POWER MEASUREMENT ARRANGEMENT

Description

State of the art

[0001] The invention relates to a current sensing arrangement. The current sensing arrangement comprises at least one electrically conductive busbar. The electrically conductive busbar is designed to carry a load current. A longitudinal section is formed in the busbar for detecting the load current flowing in the busbar. The current sensing arrangement also comprises at least one current sensor, which is arranged and configured to detect a magnetic field generated on the longitudinal section and to generate a current signal representing the load current as a function of the magnetic field.

[0002] From DE 199 469 35, a device for current measurement with magnetic field-sensitive differential sensors comprising at least two Hall sensors is known, wherein the Hall sensors are each arranged in a recess of a conductor sheet. From EP1273921A1, another current sensor is known. In one example, two conductors with recesses are arranged one above the other and are configured to carry current in the same direction. The recesses overlap, and a Hall sensor is arranged in the overlap area. A similar current sensor with two conductors comprising loops is known from US5694103A. The loops overlap, but the parallel conductors are not arranged one above the other. The conductors are configured to carry current in opposite directions. Disclosure of the invention

[0003] A current sensing arrangement according to the invention is defined in independent claim 1, advantageous embodiments in the dependent claims.

[0004] According to the invention, the current sensing arrangement of the type mentioned above has a further busbar. The further busbar is designed to carry a current, in particular direct current, with a current direction opposite to that of the load current. The further busbar, which runs parallel to the busbar, is guided in the longitudinal section of the busbar in such a way that a magnetic field generated on the longitudinal section by the further busbar can superimpose on the magnetic field of the busbar, thereby reinforcing it.

[0005] Advantageously, a particularly sensitive current sensing arrangement can be created in this way. It has been observed that with parallel busbars, especially DC busbars, magnetic fields can cancel each other out to form a low-inductance arrangement. A current sensor designed to detect a magnetic field generated in the busbar can be influenced by this low-inductance property. It has been found that the magnetic field to be detected by the current sensor can also be weakened or disturbed by the adjacent busbar. By superimposing the field from the adjacent busbar, a Hall signal, particularly a differential Hall signal, can be advantageously generated, which exhibits a high signal-to-noise ratio.

[0006] Preferably, the additional busbar is electrically isolated from the main busbar. This allows for the advantageous formation of a breakdown-resistant, low-inductance arrangement.

[0007] According to the invention, the additional busbar is designed, in particular by means of field and / or disturbance compensation, to form a low-inductance arrangement together with the busbar. Advantageously, the current measurement cannot be disturbed by the low-inductance arrangement.

[0008] In a preferred embodiment, the busbar is configured to carry a positive power supply potential, and the other busbar is configured to carry a negative power supply potential. Advantageously, this can form a DC power supply arrangement which can, for example, supply an inverter or a commutation cell for an inverter with DC current.

[0009] In a preferred embodiment of the current sensing arrangement, the current rail and the secondary current rail are each guided in a meandering pattern relative to each other in the longitudinal section such that currents flowing in opposite directions in the current rail and the secondary current rail can flow in the same direction, or entirely in the same direction, with at least one directional component in the longitudinal section. Advantageously, the opposite current direction in the secondary current rail can be deflected by means of the meander such that the current directions in the current rail and the secondary current rail are aligned in the longitudinal section. In this way, magnetic fields rotating in the same direction can be generated on the longitudinal sections of the current rail and the secondary current rail, which can reinforce each other due to the alignment of their rotation.The current sensor can thus detect the magnetic field amplified by the rectified longitudinal sections and generate an output signal representing the amplified magnetic field, which represents the current flowing in the current rail.

[0010] In a preferred embodiment, the current rail and the other current rail on the longitudinal section are each formed in opposite S-shapes, or symmetrically to each other, in particular axially symmetrically or point-symmetrically S-shaped. Advantageously, a multiple meandering current rail can be formed on the longitudinal section, which, through the windings, can strengthen the magnetic field in the concave areas of the winding by superimposing the magnetic field generated on the longitudinal section of the respective current rail itself. Additionally, a readily detectable sensor signal can be generated by superimposing the magnetic fields on the longitudinal section of the current rail and the other current rail.

[0011] Preferably, the meandering shape in the conductor rail forms an S-shape, and the meandering shape in the subsequent conductor rail forms a shape opposite to the S-shape, in particular a question mark shape. Advantageously, the S-shape and the question mark shape can be produced from the conductor rail, for example, by stamping with the same stamping tool. The question mark shape in the subsequent conductor rail can thus be formed by rotating the subsequent conductor rail about its longitudinal axis and arranging it parallel to the conductor rail.

[0012] In a preferred embodiment of the current sensing arrangement, the busbar and / or the additional busbar has a cutout in the longitudinal section. The current sensor is positioned in the area of ​​the cutout such that it can detect magnetic fields generated by the busbar sections surrounding the cutout, particularly the webs. Advantageously, the current sensor can thus detect a magnetic field generated by the webs that is oriented in the same direction as a magnetic field generated by the additional busbar, particularly the negative busbar. Advantageously, the magnetic fields of the busbar and the additional busbar can thus superimpose and reinforce each other.

[0013] In a preferred embodiment, the additional conductor rail is narrower in the region of the longitudinal section than in the areas surrounding the longitudinal section. Advantageously, the webs do not need to project as far laterally, particularly transversely to the longitudinal extent of the additional conductor rail, when viewed in a projection onto the additional conductor rail.

[0014] In a preferred embodiment, the additional conductor rail in the longitudinal section has the same cross-section or width as the sections surrounding it. More preferably, the total width of the conductor rail webs on the longitudinal section is the same as the width of the conductor rail outside the longitudinal section. Advantageously, this allows the current density in the longitudinal section to be the same as in the sections surrounding it. This also advantageously prevents the formation of hot spots in the longitudinal section.

[0015] In a preferred embodiment, the additional busbar on the longitudinal section is I-shaped, thus complementing the recess of the busbar on the longitudinal section. Advantageously, the busbars can thus form common openings for the passage of the magnetic field lines in the area of ​​the current sensor.

[0016] According to the invention, the busbar and the additional busbar are arranged parallel to each other in the longitudinal section. According to the invention, the busbar and the additional busbar each have a recess in the longitudinal section which, in an orthogonal projection, overlap to form an opening for the passage of a common magnetic field. Advantageously, this allows for a space-saving magnetic field amplification. The Hall sensor is, for example, arranged in the area of ​​the jointly formed opening. In this embodiment, the additional Hall sensor of the current sensor is arranged adjacent to the busbars and can detect at least a portion of the overlapping magnetic field lines.

[0017] In a preferred embodiment, the busbar and the other busbar on the longitudinal section are each U-shaped, with the U-openings pointing in opposite directions. Advantageously, this allows a simple way to form a through-opening for the common magnetic field, as seen in a projection of the U-openings.

[0018] In a preferred embodiment, the busbar and the other busbar each have recesses on the longitudinal section that are oppositely oriented and transverse to the longitudinal extent of the conductor track. These recesses preferably overlap to form a common opening through which magnetic field lines formed on the respective longitudinal sections pass and can be detected by the current sensor. Advantageously, this arrangement can be such that the busbars in the region of the longitudinal section and in the areas surrounding the longitudinal section each have the same cross-section, and in particular the same width.

[0019] In a preferred embodiment, the busbars are each formed by a flat, rectangular profile. For example, the busbars are each formed by a stamped grid, also called a lead frame, in particular a copper stamped grid. Advantageously, the busbars can thus be provided in a cost-effective manner.

[0020] In another preferred embodiment, the current sensing arrangement comprises a circuit carrier, wherein the circuit carrier has an electrically insulating layer, in particular a ceramic layer. In this embodiment, the busbars are each formed by an electrically conductive layer of the circuit carrier, the electrically conductive layers being insulated and separated from each other by the electrically insulating layer. Advantageously, the busbars can thus be connected to each other in a cost-effective and dielectrically resistant manner.

[0021] The current sensor can, for example, be arranged in parallel to the circuit carrier, or on a further circuit carrier that extends parallel to the circuit carrier. This further circuit carrier could be, for example, a printed circuit board (PCB), a flexible PCB, an LTCC (low-temperature cofired ceramic) circuit carrier, or an HTCC (high-temperature cofired ceramic) circuit carrier.

[0022] The electrically insulating layer of the circuit carrier is, for example, a ceramic layer, in particular an aluminum oxide layer, or a silicon nitride layer. Advantageously, the circuit carrier can thus exhibit good thermal conductivity.

[0023] The circuit carrier is preferably designed for thermally conductive contact with a heat sink and preferably has an electrically conductive back layer, which is also designed for contacting a heat sink. The additional busbar preferably forms an electrically and thermally conductive back layer of the circuit carrier. Advantageously, the current sensing arrangement can also be cooled cost-effectively in this way.

[0024] In a preferred embodiment, the circuit carrier can have, in addition to the negative current rail, further metal layers, in particular copper layers, guided in the circuit carrier plane of the negative current rail.

[0025] In a preferred embodiment, the current sensing arrangement is part of a multilayer circuit carrier. The current sensing arrangement can, for example, be configured as an intermediate layer within the multilayer circuit carrier. The multilayer circuit carrier is, for example, a ceramic circuit carrier, such as an HTCC or LTCC circuit carrier, or a multilayer printed circuit board.

[0026] The busbars are preferably made of copper or a copper alloy.

[0027] The invention also relates to an electric machine with a current sensing arrangement of the type described above. The current sensing arrangement is configured to detect a supply current of the machine and / or a DC link current. Preferably, the machine has two parallel, low-inductance busbars for its power supply, wherein the current sensor is arranged in the area of ​​the busbars and is configured to detect the current flowing on the busbars, in particular direct current, and to generate a current signal representing the detected current. The machine also has a control unit configured to control the machine depending on the current signal and, in particular, depending on the detected supply current and / or DC link current. Advantageously, the current detection of the machine can thus be carried out efficiently and with a good signal-to-noise ratio in a low-inductance busbar arrangement of the machine.

[0028] The invention will now be explained below with reference to figures and further exemplary embodiments. Further advantageous embodiments result from a combination of the features described in the figures and in the dependent claims. Figure 1 shows an embodiment of a current detection arrangement in which a negative and a positive busbar are arranged one above the other, wherein the busbars are each U-shaped on a longitudinal section on which a current sensor is arranged; Figure 2 shows an embodiment of a current detection arrangement in which a negative and a positive busbar are arranged one above the other, wherein the busbars each have a recess on a longitudinal section on which a current sensor is arranged; Figure 3 shows the in Figure 2 Current detection arrangement shown in a sectional view; Figure 4shows an embodiment of a current sensing arrangement in which a negative and a positive current rail are arranged one above the other, wherein the negative current rail has a constriction on a longitudinal section on which a current sensor is arranged for the passage of magnetic field lines and the positive current rail has a breakthrough; Figure 5 shows the in Figure 4 Current detection arrangement shown in a sectional view; Figure 6 shows an embodiment of a current detection arrangement in which a negative and a positive busbar are arranged one above the other, wherein the busbars are each formed in an S-shape opposite each other on a longitudinal section on which a current sensor is arranged; Figure 7shows an embodiment of a current sensing arrangement in which a negative and a positive busbar are arranged one above the other, wherein the busbars are each formed in an S-shape opposite each other on a longitudinal section on which a current sensor is arranged, and wherein a hole is formed in the busbars on the longitudinal section of the current sensing arrangement in which a current sensor is arranged; Figure 8 shows a variant of the one in Figure 7 The current sensing arrangement shown in a sectional view, in which the busbars are each part of a circuit carrier and are separated from each other by an electrically insulating layer of the circuit carrier; Figure 9 shows an embodiment of an electrical machine with at least one current sensing arrangement.

[0029] Figure 1Figure 1 schematically shows an embodiment of a current sensing arrangement 1 in a top view. The current sensing arrangement 1 has a negative busbar 2 and a positive busbar 3. In this embodiment, the busbars 2 and 3 are designed as flat conductors. The flat conductors each have a rectangular cross-section and can each be formed by a stamped grid, also called a lead frame, or by an electrically conductive layer of a circuit carrier. The circuit carrier is, for example, a ceramic circuit carrier comprising an electrically insulating ceramic layer and at least two electrically conductive layers, which are formed on opposite sides of the electrically insulating ceramic layer and enclose the electrically insulating layer between them.

[0030] The negative busbar 2 and the positive busbar 3 are each designed to be longitudinally extended and are arranged one above the other along a longitudinal extent 60 such that the negative busbar 2 and the positive busbar 3 can form a low-inductance arrangement.

[0031] On a longitudinal section 61 along the longitudinal extent 60, a U-shaped meander loop 4 is formed in the negative busbar 2. A U-shaped meander 5 is also formed in the positive busbar 3 on the same longitudinal section 61. The U-shaped meanders 4 and 5 are arranged one above the other in such a way that a common opening 6 is formed. A magnetic field generated by the meanders 4 and 5, in particular a direct current magnetic field flowing in the busbars 2 and 3, can thus penetrate the common opening 6. The busbars 2 and 3 have the same cross-section, in particular the same cross-sectional area, even in the region of the meanders 4 and 5, so that no hot spot can form in the current detection area on the longitudinal section 61.The field lines of the magnetic field generated by the current rails 2 and 3 each run in the same direction in the opening 6, so that the magnetic fields generated by the negative current rail 2 and the positive current rail 3 can each reinforce each other.

[0032] In the opening 6, a current sensor 7, in particular a Hall current sensor, is arranged which, together with another Hall sensor 8, can detect the magnetic field. In this way, a differential current sensor 47 can be formed by the Hall sensors 7 and 8.

[0033] Figure 1 The figure also shows, with a dashed line, another Hall sensor 9, which can be part of the current sensor 47. In this embodiment, the current sensor 47 can have two or three Hall sensors for detecting the magnetic field generated by the busbars 2 and 3.

[0034] Figure 2Figure 1 shows a current sensing arrangement 10 comprising a negative busbar 11 and a positive busbar 12. The negative busbar 11 and the positive busbar 12 are arranged one above the other along their longitudinal extent such that a low-inductance arrangement can be formed by the busbars 11 and 12. The negative busbar 11 has a recess 13 formed transversely to its longitudinal extent, and the positive busbar 12 has a recess 14 formed transversely to its longitudinal extent. The recesses 13 and 14 each point in opposite directions such that an opening 15 is formed in an overlapping area of ​​the recesses 13 and 14, jointly formed by the busbars 11 and 12.In this embodiment, a Hall current sensor 16 is arranged in the opening 15, which can be part of a current sensor that can be formed from the Hall sensor 16 and another Hall sensor 17. The Hall sensors 16 and 17 are each configured as differential Hall sensors. Figure 2 The figure also shows – depicted with a dashed line – another Hall sensor 18, which can be part of the aforementioned current sensor. The current sensor can thus comprise two or three Hall sensors.

[0035] Figure 3 shows the in Figure 2 The current sensing arrangement, already shown in a top view, is shown in a sectional view. The current sensing arrangement 10 comprises a circuit carrier which may have an electrically insulating layer 19, in particular a ceramic layer. The ceramic layer is, for example, an aluminum oxide layer or a silicon nitride layer.

[0036] The positive busbar 12 can be placed on the in Figure 2 The longitudinal section shown, on which the recesses 13 and 14 overlap, forms a magnetic field 21, and the negative current rail 11 forms a magnetic field 20. The magnetic fields 20 and 21 run in the same direction in the opening 15, so that the Hall sensor 16 can detect a reinforced magnetic field superimposed from the magnetic fields 20 and 21.

[0037] Figure 4 Figure 22 shows an embodiment of a current sensing arrangement for detecting a direct current flowing on the busbars of a low-inductance arrangement. The current sensing arrangement comprises a negative busbar 23 and a positive busbar 24, which are arranged one above the other along their longitudinal extent. The busbars 23 and 24 can each be part of a circuit carrier, in particular a ceramic circuit carrier.

[0038] The negative busbar 23 has a constriction 25 along one longitudinal section, the constriction 25 enclosing a web 26. The conductor cross-section of the busbar 23 is reduced by the constriction 25 in the area of ​​the web 26 compared to the surrounding longitudinal sections of the busbar 23.

[0039] The positive busbar 24 has a through-hole on its longitudinal section, which can overlap with the constriction 25 in such a way that two through-holes are formed by means of the superimposed busbars 23 and 24. A Hall sensor 30 or 31 is arranged in each of the through-holes, so that a magnetic field formed around the web 26 of the negative busbar and the magnetic fields of the webs 28 and 29 flanking the through-hole 27 of the positive busbar 24 can overlap and reinforce each other.

[0040] Figure 4The dashed line also shows a variant of the current sensing arrangement in which the busbar 23 has no constriction, and the positive busbar in the area of ​​the current sensor, formed by the Hall sensors 30 and 31, is ring-shaped or O-shaped, so that magnetic field lines can pass through the opening. In the variant shown with dashed lines, the busbars have the same or a larger cross-sectional area along their longitudinal extent in the area of ​​the current sensor, so that no thermal hot spot can form in the area of ​​current sensing by the Hall sensors 30 and 31 due to an increased ohmic resistance there.

[0041] Figure 5 shows the in Figure 4The current sensing arrangement shown is in a sectional view. The current sensing arrangement 22 also includes a circuit carrier with an electrically insulating layer 32. The busbars 23 and 24 each form an electrically conductive layer which encloses the electrically insulating layer 32 between them.

[0042] The magnetic fields generated by the positive busbar 24 in the area of ​​the breakthrough 27, in particular by the positive webs 28 and 29, can superimpose positively in the area of ​​the breakthrough 27 with the magnetic field generated by the web 26 of the negative busbar 23 in such a way that the current sensors 30 and 31 in the area of ​​the breakthrough 27 can detect an enhanced magnetic field superimposed from the positive and negative magnetic fields.

[0043] Figure 6Figure 1 shows an embodiment of a current sensing arrangement 33. The current sensing arrangement 33 comprises a negative busbar 36 and a positive busbar 37, which are arranged one above the other along their longitudinal extent such that a low-inductance arrangement is formed from the busbars 36 and 37.

[0044] The negative current rail 36 has an S-shaped meander loop 38, which is superimposed with an S-shaped meander loop 39 formed in the positive current rail 37 and wound in the opposite direction, such that a negative or positive current flowing on a longitudinal section of the meander loops 38 and 39 - marked by arrows - flows in the same direction, and thus the magnetic fields generated by the positive or negative currents can superimpose on each other in a field-enhancing manner.

[0045] In the recesses of the S-shaped meanders, each of which has two U-shaped meander loops arranged in a row, a Hall current sensor 34 and a Hall current sensor 35 are arranged, each of which can be part of a differentially sensing current sensor.

[0046] In this embodiment, the S-meander shape 38 of the negative busbar 36 forms in the Figure 6 The split top view shown, in comparison to the S-shaped meander 39 of the positive busbar 37, raises a question mark, insofar as the S-shapes are wound in opposite directions. The meanders 38 and 39 can be formed in the busbar 36 and 37 respectively by punching, or – in the case of a circuit carrier – by etching or laser ablation.

[0047] In the case of the stamped busbars, the question mark shape of the negative busbar 36 can be formed by a simple turning, and thus a rotation around the longitudinal axis of the busbar 36, so that when the busbars 36 and 37 are placed on top of each other, the opposite meander shape, in particular S-shape, and question mark shape is formed.

[0048] In this embodiment, the busbars 36 and 37 are formed as flat conductors with a particularly rectangular cross-section.

[0049] The busbars 36 and 37 of the current detection arrangement 33 according to Figure 6In this embodiment, the conductor cross-section is the same along the longitudinal extent, both on the longitudinal sections that lie one above the other and on the meandering longitudinal sections of the S-shaped meander loops 38 and 39. Advantageously, this prevents a hot spot from forming in the area of ​​the S-shaped meander loops 38 and 39 for current detection using the Hall sensors 34 and 35.

[0050] Figure 7Figure 1 shows an embodiment of a current sensing arrangement 40. The current sensing arrangement 40 has a positive busbar 42 and a negative busbar 41, which – as indicated by dashed arrows – can be arranged one above the other and parallel to each other. The positive busbar 42 has a meandering S-loop, and the negative busbar 41 has an S-shaped meandering loop wound in the opposite direction. These loops, lying one above the other on a longitudinal section 54, direct the current flow in the busbars – particularly as indicated by the current flow arrows – in the same direction along the longitudinal section, transverse to a common longitudinal extent 52 of the busbars 41 and 42.

[0051] Unlike in Figure 6The conductor rails have an opening along their longitudinal section, enclosed by two webs, to which the current flowing in each conductor rail can be divided. The two parallel webs of the conductor rail together form a conductor rail section.

[0052] The positive busbar 42 has an opening 43 on its longitudinal section 54, which is enclosed between two webs 45 and 46, respectively. The negative busbar 41 has an opening 44 enclosed by two webs 47 and 48. In this embodiment, a current sensor 49 is arranged in the opening or in the area of ​​the openings, which is configured to detect a magnetic field generated by the webs. The web 45 of the positive busbar 42 lies above the web 47 of the negative busbar 41, and the web 46 of the positive busbar 42 lies above the web 48 of the negative busbar 41, so that the superimposed webs can each generate a magnetic field with the same direction of rotation.

[0053] In this embodiment, the current sensor 49 arranged in the opening 43 of the positive busbar 42 and / or the opening 44 of the negative busbar 41 has two Hall sensors 50 and 52 and is configured to generate a current signal, depending on the magnetic fields detected by the Hall sensors 50 and 51, which represents the current flowing in the busbars 41 and 42.

[0054] Figure 7 Figure 1 also shows a variant of the current detection arrangement in which, in addition to the Hall sensors 50 and 51 arranged in the opening, sensors 56 and / or 57 can be arranged on the outer sides of the webs, which can detect the current flowing in the busbars 41 and 42 additionally or redundantly to the Hall sensors 50 and 51.

[0055] The busbars 41 and 42 can each – as indicated by the dashed lines – have a width along the longitudinal extension 52 that corresponds to the sum of the web widths of webs 45 and 46 or 47 and 48, respectively, or is smaller than the sum of the web widths, so that the same current density can be generated on the longitudinal section 54 as on the areas of the busbars surrounding the longitudinal sections. This prevents the formation of hot spots in the area of ​​the longitudinal section 54 of the current sensing.

[0056] Figure 8 shows a current detection arrangement 55 in a sectional view, which includes the in Figure 7The component shown comprises, in addition to, an electrically insulating layer 53, which separates the busbars 41 and 42 from each other. The busbars 41 and 42, together with the electrically insulating layer 53, form a circuit carrier. The electrically insulating layer 53 is, for example, a ceramic layer, in particular an aluminum oxide layer or a silicon nitride layer. The circuit carrier is, for example, an AMB circuit carrier (AMB = Active-Metal-Brazed), a DCB circuit carrier (DCB = Direct-Copper-Bonded), or an IMS circuit carrier (IMS = Insulated-Metal-Substrate).

[0057] The webs 45 and 46 of the positive busbar 42 are each spaced apart from the webs 47 and 48 and electrically insulated from each other in such a way that the openings 43 and 44 of the busbar 42 and 43 formed on the longitudinal section are aligned with each other and form a common opening for the passage of the magnetic fields formed in a ring shape around the webs.

[0058] The pair of bridges, formed by bridge 46 of the positive busbar 42 and bridge 48 of the negative busbar 41, generates a rectified magnetic field 57 when current flows through it. This field can form as a reinforced magnetic field from the sum of the individual magnetic fields formed around the bridges. The magnetic field 57, thus reinforced by field superposition, can be detected by the current sensor arranged in the opening, and in particular by the Hall sensor 50.

[0059] The pair of bridges, formed by bridge 45 of the positive current rail 42 and bridge 47 of the negative current rail 41, can generate a common magnetic field 56, amplified by superposition, which can penetrate the opening formed by the superimposed openings 43 and 44 and be detected there by the Hall sensor 52 of the current sensor 49. The magnetic fields 56 and 57 penetrate the opening in opposite directions.

[0060] The current sensor 49 can thus generate a current signal from the individual current signals of the Hall sensors by calculating the difference between the individual current signals, which represents the total current flowing in the bridges.

[0061] Figure 9Figure 40 shows an embodiment of an electric machine 40. The electric machine 40 comprises a stator 41 and a rotor 42, which is preferably made of permanent magnets. The electric machine 40 also comprises a power output stage 43, which in this embodiment is configured as a B6 bridge. In this embodiment, the power output stage 43 comprises a semiconductor switch half-bridge for each phase of the electric machine 40. In this embodiment, the electric machine 40 comprises three phases, and thus also three semiconductor switch half-bridges, each of which is connected to a phase output 51, 52, and 53, respectively.

[0062] The power output stage 43 is electrically connected to the stator 41 at its output side, and there to the stator coils of the stator 41. The power output stage 43 is configured to supply current to the stator 41 to generate a rotating magnetic field for rotating the rotor 42. For this purpose, the power output stage 43 is connected to a positive power supply terminal 45 and a negative power supply terminal 46, and is configured to generate an alternating current for each phase of the electric machine from a DC voltage supplied by the power supply terminals 45 and 46, in order to generate the rotating magnetic field.

[0063] The electric machine 40 also includes a processing unit 44, which can be, for example, a microcontroller, a microprocessor, or an ASIC (Application-Specific Integrated Circuit). The processing unit 44 is connected to the power output stage 43 via a connecting line 50 on its output side and is configured to control the semiconductor switches of the semiconductor switch half-bridges of the power output stage 43, in particular by pulse-width modulation, to energize the stator 41.

[0064] In this embodiment, the processing unit 44 is configured for field-oriented control of the electric machine 40. The field-oriented control of the machine 40 can be performed based on a current detected by a current sensor 47, a current sensor 48, or both current sensors 47 and 48. The electric machine 40 includes a DC link capacitor 54. The DC link capacitor 54 is connected in parallel to the positive power supply terminal 45 and the negative power supply terminal 46. The machine 40 also has a negative bus 2 and a positive bus 3, wherein the positive bus 3 connects the power output stage 43 to the positive power supply terminal 45, and the negative bus 2 connects the power output stage 43 to the negative power supply terminal 46.

[0065] In this embodiment, the intermediate circuit capacitor 54 taps the supply voltage on a longitudinal section of the parallel busbars 2 and 3. The current sensor 47 is arranged on the longitudinal section extending between the power supply terminal 45 or 46 and the intermediate circuit capacitor 45. The current sensor 47 is, for example, as shown in Figure 1 The current sensor 47 is formed by the U-shaped meanders 4 and 5 and includes the Hall current sensors 7 and 8. The current sensor 47, together with the busbars 2 and 3, can be mounted on a longitudinal section of the busbars 2 and 3 extending between the DC link capacitor 54 and the power supply terminals 45 and 46 to form the current sensing arrangement 1 according to Figure 1 form.

[0066] The current sensor 48 is mounted on a longitudinal section of the busbars 2 and 3 extending between the DC link capacitor 54 and the power output stage 43, and can detect the current flowing between the DC link capacitor 54 and the power output stage 43. The current flowing between the DC link capacitor 54 and the power output stage 43 can be stepped by the pulse-width modulated control of the power output stage, effected by the processing unit 44.

[0067] The processing unit 44 is configured to control the power output stage 43 for generating the machine current depending on the supply current or DC link current detected by the current sensor 47 and / or the current sensor 48. For this purpose, the processing unit 44 can regulate a target current, represented by a torque setpoint signal received at an input 55 of the processing unit 44, depending on the detected DC link current, detected by the sensor 48, or on a total current drawn by the machine 40, detected by the current sensor 47, or depending on both currents.

[0068] The current sensor 47 can be used – unlike previously described – according to the current sensing arrangement 10 as shown in the Figures 2 and 3 depicted, or according to the current sensing arrangement 22, as shown in the Figures 4 and 5 as shown, or according to the current sensing arrangement 33, as in Figure 6The current sensor 48 can, unlike previously described, be configured according to the diagram in the Figures 2 and 3 current sensing arrangement 10 shown, or according to the one described in the Figures 4 and 5 current sensing arrangement 22 shown, or according to the Figure 6 The current sensing arrangement 33 shown is configured as follows. The current sensors 47 and 48 can each be configured as current sensing arrangement 1 according to Figure 1 , the current detection arrangement 10 according to the Figures 2 and 3 , the current detection arrangement 22 according to the Figures 4 and 5 , or the current sensing arrangement 33 according to Figure 6 form.

[0069] The processing unit 44 of the electrical machine 40 can, for example, perform the field-oriented control of the machine 40 in accordance with the type described in DE 10 2011 076 709 A1, or in accordance with the type described in DE 10 2008 04 2978 A1.

[0070] The in Figure 9The described electric machine can, for example, be a component of an electric compressor, a component of an electric bicycle, a drive motor of an electric vehicle, a drive motor of an electric scooter, also called an e-scooter.

Claims

1. Current detecting arrangement (1, 10, 22, 33, 47, 48), wherein the current detecting arrangement (1, 10, 22, 33, 47, 48) has at least one electrically conductive busbar (2, 3, 11, 12, 23, 24, 36, 37), and the electrically conductive busbar (2, 3, 11, 12, 23, 24, 36, 37) is designed to conduct a load current, wherein a longitudinal section (61) for detecting the load current flowing through the busbar (2, 3, 11, 12, 23, 24, 36, 37) is formed in the busbar (2, 3, 11, 12, 23, 24, 36, 37), and the current detecting arrangement (1, 10, 22, 33) has at least one current sensor (7, 8, 9, 16, 17, 18, 30, 31, 34, 35) which is arranged and designed to detect a magnetic field (20, 21) generated on the longitudinal section (61) and to generate, depending on the magnetic field (20, 21), a current signal representing the load current, wherein the current detecting arrangement (1, 10, 22, 33, 47, 48) has a further busbar (2, 3, 11, 12, 23, 24, 36, 37), which is designed to conduct a current in a current direction opposite to the load current, and the further busbar (2, 3, 11, 12, 23, 24, 36, 37) running parallel to the busbar (2, 3, 11, 12, 23, 24, 36, 37) in the region of the longitudinal section (61) is led to the busbar (2, 3, 11, 12, 23, 24, 36, 37) in such a way that a magnetic field (20) generated on the longitudinal section (61) of the further busbar can be superimposed on the magnetic field (21) of the busbar (2, 3, 11, 12, 23, 24, 36, 37) in a field-reinforcing manner, wherein the further busbar (2, 3, 11, 12, 23, 24, 36, 37) is designed to form, in particular by means of field and / or interference compensation, a low-inductance arrangement together with the busbar (2, 3, 11, 12, 23, 24, 36, 37) owing to the fact that the busbar and the further busbar are designed to extend lengthways while being arranged one on top of another along a longitudinal extension, and wherein the busbar (2, 3, 11, 12, 23, 24, 36, 37) and the further busbar (2, 3, 11, 12, 23, 24, 36, 37) in the region of the longitudinal section (61) each have a recess (27, 43, 44) which, overlapping one another in an orthogonal projection, form a through-hole for allowing a common superimposed magnetic field to pass through, wherein the current sensor (30, 31, 50, 51) is arranged in the region of the opening in such a way that the current sensor (30, 31, 50, 51) can detect magnetic fields generated by busbar sections (28, 29) surrounding the through-hole (27).

2. Current detecting arrangement according to Claim 1, characterized in that the busbar (2, 3, 11, 12, 23, 24, 36, 37) is designed to conduct a positive current supply potential, and the further busbar (2, 3, 11, 12, 23, 24, 36, 37) is designed to conduct a negative current supply potential.

3. Current detecting arrangement (1, 10, 22, 33, 47, 48) according to Claim 1 or 2, characterized in that the busbar (2, 3, 11, 12, 23, 24, 36, 37) and the further busbar (2, 3, 11, 12, 23, 24, 36, 37) in the region of the longitudinal section (61) are each led to one another in a meandering manner in such a way that currents flowing through the busbar (2, 3, 11, 12, 23, 24, 36, 37) and the further busbar (2, 3, 11, 12, 23, 24, 36, 37) in opposite directions to one another on the longitudinal section (61) can each flow with at least one directional component in the same direction, or can each flow completely in the same direction.

4. Current detecting arrangement (1, 10, 22, 33, 47, 48) according to Claim 3, characterized in that the busbar (2, 3, 11, 12, 23, 24, 36, 37) and the further busbar (2, 3, 11, 12, 23, 24, 36, 37) on the longitudinal section (61) are each formed in an S-shape in opposite directions to one another, or symmetrically to one another, in particular axially symmetrically or point symmetrically in an S-shape.

5. Current detecting arrangement (1, 10, 22, 33, 47, 48) according to one of the preceding claims, characterized in that the further busbar (2, 3, 11, 12, 23, 24, 36, 37) is designed to be narrower in the region of the longitudinal section (61) than on the regions surrounding the longitudinal section (61).

6. Current detecting arrangement (1, 10, 22, 33, 47, 48) according to one of the preceding claims, characterized in that the busbar (2, 3, 11, 12, 23, 24, 36, 37) and the further busbar (2, 3, 11, 12, 23, 24, 36, 37) on the longitudinal section (61) are each formed in a U-shape (4, 5), wherein the U-openings point in opposite directions to one another.

7. Current detecting arrangement (1, 10, 22, 33, 47, 48) according to one of the preceding claims, characterized in that the busbar (2, 3, 11, 12, 23, 24, 36, 37) and the further busbar (2, 3, 11, 12, 23, 24, 36, 37) on the longitudinal section each have recesses (13, 14) formed pointing in opposite directions to one another, transversely to the longitudinal extension of the conductor track.

8. Current detecting arrangement (1, 10, 22, 33, 47, 48) according to one of the preceding claims, characterized in that the current detecting arrangement comprises a circuit carrier (19, 32, 26, 28, 29), and the circuit carrier (19, 32, 26, 28, 29) has an electrically insulating layer (19, 32), in particular ceramic layer, and the busbars (2, 3, 11, 12, 23, 24, 36, 37) are each formed by an electrically conductive layer of the circuit carrier, which are insulated and separated from one another by the electrically insulating layer (19, 32).

9. Current detecting arrangement (1, 10, 22, 33, 47, 48) according to Claim 8, characterized in that the circuit carrier (19, 32, 26, 28, 29) is designed to make contact with a heat sink and has an electrically conductive rear-side layer which is designed to make contact with a heat sink, wherein the further busbar (2, 11, 23, 36) forms an electrically conductive and thermally conductive rear-side layer of the circuit carrier (19, 32, 26, 28, 29).

10. Current detecting arrangement (1, 10, 22, 33, 47, 48) according to one of the preceding claims, characterized in that the current sensor is a differential current sensor and comprises a first and a second Hall sensor, wherein a Hall sensor is arranged in the region of the opening.

11. Current detecting arrangement (1, 10, 22, 33, 47, 48) according to Claim 10, characterized in that the current sensor comprises a third Hall sensor.

12. Electric machine (40) having a current detecting arrangement (1, 10, 22, 33, 47, 48) according to one of the preceding claims, wherein the current detecting arrangement (1, 10, 22, 33, 47, 48) is designed to detect a supply current of the machine and / or a DC-link current, wherein the machine, for the current supply, has two busbars (2, 3, 11, 12, 23, 24, 36, 37) which are led parallel to one another and with low inductance, wherein the current sensor in the region of the busbars (2, 3, 11, 12, 23, 24, 36, 37) is arranged and designed to detect the current, in particular DC current, flowing on the busbars (2, 3, 11, 12, 23, 24, 36, 37) and to generate a current signal representing the detected current, wherein the machine has a control unit (44) which is designed to control the machine in dependence on the current signal and in particular thus in dependence on detected supply current and / or DC-link current.