WO2021174282A1

WO2021174282A1 - Converter assembly

Info

Publication number: WO2021174282A1
Application number: PCT/AT2021/060081
Authority: WO
Inventors: Erwin Reisinger; Martin Schmidt
Original assignee: Avl List Gmbh
Priority date: 2020-03-05
Filing date: 2021-03-05
Publication date: 2021-09-10
Also published as: AT523610A1; AT523610B1

Abstract

The invention relates to a converter assembly for producing a controlled bridge rectifier or bridge inverter comprising at least one electronically controlled power switch (1), in particular a SiC-MOSFET or GaN-MOSFET, which is connected to a low-resistance electrical connecting terminal (2), a first circuit board (3) having at least one contactless current sensor (6), in particular a magnetic Hall effect sensor, wherein the connecting terminal (2) is connected to the power switch (1) via a wound conductor loop (5), wherein the first circuit board (3) is arranged in relation to the conductor loop (5) in such a way that the current strength of a current flowing through the conductor loop (5) can be measured by the current sensor (6).

Description

Converter assembly

The invention relates to an assembly for the compact integration of a converter with high electrical power.

From the prior art, compact, high-performance converter assemblies are known under the designation “stacks” or “inverter stacks”. Conventional inverter stacks include printed circuit boards with electrical connections, high-speed electronic power switches and driver components for controlling the electronic power switches. As a rule, these components are arranged in the closest possible packing on circuit boards in order to achieve the most compact and space-saving design of the stack possible.

Due to the compact design, however, the problem arises that there is no space left for the arrangement of measuring elements, in particular current sensors, or the arrangement of these measuring elements would result in an undesirable increase in the size of the stack.

The object of the invention is thus to implement a converter assembly which enables compact current measurement without preferably increasing the dimensions of the assembly.

According to the invention, this object is achieved by a converter assembly according to claim 1.

A converter assembly according to the invention comprises at least one electronically controlled power switch, in particular a SiC-MOSFET or GaN-MOSFET, which is connected to a low-resistance electrical connection terminal (so-called current shoe). In particular, the connection terminal can be connected to the drain or source connection of the circuit breaker. The circuit breaker can be designed as an integrated half-bridge of a converter.

Furthermore, a first printed circuit board is provided on which at least one contactless current sensor is arranged, in particular a magnetic Hall sensor. These sensors are designed to measure a magnetic field and to determine a current strength from it. The connection terminal is connected to the circuit breaker via a coiled conductor track loop, the first printed circuit board being arranged in relation to the conductor track loop in such a way that the current intensity of a current flowing through the conductor track loop can be measured by the current sensor.

The conductor track loop can in particular be U-shaped. The current sensor can be arranged essentially centered and centrally above the conductor track loop. In other words, the current sensor can be arranged above the conductor track loop in such a way that it lies essentially centrally over the geometric figure spanned by the conductor track loop in a plane. This enables a particularly good measurement of the magnetic field generated by the current flow.

The central arrangement of the current sensor between the legs of the conductor track loop, that is to say with the same distance in each case from the legs arranged in parallel, has the effect that the magnetic fields of both legs are taken into account equally in the measurement.

The centered arrangement of the current sensor along the legs of the conductor track loop, i.e. with the greatest possible distance from parts of the legs that do not run parallel to one another, has the effect that the magnetic fields of the legs result in a superimposed magnetic field that is as homogeneous as possible.

The conductor track loop can comprise a first limb and a second limb rotated by approximately 180 °. The legs can have essentially the same width and length. The legs preferably run essentially parallel to each other, so that a substantially U-shaped formation of the conductor track loop is achieved. Such a design of the conductor track loop enables a particularly trouble-free measurement of the current. The magnetic field generated by the current flow in the legs is not influenced by a further magnetic field in the area of the legs running parallel to one another, as is also formed, for example, in the area of the 180 ° rotation of the two legs to one another. The advantageous positioning of the current sensor, which is arranged above and in the middle in the area between the legs, improves the measurability of the induced magnetic field.

The conductor track loop can furthermore have a feed section and a discharge section for the current flowing through, which each enclose an angle of approximately 90 ° with the legs. This in turn enables the induced magnetic field to be measured even better. According to the invention, the distance between the legs can be less than the width of the legs.

According to the invention, the current sensor can in particular be arranged above and in the middle in the area between the legs and preferably partially overlap both legs.

An insulating carrier that ensures the distance between the conductor track loop and the first printed circuit board can be provided. This mechanical spacer enables a defined distance to be ensured between the conductor track loop and the first circuit board with the current sensor when the converter assembly is being assembled.

Furthermore, a mechanical holding element can be provided which rests on the carrier and fixes the position of the first circuit board relative to the conductor track loop by means of a stop which interacts positively with the first circuit board. This ensures that not only the normal distance between the conductor track loop and the first circuit board is fixed, but also the position of the conductor track loop relative to the first circuit board, in particular the positioning of the current sensors in the middle of the conductor track loops. The components of the converter assembly can be designed to provide a power in the range of over 100 kW at a switching frequency of the electronic power switch in the range of over 20 kHz. In particular, it can be a module with so-called active front-end converters.

Furthermore, a second circuit board with electronic driver components and a third circuit board with power supply components can be provided, the circuit boards preferably being arranged parallel to one another.

To dissipate thermal power, at least one cooling body or cooling plate connected to the electrical circuit breakers can be provided. In particular, the converter assembly can be provided with heat sinks or cooling plates on several sides. The heat sinks can be arranged below and / or to the side of the circuit breakers.

Preferably, six electronic circuit breakers arranged next to one another with connection terminals and conductor track loops can be provided, to which six current sensors arranged on the first printed circuit board are assigned. A common holding element and a common stop can be provided for positioning the first printed circuit board relative to the six conductor track loops.

In order to enable an exact non-contact measurement of the current, it can be provided according to the invention that the conductor track loop is arranged at a distance of less than 50 mm, preferably at a distance of less than 20 mm, particularly preferably at a distance of less than 10 mm from the first circuit board. The conductor track loop can also lie directly on the first circuit board, provided that sufficient electrical insulation and thermal dissipation is ensured.

The conductor track loops can be formed from copper or aluminum or comprise these materials. Further features according to the invention emerge from the claims, the figures and the following description of the figures.

The invention is explained in more detail below using Fland as a non-exclusive exemplary embodiment. 1a shows a schematic three-dimensional exploded view of an embodiment of a converter assembly according to the invention;

1b shows a schematic sectional illustration through the first printed circuit board in the area of a conductor track loop;

1c and 1d show a schematic plan view of the first printed circuit board of this embodiment of the converter assembly.

1a shows a schematic three-dimensional exploded view of an embodiment of a converter assembly according to the invention (inverter stack) with six parallel connected, bidirectionally operable half bridges for realizing a 3-phase electrical converter.

The converter assembly comprises six electrical connection terminals 2 arranged next to one another, each of which is connected to six outputs of circuit breakers 1 in the form of SiC half-bridges via winding conductor track loops 5. To ensure the distance between the circuit breakers 1 and the first printed circuit board 3 arranged above it, an elongated carrier 7 is provided. The carrier 7 is attached to a heat sink 10 ‘and stabilizes the position of the circuit breaker 1 and the first printed circuit board 3 with respect to one another.

Furthermore, on the carrier 7 there is a holding element 12 with a stop edge for positively receiving the first printed circuit board 3. When assembling the assembly, the first printed circuit board 3 is pushed under the stop edge of the holding element 12 and rests on the carrier 7; as a result, the position of the first printed circuit board 3 in relation to the circuit breaker 1 is fixed. The circuit breakers 1 are flatly connected on their underside to a massive cooling plate 10 'in order to dissipate thermal power. Also located on the face of the circuit boards for dissipating thermal power are heat sinks 10, which likewise fix the position of the circuit boards. In the assembled state, at least the circuit breakers 1 and the first printed circuit board 3 are arranged in a fixed and immovable manner with respect to one another.

The first printed circuit board 3 is arranged parallel to its surface above the level of the circuit breakers 1. Six electronic current sensors 6 in the form of integrated Hall sensors are arranged on this circuit board. The current sensors 6 are arranged in such a way that when the first printed circuit board 3 is positively and accurately introduced onto the carrier 7 and into the holding element 12, they are located as precisely as possible in the center over the winding conductor track loops 5 in order to achieve a good magnetic coupling.

The electrical coupling of the electrical connection terminals 2 to the electronic circuit breakers 1 takes place via contact plates in order to ensure a low electrical resistance. The circuit breakers 1 each have two contact surfaces 15 which, in the assembled state of the module, are connected to contacts of the driver modules on the first printed circuit board 3 located above. Furthermore, capacitor circuits 16 are arranged on the first printed circuit board 3.

Furthermore, a second printed circuit board 4 is provided, on which there are further electronic components. This second printed circuit board 4 is arranged parallel to the surface above the first printed circuit board 3 and is connected to it via plug contacts or the like.

A shielding plate 14 is arranged above the second printed circuit board 4 in order to divert electrical interference. A third printed circuit board 8 with energy supply components 9 is also located above it. Fans are arranged on the end face of the third printed circuit board 8 in order to dissipate thermal power from the energy supply components. All circuit boards are connected to one another in a common housing, so that a compact stack is formed. 1b shows a schematic sectional illustration through a circuit breaker 1 and the first printed circuit board 3 in the area of one of the conductor track loops 5. A cooling plate 10 'is shown, on which the circuit breaker 1 with the connection terminal 2 and the conductor track loop 5 is arranged. An elongated carrier 7 is arranged on the cooling plate 10 ′ and fixes the position of the circuit breaker 1.

Furthermore, a stop edge is provided on the carrier 7, which is dimensioned such that the conductor track loop 5 and the first printed circuit board 3 can rest precisely thereon. A folding element 12, which likewise comprises a stop 13, is arranged above the carrier 7. This interacts with the stop edge of the carrier 7 in such a way that the first printed circuit board 3 is fixed in its position relative to the circuit breaker 1.

Fig. 1c shows a schematic plan view of the first printed circuit board 3 of this embodiment. The six electrical connections 2, the associated six conductor track loops 5, the associated six circuit breakers 1 with their contact surfaces 15, the common carrier 7 and the common folding element 12 are shown .

It can be seen that the conductor track loop 5 is strip-shaped and comprises a feed section and a discharge section. In this illustration, the supply line section is covered by the holding element 12. A first leg 11 and a second leg 11 ‘, which are each arranged at an angle of approximately 90 ° to the inlet or outlet, are located between the supply line section and the discharge section. The first leg 11 extends in one direction, and the second leg 1 T rotated by 180 ° in the opposite direction. Such a shape of the conductor track loop 5 is referred to as meandering or U-shaped.

In the area in which the two legs 11, 11 ″ run spaced apart next to each other in opposite directions, the most homogeneous magnetic field is generated during operation, so that the current sensor 6 is as close as possible in exactly above this area a small distance, preferably below 5 mm, is arranged. This distance is essentially limited by the thickness of the first printed circuit board 3 and is ensured by the dimensions of the carrier 7.

A homogeneous magnetic field in the sense of the invention is to be understood as a magnetic field which is formed from the magnetic fields of two legs arranged in parallel through which the same current flows in opposite directions.

The expansion of the space between the legs 11, 11 is smaller in this embodiment than the width of the legs 11, 11 ″, so that a particularly homogeneous magnetic field can be generated even with low currents.

1d shows a further schematic plan view of the first printed circuit board 3 of this embodiment, the common carrier 7 and the common holding element 12 not being shown. Detail E shows schematically the course of a conductor track loop 5 under the first printed circuit board 3 with the two essentially U-shaped legs 11, 11.

However, the invention is not limited to the exemplary embodiment shown, but rather encompasses all converter assemblies within the scope of the following patent claims.

The term converter used should not be interpreted too narrowly. A converter according to the invention can be understood to mean any controlled electrical and / or electronic circuit which converts a direct voltage into another direct voltage or alternating voltage, or converts an alternating voltage into another alternating voltage or direct voltage. Such a circuit can be, for example, but not exclusively, a direct converter, a matrix converter, an AC voltage converter, a DC voltage converter, a switched bridge inverter, a switched bridge rectifier or the like. The concrete circuit implementation of the Converter is not essential. Converters provided according to the invention can also provide internal galvanic isolation and can be provided for high electrical powers, for example powers in the range of 100 kW with a direct voltage of 850 V or 300 kVA alternating current power.

List of reference symbols

1 circuit breaker

2 connection terminal

3 First circuit board

4 Second circuit board

5 conductor loop

6 current sensor

7 carriers

8 Third circuit board

9 Power supply component 10, 10 ‘heat sink

11, 11 "legs

12 retaining element

13 stop

14 shield plate

15 contact surfaces

16 Capacitor circuit

Claims

1. Comprehensive converter assembly

- At least one electronically controlled power switch (1), in particular a SiC-MOSFET or GaN-MOSFET, which is connected to a low-resistance electrical connection terminal (2),

- A first printed circuit board (3) with at least one contactless current sensor (6), in particular a magnetic Hall sensor, characterized in that

- The connection terminal (2) is connected to the circuit breaker (1) via a coiled conductor track loop (5), wherein

- The conductor track loop (5) comprises a first leg (11) and a second leg (11 ^{') rotated by 180 °,}

- The first printed circuit board (3) being arranged in relation to the conductor track loop (5) in such a way that the current strength of a current flowing through the conductor track loop (5) can be measured by the current sensor (6), wherein

- The current sensor (6) is arranged above and in the middle in the area between the legs (11, 11 ^' ).

2. Converter assembly according to claim 1, characterized in that the current sensor (6) are arranged essentially centered and centrally above the conductor track loop (5).

3. Converter assembly according to one of claims 1 or 2, characterized in that the legs (11, 11 ‘) have essentially the same width and length and in particular run essentially parallel to one another.

4. Converter assembly according to one of claims 1 to 3, characterized in that the conductor track loop (5) has a supply line and a discharge line, which each enclose an angle of approximately 90 ° with the legs (11, 11 ').

5. Converter assembly according to one of claims 1 to 4, characterized in that the distance between the legs (11, 11 ‘) is smaller than the width of the legs (11, 11‘).

6. Converter assembly according to one of claims 1 to 5, characterized in that the current sensor (6) partially overlaps both legs (11, 11 ‘).

7. Converter assembly according to one of claims 1 to 6, characterized in that an insulating carrier (7) ensuring the distance between the conductor track loop (5) from the first printed circuit board (3) is provided.

8. converter assembly according to claim 7, characterized in that a holding element (12) is provided which rests on the carrier (7) and the position of the first circuit board (3) relative to the conductor track loop (5) by a with the first circuit board (3 ) positively interacting stop (13) fixed.

9. Converter assembly according to one of claims 1 to 8, characterized in that the components of the converter assembly are designed to provide a power in the range of over 100 kW at a switching frequency of the electronic circuit breaker (1) in the range of over 20 kHz.

10. Converter assembly according to one of claims 1 to 9, characterized in that a second circuit board (4) with electronic driver components and a third circuit board (8)

Energy supply components (9), is provided, wherein the circuit boards (3, 4, 8) are preferably arranged parallel to one another.

11. Converter assembly according to one of claims 1 to 10, characterized in that at least one heat sink (10, 10 ‘) connected to the circuit breaker (1) is provided.

12. converter assembly according to one of claims 1 to 11, characterized in that six juxtaposed electronic Circuit breakers (1) with connection terminals (2) and conductor track loops (5) are provided, to which six current sensors (6) arranged on the first circuit board (3) are assigned.

13. Converter assembly according to claim 12, characterized in that a common holding element (12) and a common stop (13) for positioning the first printed circuit board (3) relative to the six conductor track loops (5) is provided.