N-component power electronic circuit with common intermediate circuit capacitor

Abstract

This invention relates to power electronic circuits, particularly power electronic circuits for vehicles, and especially power electronic circuits for vehicles having at least one drive motor, wherein power electronic modules (10, 10-i) of at least three different functional components (20, 20-i) are coupled to each other in an intermediate circuit (100) at a DC voltage level. A power electronic circuit (1) is proposed comprising a plurality of N power electronic modules (10, 10-i) of N functional components, which are coupled to each other in an intermediate circuit (100) at a DC voltage level, wherein all of the plurality of N power electronic modules (10, 10-i) are directly connected to an intermediate circuit capacitor (110).

Description

Technical Field

[0001] The present invention relates to power electronic circuits, particularly power electronic circuits for vehicles, especially power electronic circuits for vehicles having at least one drive motor, wherein power electronic modules of at least two different functional components are coupled to each other in an intermediate loop at the DC voltage level. Background Technology

[0002] In vehicles, especially those with drive motors, there are components that fulfill a variety of different functions. Besides traction inverters that ensure multi-phase energization of the motor, such as the stator, these components include, for example, low-voltage DC-DC converters for operating a low-voltage power grid (e.g., on-board electrical grid), and EMV filter circuits for batteries (especially traction batteries), where EMV stands for electromagnetic compatibility. Other functional components may include high-voltage DC-DC converters, filter circuits and / or current regulator circuits for the rotor current of separately excited synchronous motors (FSMs), or DC-AC converters for operating AC voltage consumers or for constructing chargers integrated into the vehicle.

[0003] To ensure energy coupling at the DC voltage level of the intermediate circuit, in the prior art, each power electronic module of the functional component typically has a capacitor that is electrically connected between the connecting elements of the power electronic module.

[0004] US 2020 / 328027 A1 describes a system for preventing overheating of an intermediate circuit capacitor in an electric vehicle, comprising: an intermediate circuit capacitor having a positive electrode and a negative electrode; a pair of buses, wherein a positive bus is connected to the positive electrode of the intermediate circuit capacitor and a negative bus is connected to the negative electrode of the intermediate circuit capacitor; a dielectric layer located between the positive bus and the negative bus; a pair of DC output connections connected to the bus; and a heat sink positioned below and in contact with the bus. Summary of the Invention

[0005] The technical objective of this invention is to create a power electronic circuit that minimizes structural space and improves circuit consumption, particularly in terms of high-voltage protection and efficiency.

[0006] The present invention solves this problem using a power electronic circuit according to the present invention.

[0007] The concept upon which this invention is based is to integrate a power electronic module with multiple N functional components (which are coupled to each other at a DC voltage level) into an intermediate circuit with exactly one intermediate circuit capacitor.

[0008] In particular, a power electronic circuit is proposed, comprising multiple N power electronic modules with N functional components. These power electronic modules are coupled to each other in an intermediate loop at the DC voltage level. All N power electronic modules are directly connected to the intermediate loop capacitor. Each functional component is a self-contained functional unit. Therefore, there are N distinct functional units, where N always represents a natural number greater than 2.

[0009] This allows for a simpler construction of individual power electronic modules. The structural space is reduced. Power losses due to line inductance can be decreased.

[0010] In a preferred embodiment, the intermediate circuit capacitor has two contact elements, and each of the plurality of N power electronic modules has at least one pair of connecting elements, wherein all pairs of connecting elements are connected to the two contact elements of the intermediate circuit capacitor respectively. This further minimizes line losses.

[0011] It should be noted that the power electronics module of the inverter circuit, which provides different phases for energizing the motor (e.g., the stator of a separately excited synchronous motor (FSM),) has a pair of connection elements for each phase. If three-phase current is used, the power electronics module of the inverter circuit has three pairs of connection elements. However, since these connection elements collectively fulfill a function, the inverter bridge in the sense of the present invention does not constitute a distinct functional component or functional unit. Two similar but redundant and non-cooperative functional components (e.g., two low-voltage DC-DC converters (DC / DC converters) for operating two separate low-voltage on-board power grids) constitute distinct functional components in the sense of the present invention.

[0012] Preferably, the contact element is constructed as a busbar. These buses are also referred to as busbars. The busbar is preferably constructed as a flat planar conductor, which has a localized extension in the direction perpendicular to the surface normal that is significantly smaller, typically at least one order of magnitude, than in the other two spatial directions, which are oriented parallel to the surface of the planar conductor and expand the surface of the conductor and together with the normal direction expand the three-dimensional coordinate system.

[0013] A surface conductor may have cantilever and protrusion, which are respectively constructed in a plane that coincides with the plane in which the surface conductor is spread out at the corresponding cantilever / protrusion.

[0014] To facilitate shielding for high-voltage protection, in a preferred embodiment, all voltage-carrying components in the intermediate circuit are encapsulated in a housing.

[0015] Preferably, the housing includes an electromagnetic shielding device. This significantly improves electromagnetic compatibility.

[0016] Particularly preferably, most of the N power electronic modules are integrated into the housing; even more preferably, all of the N power electronic modules are integrated into the housing.

[0017] In a particularly preferred embodiment, the electromagnetic shielding of the housing surrounds the power electronics module integrated into the housing. This achieves optimal reduction of electromagnetic interference. It also allows for at least partial use of unshielded wiring to functional components, or simplifies the construction and fabrication of additional post-filters.

[0018] A single power electronics module can be simplified and does not have capacitors between its pair of connecting elements or its multiple pairs of connecting elements (except for intermediate loop capacitors).

[0019] The intermediate circuit consists of only one intermediate circuit capacitor. This intermediate circuit capacitor is constructed in a structural unit that is electrically isolated from other components, except for the contact elements.

[0020] In this way, a power electronic module with N functional components can operate using an intermediate circuit capacitor.

[0021] This type of power electronic circuit can be used with both shielded and unshielded motors. Attached Figure Description

[0022] The invention will now be explained in more detail with reference to the accompanying drawings. Herein: Figure 1 A power electronic circuit with multiple N power electronic modules having N functional components is shown. Detailed Implementation

[0023] exist Figure 1 The diagram schematically illustrates a power electronic circuit 1. The power electronic circuit 1 comprises multiple N power electronic modules 10, 10-i. The power electronic modules 10, 10-i are coupled to each other in an intermediate loop 100 at a common DC voltage level.

[0024] The suffix "-i" represents the counting index of power electronics modules and functional components.

[0025] Power electronics modules 10, 10-i comprise multiple N different functional components 20, 20-i of power electronics. In this sense, "different" means that the functional components are separate in terms of circuit technology (except for their coupling in a common intermediate loop 100) and function. In this sense, two low-voltage DC-DC converters are different functional components, even though they are constructed of the same type or even identically. Conversely, an inverter for generating multiphase AC voltage constitutes a single functional component, although the bridges for different phases are individually connected to the intermediate loop.

[0026] To achieve energy coupling at the DC voltage level, intermediate circuit 100 has exactly one intermediate circuit capacitor 110. This intermediate circuit capacitor has two poles 111, 121, which include contact elements 112, 122. Contact elements 112, 122 are preferably configured as buses 113, 123, also referred to as busbars. Busbars 113, 123 are preferably configured as flat planar conductors 114, 124, respectively. The planar conductors 114, 124 have surfaces perpendicular to them, having dimensions smaller than those along spatial directions within the planes of the planar conductors. Preferably, at each point, the dimension along the surface normal 150 is more than an order of magnitude smaller than the extension along directions 151, 152 in the plane of the planar conductors 114, 124. The planes of the two planar conductors 114, 124 or the planar contact elements 112, 122 are preferably oriented at least partially parallel to each other (when viewed along the surface normal). Where they do not overlap, these planes are preferably guided side by side in parallel.

[0027] Contact elements 112, 122 may have cantilevered arms 115, 125 and / or branches 116, 126 and / or protrusions 117, 127, which are preferably used as connection points for connection elements 31, 32, 31-i, 32-i for functional components 20, 20-i. Therefore, each functional component has at least one pair of connection elements 31, 32, 31-i, 32-i for 30, 30-i. Between the pairs of connection elements 31, 31-i, 32, 32-i, no additional capacitors causing energy coupling are constructed in the respective power electronics modules 10, 10-i. Therefore, the power electronics modules 10, 10-i do not have capacitors between their pair of 30, 30-i or their multiple pairs of 30-k, 30-ik connecting elements 31, 31-i, 32, 32-i, or if they do, they have at most one capacitor for a function different from that of the intermediate loop capacitor (e.g., for filtering purposes). Such a capacitor (if present) typically has a capacitance that corresponds at most one-tenth (1 / 10), more preferably at most one-hundredth (1 / 100), and even more preferably at most one-hundred-and-fiftieth (1 / 150) of the capacitance of the intermediate loop capacitor. The suffix term "-k" represents the counting index of the connecting portion of functional element i to 30, 30-i, for example, in an inverter circuit used to provide multiphase current to the stator of, for example, a motor. For clarity, the power electronics modules 10, 10-i and their connecting elements 31, 32, 31-i, 32-i, 31-ik, 32-ik are presented separately from the intermediate circuit 100 and its contact elements 112, 122.

[0028] To achieve electrical shielding, the power electronic circuit 1 is preferably encapsulated in the housing 200. Particularly preferably, multiple power electronic modules 10, 10-i, and more preferably all of the power electronic modules 10, 10-i, are also surrounded by the housing 200.

[0029] To achieve good electromagnetic compatibility of the power electronic circuit 1, the housing preferably has an EMV shielding device 210.

[0030] In the illustrated embodiment, power electronic modules 10-1 to 10-7, which are exemplarily constructed with functional components in power electronic circuit 1, include: a multiphase inverter 20-1, a DC-AC converter 20-2 of a so-called onboard charger, a low-voltage DC-DC converter 20-3, a high-voltage DC-DC converter 20-4, an EMV filter 20-5 for connecting to battery 300, an air conditioning compressor 20-6, and a filter / current regulator 20-7 for the rotor current of a separately excited synchronous motor.

[0031] Only one exemplary implementation is presented.

[0032] List of reference numerals 1 Power Electronic Circuits 10,10-i Power Electronics Module 20,20-i Functional Components 20-1 Multiphase Inverter 20-2 DC-AC Converter 20-3 Low-voltage DC-DC converter 20-4 High Voltage Direct Current to Direct Current Converter 20-5 EMV filter 20-6 Air Conditioner Compressor 20-7 Filter / Current Regulator (for FSM) 30, 30-i, 30-k, 30-ik (connecting elements) 31, 31-i, 31-ik connecting elements 32, 32-i, 32-ik connecting elements 100 intermediate loop 110 Intermediate circuit capacitor 111 Extreme 112 Contact element 113 Busbar 114-faceted conductor 115 cantilever 116 branches 117 protrusions 121 poles 122 Contact element 123 Busbar 124-face type conductor 125 cantilever 126 branches 127 protrusions 150 Surface Normal 151 direction 152 direction 200 housing 210 (EMV) shielding device 300 batteries.

Claims

1. A power electronic circuit (1) comprising a plurality of N power electronic modules (10, 10-i) with N functional components, wherein the power electronic modules are coupled to each other in energy and at the DC voltage level in an intermediate circuit (100), characterized in that, All of the multiple N power electronic modules (10, 10-i) are directly connected to the intermediate circuit capacitor (110).

2. The power electronic circuit (1) according to claim 1, characterized in that, The intermediate circuit capacitor (110) has two contact elements (112, 122), and each of the plurality of N power electronic modules (10, 10-i) has at least one pair of connecting elements (31, 31-i, 31-ik, 32, 32-i, 32-ik) (30, 30-i, 30-ik), wherein all pairs of connecting elements (31, 31-i, 31-ik, 32, 32-i, 32-ik) are respectively connected to the two contact elements (112, 122) of the intermediate circuit capacitor (110).

3. The power electronic circuit (1) according to claim 2, characterized in that, The contact elements (112, 122) are busbars (113, 123).

4. The power electronic circuit (1) according to any one of the preceding claims, characterized in that, All voltage-carrying components of the intermediate circuit (100) are encapsulated in the housing (200).

5. The power electronic circuit (1) according to claim 4, characterized in that, The housing (200) includes an electromagnetic shielding device (210).

6. The power electronic circuit (1) according to claim 4 or 5, characterized in that, Most of the plurality of N power electronic modules (10, 10-i) are integrated into the housing (200).

7. The power electronic circuit (1) according to claim 6, characterized in that, All of the multiple N power electronic modules (10, 10-i) are integrated into the housing (200).

8. The power electronic circuit (1) according to any one of claims 6 or 7, characterized in that, The electromagnetic shielding device (210) of the housing (200) surrounds the power electronic module (10, 10-i) integrated into the housing (200).

9. The power electronic circuit (1) according to any one of the preceding claims, characterized in that, The plurality of N power electronic modules (10, 10-i) do not have capacitors between their pair of connecting elements (31, 31-i, 31-ik, 32, 32-i, 32-ik) or their multiple pairs of connecting elements (31, 31-i, 31-ik, 32, 32-i, 32-ik).

10. The power electronic circuit (1) according to any one of the preceding claims, characterized in that, The intermediate circuit (100) includes only one intermediate circuit capacitor (110), and the intermediate circuit capacitor (110) is constructed in the structural unit.

Images