ELECTRONIC CIRCUIT BREAKER

Abstract

An electronic protection switch includes first and second network terminals and two semiconductor switches of same kind. Each semiconductor switch is formed by an IGBT semiconductor switch and includes a switching element and a diode which is arranged antiparallel to the switching element. A first of the two semiconductor switches is arranged without a semiconductor series connection between a positive potential terminal of the first network terminal and a positive potential terminal of the second network terminal. A second of the two semiconductor switches is arranged without a semiconductor series connection between a negative potential terminal of the first network terminal and a negative potential terminal of the second network terminal. The switching element of each semiconductor switch is arranged so as to be able to conduct and switch off a current from the first network terminal to the second network terminal.

Claims

1.-7. (canceled)

8. An electronic protection switch, comprising: a first network terminal including a positive potential terminal and a negative potential terminal; a second network terminal including a positive potential terminal and a negative potential terminal; and two semiconductor switches of same kind, each of the two semiconductor switches being formed by an IGBT semiconductor switch and including a switching element and a diode which is arranged antiparallel to the switching element, with a first of the two semiconductor switches being arranged without a semiconductor series connection between the positive potential terminal of the first network terminal and the positive potential terminal of the second network terminal, with a second of the two semiconductor switches being arranged without a semiconductor series connection between the negative potential terminal of the first network terminal and the negative potential terminal of the second network terminal, and with the switching element of each of the two semiconductor switches being arranged so as to be able to conduct and switch off a current from the first network terminal to the second network terminal.

9. The electronic protection switch of claim 8, wherein precisely said two semiconductor switches are provided for switching the current between the first and second network terminals in a DC voltage network.

10. The electronic protection switch of claim 8, further comprising a voltage detection configured to measure a voltage between the positive potential terminal of the first network terminal and a ground potential and/or to measure a voltage between the negative potential terminal of the first network terminal and the ground potential and/or to measure a voltage between the positive potential terminal of the second network terminal and the ground potential and/or to measure a voltage between the negative potential terminal of the second network terminal and the ground potential.

11. The electronic protection switch of claim 8, wherein the two semiconductor switches each have a design based on an NPN-type transistor.

12. An energy network, comprising: a first energy subnetwork; a second energy subnetwork; and an electronic protection switch configured to disconnect the first energy subnetwork and the second energy subnetwork from one another, said electronic protection switch comprising a first network terminal connected to the first energy subnetwork and including a positive potential terminal and a negative potential terminal, a second network terminal connected to the second energy subnetwork and including a positive potential terminal and a negative potential terminal, and two semiconductor switches of same kind, each of the two semiconductor switches being formed by an IGBT semiconductor switch and including a switching element and a diode which is arranged antiparallel to the switching element, with a first of the two semiconductor switches being arranged without a semiconductor series connection between the positive potential terminal of the first network terminal and the positive potential terminal of the second network terminal, with a second of the two semiconductor switches being arranged without a semiconductor series connection between the negative potential terminal of the first network terminal and the negative potential terminal of the second network terminal, and with the switching element of each of the two semiconductor switches being arranged so as to be able to conduct and switch off a current from the first network terminal to the second network terminal.

13. The energy network of claim 12, embodied as a DC voltage network.

14. The energy network of claim 12, wherein the first and second energy subnetworks include at least one inductive load.

15. The energy network of claim 12, wherein precisely said two semiconductor switches of the electronic protection switch are provided for switching the current between the first and second network terminals in a DC voltage network.

16. The energy network of claim 12, wherein the electronic protection switch includes a voltage detection configured to measure a voltage between the positive potential terminal of the first network terminal and a ground potential and/or to measure a voltage between the negative potential terminal of the first network terminal and the ground potential and/or to measure a voltage between the positive potential terminal of the second network terminal and the ground potential and/or to measure a voltage between the negative potential terminal of the second network terminal and the ground potential.

17. The energy network of claim 12, wherein the two semiconductor switches of the electronic protection switch each have a design based on an NPN-type transistor.

18. A method for operating an energy network as set forth in claim 12, said method comprising opening the electronic protection switch when a ground fault occurs in the energy network.

19. The method of claim 18, further comprising ascertaining a location of the ground fault by measuring a voltage between the positive potential terminal of the first network terminal and a ground potential and/or by measuring a voltage between the negative potential terminal of the first network terminal and the ground potential and/or by measuring a voltage between the positive potential terminal of the second network terminal and the ground potential and/or by measuring a voltage between the negative potential terminal of the second network terminal and the ground potential.

Description

[0024] The invention is described and explained in more detail below on the basis of the exemplary embodiments shown in the figures, in which:

[0025] FIG. 1 shows an energy supply of a load via a known electronic switch,

[0026] FIG. 2 shows an electronic protection switch, and

[0027] FIG. 3 shows a DC voltage system.

[0028] FIG. 1 shows a known arrangement, in which an energy source 55 is connected to a load 56 via two known electronic switches 7. In this context, the electronic switches 7 are arranged in the individual feeds 57, which electrically connect the energy source 55 to the load 56. In this context, a DC voltage network is involved, for example, in which energy source 55 and load 56 are interconnected via two feeds 57, and in which a DC voltage is applied between the two feeds 57. In order to be able to disconnect the load 56 from the energy supply network 56, an electronic switch 7 is present in each of the two feeds 57 in each case. By way of the electronic switch 7 in both feeds 57, a current can only be reliably switched off in one of the two feeds 57, as may occur in a ground fault for example.

[0029] The electronic switch 7 has a series connection of two semiconductor switches 2, which are arranged in a series connection. In this context, the semiconductor switches 2 have a switching element 21 that is able to conduct and switch off a current in one direction. Diode 22, which is able to conduct a current in the opposite direction but cannot switch it off, is arranged parallel to said switching element 21. The diode 22 is thus arranged antiparallel to the switching element 21. In this context, the semiconductor switches 2 are arranged in an antiserial manner. Antiserial means that it is possible to switch off a current in one direction by way of the electronic switch 7, by means of one of the two semiconductor switches 2, and it is possible to switch off a current in the opposite direction by way of the other of the two semiconductor switches 2.

[0030] FIG. 2 shows an electronic protection switch 1. This has two semiconductor switches 2, in which the diode 22 is arranged antiparallel to the switching element 21 in each case. In contrast to the electronic switch 7 already known, this has a total of four phase terminals 31, 32, 41, 42. Two of these phase terminals 31, 32 form the first network terminal 3; a further two of these phase terminals 41, 42 form the second network terminal 4. The two feeds, to which the DC voltage is applied during use in a DC voltage network 6, are connected both at the first and at the second network terminal 3, 4. The phase terminals 31, 32, 41, 42 at the first network terminal 3 and at the second network terminal thus each have a positive potential and a negative potential of said DC voltage. In order to be able to distinguish between the terminals of the network terminals in each case, these are referred to as positive potential terminal 31, 41 and as negative potential terminal 32, 42. This designation is also retained below when the electronic protection switch is used in an AC voltage network and a phase terminal and a neutral conductor terminal are involved.

[0031] The semiconductor switches 2 are arranged in the feeds so as to interrupt an energy flow between the first network terminal 3 and second network terminal 4. This interruption may be ensured for both energy flow directions, as the same current flows between the positive potential terminal 31 of the first network terminal and the positive potential terminal 41 of the second network terminal 4 as between the negative potential terminal 32 of the first network terminal 3 and the negative potential terminal 42 of the second network terminal 4. In each case, the currents differ only in their direction. In this context, there is a forward current and return current from energy source to the load. In order to be able to interrupt the energy flow regardless of the energy flow direction, the current flows once through the switching element 21 and once through the diode 22. Thus, the current can be interrupted regardless of the energy flow direction.

[0032] In contrast to the use of two electronic switches 7 according to FIG. 1, only two times the forward losses of the semiconductor switch 2 are incurred for the electronic protection switch in the overall current circuit for forward current and return current, whereas four times as much is incurred when using two electronic switches 7. Thus, the electronic protection switch 1 may halve the losses compared to the known solution.

[0033] Due to the arrangement of the semiconductor switches 2, the first semiconductor switch is able to conduct and interrupt a current from the positive potential terminal 31 of the first network terminal 3 to the positive potential terminal 41 of the second network terminal 4, and the second semiconductor switch is able to conduct and interrupt a current from the negative potential terminal 32 of the first network terminal 3 to the negative potential terminal 42 of the second network terminal 4. A current between the two energy subnetworks can therefore be interrupted regardless of the energy flow direction.

[0034] FIG. 3 shows an energy network 5. Due to the two feeds between, this may involve a DC voltage network 6, for example. As an alternative, the embodiment of an AC voltage network is also possible. In general, this energy network 5 has a first energy subnetwork 51 and a second energy subnetwork 52. These are interconnected via two feeds 57, wherein the electronic protection switch 1 is introduced into these feeds 57 in order to be able to disconnect or interconnect the two subnetworks. In this context, the energy subnetworks 51,52 may have one or more energy sources (not shown in further detail) and/or one or more loads (not shown in further detail), such as electrical consumers. In this context, it is possible for the energy subnetworks to have a combination of energy sources and loads. In the simplest case, the one energy subnetwork 51 involves an energy source, which is embodied as a DC voltage source, and the second energy subnetwork involves a load, which is supplied with a DC voltage. With the aid of the electronic protection switch 1, it is possible to interrupt an energy flow between the two subnetworks regardless of the energy flow direction. Moreover, with this arrangement, it is possible to identify and locate an occurring fault, in particular a ground fault, by measuring and evaluating the voltage applied at the respective potentials 31, 32, 41, 42 compared to the ground potential. This is particularly advantageous for the application in a DC voltage network designed in an isolated manner.

[0035] In summary, the invention relates to an electronic protection switch, having two semiconductor switches, each with a switching element and a diode arranged antiparallel to the switching element. To improve the electronic switch, in particular with regard to the losses incurred during operation and with regard to locating faults, it is proposed that the electronic switch furthermore has a first network terminal and a second network terminal, each with a positive potential terminal and a negative potential terminal, wherein a first of the semiconductor switches is arranged without a semiconductor series connection between the positive potential terminal of the first network terminal and the positive potential terminal of the second network terminal and a second of the semiconductor switches is arranged without a semiconductor series connection between the negative potential terminal of the first network terminal and the negative potential terminal of the second network terminal, wherein the switching element of the respective semiconductor switch is arranged so as to be able to conduct and switch off a current from the first network terminal to the second network terminal. The invention further relates to an energy network, in particular a DC voltage network, with a first energy subnetwork and a second energy subnetwork, wherein the energy network has an electronic protection switch of this kind for disconnecting the first energy subnetwork and the second energy subnetwork from one another, wherein the first energy subnetwork is connected to the first network terminal and the second energy subnetwork is connected to the second network terminal. Furthermore, the invention relates to a method for operating an energy network of this kind.