DE102022204592A1 - Circuit arrangement - Google Patents

Abstract

The invention relates to a circuit arrangement (1), comprising a current and voltage sensor system (2) arranged on the network side, set up for detecting phase currents (I) and phase voltages (V) on the network side, a three-phase AC input filter (3), a three-phase active leakage current filter ( 4), three 3-level half bridges (5-x) in NPC connection, and a control device (6), with a three-phase input contact (15) being connected to the three-phase AC input filter (3) on the network side, the three-phase AC -Input filter (3) is connected on the vehicle side to the three-phase active leakage current filter (4), and wherein the three-phase active leakage current filter (4) is connected to the three 3-level half-bridges (5-x), and the control device (6) is connected to it is set up to control and/or regulate the 3-level half bridges (5-x) based on the detected phase currents (I) and phase voltages (V) as a rectifier with power factor correction.

Description

The invention relates to a circuit arrangement.

Electric vehicles can be charged with direct current or alternating current. When charging with alternating current, the alternating current, especially multi-phase, must be converted into direct current in order to be able to be fed to a vehicle-specific charging device (on-board charger, OBC).

The invention is based on the object of creating a circuit arrangement with which a galvanically coupled vehicle charging device of a vehicle can be connected to a multi-phase AC network.

The object is achieved according to the invention by a circuit arrangement with the features of patent claim 1. Advantageous embodiments of the invention result from the subclaims.

In particular, a circuit arrangement is created, comprising a current and voltage sensor system arranged on the network side, set up for detecting phase currents and phase voltages on the network side, a three-phase AC input filter, a three-phase active leakage current filter, three 3-level half-bridges in NPC connection and a control device; wherein a three-phase input contact is connected to the three-phase AC input filter on the network side, the three-phase AC input filter is connected to the three-phase active leakage current filter on the vehicle side, and wherein the three-phase active leakage current filter is connected to the three 3-level half-bridges, and wherein the control device is set up to control and/or regulate the 3-level half bridges based on the detected phase currents and phase voltages as a rectifier with power factor correction (PFC).

The circuit arrangement makes it possible to provide a connection to a multi-phase AC network and a rectification for a galvanically coupled on-board charging device. For this purpose, the circuit arrangement in particular has a three-phase active leakage current filter, which can compensate for leakage currents, in particular with the help of active switching elements. In particular, the active leakage current filter detects the leakage currents and generates compensation currents that are phase-shifted by 180°, which are capacitively coupled into the phases. Furthermore, the design of the rectifier stage in the form of three 3-level half bridges, each with four power semiconductor switches, allows a system that is easily scalable in terms of performance. By distributing a total power flow to the 12 power semiconductor switches when charging, power classes of 11 kW, 22 kW and 43 kW (with currents in the range of, for example, 16 A, 32 A and 64 A) can be covered. This can be done in particular without increasing costs or requiring more space. Furthermore, the design of the circuit arrangement allows a very compact arrangement of the components, so that the circuit arrangement can be provided in a very small space.

The circuit arrangement is designed in particular to enable a bi-directional flow of energy. Switching frequencies when controlling the power semiconductor switches are in the range from 5 kHz to 16 kHz. In particular, network-side requirements are met with a total harmonic distortion (THD) of < 5%. Furthermore, the circuit arrangement enables energy transfer into the vehicle energy system with a different load that can be adjusted to the phases (unbalanced load operation or unbalanced load compensation). The half bridges in particular have power semiconductor switches based on metal-oxide-semiconductor field effect transistors (MOSFET).

In one embodiment it is provided that power semiconductor switches of the 3-level half bridges are designed on the basis of low-loss power semiconductor switches with a large band gap. This allows the half bridges and the rectifier stage to be operated very energy-efficiently. In particular, this makes air-cooled operation possible, so that effort and installation space can be saved. In particular, power semiconductor switches based on SiC and GaN can be used here.

In one embodiment it is provided that the control device is designed as or includes an application-specific integrated circuit (ASIC). As a result, the control device can be designed to be very compact, so that only little installation space is required. Alternatively, provision can also be made to use an appropriately programmed microcontroller or microprocessor.

In one embodiment it is provided that the circuit arrangement has a cooling device on which at least the power semiconductor switches of the 3-level half bridges are arranged. The cooling device is in particular a passive cooling device.

In one embodiment it is provided that the cooling device comprises an aluminum block with cooling fins. In this way, in particular, a passive cooling device can be provided, which can be provided and operated cost-effectively.

In one embodiment it is provided that HS components and LS components are arranged on different sides of the cooling device. As a result, the installation space can be further reduced. HS refers in particular to the high side or the high side potential of the rectifier formed by the half bridges and LS refers in particular to the low side or the low side potential of the rectifier.

In one embodiment it is provided that at least one cooling channel for a fluid is formed in and/or on the cooling device. This can improve heat dissipation. The fluid can be a gaseous or liquid coolant. In the simplest case, the fluid is air, whereby the air can basically be guided actively through the cooling channel using a fan or passively.

In one embodiment it is provided that the circuit arrangement is formed in or on a charging socket of a vehicle. Due to the compact design, the circuit arrangement requires little installation space and can therefore be arranged directly in or on the charging socket or a housing of the charging socket.

In one embodiment it is provided that the circuit arrangement is formed in a charging plug. Due to the compact design, the circuit arrangement requires little space and can therefore be arranged directly in or on the charging plug. The charging plug can in particular be a charging plug of a combined charging system (CCS).

A vehicle is also created, comprising at least one circuit arrangement according to one of the described embodiments and/or at least one charging socket according to one of the described embodiments. A vehicle is in particular a motor vehicle, but can also be another land, rail, water, air or space vehicle.

A charging plug is also created, comprising at least one circuit arrangement according to one of the described embodiments. Due to the compact design, the circuit arrangement requires little space and can therefore be integrated directly into the charging plug of a charging cable.

A charging socket is also proposed, comprising at least one circuit arrangement according to one of the described embodiments.

• 1 eine schematische Darstellung einer Ausführungsform der Schaltungsanordnung;
• 2 eine schematische Darstellung zur Verdeutlichung einer Ausführungsform der Ladebuchse;
• 3 eine schematische Darstellung zur Verdeutlichung einer Ausführungsform des Ladesteckers;
• 4 eine schematische Darstellung zur Verdeutlichung einer Ausführungsform der Schaltungsanordnung;
• 5 eine schematische Darstellung zur Verdeutlichung einer Ausführungsform der Schaltungsanordnung.

The invention is explained in more detail below using preferred exemplary embodiments with reference to the figures. Show here:

• 1 a schematic representation of an embodiment of the circuit arrangement;
• 2 a schematic representation to illustrate an embodiment of the charging socket;
• 3 a schematic representation to illustrate an embodiment of the charging plug;
• 4 a schematic representation to illustrate an embodiment of the circuit arrangement;
• 5 a schematic representation to illustrate an embodiment of the circuit arrangement.

The 1 shows a schematic representation of an embodiment of the circuit arrangement 1. The circuit arrangement (1) enables a galvanically coupled vehicle charging device 20 (on-board charger, OBC) of a vehicle to be connected to an AC network.

The circuit arrangement 1 comprises a current and voltage sensor system 2 arranged on the network side, a three-phase AC input filter 3, a three-phase active leakage current filter 4, three 3-level half-bridges 5-1, 5-2, 5-3 in NPC connection and a control device 6.

The voltage sensor system 2 is set up to detect phase currents I and phase voltages V of three phases L1, L2, L3 on the network side. The detected phase currents I and phase voltages V are supplied to the control device 6 as input values.

On the mains side, a three-phase input contact 15 is connected to the three-phase AC input filter 3. The three-phase AC input filter 3 includes a differential mode filter 3-1 and a common mode filter 3-2. In front of and behind the three-phase AC input filter 3, the phases L1, L2, L3 are connected to a protective earth (PE) via capacitors (without reference numbers).

The three-phase AC input filter 3 is connected to the three-phase active leakage current filter 4 on the vehicle side. The three-phase active leakage current filter 4 serves in particular to prevent earth currents at several earth points. For this purpose, the three-phase leakage current filter 4 detects in particular the leakage currents and generates compensation currents that are phase-shifted by 180°. The compensation currents are then capacitively coupled into the phases L1, L2, L3. The three-phase active leakage current filter 4 or the compensation of the leakage currents enables operation in particular with the galvanically coupled on-board charging device 20.

The three-phase active leakage current filter 4 is connected to the three 3-level half bridges 5-x. The connection is made via a center tap 10-x of the half bridges 5-x. The three 3-level half bridges 5-x each include four power semiconductor switches T1, T2, T3, T4 (for the sake of clarity, only shown for the half bridge 5-1) each with freewheeling diodes D1, D2, D3, D4 connected in parallel (for the sake of clarity only shown for half bridge 5-1). The three 3-level half bridges 5-x are connected to Neutral Point Clamped (NPC). For this purpose, the half bridges 5-x each have two diodes D5, D6 (for the sake of clarity only shown for half bridge 5-1), the diode D5 being connected on one side to a tap 11 between the two power semiconductor switches T1, T2 on the high side HS is and the diode D6 is connected to a tap 12 between the two power semiconductor switches T3, T4 on the lowside LS. On the other hand, the diodes D5, D6 are all connected to each other and the neutral point N.

On the output side, the highside HS and the lowside LS are each connected to the neutral point N via an intermediate circuit capacitor C-HS, C-LS.

The control device 6 is set up to control and/or regulate the 3-level half bridges 5-x based on the detected phase currents I and phase voltages V as a rectifier with power factor correction (PFC). This is done in a manner known per se. For this purpose, the control device 6 controls in particular the individual power semiconductor switches Tx of the half bridges 5-x, in particular by means of a pulse width modulation (PWM) method.

On the output side, the circuit arrangement 1 can then be connected to the galvanically coupled on-board charging device 20 of the vehicle.

It can be provided that the power semiconductor switches Tx of the 3-level half bridges 5-x are designed based on low-loss power semiconductor switches with a large band gap, in particular based on SiC or GaN.

It can be provided that the control device 6 is designed as an ASIC 7 or includes one. Alternatively or additionally, the control device 6 can also include a correspondingly programmed microcontroller or a microprocessor.

It can be provided that the circuit arrangement 1 has a cooling device 30 (shown only schematically), on which at least the power semiconductor switches Tx of the 3-level half bridges 5-x are arranged.

It can be further provided that the cooling device 30 comprises an aluminum block 34 with cooling fins 35 (cf. 5 ).

It can be provided that high side (HS) components 8 ( 3 and 4 ) and low side (LS) components 9 are arranged on different sides of the cooling device 30. This allows an extremely compact design to be realized.

It can also be provided that at least one cooling channel 33 for a fluid 36 is formed in and/or on the cooling device 30.

It can be provided that the circuit arrangement 1 is formed in or on a charging socket 51 of a vehicle 50. This is schematic in the 2 shown. This is possible in particular because air cooling is possible due to the circuit design. In this embodiment, efficient power semiconductor switches (MOSFETs) based on SiC or GaN are provided in particular, as well as a cooling device according to one of the embodiments described above, which enables air cooling.

Alternatively, it can be provided that the circuit arrangement 1 is formed in a charging plug 60, for example in a CCS charging plug. This is schematic in the 3 shown. This is possible in particular because air cooling is possible due to the circuit design. In this embodiment, efficient power semiconductor switches (MOSFETs) based on SiC or GaN are provided in particular, as well as a cooling device according to one of the embodiments described above, which enables air cooling.

In the 4 a schematic representation is shown to illustrate an embodiment of the circuit arrangement, in which the circuit arrangement has a cooling device 30, on which at least the power semiconductor switches of the 3-level half bridges are arranged. A schematic perspective view of the cooling device 30 is also at the top right in the 4 shown. In this embodiment, it is particularly provided that HS components 8 and LS components 9 are arranged on different sides 31, 32 of the cooling device 30. This enables a very compact design with reduced space requirements. The HS components 8 are arranged on an upper side 31 of the cooling device 30 and the LS components 9 on a lower side 32 of the cooling device 30.

It is furthermore provided in particular that a cooling channel 33 for a fluid 35 is formed in and/or on the cooling device 30.

It can also be provided that the cooling device 30 comprises an aluminum block 34 with cooling fins 35, as shown schematically in FIG 5 is indicated. This allows for low-effort air cooling.

Reference symbol list

1

Circuit arrangement

2

Current and voltage sensors

3

AC input filter

3-1

push-pull filter

3-2

Common mode filter

4

active leakage current filter

5-x

3 level half bridge

6

Control device

7

ASIC

8th

HS components

9

LS components

10-x

Center tap

11

tap

12

tap

15

Input contact

20

Loading device

30

Cooling device

31

Top

32

bottom

33

Cooling channel

34

Aluminum block

35

cooling fins

36

Fluid

50

vehicle

51

charging socket

60

Charging plug

C-HS

DC link capacitor

C-LS

DC link capacitor

D1-D4

Freewheeling diodes

D5, D6

diode

H.S

Highside

I

Phase currents

L1

phase

L2

phase

L3

phase

L.S

Lowside

N

Neutral point

P.E

protective conductor

Tx

Power semiconductor switch

v

Phase voltages

Claims (10)

Circuit arrangement (1), comprising: a current and voltage sensor system (2) arranged on the network side, set up for detecting phase currents (I) and phase voltages (V) on the network side, a three-phase AC input filter (3), a three-phase active leakage current filter (4), three 3-level half-bridges (5-x) in NPC connection, and a control device (6), a three-phase input contact (15) being connected to the three-phase AC input filter (3) on the mains side, wherein the three-phase AC input filter (3) is connected to the three-phase active leakage current filter (4) on the vehicle side, and wherein the three-phase active leakage current filter (4) is connected to the three 3-level half bridges (5-x), and wherein the control device (6) is set up to control and/or regulate the 3-level half-bridges (5-x) based on the detected phase currents (I) and phase voltages (V) as a rectifier with power factor correction. Circuit arrangement (1) according to Claim 1 , characterized in that power semiconductor switches (Tx) have the 3-level half bridges (5-x). Base of low-loss power semiconductor switches with a large band gap are formed. Circuit arrangement (1) according to Claim 1 or 2 , characterized in that the control device (6) is designed as an ASIC or includes one. Circuit arrangement (1) according to one of the preceding claims, characterized by a cooling device (30) on which at least the power semiconductor switches (Tx) of the 3-level half bridges (5-x) are arranged. Circuit arrangement (1) according to Claim 4 , characterized in that the cooling device (30) comprises an aluminum block (34) with cooling fins (35). Circuit arrangement (1) according to Claim 4 or 5 , characterized in that the HS components (8) and the LS components (9) are arranged on different sides of the cooling device (30). Circuit arrangement (1) according to one Claims 4 until 6 , characterized in that at least one cooling channel (33) for a fluid (36) is formed in and/or on the cooling device (30). Charging socket (51), comprising at least one circuit arrangement (1) according to one of Claims 1 until 7 . Vehicle (50), comprising at least one circuit arrangement (1) according to one of Claims 1 until 7 and/or a charging socket (51). Claim 8 . Charging plug (60), comprising at least one circuit arrangement (1) according to one of Claims 1 until 7 .

Images