Disclosure of Invention
Based on the above, it is necessary to provide an online measurement system for the chip current of the crimping type IGBT device, so as to realize online measurement of the current of all chips in the crimping type IGBT device at the same time.
In order to achieve the above object, the present invention provides the following solutions:
The utility model provides an on-line measurement system of crimping IGBT device chip electric current, there is a plurality of bosss on the crimping IGBT device, measurement system includes: the integrated circuit comprises an integrating circuit and at least two groups of PCB boards, wherein each group of PCB boards sequentially comprises a first layer of PCB board, a second layer of PCB board and a third layer of PCB board from top to bottom, a plurality of current measuring coils are arranged on each group of PCB boards, and the bosses penetrate through the current measuring coils;
The current measuring coil comprises a coil framework, a first lead and a second lead, wherein the coil framework is formed by a PCB (printed circuit board) between a first circle and a second circle, the first circle and the second circle are concentric circles with different diameters, and a plurality of first through holes are uniformly distributed on the circumferences of the first circle and the second circle;
The second conducting wire is arranged on the second layer of PCB in a circumferential manner, the circle where the second conducting wire is arranged is concentric with the first circle, and the second conducting wire is arranged between the first circle and the second circle;
The first lead one end with the first input of integration circuit is connected, the first lead other end passes adjacent first through-hole on first circle and the second circle circumference in proper order, first lead encircles the coil skeleton evenly twines into coil winding, the first lead other end with second lead one end is connected, the second lead other end with the second input of integration circuit is connected.
Optionally, the current measuring coil is wired in a fishbone shape.
Optionally, a first insulating layer is disposed between the first layer PCB and the second layer PCB, and a second insulating layer is disposed between the second layer PCB and the third layer PCB.
Optionally, an insulating layer is disposed between each group of PCB boards.
Optionally, the materials used for the first wire and the second wire are copper.
Optionally, the thickness of each group of the PCB boards is 0.5mm.
Optionally, the current measurement coil further includes a second through hole, the second through hole is disposed on a circumference where the second wire is located, and the other end of the first wire passes through the second through hole and is connected with one end of the second wire.
Optionally, the current measurement coil further includes a first pin pad and a second pin pad, one end of the first wire is connected to the integrating circuit through the first pin pad, and the other end of the second wire is connected to the integrating circuit through the second pin pad.
According to the specific embodiment provided by the invention, the invention discloses the following technical effects:
The online measurement system in the invention comprises: the integrated circuit comprises an integrating circuit and at least two groups of PCB boards, wherein a plurality of current measuring coils are arranged on each group of PCB boards, a boss penetrates through the current measuring coils, the boss current is equal to the chip current, the current measuring coils comprise a coil framework, a first wire and a second wire, one end of the first wire is connected with a first input of the integrating circuit, the first wire is uniformly wound around the coil framework to form a coil winding, the other end of the first wire is connected with one end of the second wire, the other end of the second wire is connected with a second input of the integrating circuit, and the integrating circuit determines the current in the chip according to the voltage signal of the current measuring coils.
Detailed Description
The following description of the embodiments of the present invention will be made clearly and completely with reference to the accompanying drawings, in which it is apparent that the embodiments described are only some embodiments of the present invention, but not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.
The invention aims to provide a chip current online measurement system for a crimping IGBT device, which realizes the simultaneous online measurement of the currents of all chips in the crimping IGBT device.
In order that the above-recited objects, features and advantages of the present invention will become more readily apparent, a more particular description of the invention will be rendered by reference to the appended drawings and appended detailed description.
Fig. 1 is a schematic diagram of circuit arrangement on a first layer PCB of a current measurement coil according to an embodiment of the present invention, fig. 2 is a schematic diagram of circuit arrangement on a second layer PCB of a current measurement coil according to an embodiment of the present invention, and fig. 3 is a schematic diagram of circuit arrangement on a third layer PCB of a current measurement coil according to an embodiment of the present invention.
Referring to fig. 1-3, the invention provides an on-line measurement system for chip current of a crimping type IGBT device, the crimping type IGBT device is provided with a plurality of bosses, the on-line measurement system comprises: the integrated circuit comprises an integrating circuit and at least two groups of PCB boards, wherein each group of PCB boards sequentially comprises a first layer of PCB board, a second layer of PCB board and a third layer of PCB board from top to bottom, a plurality of current measuring coils are arranged on each group of PCB boards, and the boss penetrates through the current measuring coils.
Specifically, fig. 4 is a partial top view of a chip current online measurement system of a crimping type IGBT device according to an embodiment of the present invention, as shown in fig. 4, two sets of PCB boards stacked up and down are adopted in this embodiment, each set of PCB boards is provided with a plurality of current measurement coils, the current measurement coils are also referred to as Rogowski coils, each boss in the crimping type IGBT device passes through each current measurement coil, so that two sets of PCB boards are placed inside the device, the boss is connected in series with the chip, the boss current is equal to the chip current, specifically, 501 is a current measurement coil on a first set of PCB boards, 502 is a current measurement coil on a second set of PCB boards, and a boss in the device 504 passes through the current coil on the second set of PCB boards, so that the current of each chip is guaranteed to be measured by stacking the PCB boards.
The bosses are distributed in two dimensions and are arranged compactly, the distance between two adjacent rows and two adjacent columns is very small, the embodiment adopts two groups of PCB boards which are stacked up and down, the number of Rogowski coils for measuring chip current on the PCB boards is increased, each boss has a corresponding Rogowski coil in the two groups of PCB boards for measuring the current, and the problem that the number of Rogowski coils on a single group of PCB boards is insufficient if adjacent Rogowski coils distributed on one group of PCB boards are overlapped due to too close distance of the bosses is avoided. Meanwhile, the sectional area of each single-turn coil 5 of the Rogowski coil is increased by adopting two groups of PCB boards, namely, the mutual inductance of the Rogowski coil and a boss flowing through a current to be measured is increased, so that the current measurement sensitivity is increased. Therefore, on the premise of ensuring that the sensitivity is unchanged compared with a Rogowski coil for measuring the current of a single chip, the voltage quantity which is proportional to the current change rate is output to all the chip currents in the crimping IGBT device. Each Rogowski coil outgoing line is connected to a corresponding pin pad, and is connected to an external integrating circuit through the pin pad, and the integrating circuit integrates the voltage signals to finally obtain voltage signals proportional to the current to be measured. Meanwhile, a PCB with a small size is used as a carrier of the measuring system, so that limited space in the device is effectively utilized, and the device can be integrated to carry out on-line measurement of current.
The current measuring coil comprises a coil framework 3, a first lead 1 and a second lead 9, wherein the coil framework 3 is formed by a PCB (printed circuit board) between a first circle and a second circle, the first circle and the second circle are concentric circles with different diameters, a plurality of first through holes 2 are uniformly distributed on the circumferences of the first circle and the second circle, the second lead 9 is circumferentially arranged on the second layer PCB, the circle where the second lead 9 is located and the first circle are concentric circles, and the second lead 9 is arranged between the first circle and the second circle; the first wire 1 one end with the first input of integration circuit is connected, the first wire 1 other end passes adjacent first through-hole 2 on first circle and the second circle circumference in proper order, first wire 1 encircles coil skeleton 3 evenly winds into coil winding, first wire 1 other end with second wire 9 one end is connected, the second wire 9 other end with the second input of integration circuit is connected, the integration circuit is according to the voltage signal of first input and second input confirm electric current in the electric current measurement coil.
Preferably, the current measuring coil is wired in a fishbone shape.
Specifically, fig. 5 is a schematic diagram of fishbone wiring in an embodiment of the present invention, as shown in fig. 5, two adjacent first through holes on a first circle and a second circle and wires connected between the two first through holes form a single-turn coil 5, the single-turn coil 5 is rectangular, the upper side of the rectangle is a top layer wiring 8 located on a first layer PCB board, the lower side of the rectangle is a bottom layer wiring 10 located on a third layer PCB board, the left and right sides of the rectangle are the first through holes on the first circle and the first through holes on the second circle, all the single-turn coils 5 are uniformly arranged in a circular shape, and the boss is surrounded in the center. The first single-turn coil is led out through wiring, so that one end of a first wire is connected to the first pin pad 6, a single-turn coil connecting wire 11 starts from the first single-turn coil 5 and ends at the last single-turn coil 5, two adjacent single-turn coils 5 are connected, the wiring mode is called fishbone wiring, the single-turn coil connecting wire 11 connected at the last single-turn coil 5 is not connected with the first single-turn coil 5 any more, but is connected with one end of a second wire 9 through a second through hole, if the second layer PCB translates upwards to the first layer PCB, the second wire 9 is overlapped with each section of single-turn coil connecting wire 11, and the other end of the second wire 9 is led out from the Rogowski coil and connected to the second pin pad 7.
By adopting the fishbone wiring mode, noise interference caused by surrounding of the current measuring coil and other external currents can be effectively eliminated, and measuring errors caused by the existence of the external currents can be effectively reduced.
Preferably, a first insulating layer is arranged between the first layer of PCB and the second layer of PCB, a second insulating layer is arranged between the second layer of PCB and the third layer of PCB, and specifically, the insulating layer is a framework of the PCB, so that the PCB is supported and the two-layer current is isolated.
Preferably, the materials used for the first conductive wire 1 and the second conductive wire 9 are copper, which plays a role in transmitting current.
Preferably, the thickness of each group of PCB boards is 0.5mm. Specifically, the total thickness of the two groups of PCB boards is about 1mm, the size is very small, the integrated IGBT device is convenient to integrate inside the crimping IGBT device, the original packaging structure of the device is not influenced, the current measurement is carried out under the condition that the device works normally, and the PCB boards are good in strength and can withstand high temperature.
Preferably, the current measuring coil further comprises a second through hole 4, the second through hole 4 is arranged on the circumference where the second wire 9 is located, and the other end of the first wire 1 passes through the second through hole 4 and is connected with one end of the second wire 9.
Preferably, the current measuring coil further comprises a first pin pad 6 and a second pin pad 7, one end of the first wire 1 is connected with the first input of the integrating circuit through the first pin pad 6, and the other end of the second wire 9 is connected with the second input of the integrating circuit through the second pin pad 7.
Working principle:
Fig. 6 is a partial front view of a chip current on-line measurement system of a crimping type IGBT device according to an embodiment of the invention, referring to fig. 6, the upper side is a first group of PCB boards 12, the lower side is a second group of PCB boards 13, insulating materials are filled between the two groups of PCB boards, each group of PCB boards includes a first layer of PCB boards 14, a second layer of PCB boards 15 and a third layer of PCB boards 16, the first layer of PCB boards 14 is also called a top layer of PCB boards, the second layer of PCB boards 15 is also called a loop layer of PCB boards, the third layer of PCB boards 16 is also called a bottom layer of PCB boards, when the crimping type IGBT device works normally, current flows from a collector electrode plate 17 to an emitter electrode plate 18 through a chip 19, the boss current is equal to the chip current, the boss passes through the current measurement coil, the current flowing through the boss generates a magnetic field in each single turn coil 5, when the current changes, an induced voltage is generated in each single turn coil 5 by faraday electromagnetic induction law, and the induced voltage of each single turn coil 5 is proportional to the change of current, and the induced voltage is added to the output ratio of all single turns 5. The current to be measured also generates induced voltages in each section of single-turn coil connecting wire 11, the sum of the induced voltages generated by each section of single-turn coil connecting wire 11 is approximately equal to the magnitude of the induced voltages generated by the current to be measured in the second lead 9, and the induced voltages have opposite signs and can be basically counteracted, so that the first layer of PCB 14 and the second layer of PCB 15 are required to be as close as possible, the second lead 9 is close to all the single-turn coil connecting wires 11 in distance, the generated induced voltages are counteracted more, and the resulting measurement error is smaller. Thus, the open circuit voltage across the first pin pad 6 and the second pin pad 7 is approximately the sum of the induced voltages generated by all single turn coils 5, which is proportional to the rate of change of the chip current. The first pin pad 6 and the second pin pad 7 are connected with an external integrating circuit, and the voltage quantity integrated by the integrating circuit is in direct proportion to the current to be measured, namely mutual inductance exists between the current detection coil and the boss, and the open circuit voltage is equal to the mutual inductance multiplied by the change rate of the current in the boss. The open circuit voltage is divided by this mutual inductance and then integrated over time as the current in the boss.
The crimping IGBT device has compact packaging structure, and each sub-module is very close in distance, so that a current measuring instrument is inconvenient to install for measuring the chip current. In the current measurement technology of the chip of the prior crimping IGBT device, the packaging structure of the device can only be opened first, and the current of a part of chips is measured by using measuring instruments such as a commercial Rogowski coil or a commercial Hall current sensor, but the current in all chips in the device can not be measured on line at the same time under the condition that the packaging structure of the device is not opened. The online measurement system for the chip current of the crimping IGBT device provided by the embodiment of the invention has small size, can be integrated in the device to realize online measurement, and can measure all the chip currents at the same time.
In the present specification, each embodiment is described in a progressive manner, and each embodiment is mainly described in a different point from other embodiments, and identical and similar parts between the embodiments are all enough to refer to each other.
The principles and embodiments of the present invention have been described herein with reference to specific examples, the description of which is intended only to assist in understanding the methods of the present invention and the core ideas thereof; also, it is within the scope of the present invention to be modified by those of ordinary skill in the art in light of the present teachings. In view of the foregoing, this description should not be construed as limiting the invention.