Non-contact voltage and current integrated measuring device for crimping type power device

Abstract

The invention provides a non-contact voltage and current integrated measuring device for a crimping type power device. The non-contact voltage and current integrated measuring device comprises multiple layers of differential Rogowski coils, an adder and a differential circuit. Wherein the multi-layer differential Rogowski coil is provided with a plurality of stacked measuring units, the adjacent measuring units form a group, and the two measuring units in the group are stacked back to back. The measuring unit is provided with a signal layer and a loop layer; a C-shaped coil is arranged on the signal layer, and a C-shaped loop is arranged on the loop layer; one end of the C-shaped loop is connected with an outgoing line of the C-shaped coil, and the other end is connected with the adder and one input end of the differential circuit; the winding directions of the signal layer coils of the two inter-group measuring units are opposite. The device is simple in structure and low in cost, solves the problem of voltage and current device measurement and the interference problem of a traditional contact measurement method through the multi-layer differential Rogowski coil, improves the measurement accuracy and speed, reduces the risks of electric shock and equipment damage, and remarkably improves the operation safety.

Description

Technical Field

[0001] The invention relates to the technical field of voltage and current measurement, and in particular to a non-contact voltage and current integrated measurement device for a crimped power device. Background Art

[0002] In the field of high-voltage and high-power applications, high-voltage and high-power power electronic devices play a critical role in flexible DC transmission and large-capacity power conversion. Among them, as a typical high-voltage and high-power power electronic device, the crimping type power device can accurately measure its switching voltage and current, which is helpful to evaluate the switching characteristics of the device, calculate the energy loss of the switching process, and optimize the performance and efficiency of power electronic equipment. The crimping structure uses mechanical pressure to achieve electrical connection, avoiding the thermal stress concentration and fatigue cracking of the welding layer under temperature cycling, and has better thermal cycling reliability.

[0003] At present, a more common method for measuring the current of crimped power devices is the sampling resistor method, which has low cost and simple principle, but it will destroy the insulation and airtightness of the package. Therefore, most of the current commercial sensors use non-contact current measurement methods, but there are also problems, such as: the Hall sensor has limited bandwidth and is easily affected by the external magnetic field; the current sensor has strong anti-interference ability, but the volume is large and the built-in iron core; the optical fiber current sensor has a large measurement range, but the cost is high and the anti-interference ability is insufficient. Therefore, the Rogowski coil has become a more suitable execution end of the measurement device. The main reason is that the commercial Rogowski coil has non-invasiveness and good linearity, and has a good application prospect in the current test of power devices. For example, the segmented Rogowski coil proposed in the prior art has a strong spatial resolution for crimped IGBT monitoring, and can distinguish and monitor the current distribution of the internal parallel chips; and it adopts a non-invasive measurement principle to avoid the influence on the stress distribution of the crimping interface, and has a high spatial integration, which is convenient for engineering application and realizes real-time monitoring of device performance. Furthermore, although the measurement accuracy of the PCB Rogowski coil is lower than that of other commercial Rogowski coils, it is easy to integrate, has high reliability and low cost.

[0004] The current non-contact voltage measurement method mainly focuses on power line voltage measurement, and there is relatively little research on non-contact voltage measurement of devices. In terms of device switching voltage measurement, some technicians have proposed a high-anti-interference electric field probe based on shielded copper cladding and via arrays to measure the switching voltage of SiC MOSFET. This non-contact probe is based on the principle of electric field coupling and has the advantages of low invasiveness, small size and easy integration, which solves the integration problem of traditional contact probes. However, the improvement of the power density of UHV converter valves requires a more compact internal structure, which limits the installation space of the above-mentioned sensors and requires reducing the impact on equipment status monitoring.

[0005] In summary, the existing integrated research on measurement systems mainly focuses on the integration of single physical quantity measurement systems and the measured subject, while the integrated research on realizing synchronous measurement of multiple physical quantities is still relatively lacking. Therefore, it is also necessary to improve the existing crimp-type power device voltage and current measurement devices. Summary of the invention

[0006] In view of the problems existing in the prior art, the present invention provides a non-contact voltage and current measuring device for a press-fit power device which has a simple structure, low cost and can be highly integrated.

[0007] To achieve the above purpose, the technical solution adopted by the present invention is as follows:

[0008] A non-contact voltage and current integrated measuring device for a crimped power device, mainly comprising a multi-layer differential Rogowski coil, an adder and a differential circuit;

[0009] The multi-layer differential Rogowski coil is provided with a plurality of stacked measuring units, wherein adjacent measuring units form a group, and two measuring units in a group are stacked back to back;

[0010] The measuring unit is provided with a signal layer and a loop layer; the signal layer is provided with a C-shaped coil, and the loop layer is provided with a C-shaped loop; the C-shaped coil and the C-shaped loop are coaxially arranged, one end of the C-shaped loop is connected to the output line of the C-shaped coil, and the other end is connected to an input end of the adder and differential circuit; the signal layer coils of the two measuring units between the groups are wound in opposite directions;

[0011] The multi-layer differential Rogowski coil is nested outside the crimping type power device.

[0012] Optionally, the substrate of the signal layer is a ring-shaped PCB board;

[0013] The annular PCB board is provided with an outer circle through hole and an inner circle through hole;

[0014] The circle where the outer ring through holes are located is coaxially arranged with the circle where the inner ring through holes are located, and the radius of the circle where the outer ring through holes are located is greater than the radius of the circle where the inner ring through holes are located;

[0015] The C-shaped coil is wound around the annular PCB board through the outer circle through hole and the inner circle through hole.

[0016] Optionally, the wiring structure of the C-shaped coil is a triangular wiring structure.

[0017] Optionally, the C-shaped coil and the opening area of ​​the C-shaped loop overlap in the axial direction.

[0018] Optionally, the coil opening areas of the two measurement units in the group overlap in the axial direction.

[0019] Optionally, the substrate of the loop layer is a ring-shaped PCB board;

[0020] The C-shaped loop is arranged on the annular PCB board.

[0021] Optionally, the C-shaped loop is located within a projection area of ​​the C-shaped coil along the axial direction.

[0022] Optionally, the multi-layer differential Rogowski coil further includes a bottom layer;

[0023] The bottom layer is a ring structure and is located on the bottom surface of the multi-layer differential Rogowski coil.

[0024] Optionally, the multi-layer differential Rogowski coil further includes at least one shielding layer;

[0025] The shielding layer is located between the bottom layer and / or adjacent measuring units.

[0026] Optionally, the shielding layer is a segmented annular structure and is provided with at least two fan ring portions;

[0027] The sector ring parts are spliced ​​along the circumferential direction, and adjacent sector ring parts are insulated.

[0028] Compared with the prior art, the present invention has the following beneficial effects:

[0029] The present invention has a simple structure and low cost. It solves the measurement problems of voltage and current distribution devices and the interference problem of traditional contact measurement methods through multi-layer differential Rogowski coils, thereby improving the measurement accuracy and speed. At the same time, the device also reduces the risk of electric shock and equipment damage, and significantly improves the safety of operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0031] Figure 1 A schematic diagram of a device in a specific embodiment of the present invention;

[0032] Figure 2 It is a schematic diagram of the longitudinal structure of a multi-layer differential Rogowski coil in a specific embodiment of the present invention;

[0033] Figure 3 It is a schematic diagram of a top view structure of a multi-layer differential Rogowski coil in a specific embodiment of the present invention;

[0034] Figure 4 This is a schematic diagram of the structure of the first signal layer in a specific embodiment of the present invention;

[0035] Figure 5 This is a schematic diagram of the structure of the first loop layer in a specific embodiment of the present invention;

[0036] Figure 6 This is a schematic diagram of the structure of the second loop layer in a specific embodiment of the present invention;

[0037] Figure 7 This is a schematic diagram of the structure of the second loop layer in a specific embodiment of the present invention;

[0038] Figure 8 It is a schematic diagram of the signal layer winding structure in a specific embodiment of the present invention;

[0039] Fig. 9 It is a schematic diagram of the structure of the bottom layer and the shielding layer in a specific embodiment of the present invention.

[0040] In the figure: 1, first measuring unit, 2, second measuring unit, 3, first input terminal, 4, second input terminal, 5, adder, 6, differential circuit, 7, bottom layer, 8, wire, 9, outer circle through hole, 10, inner circle through hole, 101, first signal layer, 102, first loop layer, 201, second signal layer, 202, second loop layer, 701, fan ring part, 1011, first lead wire, 1012, first C-type coil, 1013, first PCB board, 1021, first C-type loop wire outlet, 1022, first C-type loop wire, 1023, second PCB board, 2011, second lead wire, 2012, second C-type coil, 2013, fourth PCB board, 2021, second C-type loop wire outlet, 2022, second C-type loop wire, 2023, third PCB board. DETAILED DESCRIPTION

[0041] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0042] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0043] In the description of the present invention, “plurality” means two or more than two, unless otherwise clearly and specifically defined.

[0044] In the present invention, unless otherwise clearly specified and limited, the terms "installation", "connection" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0045] It is worth noting that the methods used in the present invention are all conventional methods unless otherwise specified; the raw materials and devices used are all conventional commercially available products, and their sources are not specifically limited unless otherwise specified.

[0046] This embodiment provides a non-contact voltage and current integrated measurement device for a crimped power device, which mainly includes a multi-layer differential Rogowski coil, an adder and a differential circuit.

[0047] Among them, Figure 1 , Figure 2 and Figure 3 As shown, the core component of the device is a multi-layer differential Rogowski coil, which is provided with a plurality of stacked measuring units, and adjacent measuring units are arranged as a group, and the two measuring units between the groups are stacked back to back; preferably, in this embodiment, two measuring units are taken as an example for explanation, specifically including a first measuring unit 1 and a second measuring unit 2, and the two measuring units are stacked back to back. Further, through the improved design of "back-to-back stacking", the two loop layers are stacked adjacent to each other, thereby effectively realizing the decoupling of current and voltage signals. This design is different from the prior art in that the present embodiment does not simply improve the measurement accuracy by eliminating interference, but measures the current and voltage simultaneously without affecting the quality of the measurement signal through circuit layout and structural design. The advantage of this design is that the mutual influence between decoupling current and voltage can improve the accuracy and stability of the measurement, and can provide high-sensitivity current and voltage measurement in a wider frequency range to meet the requirements of different working conditions.

[0048] Each measurement unit has a signal layer and a return layer. Figure 4 and Figure 5 As shown, in the first measuring unit 1, the first signal layer 101 is located at the top layer of the multi-layer differential Rogowski coil of this embodiment, and the substrate of this layer adopts an annular PCB board, namely, the first PCB board 1013, and a first C-type coil 1012 is wound on the board, and a first lead 1011 is provided at the opening. The first loop layer 102 is located at the lower side of the first signal layer 101, and also adopts an annular PCB board of the same size and coaxial arrangement, namely, the second PCB board 1023, and a first C-type loop 1022 is provided on the board. In the first measuring unit 1, the C-type coil and the C-type loop are coaxially arranged, as shown in FIG. Figure 2As shown, one end of the first C-type loop line 1022 is connected to the end line of the first C-type coil 1012, and the first C-type loop line output line 1021 at the other end is connected to the adder 5 and the first input terminal 3 of the differential circuit 6 through the pad and the RF input line.

[0049] Further, combined with Figure 6 and Figure 7 As shown, in the second measuring unit 2, the second loop layer 202 is located at the lower side of the first loop layer 102, and also uses a coaxially arranged annular PCB board of the same size, i.e., a third PCB board 2023, and a second C-type loop 2022 is arranged on the board. The second signal layer 201 is located at the lower layer of the multi-layer differential Rogowski coil of this embodiment, and the substrate of this layer also uses a circular PCB board, i.e., a fourth PCB board 2013, and a second C-type coil 2012 is wound on the board, and a second lead 2011 is arranged at the opening. In the second measuring unit 2, the C-type coil and the C-type loop are also coaxially arranged, as shown in FIG. Figure 2 As shown, one end of the second C-type loop line 2022 is connected to the end line of the second C-type coil 2012, and the second C-type loop line output line 2021 at the other end is connected to the adder 5 and the second input terminal 4 of the differential circuit 6 through the pad and the RF input line.

[0050] In the above-mentioned two-side measurement units, the winding directions of the first and second signal layer coils are opposite; this design makes it so that under the action of the current passing through the terminals of the crimped power device, according to the right-hand screw rule, the current-related quantities generated by the two signal layers present opposite polarities, that is, one is e(t) and the other is -e(t). As for the voltage-related quantity u generated when the device is running couple (t), due to the way the electric field works, the coupling generated in the two signal layers maintains the same polarity, and the formula is:

[0051] u coil1 (t) = e(t) + u couple (t)

[0052] u coil2 (t) = -e(t) + u couple (t)

[0053] e(t)=(u coil1 -u coil2 ) / 2

[0054] u couple (t)=(u coil1 +u coil2 ) / 2

[0055] In the formula, u coil1 (t) is the output of the first C-type coil, u coil2 (t) is the output of the second C-type coil; Figure 1As shown, e(t) is the quantity output by the differential circuit, that is, the current-related quantity; u couple (t) is the quantity output by adder 5, that is, the voltage-related quantity.

[0056] Optionally, the present embodiment further arranges the C-shaped loop in each unit to be located within the projection area of ​​the C-shaped coil of the unit along the axial direction, such as Figure 3 shown.

[0057] The special structure of the back-to-back double-circuit layer designed above can not only be used to compensate and balance the influence of the vertical magnetic field. From the complete integrated structure in the figure, it can be seen that the precise spatial layout between the layers realizes the effective transmission and processing of signals. When the measurement results are processed by differential processing, the voltage-related quantities are offset to obtain pure current-related quantities; when the addition processing is performed, the current-related quantities are offset to obtain voltage-related quantities.

[0058] Furthermore, the opening areas of the C-shaped coil and the C-shaped loop in the same measurement unit overlap in the axial direction, and the coil opening areas of the two measurement units in the group overlap in the axial direction. Figure 3 As shown, the output wires of the multi-layer differential Rogowski coil of this embodiment are concentrated in one place, which is convenient for wiring and reduces external electromagnetic interference.

[0059] Furthermore, Figure 8 As shown, the first and fourth PCB boards of this embodiment are both provided with outer circle through holes 9 and inner circle through holes 10, and the circle where the outer circle through holes 9 are located is coaxially arranged with the circle where the inner circle through holes 10 are located, and the radius of the circle where the outer circle through holes 9 are located is greater than the radius of the circle where the inner circle through holes 10 are located. The wires 8 of the two C-shaped coils are both wound around the respective PCB boards through the outer circle through holes and the inner circle through holes; a preferred winding method is to wind in the form of spaced through holes on the same side, thereby forming a triangular wiring structure.

[0060] Optional, such as Figure 1 As shown, the multi-layer differential Rogowski coil of this embodiment further includes a bottom layer 7; wherein the bottom layer 7 is also in an annular structure and is located on the bottom surface of the multi-layer differential Rogowski coil. Specifically, the multi-layer differential Rogowski coil of this embodiment further includes a shielding layer, which is located on the bottom layer. In order to reduce the influence of the circulating current on the measurement result, as shown in FIG. Fig. 9 As shown, the shielding layer of this embodiment is a segmented spliced ​​annular structure, that is, it is composed of two semicircular fan ring parts 701, the fan ring parts 701 are spliced ​​along the circumferential direction, and the adjacent fan ring parts are insulated. Specifically, the fan ring part 701 is a metal layer plated on the bottom layer 7, and covers the aforementioned C-shaped coil and C-shaped loop along the axial projection, and the ends of the two fan ring parts 701 are spaced apart to form an insulating structure.

[0061] The multi-layer differential Rogowski coil is nested outside the crimp-type power device IGBT during the measurement process.

[0062] The current integrated design of the measurement system is mainly limited to the integration of a single physical quantity measurement system and the measured subject. For example, the conventional PCB Rogowski coil can only realize the measurement of a single physical quantity of current; and to realize the measurement of voltage and current dual physical quantities, the traditional solution needs to set up a set of current and voltage sensors respectively, which increases the system complexity and space occupancy; and the measurement end of the device of the present application adopts a multi-layer integrated design, which not only reduces the volume of the measurement system, but also significantly improves the spatial resolution of signal acquisition; further, through the carefully designed interlayer structure, the influence of external electromagnetic interference on the measurement results is effectively reduced, and the anti-interference ability of the measurement system is improved. Thirdly, the device of the present application realizes the synchronous measurement of voltage and current parameters, overcomes the problem of signal asynchrony in traditional measurement methods, not only simplifies the system structure, but also avoids the influence on the stress distribution of the crimping interface through the non-contact measurement principle. This is of great significance for the dynamic characteristics analysis and performance evaluation of crimping power devices. Finally, the measurement principle of the device of the present application is universal, and can be applied to crimping power devices of different specifications and models. It has a strong engineering practical value and provides a solution for the performance test of crimping power devices.

[0063] Finally, it should be noted that the above content is only used to illustrate the technical solution of the present invention, rather than to limit the scope of protection of the present invention. Simple modifications or equivalent substitutions of the technical solution of the present invention by ordinary technicians in this field do not deviate from the essence and scope of the technical solution of the present invention.

Claims

1. A non-contact voltage and current integrated measurement device for a crimped power device, characterized in that: Multilayer differential Rogowski coils, adders, and differential circuits; The multi-layer differential Rogowski coil is provided with a plurality of stacked measuring units, wherein adjacent measuring units form a group, and two measuring units in a group are stacked back to back; The measuring unit is provided with a signal layer and a loop layer; the signal layer is provided with a C-shaped coil, and the loop layer is provided with a C-shaped loop; the C-shaped coil and the C-shaped loop are coaxially arranged, one end of the C-shaped loop is connected to the output line of the C-shaped coil, and the other end is connected to an input end of the adder and differential circuit; the signal layer coils of the two measuring units between the groups are wound in opposite directions; The multi-layer differential Rogowski coil is nested outside the crimping type power device.

2. The non-contact voltage and current integrated measurement device for a crimped power device according to claim 1, characterized in that: The substrate of the signal layer is a ring-shaped PCB board; The annular PCB board is provided with an outer circle through hole and an inner circle through hole; The circle where the outer ring through holes are located is coaxially arranged with the circle where the inner ring through holes are located, and the radius of the circle where the outer ring through holes are located is greater than the radius of the circle where the inner ring through holes are located; The C-shaped coil is wound around the annular PCB board through the outer circle through hole and the inner circle through hole.

3. The non-contact voltage and current integrated measurement device for a crimped power device according to claim 1 or 2, characterized in that: The wiring structure of the C-shaped coil is a triangular wiring structure.

4. The non-contact voltage and current integrated measurement device for a crimped power device according to claim 1, characterized in that: The C-shaped coil and the opening area of ​​the C-shaped loop overlap in the axial direction.

5. The non-contact voltage and current integrated measurement device for a crimped power device according to claim 4, characterized in that: The coil opening areas of the two measuring units in the group overlap in the axial direction.

6. The non-contact voltage and current integrated measurement device for a crimped power device according to claim 1, characterized in that: The substrate of the loop layer is a ring-shaped PCB board; The C-shaped loop is arranged on the annular PCB board.

7. The non-contact voltage and current integrated measurement device for a press-fit power device according to claim 1 or 6, characterized in that: The C-shaped loop is located within the projection area of ​​the C-shaped coil along the axial direction.

8. The non-contact voltage and current integrated measurement device for a press-fit power device according to claim 1, characterized in that: The multi-layer differential Rogowski coil also includes a bottom layer; The bottom layer is a ring structure and is located on the bottom surface of the multi-layer differential Rogowski coil.

9. The non-contact voltage and current integrated measurement device for a press-fit power device according to claim 8, characterized in that: The multi-layer differential Rogowski coil further comprises at least one shielding layer; The shielding layer is located between the bottom layer and / or adjacent measuring units.

10. The non-contact voltage and current integrated measurement device for a press-fit power device according to claim 9, characterized in that: The shielding layer is a segmented annular structure and is provided with at least two sector ring parts; The sector ring parts are spliced ​​along the circumferential direction, and adjacent sector ring parts are insulated.

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