Multilevel Converter

Abstract

Capacitor 2; -Resistor 3, a first switch 4 operated by a first motor drive 40; a second switch 5 operated by a second motor drive 50; A multilevel converter 1 including: The multilevel converter 1, in which the first switch 1, when closed, connects the capacitor 2 to the resistor 3 and shorts out the resistor 3, and the second switch 5, when closed, connects the capacitor 2 to ground potential 21.

Description

[Technical field]

[0001] The present invention relates to a multilevel converter. [Background technology]

[0002] A multilevel converter basically consists of a number of semiconductor switches, capacitors and coils. Generally, the capacitors used store a large amount of energy. To allow reliable maintenance or fault correction of a multilevel converter, all components must be transferred to a de-energized state before maintenance. Summary of the Invention [Problem to be solved by the invention]

[0003] An object of the present invention is to provide a multilevel converter which is easy to maintain, has a simple structure, and can be safely and repeatedly switched to a non-energized state. [Means for solving the problem]

[0004] This problem is solved by a device according to claim 1. Advantageous further configurations are set out in the dependent claims.

[0005] According to a first embodiment, the present invention provides a method for manufacturing a semiconductor device comprising: A capacitor; -Resistance and a first switch operated by a first motor drive; a second switch operated by the second motor drive; A multilevel converter including the above is proposed.

[0006] In this case, the first switch, when closed, connects the capacitor to the resistor and shorts out the resistor, and the second switch, when closed, connects the capacitor to ground potential. The first switch is closed before the second switch.

[0007] The multilevel converter is very simply and inexpensively constructed to be disconnected, i.e. to be discharged and to be grounded. At this time, the multilevel converter assumes a non-conducting state. The first and second switches have their own motor drives, which are individually controllable. After shorting the capacitor by the first switch with or through a resistor, the capacitor is substantially discharged. Finally, the second switch grounds the capacitor and ensures that the multilevel converter is transferred to a non-conducting state. During this operation, the switches are therefore closed in a certain sequence.

[0008] The multi-level converter may be configured in any manner. In this case, the first switch includes a first contact tooth and a second contact tooth; the first contact teeth and the second contact teeth are conductively connected to the resistor; The contact tooth, the resistor and the second contact tooth form a series electrical circuit.

[0009] Each of the plurality of contact teeth has a contact surface.

[0010] The multi-level converter may be configured in any manner. In this case, the second switch includes a movable contact; the movable contact is conductively connected to ground potential;

[0011] The movable contact may be formed, for example, as a contact bar which is conductively connected to ground potential via a cable.

[0012] The multi-level converter may be configured in any manner. In this case, the contact module comprises a first connecting contact and a second connecting contact, the first connecting contact has a first contact and a second contact; The second connecting contact has a first contact and a second contact.

[0013] The multi-level converter may be configured in any manner. In this case, In a closed state of the first switch, the contact teeth contact the first contact of the first connecting contact and the second contact teeth contact the first contact of the second connecting contact, and in a closed state of the second switch, the movable contact contacts the second contact of the first connecting contact and the second contact of the second connecting contact.

[0014] The first switch is therefore formed by the contact teeth and the first contacts of the first and second connecting contacts, and the second switch is therefore formed by the movable contact and the second contacts of the first and second connecting contacts.

[0015] Instead, a contact bar contacts the first connecting contact and the second connecting contact.

[0016] The multi-level converter may be configured in any manner. In this case, The capacitor is part of the cell.

[0017] The multi-level converter may be configured in any manner. In this case, - a plurality of capacitors are provided which are part of individual cells; - a plurality of cells (9) are provided, - a first connecting contact (7.1) and a second connecting contact (7.2) are respectively associated with each cell, - each cell (9) can be discharged by two contact teeth (4.1, 4.2) and one resistor (3), Each cell (9) can be grounded by a common movable contact (5.1).

[0018] Depending on the requirements, the multilevel converter may have several capacitors arranged in a cell, either individually or together. In the case of an embodiment with several cells, each of these cells must be arranged to be connectable by a first switch and a second switch. A separate resistor or several resistors may be associated with each cell. Each cell is connected by a common second switch. As a result, the cells may be connected to ground potential via the second switch. A unique first switch may be assigned to each cell. The capacitors of the cells are discharged by this first switch.

[0019] The multi-level converter may be configured in any manner. In this case, -The multilevel converter operates within the medium voltage range of 20 kV.

[0020] The multi-level converter may be configured in any manner. In this case, Each cell comprises at least one semiconductor switch element and an inductance.

[0021] According to another embodiment, a method for shutting down a multilevel converter is proposed, in which: In a first step, a first switch is operated by the first motor driver to short the capacitor to the resistor; in a second step, a second switch is operated by the second motor driver to connect the capacitor to ground potential; Only when the capacitor is discharged is the second step carried out.

[0022] During this interruption, i.e. when the multilevel converter is switched off, the capacitor is discharged and after this discharge it is also connected to ground. For this reason, it is important that the connection to ground, i.e. the operation of the second switch, is carried out only when the capacitor is completely or at least almost completely discharged. This allows reliable operation of the multilevel converter.

[0023] The invention and its advantages will be explained in more detail below with reference to the accompanying drawings. [Brief description of the drawings]

[0024] [Figure 1] FIG. 1 is a circuit diagram of a multilevel converter. [Diagram 2] FIG. 2 is a first detailed diagram of a multilevel converter having a first switch and a second switch. [Diagram 3] FIG. 2 is a second detailed diagram of the multilevel converter having a first switch and a second switch. [Figure 4] FIG. 4 is a detailed diagram of a first switch and a second switch. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0025] The same reference numbers are used for identical or identically acting components. Moreover, for clarity, only the reference numbers necessary to explain the respective figures are shown in the individual figures. Therefore, the illustrated embodiments are merely examples of how the inventive multilevel converter can be constructed and therefore do not ultimately limit the invention.

[0026] FIG. 1 shows a first embodiment of a multilevel converter 1. This multilevel converter 1 comprises at least one capacitor 2 which is part of a cell 9. Furthermore, at least one resistor 3 is provided which can be connected in parallel to the capacitor 2 or connected to the capacitor 2 by a first switch 4 and a first motor drive 40. The capacitor 2 is thereby short-circuited to or through the resistor 3. Furthermore, a second switch 5 is provided which can connect the capacitor 2 to a ground potential 3 by a second motor drive 50. When the capacitor 2 is short-circuited to or through the resistor 3, the capacitor 2 is discharged. When the capacitor 2 is connected to a ground potential 20, the capacitor 2 is grounded. The short-circuit is always performed before the grounding. After the short-circuit and the discharge of the capacitor 2 associated with the short-circuit and the grounding, work such as for example maintenance can be performed on the multilevel converter without any risk to persons. In the embodiment shown here, the multilevel converter 1 comprises a cell 9 with a capacitor 2. Preferably, the multi-level converter 1 may comprise twelve cells 9 each having at least one capacitor 2 .

[0027] 2-4 show the multilevel converter 1 as well as the first switch 4 and the second switch 5 in detail. All components of the multilevel converter 1 are arranged in a housing 3 with a frame. The first switch 4 has at least one contact tooth 4.1 and one second contact tooth 4.2. Each contact tooth consists of a support with a first contact plate and a second contact plate. In this case, these contact plates are arranged on two opposite sides of the support. Preferably, each of these contact teeth 4.1, 4.2 or each of these contact plates of each contact tooth is electrically connected to at least one resistor 3 via a first conductor 6,1 and a second conductor 6.2. The contact teeth 4.1, 4.2 and the at least one resistor 3 form a series electrical circuit via the conductors 6.1, 6.2. Furthermore, the contact teeth 4.1, 4.2 are arranged on a switching support piece 41. The switching support piece 41 is made of a non-conductive material. As a result, the two contact teeth 4.1, 4.2 are insulated from one another and therefore non-conductive. The switching support 41 is preferably connected to a first motor drive 40 via a mechanism 42, which is formed, for example, as a toggle lever arrangement. The first motor drive 40 is preferably configured as a linear motor with a rotating spindle.

[0028] The second switch 5 has a movable contact 5.1 formed as a contact bar. The movable contact 5.1 or bar is connected to ground potential 20 via a conductor (not shown here). Preferably, the second switch 5, in particular the movable contact 5.1 of the second switch 5, operates a second motor drive 50 via a further mechanism 52, for example formed as a toggle lever arrangement. Preferably, the second motor drive 50 is configured as a linear motor with a rotating spindle.

[0029] Furthermore, a contact module 7 is provided which can be connected by both the first switch 4 and the second switch 5. In this case, the contact module 7 comprises at least one first connection contact 7.1 and at least one second connection contact 7.2 which are arranged on a support made of insulating material. Each of the two connection contacts 7.1, 7.2 comprises a first contact 7.11, 7.21 and a second contact 7.12, 7.22. The first connection contact 7.1 is conductively connected to the first side 2.1 of the capacitor 2 and the second connection contact 7.2 is conductively connected to the second side 2.2.

[0030] The first motor drive 40 operates the first switch 4 such that the first motor drive 40 acts on the mechanism 42 on the switching support 41. In this case, the switching support 41 moves vertically downwards or upwards towards the contact module 7. That is, when the first switch 4 is operated, the first contact tooth 4.1 is connected via the first contact 7.11 of the first connecting contact 7.1, and the second contact tooth 4.2 is connected via the first contact 7.21 of the second connecting contact 7.2. In this case, the capacitor 2 is short-circuited via the resistor 3 and discharged.

[0031] The second motor drive 50 operates the second switch 5 so that the second motor drive 50 acts on the movable contact 5.1 by means of the mechanism 52. In this case, the movable contact 5.1 moves vertically from bottom to top towards the contact module 7. In this case, it is preferably returned by a distance of at least 280 mm. This distance is ensured in particular for a multi-application range of 20 kV. In other words, the second contacts 7.12, 7.22 of the connecting contacts 7.1, 7.2 are separated from the movable contact 5.1 by at least 280 mm in the open, i.e. non-conducting state. That is to say, upon operation of the second switch 5, the movable contact 5.1 is conductively connected to the connecting contacts 7.1, 7.2 via the respective second contacts 7.12, 7.22. Thus, the ground potential 20 and the capacitor 2 are connected. The capacitor 2 is grounded.

[0032] Thus, the contact module 7 with the connecting contacts 7.1, 7.2 provides a common contact for connection to the resistor 3 and to the ground potential 20. Both the switching support piece 41 and the movable contact 5.1 formed as a bar are moved vertically by corresponding motor drives 40, 50 to finally perform the switching.

[0033] In this case, the first switch 4 with the contact teeth 4.1, 4.2, i.e. the switching support 41, is always actuated before the actuation of the second switch 5, i.e. the first movable contact 5.1. A certain period must be ensured between the actuation of the first switch 4 and the second switch 5, during which a complete discharge can be completed. Preferably, the connecting contacts 7.1, 7.2 of the contact module 7 are formed as elastic contacts.

[0034] The multi-level converter 1 may have a plurality of capacitors 2. Preferably, a first switch, a second switch and a resistor are each associated with a respective capacitor. In the case of a plurality of first switches, these first switches are commonly driven or operated by a first motor driving device 40. A plurality of second switches are commonly driven or operated by a second motor driving device 50.

[0035] The motor drives 40, 50 are operated or controlled by a control device, which comprises or is configured as a means for always operating the first motor drive 40 and then the second motor drive 50. To this end, the multilevel converter 1 may comprise limit switches which transmit the operation of the first switch 4 and the second switch 5 to the control device. Thus, the switching sequence of the first switch 4 and the second switch 5 is determined.

[0036] In the case of a multilevel converter with a number of cells 9 and a number of capacitors 2, the switches 4, 5 are accordingly multiple. The contact module 7 therefore has a pair of individual connection contacts 7.1, 7.2 for each cell 9 or capacitor 2. There is also a respective pair of contact teeth 4.1, 4.2 with corresponding contact surfaces. The movable contact 5.1 is suitably dimensioned so that it can contact all connection contacts of the multilevel converter and thus ground the plurality of cells 9 with all capacitors 2. [Explanation of symbols]

[0037] 1. Multilevel Converter 2. Capacitor 3. Resistance 4 First Switch 4.1 First contact tooth 4.2 Second contact tooth 5 Second Switch 6.1 First conductor 6.2 Second conductor 7 Contact Module 7.1 First connecting contact 7.2 Secondary connecting contact 7.11 First contact of 7.1 7.21 First contact of 7.2 7.12 Second contact of 7.1 7.22 Second contact of 7.2 9 Cell 10. Housing 20 Ground potential 40 First motor drive unit 42 Mechanism 50 Second motor drive unit 52 Mechanism

Claims

1. - a capacitor (2), -Resistor (3), a first switch (4) operated by a first motor drive (40); a second switch (5) operated by a second motor drive (50); A multilevel converter (1) comprising: The multilevel converter (1), in which the first switch (1), when closed, connects the capacitor (2) to the resistor (3) and shorts out the resistor (3), and the second switch (5), when closed, connects the capacitor (2) to ground potential (20).

2. - said first switch (4) comprises a first contact tooth (4.1) and a second contact tooth (4.2); - said first contact tooth (4.1) and said second contact tooth (4.2) are conductively connected to said resistor (3), - A multilevel converter (1) according to claim 1, wherein the contact tooth (4.1), the resistor (3) and the second contact tooth (4.2) form a series electric circuit.

3. - said second switch (5) comprises a movable contact (5.1), - A multilevel converter (1) according to claim 1 or 2, wherein the movable contact (5.1) is conductively connected to a ground potential (20).

4. - a contact module (7) comprising a first connecting contact (7.1) and a second connecting contact (7.2), - said first connecting contact (7.1) has a first contact (7.11) and a second contact (7.12), - A multilevel converter (1) according to any one of claims 1 to 3, wherein the second connecting contact (7.2) has a first contact (7.21) and a second contact (7.22).

5. A multilevel converter (1) according to any one of claims 1 to 4, wherein in the closed state of the first switch (4), the contact teeth (4.1) are in contact with the first contact (7.11) of the first connecting contact (7.1) and the second contact teeth (4.2) are in contact with the first contact (7.21) of the second connecting contact (7.2), and in the closed state of the second switch (5), the movable contact (5.1) is in contact with the second contact (7.12) of the first connecting contact (7.1) and with the second contact (7.22) of the second connecting contact (7.2).

6. A multilevel converter (1) according to any one of the preceding claims, further comprising a cell (9), the capacitor (2) being part of the cell (9).

7. A multilevel converter (1) according to any one of claims 1 to 6, wherein the cell (9) may comprise a plurality of capacitors (2).

8. - a plurality of cells (9) are provided, a first connecting contact (7.1) and a second connecting contact (7.2) are respectively associated with each cell, - each cell (9) can be discharged by two contact teeth (4.1, 4.2) and one resistor (3), A multilevel converter (1) according to any one of claims 1 to 7, wherein each cell (9) can be grounded by a common movable contact (5.1).

9. A multilevel converter (1) according to any one of claims 1 to 8, comprising 12 cells (9), each cell (9) outputting a voltage of 2 kV.

10. The multilevel converter (1) according to any one of claims 1 to 9, wherein the multilevel converter (1) operates within the medium voltage range of 20 kV.

11. A multilevel converter (1) according to any one of claims 1 to 10, wherein each cell (9) comprises at least one semiconductor switch element and an inductance.

12. A method for shutting down a multilevel converter (1) according to any one of claims 1 to 11, comprising: - in a first step, a first switch (4) is operated by a first motor driver (40) to short-circuit the capacitor (2) to the resistor (3); in a second step, a second switch (5) is operated by a second motor drive (50) to connect said capacitor (2) to ground potential (20); The method, wherein the second step is carried out only when the capacitor (2) is discharged.

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