Power converter module
Patent Information
- Authority / Receiving Office
- DE · DE
- Patent Type
- Patents
- Current Assignee / Owner
- SIEMENS MOBILITY GMBH
- Filing Date
- 2024-09-19
- Publication Date
- 2026-07-16
AI Technical Summary
Existing power converter modules face challenges in achieving uniform current distribution and low inductance across power semiconductor modules, leading to inefficiencies and high switching losses, particularly at high frequencies.
The design includes planar busbars that are angled and non-penetrating, with insulating layers and recesses to facilitate mechanical connections, ensuring uniform current distribution and low inductance, while using copper material for good conductivity and insulating films for electrical insulation.
This design achieves uniform inductive behavior and lower switching losses, enhancing energy efficiency and facilitating easy assembly with reduced inductance and improved accessibility.
Smart Images
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Abstract
Description
[0001] The invention relates to a power converter module, a power converter comprising at least one power converter module according to the invention, and a vehicle, in particular a rail vehicle, comprising at least one power converter module according to the invention or at least one power converter according to the invention.
[0002] European patent application EP 3 404 818 A1 discloses a semiconductor circuit arrangement in which the DC and AC terminals of half-bridge modules are connected by means of positive and negative DC busbars and AC busbars such that the busbars are arranged without interpenetration, and a symmetrical current distribution across electrically parallel-connected half-bridge modules and a low overall inductance are achieved due to minimal inductance differences. Interpenetration-free means that none of the busbars needs to penetrate another to be connected to the terminals of the half-bridge modules. The AC busbars form the busbar closest to the half-bridge modules, and the DC busbars form the second nearest or furthest busbar.The exact design, in particular of the DC busbars and their connections to the DC terminals of the half-bridge modules, is not specified.
[0003] The object of the invention is therefore to specify embodiments of the DC busbars and their connections in a power converter module. This object is achieved by the respective features of the independent claims. Further developments are specified in the respective dependent claims.
[0004] A power converter module according to the invention comprises a heat sink with a planar top surface, a plurality of power semiconductor modules, wherein the power semiconductor modules each have a basically cuboid module housing with end faces, longitudinal sides, and top and bottom surfaces, each having DC voltage connections and AC voltage connections on the top surface, wherein the DC voltage connections are arranged in the region of a first end face and the AC voltage connections in the region of a second end face, and wherein first DC voltage connections for a first voltage potential are arranged near the first end face and second DC voltage connections for a second voltage potential are arranged further away from the first end face, and are arranged in parallel rows on the top surface of the heat sink, each row comprising power semiconductor modules arranged side by side and spaced apart from one another.and wherein the second end faces of the module housings of adjacent rows face each other and their first end faces face away from each other, a plurality of busbars, wherein a first busbar electrically connects the first DC terminals and a second busbar electrically connects the second DC terminals of the power semiconductor modules of the rows, wherein the first and the second busbars are planar at least in the region of the power semiconductor modules to be connected and are arranged parallel to each other and one above the other at least in the planar region, and wherein the planar region is arranged at a distance above the power semiconductor modules. The converter module is characterized in thatthat the first busbar is angled in a region between the first and second DC terminals of the respective power semiconductor module and is guided perpendicularly to the planar region up to a plane of the first DC terminals, is angled in the direction of the first DC terminals on the plane of the first DC terminals and forms a first connection region, that the second busbar is also angled in the region between the first and second DC terminals or in a region between the second DC terminals and the AC terminals of the respective power semiconductor module and is guided perpendicularly to the planar region up to a plane of the second DC terminals, is angled in the direction of the second DC terminals on the plane of the second DC terminals and forms a second connection region,and that the first connection area is mechanically connected to the first DC voltage terminals and the second connection area to the second DC voltage terminals of the respective power semiconductor module.
[0005] A power converter according to the invention, in particular for an electric drive system of a vehicle, comprises at least one power converter module according to the invention.
[0006] A vehicle according to the invention comprises at least one converter module according to the invention or at least one converter according to the invention, wherein the vehicle is in particular designed as a rail vehicle.
[0007] Such a rail vehicle is designed in particular for local, regional or long-distance transport and especially as a multiple unit train with a number of carriages for the transport of passengers.
[0008] In accordance with the semiconductor switching arrangement described in the introduction of European Patent Application EP 3 404 818 A1, the arrangement according to the invention of the power semiconductor modules and the busbars connecting them, which are arranged without penetration, advantageously leads, particularly at high frequencies at which the power semiconductor switches of the power semiconductor modules are switched, to a uniform distribution of the currents across the power semiconductor modules, a uniform inductive behavior of the power semiconductor modules, and lower switching losses, resulting in higher energy efficiency of the power converter module. The power semiconductor switches are based, for example, on silicon (Si), silicon carbide (SiC), or gallium nitride (GaN).
[0009] The power semiconductor modules can each be configured as a half-bridge module, also in accordance with European patent application EP 3 404 818 A1. By appropriately connecting the AC voltage terminals of the majority of the power semiconductor modules and using suitable control, the converter module can, for example, function as a pulse inverter, which converts a DC voltage, for example from the DC link of a power converter, into a three-phase AC voltage of variable amplitude and frequency to supply one or more three-phase drive motors, or as a rectifier, for example from a four-quadrant converter, which converts a single-phase AC voltage from a transformer connected to a supply network into a DC voltage to supply the DC link of the power converter.
[0010] In addition to the DC and AC voltage connections, the power semiconductor modules each have control connections via which the switching of the power semiconductor switches can be controlled by a control unit of the power converter. The control connections and the control unit are connected, for example, via control lines, in particular electrical and / or optical ones, with the control connections being located, for example, on the top of the module housing and between the AC voltage connections and the second DC voltage connections, and the control lines being routed in the power converter module in the area between the top of the module housing and the underside of the second busbar.
[0011] The module housings of the power semiconductor modules are preferably mechanically connected to the heat sink, on whose planar upper surface they are arranged, particularly via screw connections. A thermally conductive underside of the module housing is also thermally connected to the heat sink, so that heat generated in the power semiconductor modules during operation of the power converter module can be dissipated into the heat sink.
[0012] According to the invention, the planar region formed by the first and second busbars is arranged above and, for example, in a plane parallel to the top surface of the heat sink. The planar region preferably covers the AC terminals and the second DC terminals, but not the first DC terminals of the respective power semiconductor module. Rather, the planar region terminates in the area between the first and second DC terminals of the respective power semiconductor module, in which at least the first busbar is angled and guided perpendicular to the planar region.The area above the first DC terminals and the first terminal area of the first busbar, not covered by the planar area, allows for a conveniently simple mechanical connection between the first terminal area and the first DC terminals of the respective power semiconductor module due to the resulting good accessibility. Screws with a known screw head, such as slotted, Phillips, Allen, hex, or Torx, are preferably used for these mechanical connections. Accordingly, the tool is designed as a manual or automated screwdriver compatible with the screw head.
[0013] The first and second busbars, angled in the area of the first and second DC terminals of the respective power semiconductor module, do not have sharp edges at the transition from the planar area to the vertically guided area, nor at the transition from the vertically guided area to the terminal area. Instead, they preferably have a rounded edge with a specific radius, which facilitates the simple manufacture of the first and second busbars. The busbars are typically made of a copper material with good electrical conductivity.
[0014] According to a further development of the power converter module according to the invention, at least one layer of an electrically insulating material is arranged between the first and the second busbar, wherein the insulating layer is in particular designed as an insulating film, which is arranged on the first busbar at least on the underside facing the second busbar and / or on the second busbar at least on the top side facing the first busbar.
[0015] The insulating film preferably covers at least a portion of the planar area in which the first and second busbars are arranged or stacked directly above one another. Furthermore, an insulating film can be arranged, for example, on both the top and bottom surfaces of the first and second busbars. The films preferably extend beyond the edges of the first busbar to such an extent that they form a sufficiently long creepage distance to prevent charge equalization between the first and second busbars in these edge regions. Preferably, the films are bonded together in the overlapping area, in particular by adhesive.
[0016] In particular, the first and second busbars together with a layer or film arranged between them can be designed as a lamination, at least in the planar area, in which both busbars are bonded to the layer or film.
[0017] By stacking the first and second busbars directly on top of each other or by lamination, a low inductance of the busbars or the DC busbar system can advantageously be achieved.
[0018] According to a further development of the power converter module according to the invention, the second connection areas of the second busbar are mechanically connected to the second DC terminals of the respective power semiconductor module by means of screw connections, and the first busbar or the first and the second busbar have connection-specific recesses above the second DC terminals of the respective power semiconductor module, wherein a cross-section of the respective recess in the plane of the planar area is smaller than a cross-section of a screw head perpendicular to a longitudinal axis of a screw used for the respective screw connection.
[0019] The recesses in the first busbar, or in both the first and second busbars, particularly when they are laminated, serve to mechanically connect the second connection area to the second DC terminals of the respective power semiconductor module using a suitable tool and screws, thereby electrically connecting the second busbar to the respective power semiconductor module. Due to the non-penetrating arrangement of the first and second busbars, and the placement of the second DC terminals on the power semiconductor modules further away from the first end face of the module housing, the second DC terminals are not directly accessible, unlike the first DC terminals. In particular, the second DC terminals of the power semiconductor modules not located at the ends of the rows are practically inaccessible from the side.For this reason, recesses are provided above the second DC voltage connections in the busbar(s) through which the tool can be guided into the area of the second DC voltage connections of the respective power semiconductor module.
[0020] To reduce the adverse effect of the recesses on the inductance of the busbars, an individual recess is provided for every second DC connection. Each recess has a cross-section smaller than the cross-section of the screw head used for the mechanical connection. Particularly when the first and second busbars are designed as a single laminate, it is therefore necessary to position the screws intended for the mechanical connection below the first busbar, or between the underside of the first or second busbar and the second connection area, before the second connection area of the second busbar is joined to the second DC connections of the respective power semiconductor module. This is because, after this joining, the screws can no longer be inserted into this area via the recesses.
[0021] A layer or film arranged between the first and second busbars preferably projects far enough into the respective recess to ensure a sufficiently long creepage distance or sufficient insulation distance between the edges of the busbars. The use of a film has the advantage that, due to its mechanical flexibility, it can be pushed aside without damage, for example, by a tool guided through the recess, and returns to its original shape after the tool is removed. Preferably, however, the film should not be touched during installation to avoid potential damage.
[0022] The screws used for the mechanical connections, preferably corresponding to the mechanical connections of the first connection areas of the first busbar with the first DC terminals of the respective power semiconductor module, again have a known screw head, for example slotted, Phillips, Allen, hexagonal or Torx, and the tool is designed as a manual or automated screwdriver compatible with the screw head.
[0023] According to a further development of the power converter module according to the invention based on the above further development, at least one holding device is provided in the area of the respective second connection area of the second busbar, by means of which the screws used for the screw connections are held at least before the mechanical connection of the second connection area with the second DC voltage connections of the respective power semiconductor module.
[0024] For example, the mounting devices are designed so that they are first fitted with the connecting screws before the fitted mounting device is attached to the second busbar in the area of the second connection points. Fitting the screws before mounting the mounting device to the second busbar is particularly useful if the screw length is greater than the distance between the second connection point and the second or first busbar located above it.
[0025] The holding devices serve to temporarily hold the screws in the area of the respective second connection area of the second busbar, particularly during the above-described joining of the second connection areas with the second DC voltage connections of the respective power semiconductor module, and preferably after their joining, to guide in particular the respective screw head of the screws, so that it is reliably accessible for the tool guided through the recess.
[0026] Preferably, after the mechanical connections of the second connection areas to the second DC terminals of the power semiconductor modules have been made, the holding devices remain connected to the second busbar, so that if the mechanical connections are subsequently loosened, the screws continue to be held and guided.
[0027] The holding device can be made, for example, from an electrically insulating plastic material, in particular by means of an injection molding process or a printing process.
[0028] According to a further development of the power converter module according to the invention, an insulating body is arranged at least in the area between the first and second DC voltage connections of the respective power semiconductor module.
[0029] No insulating layer or foil is provided at the level of the DC connections or connection areas, and possibly in at least a section of the parallel vertical guide of the first and second busbars. In this uninsulated area, and partially overlapping with it, the insulating body serves to ensure a sufficiently long creepage and clearance distance between the busbars.
[0030] The insulating body is designed, for example, to project laterally beyond the connection areas and the vertical guide of the busbars, and can at least partially enclose one or both of the connection areas laterally. In principle, the insulating body can encompass connection areas of several adjacent power semiconductor modules or even all power semiconductor modules in a row. Preferably, however, an individual insulating body is provided for each power semiconductor module, which can, for example, be formed as a single unit with the mounting device and attached together with it to the second busbar.
[0031] Depending on the holding device, the insulating body is made, for example, of an electrically insulating plastic material, in particular by means of an injection molding process or a printing process.
[0032] According to a further development of the power converter module according to the invention, the plurality of busbars additionally comprises third busbars, wherein the third busbars are each electrically connected to AC voltage connections of at least one power semiconductor module, and wherein the third busbars are arranged below and spaced apart from the second busbar.
[0033] According to a further development of the power converter module according to the invention based on the above further development, in a region of the distance between adjacent power semiconductor modules of a row, the length of the vertical guide of the first and second busbars is at least partially reduced, and at least one of the third busbars is guided in this region.
[0034] The third busbars, extending laterally from a series of power semiconductor modules or from the planar area within such a region of reduced length of the vertical guides of the first and second busbars (where this reduced length can also be zero), form, for example, fifth connection areas for AC voltage connections of the converter module. If, for example, the converter module configuration provides three third busbars and corresponding three AC voltage connections, these can be used to connect, for example, motor cables for the three phases of one or more three-phase drive motors. If, for example, the converter module configuration provides two third busbars and corresponding two AC voltage connections, these can be used to connect, for example, a secondary winding of a transformer.
[0035] The reduced length in this area ensures that sufficient insulation distance is maintained between the third busbars and the first and second busbars arranged above them, even in the edge area of the planar area.
[0036] According to a further development of the power converter module according to the invention, the first busbar forms at least a third connection area and the second busbar forms at least a fourth connection area, wherein the power converter module can be connected to DC voltage potentials, in particular of another power converter module and / or a DC voltage component, by means of the third and fourth connection areas, and the third busbars each form at least a fifth connection area, wherein the power converter module can be connected to AC voltage potentials, in particular of an AC voltage component, by means of the fifth connection areas.
[0037] The third and fourth connection areas of the first and second busbars can, for example, be used to connect the converter module directly or via coupling busbars to corresponding connection areas of another converter module of the converter. Preferably, the low inductance of the first and second busbars is maintained in this connection, which means, for example, in a converter configuration with a rectifier, whose function is performed by a first converter module, and a pulse inverter, whose function is performed by a second converter module, the two converter modules can be connected via a common low-inductance DC link. This DC link, or...The third and fourth connection areas of a respective power converter module or the coupling busbars can also be used to connect further components of the power converter, such as a brake controller, a resonant circuit, additional DC link capacitors and / or line chokes, as well as further components outside the power converter, such as an auxiliary power converter and / or a traction battery.
[0038] In contrast, the fifth connection points of the third busbars can be used to connect the converter module, for example, to an AC load, in particular one or more three-phase drive motors, or to an AC voltage source, such as the secondary winding of a transformer. Thus, the fifth connection points of the third busbars of the aforementioned first converter module can serve as AC terminals of the converter, via which it is connected to a transformer, and the fifth connection points of the third busbars of the aforementioned second converter module can serve as AC terminals of the converter, via which it is connected to a number of three-phase drive motors.
[0039] The DC potentials are, for example, a positive and a negative potential of the DC link, where the negative potential can be, for example, ground. The AC potentials, on the other hand, correspond, for example, to either one phase of the transformer or the three phases of a three-phase AC voltage of variable amplitude and frequency, which are provided by the second converter module.
[0040] According to a further development of the power converter module according to the invention, the power converter module further comprises a plurality of capacitors, each capacitor having a capacitor housing and DC voltage connections, the capacitors being arranged above the planar region of the first and second busbars, and the DC voltage connections of the capacitors being arranged on a side of the capacitor housing facing the planar region and being connected to capacitor connection regions of the first and second busbars.
[0041] The capacitors are preferably each part of a distributed DC link capacitor of the power converter. The number of capacitors can, for example, correspond to the number of power semiconductor modules of the power converter module and be arranged in series, just like them. Likewise, the number of capacitors can be determined based on the desired total capacitance of the DC link capacitor. When several power converter modules are connected to form a single power converter, the respective number of capacitors in the power converter modules can also differ and, in particular, again depend on the desired total capacitance of the DC link capacitor.
[0042] The capacitor housing is designed, for example, as a cylindrical or cuboid housing. Particularly in the case of a cylindrical capacitor housing, also referred to as a capacitor can, one or two DC voltage terminals for the positive and negative voltage potentials are arranged on the top side of the housing, while a sensor is arranged on the bottom side to detect a capacitor defect. The longitudinal axis of such a cylindrical capacitor housing is preferably oriented perpendicular to the planar area of the first and second busbars, allowing the majority of capacitors to be arranged side by side on the top side of the planar area.
[0043] The capacitors, or rather their upper surfaces, are preferably arranged a short distance above the planar area. This short distance advantageously results not only in reduced inductance but also in a lower overall height for the converter module. Furthermore, the DC terminals of the capacitors are preferably positioned a short distance from the DC terminals of the power semiconductor modules to ensure advantageously low inductance for this connection as well.
[0044] The DC terminals of the capacitors are mechanically connected to the respective capacitor terminals of the first and second busbars, for example, via screw connections, thus establishing an electrical connection to the respective busbar. The second busbar has a recess at the capacitor terminals of the first busbar, while the first busbar has a recess at the capacitor terminals of the second busbar. These recesses are dimensioned to ensure sufficient insulation between the screw used for the respective screw connection, or the screw head thereof, and the electrically unconnected busbar.
[0045] Due to the capacitors' placement above the planar area or on the top of the first busbar, the screws are inserted into or through the capacitor connection areas from the underside of the planar area or the underside of the first or second busbar and tightened to the DC terminals. However, the small distance between the plane of the DC terminals of the power semiconductor modules and the planar area or the underside of the second busbar, achieved to minimize inductance, means that after mechanically connecting the busbars to the DC terminals of the power semiconductor modules, the capacitors can no longer be connected to the first and second busbars. This is because the space available below the planar area is insufficient to connect the capacitors' DC terminals to the busbars using the screws.
[0046] For this reason, during the assembly of the power converter module, the capacitors are first connected to the first and second busbars in one assembly step, before their terminals are connected to the DC terminals of the power semiconductor modules in a subsequent assembly step. Preferably, the rows of power semiconductor modules have already been mechanically and thermally connected to the heat sink before this subsequent assembly step.
[0047] In addition to the mechanical connection of the capacitors or their DC terminals to the first and second busbars, the capacitor housings are preferably also mechanically connected to a capacitor holding device of the power converter module and are held in a fixed position by this device. Such a capacitor holding device comprises, for example, two brackets which are arranged on opposite sides of the rows of power semiconductor modules or at the row ends and are mechanically connected to the heat sink. The two brackets are connected to each other, for example, along the rows by means of several connecting struts, on which suitable fastening means for attaching the capacitor housings to the connecting struts are arranged.On the side facing away from the capacitor housings, the connecting struts can additionally serve to attach mounting devices for control and / or monitoring equipment of the power converter module. Such equipment is connected, for example, via electrical and / or optical lines to control terminals of the power semiconductor modules and / or to sensors arranged on the power semiconductor modules and / or the capacitors.
[0048] According to a further development of the power converter module according to the invention, cooling fins are formed on at least one underside of the heat sink, or the heat sink has a planar underside parallel to the planar top surface, which is mechanically and thermally connected to another heat sink forming cooling fins, or at least one cooling channel is formed in the heat sink for a flow of a cooling liquid supplied from outside the heat sink.
[0049] In these configurations, the heat dissipated from the power semiconductor modules into the heat sink during operation of the converter module is dissipated from the heat sink to the ambient atmosphere, for example, via cooling fins. Preferably, the converter module is arranged, particularly within a converter housing, such that the cooling fins can be exposed to airflow during vehicle movement. Alternatively or additionally, a forced airflow generated by one or more fans can be directed over the cooling fins. If, however, the heat is dissipated from the heat sink to the ambient atmosphere via a coolant flowing through the heat sink, the coolant is typically cooled outside the converter module or the converter housing before being returned to the heat sink.This cooling of the coolant is achieved, for example, by means of an air-water heat exchanger, through which driving air or a forced airflow is directed.
[0050] The heat sink of the power converter module is made of aluminum, which advantageously offers good thermal conductivity at a low weight. The heat sink can be dedicated to a single power converter module or to multiple modules. A shared heat sink can be particularly useful when several power converter modules are located close to each other and electrically connected, for example, via a common DC link.
[0051] According to a further development of the power converter module according to the invention, the power semiconductor modules in the adjacent rows are arranged such that the second end faces of the module housings face each other directly or offset.
[0052] An offset arrangement of the power semiconductor modules, viewed along the rows, can, for example, create several larger gaps between adjacent power semiconductor modules in one of the rows, each containing a connection area for a third busbar. In contrast, adjacent power semiconductor modules in the other row can, for example, have the same distance between them.
[0053] The invention is explained in more detail below using exemplary embodiments. These include: Fig. 1 a side view of a rail vehicle with an electric drive system, the converter of which comprises three converter modules according to the invention, Fig. 2 a top view of a power converter module according to the invention with a plurality of power semiconductor modules and their connection by means of busbars, Fig. 3 a side view of the power converter module of the Fig. 2, Fig. 4 a detailed view of the side view of the Fig. 3, and Fig. 5 the side view of the power converter module of the Fig. 3 with an alternative design of the second power rail.
[0054] Fig. Figure 1 schematically shows a rail vehicle TZ designed as a multiple unit for passenger transport in a side view. The rail vehicle TZ comprises several coupled cars, of which only one end car EW and a first intermediate car MW coupled to it are shown as examples. The cars EW and MW each have a passenger compartment (not shown) in their respective car bodies WK, which is accessible to passengers both via doors in the side walls of the respective car and via a gangway between adjacent cars. The car bodies WK are supported by two bogies each on the track of a rail network (not shown), with the bogies of the end car EW being designed as powered bogies TDG with drive motors of the AS drive system arranged within them, each driving one wheelset.The bogies of the intermediate car MW, however, are designed as unpowered running bogies LDG.
[0055] The AS drive system of the rail vehicle TZ comprises, in addition to the drive motors in the TDG bogies, further components which are shown schematically in the end car EW, but are preferably arranged in respective containers in the roof and underfloor areas of the end car EW in order to provide a passenger compartment in this car as well. The AS drive system is supplied with electrical energy by an overhead line (not shown) of a supply network, to which a supply voltage, for example a single-phase AC voltage of 25 kV, 50 Hz or 15 kV, 16.7 Hz, is applied. A pantograph PAN is arranged in the roof area of the end car EW for an electrical connection between the AS drive system and the overhead line.
[0056] The electrical energy from the supply network is fed to a transformer TF of the drive system AS, which transforms the single-phase AC voltage on the primary side into a single-phase AC voltage with a lower voltage level on the secondary side. A power converter SR is connected to the secondary side of the transformer TF, which converts the single-phase AC voltage into a DC voltage for a DC link using a rectifier GR, for example, a four-quadrant converter. Two inverters WR, for example, pulse-width modulation (PWM) inverters, of the power converter SR are connected to the DC link. These inverters each convert the DC voltage into a three-phase AC voltage with variable voltage level and frequency, which powers the drive motors in the traction bogies TDG. The drive motors are, for example, three-phase asynchronous motors.Both the rectifier GR and the inverters WR are designed as individual converter modules SRM. The function of the converter modules SRM is controlled by a central control unit ST, in particular a drive control unit, of the rail vehicle TZ, which is connected to the converter SR. In addition to the drive system AS shown as an example, the rail vehicle TZ can include other corresponding drive systems, depending in particular on the required drive power, the components of which are arranged in or on other cars of the rail vehicle TZ. Alternatively, the inverters WR can also be connected to a DC power supply network via a line choke.
[0057] Fig. Figure 2 schematically shows a top view of a power converter module SRM with an exemplary arrangement of nine power semiconductor modules HM1-HM9. The power converter module SRM, or rather its power semiconductor modules HM1-HM9, exemplifies the function of a pulse inverter, as used in the AS drive system of the Fig. 1 is used to supply two drive motors each. The power semiconductor modules HM1-HM9 are designed as identical half-bridge modules, whose respective power semiconductor switches are controlled by the control unit ST via signal lines and respective control connections STA on a top surface GOS of the module housing G.
[0058] The power semiconductor modules HM1-HM9 of the SRM power converter module are mounted on a planar top surface KKOS of a Fig. The two heat sinks (KK) are arranged on the underside of the module housing (G) of the respective power semiconductor module (HM1-HM9) and connected to it both mechanically and thermally. The thermal connection to the underside (GUS) of the module housing (G) of the respective power semiconductor module (HM1-HM9) serves to dissipate heat generated in the power semiconductor modules (HM1-HM9) during operation of the power converter module (SRM). The heat sink (KK) itself may, for example, have cooling fins on its underside (KKUS) through which heat can be transferred to the ambient air flowing over the cooling fins.
[0059] The power semiconductor modules HM1-HM9 are arranged on the heat sink KK in two parallel rows R1 and R2. In the first row R1, six power semiconductor modules HM1-HM6 are arranged side by side and spaced apart along a longitudinal axis LA of the heat sink KK or the power converter module SRM. In the second row R2, three power semiconductor modules HM7-HM9 are arranged side by side and spaced apart. The power semiconductor modules HM1-HM9 of both rows R1 and R2, or rather their opposing second end faces GS2 of the module housings G, are also spaced apart along a transverse axis QA of the heat sink KK or the power converter module SRM.
[0060] Each of the power semiconductor modules HM1-HM9 has multiple electrical connections on the top surface GOS of the module housing G. In addition to the control connections STA located along one long side GLS of the module housing G, AC connections ACA are located along the second end face GS2 of the module housing G, and the first DCA1 and second DCA2 connections are located along the first end face GS1. The second DCA2 connections are located further away from the first DCA1 connection than the first DCA1 connection.
[0061] The DC voltage terminals DCA1, DCA2 and the AC voltage terminals ACA of the power semiconductor modules HM1-HM9 are each connected to one or more busbars or electrically connected in parallel. These busbars, viewed along the vertical axis HA of the heat sink or the converter module SRM, are arranged above the power semiconductor modules HM1-HM9, one above the other or next to each other. The busbars are designed to be non-penetrating.
[0062] One in Fig. The first busbar SS1, marked with a dashed line, connects the first DC terminals DCA1 of all nine power semiconductor modules HM1-HM9. In the busbar arrangement, the first busbar SS1 represents the uppermost level. The first busbar SS1 has a planar area that covers a large portion of the area occupied by the module housings G of the power semiconductor modules HM1-HM9. In the area of the first DC terminals DCA1 of each power semiconductor module HM1-HM9, a first connection area AB1 is formed on the first busbar SS1, via which the first busbar SS1 is mechanically and electrically connected to the first DC terminals DCA1. A third connection area AB3 connects the first busbar SS1 to, for example, a positive voltage potential of the DC link of the converter SR.with a first busbar of a further converter module SRM of the converter SR with the function of a rectifier GR according to the embodiment of the . Fig. 1 connected.
[0063] A second busbar SS2, marked with a dashed line, connects the second DC terminals DCA2 of all nine power semiconductor modules HM1-HM9. In the busbar arrangement, the second busbar SS2 represents the middle layer. Similar to the first busbar SS1, the second busbar SS2 also has a planar section, which likewise covers a large portion of the module housings of the power semiconductor modules HM1-HM9. The planar sections of the first busbar SS1 and second busbar SS2 are positioned close together to achieve low inductance of the DC busbar system of the converter module SRM. Electrical insulation between the first busbar SS1 and the second busbar SS2 is provided by a foil made of an electrically insulating material, in particular a plastic material.Additionally, such a foil can also be arranged on the top of the first busbar SS1, for example to provide protection against contact, should this be necessary. The foil, or both foils, each extend a certain length beyond the edges of the first busbar SS1 to create a sufficiently long creepage distance between the two busbars SS1 and SS2.
[0064] In the area of the second DC terminals DCA2 of the respective power semiconductor module HM1-HM9, a second connection area AB2 is formed on the second busbar SS2, via which the second busbar SS2 is mechanically and electrically connected to the second DC terminals DCA2. A fourth connection area AB4 connects the second busbar SS2 to, for example, a negative voltage potential of the DC link of the converter SR or to the second busbar of another converter module SRM of the converter SR.
[0065] The first and second busbars SS1, SS2, in addition to the first and second connection areas AB1, AB2, also have capacitor connection areas KAB1, KAB2 distributed throughout the planar area. These capacitor connection areas KAB1, KAB2 serve to electrically connect the DC voltage connections KDCA1, KDCA2 of capacitors KON located above the first busbar SS1 or the lamination to the busbars SS1, SS2. The number of capacitor connection areas KAB1, KAB2 depends on the number of capacitors KON and the number of DC voltage connections KDCA1, KDCA2 of the respective capacitor KON. Neither the capacitor connection areas nor the capacitors are in Fig. 2 shown in detail.
[0066] A total of three third busbars SS31, SS32, SS33, each marked with a dash and dotted line, connect the AC terminals ACA of three power semiconductor modules HM1-HM9, wherein a first SS31 of the third busbars connects the AC terminals ACA of the first, second and seventh power semiconductor modules HM1, HM2, HM7, a second SS32 of the third busbars connects the AC terminals ACA of the third, fourth and eighth power semiconductor modules HM3, HM4, HM8, and a third SS33 of the third busbars connects the AC terminals ACA of the fifth, sixth and ninth power semiconductor modules HM5, HM6, HM9. In the arrangement of the busbars, the third busbars SS31, SS32, SS33 represent the lower level. Each of these third busbars has a fifth connection area AB5, which extends from below the first and second busbars SS1, SS2 to the side of the second row R2.The three fifth connection areas AB5 are configured according to the embodiment shown in the . Fig. 1 is connected to motor cables from two drive motors. The SRM power converter module provides the three phases of the three-phase AC voltage for supplying the drive motors via these connection areas AB3.
[0067] Fig. Figure 3 schematically shows a side view of the SRM power converter module. Fig. 2, where only the first power semiconductor module HM1 or HM7 of the parallel rows R1, R2 of the power semiconductor modules HM1-HM9 is shown. The module housings G of the power semiconductor modules HM1, HM7 are mechanically connected to the heat sink KK, with the undersides GUS of the module housings G additionally being thermally connected to the planar top surface KKOS of the heat sink KK. The underside KKUS of the heat sink KK is also designed to be planar, but can have or form cooling fins that are, for example, aligned parallel to the longitudinal axis LA or the transverse axis QA of the heat sink KK.
[0068] The AC terminals ACA on the respective second end face GS2 of the module housing G of the power semiconductor modules HM1 and HM7 are electrically connected to each other via the first SS31 of the three busbars. The third busbar SS31 is located at the same level as the AC terminals ACA and is mechanically and electrically connected to them by means of screw connections (not shown).
[0069] The first DC voltage terminals DCA1, located on the respective first end face GS1 of the module housing G of the power semiconductor modules HM1 and HM7, are mechanically and electrically connected to the respective first terminal area AB1 of the first busbar SS1 by means of screw connections (not shown). The first terminal area AB1 of the first busbar SS1 is located at the same level as the first DC voltage terminals DCA1 and transitions into a perpendicular section of the first busbar SS1 in the area between the first DCA1 and the second DC voltage terminals DCA2. At a distance from the top surface GOS of the module housing G, or from the terminals ACA, DCA1, and DCA2, this perpendicular section transitions into the planar section PB of the first busbar SS1.
[0070] The second DC voltage connections DCA2, also located in the area of the respective first end face GS1 of the module housing G of the power semiconductor modules HM1, HM7, but further away from it, are mechanically and electrically connected to a respective second connection area AB2 of the second busbar SS2, again by means of screw connections (not shown). The second connection area AB2 is also located at the level of the second DC voltage connections DCA2 and transitions in the area between the second DCA2 and the first DC voltage connections DCA1 into a section of the second busbar SS2 that runs perpendicular to this level. The first and second busbars SS1, SS2, which are arranged at a small distance from each other, or rather the lamination of these two busbars SS1, SS2, are thus extended to the level of their respective connection areas AB1, AB2.
[0071] Capacitors KON are arranged above and at a short distance from the planar area PB of the first and second busbars SS1, SS2. DC terminals KDCA1, KDCA2 are located on the underside of the exemplary cylindrical capacitor housing GKON of each capacitor KON. These terminals are mechanically and electrically connected to the respective capacitor connection areas KAB1, KAB2 of the first and second busbars SS1, SS2 by means of screw connections (not shown). A longitudinal axis of each capacitor housing KONG is aligned parallel to the vertical axis of the heat sink KK or the power converter module SRM.
[0072] The KONG capacitor housings are mechanically connected to a capacitor mounting device (not shown) of the SRM power converter module. This device comprises, for example, two brackets located at the respective ends of rows R1 and R2 and mechanically connected to the heat sink. The two brackets are connected to each other, for example, by several connecting struts, to which suitable fasteners are attached to mechanically connect the KONG capacitor housings. On a side facing away from the KONG capacitor housings, the connecting struts can additionally serve to attach a mounting device for control and / or monitoring equipment of the SRM power converter module.These devices are connected, for example, via electrical and / or optical lines to control terminals STA of the power semiconductor modules HM1-HM9 and / or to sensors arranged on the power semiconductor modules HM1-HM9 and / or the capacitors KON.
[0073] The mechanical connection of the DC terminals KDCA1, KDCA2 of the capacitors KON to the first and second busbars SS1, SS2, or to the lamination, is made using screw connections. The screws must be inserted from the underside of the second busbar SS2 into the respective threads of the DC terminals KDCA1, KDCA2. Due to the small distance between the underside of the second busbar SS2 and the top surface GOS of the module housing G, screwing the capacitors KON to the first and second busbars SS1, SS2 is no longer possible if the first and second busbars SS1, SS2 have already been screwed to the power semiconductor modules HM1-HM9 or their DC terminals DCA1, DCA2.For this reason, during the assembly of the SRM power converter module, the DC connections KDCA1, KDCA2 of the capacitors KON should first be screwed to the first and second busbars SS1, SS2, before they are screwed to the DC connections DCA1, DCA2 of the power semiconductor modules HM1-HM9 which are already connected to the heat sink KK.
[0074] Fig. Figure 4 shows an enlarged section of the side view of the Fig. Figure 3 shows only the first power semiconductor module HM1 and the capacitor KON located above the planar area PB. Various recesses in the first and second busbars SS1 and SS2 are also shown schematically; these recesses are not necessarily located in the same plane in a sectional view. The diagram depicts the state after the capacitors KON have been connected to the first and second busbars SS1 and SS2, and the busbars SS1, SS2, and SS3 to the DC and AC terminals DCA1, DCA2, and ACC of the power semiconductor modules HM1-HM9 of the converter module SRM, using the respective screw connections. Therefore, only the screw head SK of each screw connection is shown, while the screw thread is already engaged in the internal thread of the respective terminal. The screw head is shown as a slot for illustrative purposes only.
[0075] The screws used to connect the second terminal AB2 of the second busbar SS2 to the second DC terminals DCA2 are held and guided by a retaining device HV during tightening. The retaining device HV is made, for example, of an electrically insulating plastic material and is designed to accommodate the required number of screws. Before or after the screws are inserted into the retaining device HV, it is mechanically connected to the second busbar SS2, for example, by means of a clamping mechanism.
[0076] Above the second DC terminals DCA2 or the second connection area AB2, the first and second busbars SS1, SS2 have a recess AU in the planar area PB. As indicated by the dashed vertical lines, the recess AU in the plane of the planar area PB has a cross-section that is smaller than the cross-section of the screw head SK located below it. However, the cross-section of the recess AU is sufficiently large to allow a tool for tightening the screw to pass through it. In addition to this small cross-section, an individual recess AU is preferably provided for each screw in order to minimize any negative influence of these recesses AU, required for assembly, on the inductive properties of the first and second busbars SS1, SS2 or the lamination.
[0077] For the mechanical connection of the DC terminals KDCA1, KDCA2 of the capacitor KON to the first and second busbars SS1, SS2, the busbars have capacitor connection areas KAB1, KAB2. In the first capacitor connection area KAB1, which serves to connect the first busbar SS1 to the first DC terminal KDCA1 of the capacitor KON, the second busbar SS2 is interrupted or has a recess. The cross-section of this interruption or recess in the plane of the planar area PB is selected such that a sufficiently long clearance and creepage distance exists between the edge of the second busbar SS2 and the first DC terminal KDCA1 or the screw head SK of the connection.Similarly, in the second capacitor connection area KAB2, which serves to connect the second current rail SS2 with the second DC voltage connection KDCA2 of the capacitor KON, the first current rail SS1 is interrupted or has a recess whose cross-section is selected accordingly.
[0078] A film IF made of an electrically insulating material is arranged on both the top and bottom surfaces of the first busbar SS1. This film serves as electrical insulation, particularly on the underside facing the second busbar SS2, allowing the two busbars SS1 and SS2 to be guided parallel to each other at a very small distance or to form a lamination in which the second busbar SS2 is also in contact with the film. The film IF is preferably arranged as shown in Fig. As shown in Figure 4, the foil IF extends beyond the edge of the respective recess AU. Starting from the planar area PB, the foil IF extends along the top and bottom of the first busbar SS1, for example, to the middle of the vertically guided section. To ensure sufficient electrical insulation between the first SS1 and the second busbar SS2 in the area below the vertical section and in the area between the DC terminals DCA1 and DCA2, an insulating body IK made of an electrically insulating plastic material is arranged between them. This preferably overlaps a portion of the foil IF, as shown in Figure 4. Fig. 4 is shown as an example. The insulating body IK and the holding device HV can, for example, be manufactured in one piece from the same plastic material.
[0079] Fig. Figure 5 shows the side view of the SRM power converter module. Fig. 3 with an alternative design, specifically of the second busbar SS2. In contrast to the design of the Fig. 3. The second connection area AB2 does not transition into a part of the second busbar SS2 perpendicular to this plane in the area between the second DCA2 and the first DC connections DCA1, but rather in an area facing away from this plane. The first and second busbars SS1, SS2 are accordingly parallel over a smaller portion of the planar area PB and are also spaced further apart from each other in their respective perpendicular sections. This is in contrast to the design of the converter module SRM. Fig. 3. This more distant routing of the first and second busbars SS1, SS2 in the area of the DC terminals DCA1, DCA2 leads to a higher inductance of the DC busbars, which results in higher switching losses. Reference symbol list AB1 First connection area (first busbar) AB2 Second connection area (second busbar) AB3 Third connection area (first busbar) AB4 Fourth connection area (second busbar) AB5 Fifth connection area (third busbar) ACA AC terminals (power semiconductor module) AS drive system AU Exclusion (above second connection area) DCA1 First DC Connections (Power Semiconductor Module) DCA2 Second DC Voltage Connections (Power Semiconductor Module) EW Endwagen G Module housing (power semiconductor module) GLS Long side (module housing) GOS Top (Module Housing) GR rectifier GS1, GS2 First, second end face (module housing) GUS underside (module housing) HA vertical axis (heat sink, power converter module) HM1-HM9 Power Semiconductor Modules HV holding device IF foil (insulating) IK Insulation Body KAB1, KAB2 Capacitor connection areas KDCA1, KDCA2 DC terminals (capacitor) KK heat sink KKOS Top Heatsink KKUS underside of heat sink KON Capacitor KONG capacitor housing LA Longitudinal axis (heat sink, power converter module) LDG running bogie MW mid-car PAN pantograph PB Planar area QA transverse axis (heat sink, power converter module) R1, R2 series (power semiconductor modules) SK screw head SR power converter SRM power converter module ST control unit STA control connections (power semiconductor module) TDG drive bogie TF transformer TZ rail vehicle WK wagon body WR Inverter QUOTES INCLUDED IN THE DESCRIPTION
[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature
[0000] EP 3 404 818 A1 [0002, 0008, 0009]
Claims
[1] Power converter module (SRM), comprising: - a heat sink (HS) with a planar top surface (HSS), - a plurality of power semiconductor modules (HM1-HM9), wherein the power semiconductor modules (HM1-HM9) - each have a basically cuboid-shaped module housing (G) with end faces (GS1, GS2), long sides (GLS) and top and bottom faces (GOS, GUS), - on the top side (GOS) each have DC voltage terminals (DCA1, DCA2) and AC voltage terminals (ACA), wherein the DC voltage terminals (DCA1, DCA2) are arranged in the region of a first end face (GS1) and the AC voltage terminals (ACA) are arranged in the region of a second end face (GS2), and wherein first DC voltage terminals (GS1) for a first voltage potential are arranged near the first end face (GS1) and second DC voltage terminals (GS2) for a second voltage potential are arranged further away from the first end face (GS2), and - are arranged on the top (KKOS) of the heat sink (KK) in parallel rows (R1, R2), each row (R1, R2) comprising power semiconductor modules (HM1-HM6, HM7-HM9) arranged side by side and spaced apart from each other, and wherein the second end faces (GS2) of the module housings (G) of adjacent rows (R1, R2) face each other and their first end faces (G1) face away from each other, - a plurality of busbars (SS1, SS2), wherein a first busbar (SS1) electrically connects the first DC terminals (DCA1) and a second busbar (SS2) electrically connects the second DC terminals (DCA2) of the power semiconductor modules (HM1-HM9) of the rows (R1, R2), wherein the first and the second busbar (SS1, SS2) are planar at least in the region of the power semiconductor modules (HM1-HM9) to be connected and are arranged parallel to each other and one above the other at least in the planar region (PB), and wherein the planar region (PB) is arranged at a distance above the power semiconductor modules (HM1-HM9), characterized by , that - the first busbar (SS1) is angled in an area between the first and second DC terminals (DCA1, DCA2) of the respective power semiconductor module (HM1-HM9) and is guided perpendicular to the planar area (PB) up to a plane of the first DC terminals (DCA1), is angled in the direction of the first DC terminals (DCA1) on the plane of the first DC terminals (DCA1) and forms a first connection area (AB1), - the second busbar (SS2) is also angled in the area between the first and second DC terminals (DCA1, DCA2) or in an area between the second DC terminals (DCA2) and the AC terminals (ACA) of the respective power semiconductor module (HM1-HM9) and is led perpendicular to the planar area (PB) up to a plane of the second DC terminals (DCA2), is angled in the direction of the second DC terminals (DCA2) on the plane of the second DC terminals (DCA2) and forms a second terminal area (AB2), and - the first connection area (AB1) with the first DC voltage connections (DCA1) and the second connection area (AB2) with the second DC voltage connections (DCA2) of the respective power semiconductor module (HM1-HM9) are mechanically connected. [2] Power converter module (SRM) according to claim 1, characterized by, that at least one layer of an electrically insulating material is arranged between the first and the second busbar (SS1, SS2), wherein the insulating layer is in particular designed as an insulating film (IF) which is arranged on the first busbar (SS1) at least on the underside facing the second busbar (SS2) and / or on the second busbar (SS2) at least on the top side facing the first busbar (SS1). [3] Power converter module (SRM) according to any of the preceding claims, characterized by , that - the second connection areas (AB2) of the second busbar (SS2) are mechanically connected to the second DC voltage connections (DCA2) of the respective power semiconductor module (HM1-HM9) by means of screw connections, and - the first busbar (SS1) or the first and second busbars (SS1, SS2) above the second DC terminals (DCA2) of the respective power semiconductor module (HM1-HM9) has or have connection-specific recesses (AU), wherein a cross-section of the respective recess in the plane of the planar area (PB) is smaller than a cross-section of a screw head (SK) perpendicular to a longitudinal axis of a screw used for the respective screw connection. [4] Power converter module (SRM) according to claim 3, characterized by , that in the area of the respective second connection area (AB2) of the second busbar (SS2) at least one holding device (HV) is provided, by means of which the screws used for the screw connections are held at least before the mechanical connection of the second connection area (AB2) with the second DC voltage connections (DCA2) of the respective power semiconductor module (HM1-HM9). [5] Power converter module (SRM) according to any of the preceding claims, characterized by , that at least in the area between the first and second DC voltage terminals (DCA1, DCA2) of the respective power semiconductor module (HM1-HM9) an insulating body (IK) is arranged. [6] Power converter module (SRM) according to any one of the preceding claims, characterized by , that the majority of busbars comprise third busbars (SS31-SS33), wherein the third busbars (SS31-SS33) are each electrically connected to AC terminals (ACA3) of at least one power semiconductor module (HM1-HM9), and wherein the third busbars (SS31-SS33) are arranged below and spaced apart from the second busbar (SS2). [7] Power converter module (SRM) according to claim 6, characterized by, that in a range of the distance between adjacent power semiconductor modules (HM1-HM6, HM7-HM9) of a row (R1, R2) a length of the vertical guide of the first and second busbars (SS1, SS2) is at least partially reduced, and in this range at least one of the third busbars (SS31, SS32, SS33) is guided. [8] Power converter module (SRM) according to claim 6 or 7, characterized by , that - the first busbar (SS1) shall have at least a third connection area (AB3) and the second busbar (SS2) shall have at least a fourth connection area (AB4), wherein the converter module (SRM) can be connected to DC potentials, in particular of another converter module (SRM) and / or a DC component, by means of the third and fourth connection areas (AB3, AB4), and - the third busbars (SS31-SS33) each form at least a fifth connection area (AB5), wherein the power converter module (SRM) can be connected to AC potentials, in particular an AC component, by means of the fifth connection areas (AB5). [9] Power converter module (SRM) according to any of the preceding claims, characterized by that the power converter module (SRM) further comprises a plurality of capacitors (CON), wherein - each capacitor (KON) has a capacitor case (KONG) and DC voltage terminals (KDCA1, KDCA2), - the capacitors (KON) are arranged above the planar area (PB) of the first and second busbars (SS1, SS2), and - the DC terminals (KDCA1, KDCA2) of the capacitors (KON) are arranged on a side of the capacitor housing (KONG) facing the planar area (PB) and are connected to capacitor terminal areas (KAB1, KAB2) of the first and second busbars (SS1, SS2). [10] Power converter module (SRM) according to any one of the preceding claims, characterized by , that - at least on one underside (KKUS) of the heat sink (KK) cooling fins are formed, or - the heat sink (CC) has a planar bottom surface (BSS) parallel to the planar top surface (BSS), which is mechanically and thermally connected to another heat sink forming cooling fins, or - at least one cooling channel is formed in the cooling element (CE) for a flow of coolant supplied from outside the cooling element (CE). [11] Power converter module (SRM) according to one of the preceding claims, wherein the power semiconductor modules (HM1-HM9) are arranged in the adjacent rows (R1, R2) such that the second end faces (GS2) of the module housings (G) face each other directly or offset. [12] Power converter (SR), in particular for an electric drive system (AS) of a vehicle, comprising at least one power converter module (SRM) according to any one of claims 1 to 11. [13] Vehicle comprising at least one converter module (SRM) according to any one of claims 1 to 11 or at least one converter (SR) according to claim 12, wherein the vehicle is in particular designed as a rail vehicle (TZ).