direct current components and/or the respective decay profiles, the triggering step 1600 is carried out with the determined switching delay 1400, with the triggering of the medium and/or high voltage switch 10, with the switching delay 1400 thus determined, so that the medium and/or high voltage switch(es) 10 switch(es) off the current at the switch-off time 1200.

In the case of a negative plausibility and/or threshold value check 1500, the alternative triggering step 1650 with a predetermined switching delay 1450 is used to switch off the medium and/or high voltage switch(es) 10 with the predetermined switching delay 1450.

List of reference symbols

1

Medium and/or high voltage switchgear, also known as switchgear;

4

display element;

10

Medium and/or high voltage switches;

11

Low voltage room;

12

switch room;

14

Power supply and power outage compartment;

15

vacuum interrupter;

16

Switching contacts of the vacuum interrupter 15;

30

Drive with spring-loaded drive 40;

35

Power transmission arrangement between drive 30 and vacuum interrupter 15;

40

Spring-loaded drive;

50

protective device;

60

additional electronics;

61

first signal or data lines;

62

second signal or data lines;

80

power supply;

90

current output;

100

current sensor;

1000

shutdown signal;

1001

first procedural step;

1100

second procedural step;

1200

switch-off time;

1300

third procedural step;

1400

switching delay;

1450

predefined switching delay;

1500

Plausibility and/or threshold check as an optional fourth procedural step;

1600

trigger step;

1650

alternative trigger step with the specified switching delay 1450.

Claims (10)

Method for switching off currents with a medium and/or high voltage switchgear (1) with adaptive switching times, wherein the medium and/or high voltage switchgear (1) has: - at least one medium and/or high voltage switch (10) with at least one vacuum interrupter (15) per phase, - at least one protective device (50) for triggering a switching operation of the medium and/or high voltage switch(es), and - at least one current sensor (100) per phase for determining the current flow in the respective phase, characterized in that ▪ in response to a switch-off signal (1000) or a switch-off detection of the protective device (50), the current flow through the respectively assigned vacuum interrupter(s) (15) is determined by means of the at least one current sensor (100) per phase, ▪ from the respective current flows per phase, a A direct current component of the respective current flow per phase and a temporal progression of the direct current components are determined, ▪ a decay progression of the direct current components and a switch-off time (1200) are determined from the temporal progressions of the direct current components determined for each phase, ▪ a switching delay (1400) is determined from the switch-off time (1200), which causes a switch-off at the specific switch-off time (1200), and ▪ triggering the medium and/or high voltage switch (10) with the switching delay (1400) determined in this way, so that the medium and/or high voltage switch(es) (10) switch(es) off the current at the switch-off time (1200). Procedure according to Claim 1 , characterized in that the switch-off time (1200) is the earliest possible switch-off time (1250). Procedure according to Claim 1 or 2 , characterized in that the medium and/or high voltage switch(es) (10) are operated by means of one or more spring-loaded drives (40) or by means of one or more magnetic actuators, and that the switching contacts (16) of the vacuum interrupter(s) (15) are separated by the spring-loaded drives (40) or the magnetic actuators, thus interrupting the flow of current at the switch-off time (1200). Method according to one of the preceding claims, characterized in that the current flows measured with the current sensor(s) are transmitted to the protective device (50) and the determination of the switch-off time (1200) is carried out in the protective device (50) and the protective device (50) causes the medium and/or high voltage switch (10) to be triggered with the determined switching delay (1400) such that the medium and/or high voltage switch(es) (10) switch(es) off the current at the switch-off time (1200). Method according to one of the preceding Claims 1 until 3 , characterized in that the current flows measured with the current sensor(s) are transmitted to additional electronics (60) and the determination of the switch-off time (1200) is carried out in the additional electronics (60) in response to a switch-off signal (1000) from the protective device (50), and the additional electronics (60) forwards the switch-off signal (1000) from the protective device (50) to the medium- and/or high-voltage switch(es) (10) with a delay of the determined switching delay (1400), thus causing the medium- and/or high-voltage switch(es) (10) to switch off the current at the switch-off time (1200). Procedure according to the Claim 5 , characterized in that the functionality of the additional electronics (60) is monitored by the protective device (50) and if the additional electronics (50) is not functioning properly, the medium and/or high voltage switch(es) (10) is switched off with a predetermined switching delay (1400). This ensures an emergency shutdown even if the additional electronics fails. Method according to one of the preceding claims, characterized in that a plausibility and/or threshold value check (1500) of the respective current flows per phase determined with the current sensors (100) and/or the respective direct current components determined and/or the respective time profiles of the direct current components and/or the respective decay profiles is carried out and in the event of a negative plausibility and/or threshold value check (1500) the medium and/or high voltage switch(es) (10) is switched off with a predetermined switching delay (1450). Additional electronics (60) for medium and/or high voltage switchgear (1) for switching off currents with adaptive switching times, characterized in that the additional electronics (60) are designed: - to receive a switch-off signal (1000) or a switch-off detection at a first signal input, - to receive second signals from current sensors (100) at one or more second signal inputs, - and to determine a direct current component of the respective current flow per phase and a temporal progression of the direct current components from the second signal(s), - to determine a decay progression of the direct current components and a switch-off time (1200) from the temporal progressions of the direct current components determined for each phase, - to determine a switching delay (1400) from the switch-off time (1200), and - after the determined switching delay (1400) has elapsed, to send a trigger signal to a trigger output which is suitable for triggering and switching off one or more medium and/or high voltage switches (10) to effect. Protection device (50) for medium and/or high voltage switchgear (1) for switching off currents with adaptive switching times, characterized in that the protection device (50) is designed to receive first signals at one or more first signal inputs and at one or more to receive second signals at second signal inputs, it being determined from the first signal(s) and/or second signals whether a fault shutdown is required, and in the event of a fault shutdown being required: ▪ to receive second signals from current sensors at one or more second signal inputs, ▪ and to determine a direct current component of the respective current flow for each phase and a temporal progression of the direct current components from the second signal(s), ▪ to determine a decay progression of the direct current components and a shutdown time (1000) from the temporal progressions of the direct current components determined for each phase, ▪ to determine a switching delay (1200) from the shutdown time (1000), and ▪ after the determined switching delay (1400) has elapsed, to send a trigger signal to a trigger output which is suitable for triggering one or more medium and/or high voltage switches (10). Medium and/or high voltage switchgear (1) for switching off currents with adaptive switching times, wherein the medium and/or high voltage switchgear (1) comprises: - at least one medium and/or high voltage switch (10) with at least one vacuum interrupter (15) per phase, - at least one protective device (50) for triggering a switching operation of the medium and/or high voltage switch(es) (10), and - at least one current sensor (100) per phase, characterized in that the protective device (50) is a protective device (50) according to Claim 9 and/or the medium and/or high voltage switchgear (1) further comprises additional electronics (60) according to Claim 8 having.

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