Busbar module equipped with current sensors

Abstract

Busbar module (1) equipped with a current sensor, characterized in that the module has: a multitude of busbars (2) in which currents flow; a casting element (3) through which the plurality of busbars (2) are cast to form a single-piece body; a current sensor (4) that measures a current value in at least one part of the plurality of busbars (2); and a sensor circuit board (7) on which the current sensor (4) is mounted, wherein: the current sensor (4) has a magnetoresistive element and measures the value of the current in a busbar (2) by detecting the strength of the magnetic field generated around the busbar (2) by the flow of the current in the busbar (2); the multiple busbars (2) are arranged along a width direction which is perpendicular to a length direction of the busbars (2) and a thickness direction of the busbars (2); the current sensor (4) is arranged adjacent to the busbars (2) in the thickness direction and is spaced apart from the busbars (2); and at least a pair of shielding plates (5a and 5b) are provided which sandwich around the current sensor (4) and the busbars (2) in the thickness direction to shield the magnetic field, the pair of shielding plates (5a and 5b) are arranged in positions that sandwich around the current sensor (4) and the busbars (2) in the thickness direction, a recess (30) is formed in the potting part (3), wherein the current sensor (4) is contained within the recess (3), a lid (6) is attached to the potting part (3) to cover an opening of the recess (30), one shielding plate (5a) of the pair of shielding plates (5a and 5b) is encased in the potting part (3), and the other shielding plate (5b) of the pair of shielding plates (5a and 5b) is encased in the lid (6), the cover (6) is formed separately from the sensor circuit board (7), and the sensor circuit board (7) is contained within the recess (3) with the current sensor.

Description

Technical field

[0001] The present invention relates to a busbar module equipped with a current sensor, comprising a plurality of busbars and a current sensor for measuring current values ​​in the busbars. State of the art

[0002] A busbar module equipped with a current sensor is known, comprising a plurality of busbars and current sensors for measuring current values ​​in the busbars (see PTL 1 below). Such a busbar module equipped with a current sensor is used in electronic devices such as electrical power transformers, etc.

[0003] A Hall effect sensor can be used, for example, as a current sensor. When current flows through a busbar, a magnetic field is generated around the busbar. The Hall effect sensor detects the strength of this magnetic field, and this value is used to calculate the current. The sensitivity of a Hall effect sensor to the magnetic field is relatively low. For this reason, a magnetic flux concentration core is provided around the busbar, and the Hall effect sensor is positioned within a gap formed in this core (see [reference]). Fig. 20 and Fig. 21). This ensures that a strong magnetic field acts on the Hall element.

[0004] Furthermore, to achieve a compact magnetic flux concentration core and maintain high sensitivity, etc., the Hall element is positioned close to the busbar. In many cases, the Hall element is in contact with the busbar.

[0005] When an alternating current flows in the busbar, an alternating magnetic field is generated around it. This field can induce eddy currents in the magnetic flux concentration core, potentially causing heating. Therefore, when a magnetic flux concentration core is used, heat can be transferred from the core to the Hall element, easily leading to a temperature increase. Furthermore, if the Hall element is in contact with the magnetic flux concentration core, resistance heat generated by the busbar can also be readily transferred to it.In this way, since the heat transferred from the busbar or the magnetic flux concentration core causes a temperature increase of the sensor, there is a problem in that the operating lifetime of the current sensor will tend to be short if a Hall element is used as the current sensor. List of patent literature

[0006] PTL 1: JP 2014 - 006 118 A

[0007] DE 10 2007 062 633 B4 discloses an arrangement for the potential-free measurement of currents flowing in opposite directions in two parallel primary conductors. The magnetic differential field is detected by means of a differential field sensor. To reduce measurement errors, the primary conductors and the differential field sensor are arranged between two metal parts, which are designed as shielding plates made of highly permeable material, each with a web. The webs extend on both sides of the primary conductor arrangement, essentially parallel to it. At least one of the shielding plates has a U-shape in cross-sectional planes, with each pair of legs extending perpendicular to the U-shaped cross-sectional planes in a longitudinal direction.The two shielding plates are arranged in such a way that at least one pair of legs of one of the two shielding plates is aligned with the other of the two shielding plates, leaving an air gap on each leg.

[0008] JP 2008 275 321 A discloses a current sensor that detects a current flowing through a busbar by means of a current supplied to a first feedback coil and a second feedback coil to set the detection output of a Hall element to zero. A magnetic shielding object magnetically shields the Hall element, the first feedback coil, and the second feedback coil from an external magnetic field by covering them with an upper magnetic shielding element and a lower magnetic shielding element. When covered, cavities are formed between the upper and lower magnetic shielding elements. When the cavities are formed, the magnetic field strength acting on a magnetosensitive surface of the Hall element is reduced compared to the case where the cavities are not formed.

[0009] JP 2013-011469A discloses a current sensor comprising a magnetoelectric transducer formed on the surface of a sensor substrate and a magnetic shielding element surrounding both the sensor substrate and a measuring conductor. The magnetoelectric transducer exhibits the property that an output signal varies along a formation surface depending on an applied magnetic field. This formation surface is parallel to an xy-plane and orthogonal to the z-direction. A boundary line formed by an inner wall surface of the magnetic shielding element, divided by the xz-plane passing through the formation surface, extends in the x-direction and has a symmetrical structure about a baseline passing through the formation surface.A gap is formed at a section where the symmetrical structure is formed in the magnetic shielding part, and the height position of the gap and the height position of the sensor substrate are the same in the z-direction.

[0010] US Patent 4,504,787 A discloses an electrical watt-hour meter for measuring AC power consumption, comprising a pair of parallel busbars through which all the power to be measured is passed, a magnetoresistive bridge sensor arranged between the pair of busbars such that the current flow in one or both of the busbars generates a corresponding voltage signal from the sensor indicating the total amount of current flowing in the busbars, and a signal processing system that uses the signal from the sensor to generate an output signal indicating the total AC power passed through the busbars.

[0011] JP 2015-49184A discloses an inverter device. In this device, first magnetic materials and busbars for three phases are integrally formed with a first insulating element. The busbars penetrate the first insulating element, and each busbar runs between the first magnetic material and a second magnetic material. A control board is attached to the top surface of the first insulating element by threads or the like. Recesses for the element housings are provided on the top surface of the first insulating element, and magnetically sensitive elements are arranged in these recesses. The second magnetic material for each phase is integrally formed with a second insulating element for each phase. Both ends of the second magnetic materials protrude from the respective second insulating elements. The second insulating elements are attached to the control board by threads or the like.Both ends of the second insulating elements extend through the insertion holes for magnetic material on the control board. Summary of the invention

[0012] Since magnetoresistive elements such as GMR and TMR elements exhibit high sensitivity, they can measure current without the use of a magnetic flux concentration core. By using a current sensor that does not require a magnetic flux concentration core, the sensor can be positioned away from the busbars, thus reducing the heat transferred by the core and busbars and extending the sensor's service life.

[0013] However, since the sensitivity of a magnetoresistive element is high, if such a device is used as a current sensor, the current sensor is easily affected by magnetic fields generated by currents flowing in busbars adjacent to the busbar whose current is being measured, so there is a problem in that it is difficult to achieve high accuracy in measuring the value of the current.

[0014] In view of the background described above, the present invention has a main objective of providing a busbar module equipped with a current sensor which is able to prevent a temperature increase of the current sensor and to measure the busbar current with high accuracy.

[0015] This problem is solved by a busbar module equipped with a current sensor, as specified in claim 1.

[0016] Advantageous embodiments are specified in the dependent patent claims.

[0017] According to claim 1, a current sensor is configured as a magnetoresistive element. Since the sensitivity of a magnetoresistive element is high, it is unnecessary to use a magnetic flux concentration core. This prevents the conventional problems of heat generation due to eddy currents flowing in the magnetic flux concentration core and heat transfer to the current sensor.

[0018] Since the current sensor of the busbar module equipped with a current sensor can still be arranged separately from the busbars, resistance heat transfer to the current sensor is prevented. Because a current sensor using a magnetoresistive element has high sensitivity, the magnetic field of a busbar can be detected even when the current sensor is spaced away from the busbar.

[0019] In this way, the busbar module equipped with a current sensor can suppress the transfer of heat from a magnetic flux concentration core or busbar to the current sensor. As a result, the problem of temperature rise and the reduction in the operating life of the current sensor can be prevented.

[0020] Furthermore, in the busbar module described above, which is equipped with a current sensor, a multitude of busbars are arranged along the width direction. Additionally, a current sensor is positioned adjacent to a busbar in the thickness direction (see Fig. 1) For this reason, the current sensor is no longer located between a pair of busbars, but can be positioned with sufficient separation from adjacent busbars. Thus, the current sensor is not easily affected by the magnetic fields generated by neighboring busbars.

[0021] If a magnetic field generated by an adjacent busbar continues to be transmitted to a current sensor, the shielding plates can block the magnetic field. This reduces the effects of magnetic fields generated by adjacent busbars on the current sensor, allowing the current value in a busbar to be accurately measured using the current sensor.

[0022] Furthermore, according to the second embodiment, the current sensor and the busbars are arranged between a pair of shielding plates in the thickness direction.

[0023] This means that the pair of shielding plates is arranged separately, so they are not connected to each other. As described below, the pair of shielding plates could be connected together, but in this case, problems would arise, such as the large amount of metal required to form the shielding plates, thus increasing the manufacturing costs of the busbar module equipped with a current sensor, and the weight would be high. However, if a pair of shielding plates is provided, such a problem is unlikely to occur.

[0024] As described above, the present disclosure provides a busbar module equipped with a current sensor, which can suppress a temperature rise of the current sensor and allow the value of a current flowing in a busbar to be measured accurately. Brief description of the drawings Fig. Figure 1 shows a cross-sectional view of a busbar module equipped with a current sensor according to a first embodiment, taken in a plane II which is in Fig. 2 is indicated. Fig. Figure 2 shows a cross-sectional view, which is in a Fig. Level II-II is taken as specified in point 1. Fig. Figure 3 shows a cross-sectional view, which is in a Fig. Level III-III is taken as specified in point 1. Fig. Figure 4 shows an enlarged main part of Fig. 1. Fig. Figure 5 shows a cross-sectional view of an electrical power converter according to the first embodiment, wherein the view is in a Fig. Level VV is taken as specified in section 6. Fig. Figure 6 shows a cross-sectional view, which is in a Fig. Level VI-VI is taken as specified in section 5. Fig. Figure 7 shows a cross-sectional view, which is in a Fig. Level VII-VII is taken as specified in section 5. Fig. Figure 8 shows a circuit diagram of the power converter according to the first embodiment. Fig. Figure 9 shows a cross-sectional view of a busbar module equipped with a current sensor according to a second embodiment. Fig. Figure 10 shows a cross-sectional view, which is in a Fig. The specified level XX has been taken. Fig. Figure 11 shows a cross-sectional view of a busbar module equipped with a current sensor according to the second embodiment, which has a V-phase busbar and a W-phase busbar, each equipped with a respective current sensor. Fig. Figure 12 shows a circuit diagram of a power converter according to a third embodiment. Fig. Figure 13 shows a circuit diagram of a power converter according to a fourth embodiment. Fig. Figure 14 shows a circuit diagram of a power converter according to a fifth embodiment. Fig. Figure 15 shows a cross-sectional view of a busbar module equipped with a current sensor according to a sixth embodiment. Fig. Figure 16 shows a cross-sectional view of a busbar module equipped with a current sensor according to a seventh embodiment. Fig. Figure 17 shows a cross-sectional view of a busbar module equipped with a current sensor according to an eighth embodiment. Fig. Figure 18 shows a conceptual representation of current sensors and busbars of a first comparative example. Fig. Figure 19 shows a conceptual representation of current sensors and busbars of a second comparative example. Fig. Figure 20 shows a conceptual representation of current sensors and busbars of a third comparative example. Fig. Figure 21 shows a cross-sectional view, which is in a Fig. The level XXI-XXI specified in 20 has been taken. Description of exemplary implementations

[0025] The busbar module equipped with a current sensor can be used for an electrical power converter that performs a conversion between direct current electrical power and alternating current electrical power. First embodiment

[0026] A first embodiment of the busbar module 1 equipped with a current sensor is described with reference to Fig. 1 to 8 described. As it is in Fig. As shown in Figures 1 to 3, the busbar module 1, equipped with a current sensor, according to the present embodiment, has a plurality of busbars 2 (2a, 2b and 2c) in which currents flow, current sensors 4 (4a to 4c) and shielding plates 5. Each of the current sensors 4 measures the value of a current in at least a portion of the plurality of busbars 2 (2a to 2c). The shielding plates 5 shield the magnetic fields generated around the busbars 2.

[0027] The current sensors 4 (4a to 4c) are each equipped with a magnetoresistive element and detect the intensity of the magnetic field generated around the busbar 2 when current flows through it.

[0028] The busbars 2 (2a to 2c) are arranged along a width direction (X direction) which is at right angles to both the thickness direction (Z direction) and the extension direction (Y direction) of the busbars 2.

[0029] The current sensors 4 are spaced apart from the respective busbars 2 and arranged in positions adjacent to the respective busbars 2 in the Z-direction.

[0030] The busbars 2 and the current sensors 4 are covered on both sides in the Z-direction by the shielding plates 5. According to the present embodiment, the shielding plates extend over a wider area than that of the busbars 2, whereas they overlap with the respective current sensors 4 when viewed from the Z-direction.

[0031] As it is in the Fig. 5 and Fig. As shown in Figure 6, the busbar module 1, equipped with a current sensor, is used in the present embodiment for an electrical power converter 10, which performs power conversion between direct current (DC) and alternating current (AC) power. The electrical power converter 10 is a vehicle-integrated power conversion device installed in a vehicle such as a hybrid or electric vehicle.

[0032] The busbar module 1, equipped with a current sensor according to the present embodiment, is provided with a potting element 3 that seals the plurality of busbars 2 to form a single-piece body. Additionally, according to the present embodiment, each of the busbars 2 is provided with a current sensor 4. Each busbar 2 and the corresponding current sensor 4 are sandwiched together on both sides in the Z-direction by a pair of shielding plates 5 (5a and 5b). According to the present embodiment, the potting element 3 is formed from a non-magnetic resin material.

[0033] As it is in Fig. As shown in Figure 1, a section of the potting compound 3 is arranged between each current sensor 4 and the corresponding busbar 2. A gap G is formed between each current sensor 4 and the corresponding potting compound 3. According to the present embodiment, the current sensors 4 are each composed of a magnetoresistive element, such as a GMR (giant magnetoresistive) element or a TMR (tunnel magnetoresistive) element.

[0034] The current sensors 4 are mounted on a sensor circuit board 7. The potting compound 3 is formed with post sections 31. The tip of each post section 31 is inserted into a through-hole 79 formed in the sensor circuit board 7 and is thermally crimped. The sensor circuit board 7 is thus firmly attached to the post sections 31.

[0035] Electronic components 70 other than the current sensors 4 are mounted on the sensor circuit board 7. The electronic components 70 are arranged between the circuit substrate 7 and the potting compound 3. The electronic components 70 can each be, for example, a decoupling capacitor or a filter circuit.

[0036] Furthermore, a recess 30 is formed in the potting compound 3. The sensor circuit board 7, the current sensors 4, and the electronic components 70 are contained within the recess 30. A cover 6 is attached to the potting compound 3 to cover the opening of the recess 30. The current sensors 4, etc., are thereby enclosed and potted within the recess 30.

[0037] One shielding plate (5a) of each pair of shielding plates 5 (5a and 5b) is encased in the potting part 3. The other sealing plate (5b) of the pair is encased in the cover 6.

[0038] According to the present embodiment, the three busbars of the first busbar 2a, the second busbar 2b, and the third busbar 2c are encapsulated by the potting element 3. The first current sensor 4a is arranged in a position adjacent to the first busbar 2a in the Z-direction, and the second current sensor 4b is arranged in a position adjacent to the second busbar 2b in the Z-direction. Additionally, the third current sensor 4c is arranged in a position adjacent to the third busbar 2c in the Z-direction. The three current sensors 4a to 4c are arranged such that the direction for detecting a magnetic field (magnetic detection direction) coincides with the X-direction.

[0039] The first busbar 2a and the first current sensor 4a are arranged between a first pair of shielding plates 51, and the second busbar 2b and the second current sensor 4b are arranged between a second pair of shielding plates 52. Additionally, the third busbar 2c and the third current sensor 4c are arranged between a third pair of shielding plates 53.

[0040] As it is in Fig. As shown in Figure 4, when an alternating current flows through the first busbar 2a, a magnetic field is generated around the first busbar 2a. The first current sensor 4a measures the intensity of the magnetic field Ha. Similarly, the magnetic field generated around the second busbar 2b is measured by the second current sensor 4b, and the magnetic field generated around the third busbar 2c is measured by the third current sensor 4c.

[0041] The sensor circuit board 7 is connected to a control circuit board 85 of the power converter 10 as described below (see Fig. 5) The sensor circuit board 7 sends the measured current value from each of the busbars 2 (2a to 2c) to the control circuit board 85. The control circuit board 85 feeds the measured values ​​back to the power conversion device 10 for use in an operational control system, etc.

[0042] As it is in Fig. As shown in Figure 4, the first busbar 2a and the first current sensor 4a are covered on both sides in the Z-direction by a pair of shielding plates 5a and 5b (first shielding plate pair 51). The second busbar 2b and the third busbar 2c are configured similarly. The shielding plates 5a and 5b shield the magnetic field H generated by the busbars 2, preventing it from escaping excessively. However, in some cases, the magnetic field H is not necessarily completely shielded by the shielding plates 5a and 5b. For example, part of a magnetic field Hb generated by the second busbar 2b (magnetic field Hb') may escape from the second pair of shielding plates 52. In this case, the magnetic field Hb' is shielded by the first pair of shielding plates 51, so that the first current sensor 4a is not significantly affected by the magnetic field Hb'.

[0043] Similarly, since the second current sensor 4b is located between the second pair of shielding plates 52, any magnetic fields escaping from the adjacent busbars 2 (the first and third busbars 2a and 2c) are shielded by the second pair of shielding plates 52. Therefore, the second current sensor 4b will not be significantly affected by the magnetic fields from these adjacent busbars 2. This also applies to the third current sensor 4c.

[0044] The configuration of the power converter 10 is described below. As it is in the Fig. 5 and Fig. As shown in Figure 6, the power converter 10 according to the present embodiment comprises a plurality of semiconductor modules 8 and a plurality of cooling tubes 87 for cooling the semiconductor modules 8. The semiconductor modules 8 and the cooling tubes 87 are layered alternately to form a layered unit 11.

[0045] Each semiconductor module 8 has a main body 81 containing semiconductor devices 82 (see Fig. 8), power terminals 83 projecting from the main body 81, and control terminals 84. The power terminals 83 have a positive terminal 83a and a negative terminal 83b to which a DC voltage is applied, and an AC terminal 83c connected to an AC load 892 (see Fig. 8) is connected. The busbars 2 according to the present embodiment are connected to the AC terminals 83c. The housing 12 of the power transformer 10 is formed with a connector insertion opening 121 for inserting a connector (not shown). When the connector is inserted into the insertion opening 121 for connection to the busbars 2, it is ensured that the busbars 2 are electrically connected to the AC load 892.

[0046] The positive terminal 83a and the negative terminal 83b are each connected to a capacitor 86 via a positive-side metal plate 88a and a negative-side metal plate 88b, respectively. The control terminals 84 are connected to the control circuit board 85. The control circuit board 85 controls the on / off operation of each terminal module 8. Thus, the DC voltage applied to the positive terminal 83a and the negative terminal 83b of the semiconductor module is converted into an AC voltage, which is output from the busbars 2 (2a to 2c).

[0047] The control circuit board 85 is connected to the sensor circuit board 7 by a connecting line (not shown) (see Fig. 1) in the busbar module 1 equipped with a current sensor. As described above, the sensor circuit board 7 sends measured values ​​of the current flowing in each of the busbars 2 (2a to 2c) to the control circuit board 85. The control circuit board 85 uses the measured values ​​to control the semiconductor modules 8, etc.

[0048] As it is in Fig. As shown in Figure 7, two cooling tubes 87, adjacent in the X-direction, are connected at both ends in the Y-direction by connecting tubes 17. Furthermore, a cooling tube 87a, positioned at one end of the plurality of cooling tubes 87 in the X-direction, is connected to an inlet tube 13 for introducing a coolant 15 and to an outlet tube 14 for expelling the coolant 15. The coolant 15 entering the inlet tube 13 flows through the connecting tubes 17 and through all cooling tubes 87, and is then expelled through the outlet tube 14. In this way, the individual semiconductor modules 8 are cooled.

[0049] Furthermore, the layered unit 11 is arranged between a pair of walls 122 and 123 of the housing 12. A pressing element 16 (leaf spring) is arranged between a wall 122 and the layered unit 11. The pressing element 16 presses the layered unit 11 in the X direction, thereby holding the layered unit 11 pressed against the outer wall 123 of the housing 12. This maintains contact pressure between the retaining conductor modules 8 and the cooling tubes 87, thus securing the layered unit 11 within the housing 12.

[0050] The electrical circuit of the power converter 10 is described below. In this example, as shown in Fig. As shown in Figure 8, a plurality of semiconductor elements 82 (IGBT elements) contained in the terminal modules 8 are used to form an inverter circuit. The DC power supplied from the DC power supply 891 is converted into AC power by switching each of the semiconductor devices 82 on and off. The converted AC power is used to drive the AC load 892 (three-phase AC motor). This propels the vehicle.

[0051] Advantageous effects according to the present embodiment are described below. As described above, magnetoresistive elements are used to form the current sensors 4 according to the embodiment. Since magnetoresistive elements have high sensitivity, it is not necessary to provide a magnetic flux concentration core. This eliminates the conventional problem of an eddy current flowing through a magnetic flux concentration core and the resulting heat transfer to the current sensors 4.

[0052] Furthermore, according to the present embodiment, as it is in Fig. As shown in Figure 1, the current sensors 4 are arranged at positions spaced away from the busbars 2. This eliminates the problem of resistance heat from the busbars 2 being transferred to the current sensors 4. The current sensors 4, which use magnetoresistive elements to provide high sensitivity, can detect the magnetic fields of the busbars 2 even when spaced away from them.

[0053] Thus, according to the present embodiment, heat transfer from the magnetic flux concentration cores or the busbars 2 to the current sensors 4 can be prevented. As a result, the problem of temperature rise and the reduction in the operating life of the current sensor can be avoided.

[0054] This means that, as it says in Fig. 20 and Fig. As shown in Figure 21, if each current sensor 94 uses a Hall element as per the prior art, it is necessary to provide a magnetic flux concentration core 99, since Hall elements have low sensitivity to magnetic fields. Thus, due to the effect of the alternating magnetic field generated around a busbar 92, an eddy current flows in the magnetic flux concentration core 99. This allows the magnetic flux concentration core 99 to be heated by the eddy current, and the heat can be transferred to the current sensor 94. Furthermore, for reasons of size reduction and improved sensitivity of the magnetic flux concentration core 99, in some cases the Hall element is arranged in contact with the busbar. This makes it likely that resistance heat generated in the busbar 92 will be transferred to the Hall element (the current sensor).

[0055] Thus, in the case of the current sensor 94, which uses a Hall element, heat is easily transferred from the busbar 92 and the magnetic flux concentration core 99, causing the temperature to rise. For this reason, the service life of the current sensor 94 tends to be reduced. However, since the current sensor 4, which uses a magnetoresistive element as in the present embodiment, does not require a magnetic flux concentration core, heat transfer from the magnetic flux concentration core to the current sensor 4 is prevented. Furthermore, since the sensitivity of the current sensor 4, which uses a magnetoresistive element, is high, the magnetic field of the busbar 2 can be detected even when the current sensor 4 is spaced away from the busbar 2.Disconnecting the current sensor 4 from the busbar 2 prevents heat from the busbar 2 from being transferred to the current sensor 4 in such a way that the temperature increases.

[0056] Furthermore, according to the present embodiment, as it is in Fig. As shown in Figure 1, the multiple busbars 2 are arranged along the X-direction. Each current sensor 4 is positioned adjacent to the corresponding busbar 2 in the Z-direction. Thus, no current sensor 4 is located between two busbars 2, and each current sensor 4 can be positioned with sufficient separation from adjacent busbars 2. Therefore, each current sensor 4 is less sensitive to the effects of magnetic fields generated by adjacent busbars 2.

[0057] In particular, let us consider an example such as that found in Fig. Figure 18 shows a plurality of busbars 92 arranged along the thickness direction (Z' direction) of the busbars 92, with the current sensors 94 positioned close to adjacent busbars 92 in the Z' direction. Since in this case each current sensor 94 is close to adjacent busbars 92, there is a risk that the current sensor 94 will be affected by the magnetic fields of these adjacent busbars 92, making accurate measurement of the electrical current values ​​impossible.

[0058] Furthermore, if each current sensor 94 is arranged between a busbar 92 and a shielding plate 95, as described in Fig. As shown in Figure 19, the current sensor 94 is affected by the magnetic field Hb' of an adjacent busbar 92, which makes an accurate measurement of the electric current values ​​impossible.

[0059] In contrast, according to the present embodiment, as described in Fig. As shown in Figure 1, when the multiple busbars 2 are arranged along the width direction (X-direction) and the current sensors 4 are positioned adjacent to the busbars 2 in the thickness direction (Z-direction), the current sensors 4 are positioned at locations sufficiently separated from the adjacent busbars 2. As a result, the current sensors 4 are less sensitive to magnetic fields generated by the adjacent busbars 2.

[0060] According to the present embodiment, the current sensors 4 and the busbars 2 are covered on both sides in the Z-direction by the shielding plates 5 (5a and 5b). Thus, as shown in Fig. As shown in Figure 4, if there is an escape of the magnetic field H generated by adjacent busbars 2, the shielding plates 5a and 5b block the magnetic field H. Thus, the effects of the magnetic field H from the adjacent busbars 2 on a current sensor 4 can be further reduced. Therefore, the value of the current in a busbar 2 can be accurately measured using a current sensor 4.

[0061] According to the present embodiment, as it is in Fig. As shown in Figure 1, a section of the potting compound 3 is arranged between the current sensors 4 and the respective busbars 2.

[0062] Since the resistance heat generated by the busbars 2 can be shielded by the potting compound 3, it is more effectively prevented that resistance heat is transferred to the current sensors 4. Thus, a temperature increase of the current sensors 4 can be minimized more effectively.

[0063] According to the present embodiment, as it is in Fig. As shown in Figure 1, a gap G is formed between the current sensors 4 and the potting compound 3. This ensures that contact between the current sensors 4 and the potting compound 3 is prevented. This prevents heat generated by the busbars 2 from being transferred to the potting compound 3 and subsequently to the current sensors 4. In this way, the temperature rise of the current sensors 4 can be minimized more effectively.

[0064] According to the present embodiment, the busbars 2 and the current sensors 4 are arranged in a sandwich-like manner between the pair of shielding plates 5 (5a and 5b) in the Z-direction.

[0065] For this reason, the current sensors 4 are less sensitive to the effects of magnetic fields generated by adjacent busbars 2. That is to say, as is stated in Fig. As shown in Figure 15, a current sensor 4 and a busbar 2 can be enclosed in the Z-direction by means of a single shielding plate 5. However, in this case, eddy currents would be produced in the shielding plate 5 by alternating magnetic fields generated by the busbar 2, and these eddy currents could flow in a connecting section 59 of the shielding plate 5. Therefore, eddy currents could flow near the current sensor 4, and the adjacent current sensor 4 could be affected by the magnetic fields generated by these eddy currents. However, according to the present embodiment, a pair of shielding plates 5a and 5b without connecting sections 59 is used, which prevents eddy currents from flowing near the current sensor 4 and prevents the magnetic fields generated by the eddy currents from affecting the current sensor 4.

[0066] Furthermore, the use of a pair of shielding plates 5 (5a, 5b) that are not connected, as in the present embodiment, can reduce the amount of metal material forming the shielding plates 5. In this way, the weight and manufacturing costs of the busbar module equipped with a current sensor can be reduced.

[0067] According to the present embodiment, as it is in Fig. Figure 1 shows one shielding plate 5a of a pair of shielding plates 5a and 5b encased in the potting part 3, and the other shielding plate 5b encased in the lid 6.

[0068] In this way, the cover 6 can be used to cover the opening of the recess 30 and also to secure the outer shielding plate 5b. Therefore, it is not necessary to provide a separate, special part for attaching the other shielding plate 5b to the potting compound 3, thus reducing the number of parts required. This, in turn, reduces the manufacturing costs of the busbar module 1 equipped with a current sensor.

[0069] According to the present embodiment, as described in Fig. As shown in Figure 1, other electronic components 70, besides the current sensors 4, are arranged between the circuit board 7 and the potting compound 3. Thus, the space between the circuit board 7 and the potting compound 3 can be effectively used to accommodate the electronic components 70. This reduces wasted space and allows the busbar module 1, equipped with the current sensor, to be made compact in size.

[0070] According to the embodiment described above, a busbar module equipped with a current sensor is provided which is able to minimize a temperature increase of the current sensors and to correctly measure current values ​​in the busbars. Second embodiment

[0071] According to the following embodiment, unless otherwise specified, elements that are identical to components of the first embodiment are designated by the same reference numerals as those according to the first embodiment.

[0072] According to the present embodiment, the mounting positions of the current sensors 4 are changed. According to the embodiment, as shown in Fig. As shown in Figure 9, of the three busbars 2a, 2b, and 2c, current sensors 4 are provided only for the first busbar 2a and the second busbar 2b, and no current sensor 4 is provided for the third busbar 2c. According to the present embodiment, it is ensured that the current values ​​are measured only for two busbars 2 (first and second busbars 2a and 2b), and it is ensured that the current value in the third busbar 2c is calculated using the measured values. Such a calculation is possible because three-phase currents flow in the three busbars 2.

[0073] As it is in Fig. As shown in Figure 10, the first busbar 2a is equipped with two first current sensors 4a. This ensures that if one of the two first current sensors 4a should fail, the current value in the first busbar 2a is measured using the other of the first current sensors 2a. The second busbar 2b is similarly equipped with two current sensors 4b.

[0074] In other respects, the arrangement and the advantageous effects are the same as those according to the first embodiment.

[0075] According to the present embodiment, as described in Fig. As shown in Figure 10, current sensors 4 are provided for the U-phase busbars 2 (first busbar 2a) and the V-phase busbars 2 (second busbar 2b), however, the present invention is not limited thereto. That is to say, as shown in Figure 10, current sensors 4 are provided for the U-phase busbars 2 (first busbar 2a) and the V-phase busbars 2 (second busbar 2b), but the present invention is not limited thereto. That is to say, as shown in Figure 10, current sensors 4 are provided for the U-phase busbars 2 (first busbar 2a) and the V-phase busbars 2 (second busbar 2b). Fig. Figure 11 shows that current sensors 4 can be provided for the V-phase busbars 2 (second busbar 2b) and for the W-phase busbars 2 (third busbar 2c). Third example

[0076] According to the present embodiment, the circuit of the power converter 10 is modified. As shown in Fig. As shown in Figure 12, the power converter 10, according to the present embodiment, comprises a coil 893 and a voltage-boosting semiconductor module 8b. The coil 893 and the voltage-boosting semiconductor module 8b form a voltage-boosting circuit 101. Additionally, an inverter circuit 102 is constructed by a plurality of inverter semiconductor modules 8a. The power converter 10, according to the present embodiment, ensures that the voltage of a DC power source 891 is boosted by the voltage-boosting circuit 101, followed by the conversion of the DC power to AC power by the inverter circuit 102. Current sensors 4 are provided for the busbars 2 that connect the inverter circuit 102 and the AC load 892.

[0077] In other respects, the arrangement and the advantageous effects are the same as those according to the first embodiment. Fourth embodiment

[0078] According to the present embodiment, the mounting positions of the current sensors 4 have been changed.

[0079] As it is in Fig. As shown in Figure 13, according to the present embodiment, a current sensor 4 is connected to a voltage boost busbar 2. L The voltage boost semiconductor module 8b is provided to connect the coil 893. The current sensor 4 is used to measure the current flowing through the voltage boost busbar 2. L current flows. The control circuit board 85 is configured to calculate the temperature of the coil 893 using the measured values ​​derived from the current sensor 4. When the current is passed through the boost busbar 2 L If the flowing current exceeds a predetermined threshold, the control circuit board 85 judges that the temperature of the coil 893 is excessively high and limits the current.

[0080] The negative electrode of the DC power source 891 is connected to the semiconductor modules 8 (8a, 8b) via a negative busbar 2n. The voltage boost busbar 2 L and the negative busbar 2n are arranged adjacent to each other in the X-direction, in a similar manner to that of busbars 2a to 2c according to the first embodiment. It is ensured that the voltage boost busbar 2 L and the current sensor 4 is covered from both sides in the Z direction by shielding plates 5.

[0081] In other respects, the arrangement and the advantageous effects are the same as those according to the first embodiment. Fifth embodiment

[0082] According to the present embodiment, the mounting position of the current sensor 4 has been changed. As shown in Fig. As shown in Figure 14, the power converter 10 in the present embodiment, similar to the first embodiment, does not have a voltage boost circuit, but only the inverter circuit 102. The positive electrode of the DC power source 891 is electrically connected to the semiconductor modules 8 via a positive busbar 2p. Additionally, the negative electrode of the DC power source 891 is electrically connected to the semiconductor modules 8 via a negative busbar 2n. The capacitor 86 is provided between the positive busbar 2p and the negative busbar 2n. A current sensor 4 is installed on the positive busbar 2p such that it is located within the area where the positive busbar 2p connects the DC power supply 891 and the capacitor 86.

[0083] According to the present embodiment, the positive busbar 2p and the negative busbar 2n are arranged such that they are adjacent to each other in the X-direction, similar to the busbars 2a to 2c according to the first embodiment. The positive busbar 2p and the current sensor 4 are configured such that they are covered on both sides in the Z-direction by the shielding plates 5.

[0084] According to the present embodiment, the current flowing in the busbar 2p is measured by the current sensor 4, and the measured values ​​are used by the control circuit board 85 to calculate the temperature of the capacitor 86. If the current flowing in the positive busbar 2p exceeds a predetermined threshold, the control circuit board 85 judges that the temperature of the capacitor 86 is excessively high and limits the current.

[0085] In other respects, the arrangement and advantageous effects are the same as those according to the first embodiment. Sixth embodiment

[0086] According to the present embodiment, the shape of the shielding plate 5 is modified. As shown in Fig. As shown in Figure 15, each shielding plate 5 is shaped in a ring form. A busbar 2, a current sensor 4, and a sensor circuit board 7 are arranged inside the ring-shaped shielding plate 5.

[0087] Each shielding plate 5 has two main plate sections 58 and two connecting sections 59. The connecting sections 59 connect the two main plate sections 58 to each other. The busbar 2 and the current sensor 4 are covered on both sides in the Z-direction by the two main plate sections 58.

[0088] The advantageous effects of the present embodiment are described below. With the configuration described above, the busbar 2 and the current sensor 4 are surrounded on four sides by the annular shielding plate 5. Accordingly, the magnetic field generated by the busbar 2 can be shielded more effectively.

[0089] In other respects, the arrangement and advantageous effects are the same as those according to the first embodiment. Seventh embodiment

[0090] According to the present embodiment, the shape of the shielding plate 5 is modified. As shown in Fig. As shown in Figure 16, a shielding plate 5 according to the present embodiment has two main plate sections 58 and a connecting section 59. The single connecting section 59 connects the two main plate sections 58. A busbar 2 and a current sensor 4 are covered on both sides in the Z-direction by the two main plate sections 58.

[0091] In other respects, the arrangement and the advantageous effects are the same as those according to the first embodiment. Eighth example

[0092] According to the present embodiment, the shape of the shielding plate 5 is modified. As shown in Fig.As shown in Figure 17, a shielding plate 5 is formed in a cylindrical shape. A busbar 2, a current sensor 4, and a sensor circuit board 7 are arranged inside the cylindrical shielding plate 5. The busbar 2 and the current sensor 4 are covered on both sides in the Z-direction by the cylindrical shielding plate 5.

[0093] In other respects, the arrangement and the advantageous effects are the same as those according to the first embodiment. Reference symbol list 1 busbar module equipped with a current sensor 2 busbar 3 Potting part 4 Current sensor 5 Shielding plate

Claims

[1] Busbar module (1) equipped with a current sensor characterized by , that the module exhibits: a multitude of busbars (2) in which currents flow; a casting element (3) through which the plurality of busbars (2) are cast to form a single-piece body; a current sensor (4) that measures a current value in at least one part of the plurality of busbars (2); and a sensor circuit board (7) on which the current sensor (4) is mounted, wherein: the current sensor (4) has a magnetoresistive element and measures the value of the current in a busbar (2) by detecting the strength of the magnetic field generated around the busbar (2) by the flow of the current in the busbar (2); the multiple busbars (2) are arranged along a width direction which is perpendicular to a length direction of the busbars (2) and a thickness direction of the busbars (2); the current sensor (4) is arranged adjacent to the busbars (2) in the thickness direction and is spaced apart from the busbars (2); and at least a pair of shielding plates (5a and 5b) are provided which sandwich around the current sensor (4) and the busbars (2) in the thickness direction to shield the magnetic field, the pair of shielding plates (5a and 5b) are arranged in positions that sandwich around the current sensor (4) and the busbars (2) in the thickness direction, a recess (30) is formed in the potting part (3), wherein the current sensor (4) is contained within the recess (3), a lid (6) is attached to the potting part (3) to cover an opening of the recess (30), one shielding plate (5a) of the pair of shielding plates (5a and 5b) is encased in the potting part (3), and the other shielding plate (5b) of the pair of shielding plates (5a and 5b) is encased in the lid (6), the cover (6) is formed separately from the sensor circuit board (7), and the sensor circuit board (7) is contained within the recess (3) with the current sensor. [2] Busbar module (1) equipped with a current sensor according to claim 1, characterized by , that the module has the potting element (3) through which the plurality of busbars (2) are potted to form a single-piece body, wherein part of the potting element (3) is arranged between the current sensor (4) and the busbars (2). [3] Busbar module (1) equipped with a current sensor according to claim 1 or 2, characterized by, that a gap (G) is formed between the current sensor (4) and the potting part (3). [4] Busbar module (1) equipped with a current sensor according to one of claims 1 to 3, characterized by , that the casting part (3) has post sections (31) which are formed within the recess (30) and project in the thickness direction, wherein: a through-hole (79) which runs in the thickness direction, is formed in the sensor circuit board (7), each post section (31) is inserted into the passage opening (79), and a tip part of each post section (31) is thermally caulked. [5] Busbar module (1) equipped with a current sensor according to one of claims 1 to 4, characterized by , that the potting element (3) is configured such that it is not present between two adjacent current sensors (4).

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