WO2016005166A1

WO2016005166A1 - Redundant power electronics circuit having parallel series circuits composed of a power semiconductor device and a circuit breaker

Info

Publication number: WO2016005166A1
Application number: PCT/EP2015/063802
Authority: WO
Inventors: Markus Pfeifer; Marvin TANNHÄUSER
Original assignee: Siemens Aktiengesellschaft
Priority date: 2014-07-09
Filing date: 2015-06-19
Publication date: 2016-01-14
Also published as: DE102015206531A1

Abstract

The invention relates to a redundant power electronics circuit (12) in the form of a parallel circuit composed of at least two identical or at least similar power semiconductor devices (10); a circuit breaker (16) is connected in series to each power semiconductor device (10). Also disclosed is a converter comprising a power electronics circuit (12) of said type.

Description

description

REDUNDANT POWER ELECTRONICS CIRCUIT WITH PARALLEL TERMINAL CIRCUITS

POWER SUPPLY AND FUSE

The invention relates to an at least one Leistungshalblei ^¬ ter comprehensive power electronics circuit, for example an inverter circuit, and an inverter, and whose

Converter circuit with a power electronics circuit.

Semiconductors, especially power semiconductor, the power semiconductor switches and electrical circuits Leistungshalblei ^¬ tern or semiconductor power switches, for example so-called IGBTs, are known per se. One application for power semiconductor switches and electrical circuits with power semiconductor switches are so-called inverter, so rectifier, inverter and frequency converter.

By too high currents or too high frequencies or by defects in the semiconductor layers even at not too high currents and not too high frequencies power semiconductors and power semiconductor switches - collectively referred to as semiconductor devices - can be destroyed. In the case of such a destruction of a semiconductor component is usually the entire function of a

Circuit or a device with such a circuit questioned.

In the case of such an error case, it is not possible to predict which state the respective defective semiconductor ^component will take. The semiconductor device may be conductive (plated through) or non-conductive (open) due to the defect. To detect a particular condition of a defective semiconductor device is a very fast detection and Ansteue- is tion required to an optionally due to a De ^¬ fekts permanently conducting semiconductor device using white ^¬ more excellent switch, thus for example either further semiconductor components in the form of power semiconductor switches or mechanical switch, for example contactors, to be disconnected from the respective system. However, a protective device increases the number of necessary components and he ^¬ increases the space required in each case, in the case of shooters even many times. If no such protective device or comparable protective measures are available, uncontrolled equalizing currents occur in the event of a fault. Thus, in the case of a defective semiconductor component which is conductive due to the defect, further semiconductor components and the respective circuit as a whole, that is, for example, an inverter, can be destroyed.

It is an object of the present invention to specify a circuit, in particular a circuit which can be used in the field of power electronics, which is suitable for maintaining the original function even in the event of a defect occurring during operation of a semiconductor component included in the circuit. This object is achieved by means of a redundant power electronics circuit with the features of claim 1. The power electronics circuit comprises in a parallel connection at least two identical or at least similar power semiconductors, wherein a fuse is connected in series with each power semiconductor. Due to the parallel connection, the power electronics circuit ^¬ tion includes the respective power semiconductor in redundant form, so that the power electronics circuit can be referred to collectively as a redundant power electronics circuit.

, The name of the encompassed by the power electronics circuit power semiconductor means that it is in each case identical power ^¬ types of semiconductors to be equal or at least similar, so for example each to

MOSFETs, IGBTs or power diodes, as well as that the power semiconductors connected in parallel are equal in terms of their current carrying capacity or at least within the scope of usual tolerances Tole ^¬ . The semiconductor components connected in parallel in the redundant power electronic circuit have their own fuse assigned in each parallel branch, in particular a fuse in the form of a fuse. Each fuse is sized so that it is automatically separated from the other still-functioning semiconductor devices in a resulting due to a short circuit fault ^¬ a semiconductor device, short-circuit current and data to the circuit can be operated. The parallel-connected semiconductor components themselves are preferably dimensioned so that in case of failure of one or more semiconductor devices, the remaining, still functioning semiconductor components in combination each have a required current carrying capacity, so that the respective

Load current can continue to flow over the remaining semiconductor devices and thus the overall functionality of the ^¬ particular circuit is ensured. In the event that the current carrying capacity of the remaining semiconductor devices for the intended rated current is not sufficient, the respective circuit can still be operated at least with reduced power.

The advantage of the invention is that parallel switching means of the patent and a defective semiconductor device can be automatically disconnected from the remaining circuitry of the present in each parallel branch fuse and operation of the circuit and its original functionality is further ensured Anson ^¬ th. Depending on the type and number of semiconductor devices, the further function is optionally ensured without restrictions. At least the other function with reduced power is guaranteed.

EP 0 989 611 A discloses an approach in which a short-circuit current flowing due to the defect of a semiconductor device is used in order to achieve a desired state in view of the defect. There, the defective semiconductor component by melting a special Lei layer in a defined short circuit. In the approach according to the invention, however, a short circuit is to be avoided and by means of the parallel circuit and the fuse present in each branch takes place at a defective semiconductor device and then flowing short-circuit current triggering the fuse of each affected parallel branch, which eliminates the short circuit existing due to the defect becomes. Advantageous embodiments of the invention are the subject of the dependent claims. The references used in this case point to the further development of the subject of the Hauptanspru ^¬ ches by the features of the respective sub-claim. They are not to be construed as a waiver of achieving an independent, objective protection for the Merkmalskombina ^¬ tions of the related dependent claims. Furthermore, with a view to an interpretation of the claims in a closer specification of a feature in a subordinate claim, it is to be assumed that such a restriction does not exist in the respective preceding claims.

Circuits in accordance with the approach proposed here are particularly suitable for applications in which a high level of fail-safety is or even has to be guaranteed, for example in drives of electric or hybrid electric vehicles, rail vehicles and drives for use in the process industry. , Production and energy technology.

In a particular embodiment of a redundant power electronics circuit, the power semiconductors switches in the form of IGBTs, MOSFETs or the like are correspondingly in the case of the parallel-connected power semiconductors. Such power semiconductor switches are electronic

Switch in converters known per se. With the approach proposed here, the reliability of a Significantly increase converter circuit or a drive with such a converter circuit.

In a redundant power electronics circuit with derar- term power semiconductor switches, such as IGBTs, each having a gate terminal, a collector terminal and emitter terminal ei ^¬ NEN, are within the scope of the parallel circuit ^¬ one hand, the collector terminals and the

Emitter connections to a common collector or

Emitter terminal and on the other hand, the gate terminals merged to a common gate terminal of the redundant Leistungselektro ^¬ nikschaltung. The control of all encompassed by the power electronics circuit and parallel power semiconductor switch is thus effected via the one central gate of the power electronics scarf ^¬ tion. The power electronics circuit itself thus acts as a single power semiconductor switch and, just like the latter, is connected and controllable within a surrounding circuit.

Especially in the case of a power electronics circuit having power semiconductor switches connected in parallel, for example IGBTs or MOSFETs, it is advantageously provided that a current ^carrying capacity of each individual power semiconductor switch ^encompassed by the parallel circuit is chosen such that, in the event of a defect of a power semiconductor switch or more than one power semiconductor switch, the remaining one Leis ^¬ semiconductor switch or the remaining power semiconductor switch having a suffi- for an expected load current sponding current carrying capacity or have. Then, the power electronics circuit can continue to operate also in case of failure of one or more power semiconductor switches without restrictions, so that for example there is no reduction of the load current is necessary and, for example, at a drive having a converter with at least ei ^¬ ner such power electronics circuit results not reduced torque , b

In a particular embodiment of the power electronics circuit, at least one bonding wire acts as a fuse in each parallel branch. The advantage of this execution ^¬ form is that an already necessary connection of the parallel-connected power semiconductor is simple and easy to automate produced by means of bonding wires, and that such bonding wires now receive a multiple function, namely, function both as a connection and contact elements and ^¬ other hand, as fuses. A separate fuse in each parallel branch is no longer required.

In a further particular embodiment of the redundant power electronics circuit, a monitoring device associated therewith or included therein and means for detecting a terminal voltage and a terminal current of the power electronics circuit are provided, wherein by means of the monitoring device measured values for terminal voltage and terminal current with predetermined or predeterminable expected values are comparable and being dependent from the result of the comparison, an output signal can be output. Means egg ^¬ ner such a monitoring device is automatically occurring in operation failures of one or more power semiconductor ^¬ recognizable and by means of a dispensable by the surveil ^¬ monitoring means output signal, for example, a display element, for example a light emitting diode controlled. Such a display element makes a user of the power electronics circuit or of a circuit or a device with a plurality of such power electronics circuits aware of the defect and, especially in the case of several power electronics circuits, makes it easy to localize the affected power electronics circuit.

A power electronics circuit of the type described here and below is also particularly suitable for use in a converter, in particular a converter in the form of a rectifier, inverter and frequency converter. In this respect, the invention is also an inverter with at least one redundant power electronics circuit of the type described here and below.

In a particular embodiment of an inverter with at least one half-bridge circuit, two power electronics circuits connected in series in the or each half-bridge circuit of the type described here and in the following are provided. As is known, in a half-bridge circuit with electronically controllable switches, usually only one or the other electronic switch is always activated. In the case of a defect in one of the power electronics circuits and a triggering of the other power electronics circuit, a power electronics circuit functioning as an electronic switch of the type described here and below results in a short-circuit current across the respective half-bridge, so that a triggering of the fuse assigned to the power semiconductor concerned can be expected can. In this way, the power semiconductor affected by the defect is separated from the overall circuit, ie the converter circuit. The function of the affected half-bridge is retained. As a result, the function of the converter circuit as a whole is maintained and, for example, a drive with a converter circuit also remains in operation.

The power electronics circuit proposed here and individual or combined embodiments thereof are not limited to use in the field of power electronics, so that the invention is generally also a circuit with the features described herein and below and advantageously ensures increased reliability of a surrounding overall circuit.

An embodiment of the invention will be explained in more detail with reference to the drawing. Corresponding objects or elements are provided in all figures with the same reference numerals. Show it

1 shows an embodiment of a circuit according to the invention,

2 shows a further embodiment of the circuit according to

1,

3 to

5 shows further embodiments of the circuit according to FIG. 1,

6 shows a half-bridge circuit with two sub-circuits shown in FIG 1 and FIG 7 shows a circuit according to FIG 1 with one of these zugeord ^¬ Neten monitoring device.

The illustration in FIG. 1 shows two semiconductor components 10, namely two so-called IGBTs (IGBT1, IGBT2), more precisely two IGBTs, each having an antiparallel freewheeling diode, comprehensive power electronics circuit 12, which is referred to below as circuit 12 for short. The two half ^¬ conductor devices 10 are connected in parallel within the circuit 12, and in each parallel branch 14 is connected in series with the respective gene semiconductor device 10 is a fuse 16 (Fl, F2).

Each IGBT included in the circuit 12 comprises a gate, a collector and an emitter terminal in a manner known per se. Due to the parallel ^¬ circuit of the IGBTs used here as an example of basically any semiconductor devices 10, the scarf ^¬ device 12 itself also has a gate terminal 20, a collector terminal 22 and an emitter terminal 24. The circuit 12 with at least two IGBTs connected in parallel can thus be connected and controlled just like a single IGBT. For a respective surrounding circuit, for example a converter circuit, it does not matter if a individual IGBT or a circuit 12 of the type shown in Figure 1 is driven.

The illustration in FIG 2 corresponds to position in FIG 1 is substantially the illustration and shows that the number of parallel branches ^¬ 14 and the number of parallel-connected semiconductor components 10 is basically optional. In any case, each parallel branch 14 comprises a semiconductor component 10 and a fuse 16 connected in series therewith. The parallel branches 14 of the circuit 12 are accordingly functionally identical and the circuit 12 overall realizes the function of one of the semiconductor components 10 placed in all parallel branches. The parallel connection of the semiconductor components 10 causes redundancy of the semiconductor components 10. In the case of a defect of one of the semiconductor devices 10 such that the semiconductor device 10 becomes conductive and loses its actual function, a current, for example a short-circuit current, permanently flows through the respective parallel branch 14 the defective semiconductor device 10. in one entspre ^¬ sponding current strength, so at least for a short circuit ^¬ stream, this leads to an activation of the fuse 16 in the respective parallel branch 14. thus, the parallel branch 14 is electrically separated and no function in the circuit 12th The defective semiconductor component 10 is therefore automatically disconnected from the circuit 12. With the response (burning through) of the fuse 16, the briefly flowing current / short-circuit current is interrupted immediately. Thereafter, the current flowing through the circuit 12 splits to the remaining parallel branches 14. Due to the functional identity of all parallel branches 14, the functionality of the circuit 12 is retained even after the failure of a semiconductor component 10 or possibly several semiconductor ^components 10.

The resulting circuit 12 may be referred to as a redundant IGBT or as a redundant IGBT with increased reliability, for example in the case of IGBTs as semiconductor components 10 become. The function of the circuit 12 as a whole is identical to the function of each of the at least two parallel branches 14 included individual semiconductor device 10, so that the circuit 12 acts as a whole as a single IGBT. By this function of the circuit 12 is maintained even with a defect of one of the parallel-connected semiconductor devices 10 or possibly more such semiconductor devices 10, the increased reliability is guaranteed. The illustrations in Figures 3, 4 and FIG 5 show that it is not at ^¬ depends on the type of the respective semiconductor component 10, as long as in all the parallel branches 14 same semiconductor devices 10, particularly with respect to their jewei ^¬ time current carrying capacity same or at least within the framework usual tolerances same semiconductor devices 10, are located.

In the illustration in FIG. 3, according to the exemplary embodiment according to FIG. 1 and FIG. 2 and the local IGBTs (IGBT1, IGBT2 or IGBT1, IGBT2 .. IGBTn), diodes (HL1, HL2 .. HLn) are shown as a further example ge ^¬ shows according to the procedure here ^¬ chosen approach Redundant semiconductor devices 10th The illustration in FIG 4 shows a symbolically illustrated in the form of a conventional switch switchable semiconductor component 10 (HL1, H2 .. HLn) to the applicability of the approach proposed here for reason ^¬ additionally any semiconductor devices 10 and expressly for redundant execution of non underlined for use in the field of power electronics semiconductor devices 10 again. Furthermore, as the illustration in FIG. 5 illustrates, it is also not important how the series connection of one (switchable or non-switchable) semiconductor component 10 (HL1, H2..HLn) and one fuse 16 (F1, F2, .. Fn) in the individual parallel branches 14 is realized. In the illustrations in FIGS. 1 to 4, a placement of the fuses 16 at an upper contact point of the respective semiconductor component 10 has been shown. The illustration in FIG. 5 shows an alternative and equivalent embodiment. form with at the lower contact point of the semiconductor devices 10 placed fuses 16th

The illustration in Figure 6 is a half-bridge circuit (half-bridge) 30, as for example in an output stage of an inverter for driving a polyphase machine ver ^¬ reversible. The half-bridge 30 is shown to include two formwork ^¬ obligations 12 according to FIG 1, each with two IGBTs (IGBT1, IGBT2, IGBT3, IGBT4). In principle, more than two IGBTs are also possible for each circuit 12 according to FIG. 2, FIG. 4 and FIG. 5. Each of the two circuits 12 is hereinafter referred to as redundant IGBT.

In the situation shown in FIG. 6, it is assumed (left side of the representation) that in the upper redundant IGBT one of the two IGBTs, here the IGBT with the designation IGBT2, fails and becomes permanently conductive. As soon as ^¬ raufhin is switched on only the lower redundant IGBT due to a drive to the gate input 20, a high short-circuit current i _K s flows due to the applied DC voltage U _D c by the upper redundant I ^¬ th IGBT and by the lower redundant IGBT. In the upper redundant IGBT, the total short-circuit current i _K s will flow via the defective semiconductor component 10 (IGBT2) and the fuse 16 (F2) connected in series therewith. Of the

Short-circuit current i _K s triggers this fuse 16 (F2). In un ^¬ direct redundant IGBT, the short-circuit current i _K s divides the here two parallel branches 14 and to their respective Si ^¬ fuses 16 (F3, F4) does not trigger. After the fuse 16 (F2) in exactly the parallel branch 14 with the defective half ^¬ semiconductor component 10 (IGBT2) has tripped, the defective semiconductor device is 10 (IGBT2) separated from the rest of the circuit 12, 30, as shown on the right side of depicting ^¬ ment in FIG 6 is shown. The further operation of the half-bridge circuit 30 is thus still possible despite the failed semiconductor component 10. As a fuse or fuses 16 comes in all the embodiments described here suitably dimensioned, for contacting the respective semiconductor device 10 be ^¬ voted bonding wires (not shown separately) or other conductor tracks into consideration. The use of a bonding wire or other conductor track is described below - but without renouncing any further generality - on the ^{example of} a bonding wire. Such a bonding wire acts at a corresponding amperage as the

Melting conductor of a fuse. According to this burns at a current above a predetermined by the dimensioning ^¬ tion and the material properties of the bonding wire threshold value, and thus separates the respective parallel ^¬ branch 14 with the connected (connected in series) semiconductor device 10 and as a result, the semiconductor ^¬ component 10 from the respective overall circuit. This achieves the same function as a fuse.

The illustration in FIG. 7 shows an embodiment of a circuit 12 according to FIG. 1 with an integrated current and

Voltage measurement. Instead of two parallel branches 14, there are also more than two parallel branches 14, and other IGBTs can also be used for other semiconductor components 10. In the event of failure of one of the redundant semiconductor devices 10, the terminal behavior of the circuit 12 changes, for example, in the form of a breakdown of the voltage between the collector terminal 22 and the emitter terminal 24 until the respective fuse 16 is triggered. When the voltage between the collector terminal 22 and the emitter terminal 24 (or generally the terminal voltage) and the current at the collector terminal 22 (or generally the terminal current) are known and for example by means of acting as a monitoring device driver circuit 32 with each recorded measured values (in the illustration by appropriate measuring devices, namely a voltmeter and a

Ammeter), can be automatically determined whether one of the redundant semiconductor devices 10 has failed. A combination of the functionality for controlling a redundant IGBT and for monitoring the IGBTs covered thereby and correspondingly the use of a driver circuit 32 as a monitoring device is advantageous because the driver circuit 32 usually has the abovementioned measured values anyway, so that only a minimal effort is required to monitor them the measured values are required in relation to respectively expected values (expected values). In addition, the driver circuit 32 are the SchaltZeitpunkte and thus the

Times in which the voltage between the collector terminal 22 and the emitter terminal 24 disappears or substantially disappears anyway due to ent ^¬ speaking control, before, so that the monitoring can be done without special additional effort outside the activation times. Depending on the result of the respective comparison, the driver circuit 32 or another monitoring device outputs an output signal 34 which indicates a possible defect of a semiconductor component 10 encompassed by the respective associated circuit 12. Due to such output signal 34, a display element, for example a light emitting diode (not shown), driven ^¬ the. Due to the monitoring, an exchange of a circuit 12 which is affected by a defect of a semiconductor component 10 or a plurality of semiconductor components 10 can take place in a timely manner. Until then, the further functionality of the scarf ^¬ device 12 is guaranteed in any case due to the redundant semiconductor devices 10 included. While the invention has been further illustrated and described in detail by the exemplary embodiment, the invention is not limited by the disclosed or disclosed examples, and other variations can be derived therefrom by those skilled in the art without departing from the scope of the invention.

Individual standing in the foreground aspects of here is rich ^¬ th description can thus be briefly summarized as follows: It proposes a circuit 12 in zumin- at least two parallel branches 14 each have the same Halbleiterbau ^¬ elements 10 and each one connected in series Si ^¬ insurance 16 includes. The resulting circuit 12 realizes the functionality of the parallel connected semiconductor devices 10. A defect of the semiconductor devices 10 may result in a then current flowing to trigger connected with the defective semiconductor device 10 in series Siche ^¬ tion sixteenth With the triggering of the fuse 16, the defective semiconductor device 10 is disconnected from the circuit 12 and the function of the circuit 12 is maintained with the one or the remaining parallel branch (s) 14. The circuit 12 is for use in a variety of forms into consideration. In addition to the illustrated specific embodiment of a use in a half bridge 30 or a converter with a plurality of such half bridges 30, for example, a use in a so-called inverse converter (buck-boost converter) or in a boost converter (boost converter) comes into consideration a circuit 12 with a plurality of switchable semiconductor devices 10 in place of a usually provided there each simple electronic switch occurs.

Reference sign list

10 power semiconductor / semiconductor device

12 power electronics circuit / circuit

14 parallel branch

16 fuse

18 (free)

20 gate connection

22 collector connection

24 emitter connection

26 (free)

28 (free)

30 half-bridge circuit / half-bridge

32 driver circuit

34 output signal

Claims

claims

1. Redundant power electronics circuit (12) in the form of a parallel connection of at least two identical or at least similar power semiconductors (10), wherein in series with each power semiconductor (10) a fuse (16) is connected.

2. Redundant power electronics circuit (12) according to claim 1, with power semiconductors (10) in the form of IGBTs or

MOSFETs.

3. Redundant power electronics circuit (12) according to claim 2, wherein each IGBT or MOSFET has a gate, a collector terminal and an emitter terminal, wherein in the context of the parallel circuit on the one hand the collector terminals and on the other hand, the emitter terminals to a ge ^¬ common collector or emitter terminal ( 22, 24) of the redundant power electronics circuit (12) are brought together and on the other hand, the gate terminals to a common gate terminal (20) of the redundant power electronics ^{scarf ¬} tion (12) are merged.

4. A redundant power electronics circuit (12) according to claim 2 or 3, comprising a current carrying capacity of each of the parallel circuit IGBTs or MOSFETs such that in case of a defect of an IGBT or MOSFETs or more than one IGBTs or MOSFETs of the remaining IGBT or MOSFET or the remaining IGBTs or MOSFETs have or have sufficient current carrying capacity for an expected load current.

5. Redundant power electronics circuit (12) according to any one of the preceding claims, wherein a bonding wire acts as a fuse (16).

6. Redundant power electronics circuit (12) according to one of the preceding claims, with a monitoring device means (32) and means for detecting a terminal voltage and a terminal current of the power electronics circuit (12), wherein by means of the monitoring device (32) measured values for terminal voltage and the terminal current with predetermined or predetermined expected values are comparable and wherein depending on the result of the comparison a ^{Ausgangssig ¬} nal (34) can be output.

7. converter with at least one redundant Leistungselek- tronikschaltung (12) according to one of claims 1 to 6.

8. converter with at least one half-bridge circuit (30) and two in the or each half-bridge circuit (30) connected in series power electronics circuits (12) according to one of claims 1 to 6.