CN218243310U

CN218243310U - Double-pulse test laminated busbar for switching device and test system

Info

Publication number: CN218243310U
Application number: CN202221251380.2U
Authority: CN
Inventors: 李向峰
Original assignee: Cowell Technology Co ltd
Current assignee: Cowell Technology Co ltd
Priority date: 2022-05-23
Filing date: 2022-05-23
Publication date: 2023-01-06
Anticipated expiration: 2032-05-23

Abstract

A double-pulse test laminated busbar and a test system for a switching device belong to the technical field of testing of switching devices and solve the problem of how to design a laminated busbar with low stray inductance; the utility model discloses a stromatolite female row, when carrying out switching device dipulse test, on stromatolite female row upper surface, the electric current flows first copper-clad plate to pass flexible coil current sensor and accomplish the detection of electric current; on the lower surface of the low-inductance laminated busbar, current flows through the second copper-clad plate, and then passes through the flexible coil current sensor to complete the detection of the current; the copper-clad plate is not required to be connected with wires in a crossing mode, the length of a test circuit is shortened, and therefore stray inductance of the circuit is reduced.

Description

Double-pulse testing laminated busbar and testing system for switching device

Technical Field

The utility model belongs to the technical field of the testing of switching device, a female row of switching device dipulse test stromatolite and test system is related to.

Background

1. Double pulse testing of switching devices

The double pulse test is a test method widely applied to characteristic evaluation of a switching device, such as an IGBT power switching device, and the test method can evaluate not only the switching characteristic of an object element but also the reverse recovery characteristic of a Fast Recovery Diode (FRD) used together with the IGBT. The evaluation of the circuit in which the reverse recovery characteristic occurs when conducting to cause loss is very effective.

As shown in fig. 9, the double pulse test is to give two pulses to the switching device under test as the driving control signal, wherein the falling edge of the first pulse is the observed time of the turn-off process, and the rising edge of the second pulse is the observed time of the turn-on process. The significance of the double-pulse test of the switching device is as follows: 1) Comparing parameters of different switching devices; 2) Evaluating the function and performance of a switching device driving board; 3) Acquiring main parameters of the switching device in the switching-on and switching-off processes to evaluate whether the values of Rgon and Rgoff are proper or not. Usually, the knowledge of a certain type of switching device is mainly obtained by reading the corresponding datasheet, but actually, the parameters described in the data sheet are tested based on some given external parameters, and the external parameters in practical application are personalized and often different, so that some of the parameters cannot be directly used. We need to understand the more realistic behavior of switching devices in specific applications; 4) Whether improper oscillation exists in the process of switching on and switching off; 5) Evaluating the reverse recovery behavior and the safety margin of the diode; 6) Whether the voltage spike is proper when the switching device is turned off and whether improper oscillation exists after the switching device is turned off; 7) Evaluating the current sharing characteristic of the parallel connection of the switching devices; 8) And measuring stray inductance of the busbar.

2. The traditional Rogowski coil intervention mode has the defects

In a double-pulse test, power switching devices such as an IGBT to be tested are usually in a half-bridge structure, and two current sensors are required to measure currents of an upper bridge arm and a lower bridge arm respectively. The conventional laminated busbar current sensor is connected in the following manner: the upper surface and the lower surface of the laminated busbar are respectively bridged with a conducting wire, and the conducting wire penetrates through the Rogowski coil on the upper surface and the Rogowski coil on the lower surface, so that the current flowing through the upper surface and the lower surface is detected.

3. Influence of stray inductance energy storage on switching device

When a switching device is subjected to double-pulse testing, a line stray inductor exists in a peripheral testing circuit, under the trend that the switching device is high in voltage, high in current and high in switching frequency, the influence of a voltage peak caused by the stray inductor is larger and larger, and very large di/dt can be generated in the rapid turn-off process of the switching device, so that the voltage peak can be formed at two ends of the switching device due to the stray inductor in the testing circuit, the switching device can be broken down by the voltage peak, the damage to the switching device is caused, and the influence on high-frequency switching devices such as silicon carbide base and the like is particularly serious.

Stray inductance stores energy by magnetic field, and the calculation formula of stray inductance magnetic field energy storage is as follows:

wherein I denotes the rated current, L _s The stray inductance of the line is defined, and the rated current is set according to the requirement of a customer and cannot be changed, so that the only method for reducing the magnetic field energy storage of the stray inductance can only be to reduce L as much as possible _s The value of (c).

Therefore, it is highly desirable to design a laminated busbar with low stray inductance to meet the requirement of the double pulse test of the switching device.

SUMMERY OF THE UTILITY MODEL

An object of the utility model is to design a simple structure, stromatolite that stray inductance is low is female arranges to satisfy switching device's the demand of dipulse test.

The utility model discloses a solve above-mentioned technical problem through following technical scheme:

a switching device double-pulse test laminated busbar comprises: the flexible coil current sensor comprises a dielectric substrate (10), a first flexible coil current sensor (21), a second flexible coil current sensor (22), a first copper-clad plate (11) and a second copper-clad plate (12) which cover the upper surface and the lower surface of the dielectric substrate (10); the first flexible coil current sensor (21) and the second flexible coil current sensor (22) are fixed on the medium substrate (10), the through holes of the first flexible coil current sensor (21) and the second flexible coil current sensor (22) are in the same direction, the first copper-clad plate (11) penetrates through the first flexible coil current sensor (21), and the second copper-clad plate (12) penetrates through the second flexible coil current sensor (22).

The utility model discloses a stromatolite female row, when carrying out switching device dipulse test, on stromatolite female row upper surface, the electric current flows first copper-clad plate to pass flexible coil current sensor and accomplish the detection of electric current; on the lower surface of the low-inductance laminated busbar, current flows through the second copper-clad plate, and then passes through the flexible coil current sensor to complete the detection of the current; the copper-clad plate is not required to be connected with a lead in a crossing mode, the length of a testing circuit is shortened, and therefore stray inductance of the circuit is reduced.

Furthermore, the medium substrate (10) is provided with a first mounting hole (101), a second mounting hole (102), a third mounting hole (103) and a fourth mounting hole (104); the first copper-clad plate (11) and the second copper-clad plate (12) are both provided with a first insulation groove and a second insulation groove, and the sum of the lengths of the first insulation groove and the second insulation groove is smaller than the width of the copper-clad plates; on the upper surface of the dielectric substrate (10), a first mounting hole (101), a second mounting hole (102) and a third mounting hole (103) are positioned inside the first insulating groove, and a fourth mounting hole (104) is positioned inside the second insulating groove; on the lower surface of the dielectric substrate (10), a first mounting hole (101) is positioned inside the second insulating groove, and a second mounting hole (102), a third mounting hole (103) and a fourth mounting hole (104) are positioned inside the first insulating groove; the first flexible coil current sensor (21) passes through the third mounting hole (103) and the fourth mounting hole (104) and is mounted on the medium substrate (10), and the second flexible coil current sensor (22) passes through the first mounting hole (101) and the second mounting hole (102) and is mounted on the medium substrate (10).

In one embodiment, the first flexible coil current sensor (21) and the second flexible coil current sensor (22) are mounted perpendicular to the dielectric substrate (10).

In one embodiment, the first flexible coil current sensor (21) and the second flexible coil current sensor (22) adopt Rogowski coils.

In one embodiment, the dielectric substrate (10) is a PCB.

In one embodiment, the first mounting hole (101), the second mounting hole (102), the third mounting hole (103) and the fourth mounting hole (104) are arranged on a straight line along the Y-axis direction.

In one embodiment, the length of the first insulation groove is greater than the length of the second insulation groove.

In one embodiment, the first insulation groove and the second insulation groove are U-shaped grooves.

A switching device double-pulse testing system adopting the laminated busbar comprises: a support capacitor C, a solid-state switch KT, a first switch K1 and a second switch K2; the positive electrode of the supporting capacitor C is connected with one end of a solid-state switch KT, the other end of the solid-state switch KT is connected with a first copper-clad plate (11) of the laminated busbar, and the negative electrode of the supporting capacitor C is connected with a second copper-clad plate (12); after the first switch K1 and the second switch K2 are connected in series, the non-series end of the first switch K1 is connected to the common connection point of the solid-state switch KT and the first copper-clad plate (11), and the non-series end of the second switch K2 is connected to the common connection point of the support capacitor C and the second copper-clad plate (12).

Further, the double pulse test system further comprises: a switching tube Q1, a switching tube Q2 and an inductive load L; the switching tube Q1 and the switching tube Q2 form a half-bridge structure, a collector of the switching tube Q1 is connected with a first copper-clad plate (11), and an emitter of the switching tube Q2 is connected with a second copper-clad plate (12); one end of the inductive load L is connected to the midpoint of the half-bridge structure, and the other end of the inductive load L is connected to the common point of the first switch K1 and the second switch K2 in series.

The utility model has the advantages that:

Drawings

Fig. 1 is a schematic front view of an upper surface structure of a laminated busbar according to a first embodiment of the present invention;

fig. 2 is a schematic front view of a lower surface structure of a laminated busbar according to a first embodiment of the present invention;

fig. 3 is a schematic view of an arrangement structure of mounting holes formed in an upper surface of a dielectric substrate of a laminated busbar according to a first embodiment of the present invention;

fig. 4 is a schematic structural diagram of a first copper-clad plate of a laminated busbar according to an embodiment of the present invention;

fig. 5 is an installation schematic diagram of a first copper-clad plate and a dielectric substrate of a laminated busbar according to an embodiment of the present invention;

fig. 6 is a schematic structural diagram of a second copper-clad plate of a laminated busbar according to the first embodiment of the present invention;

fig. 7 is an installation schematic diagram of a second copper-clad plate and a dielectric substrate of a laminated busbar according to the first embodiment of the present invention;

fig. 8 is a schematic structural diagram of a switching device double-pulse testing system according to a second embodiment of the present invention;

fig. 9 is a double pulse waveform diagram for a double pulse test of a switching device.

Detailed Description

To make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the embodiments of the present invention are clearly and completely described below in combination with the technical solution of the embodiments of the present invention, and obviously, the described embodiments are some, but not all embodiments of the present invention. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative efforts belong to the protection scope of the present invention.

The technical solution of the present invention is further described below with reference to the drawings and specific embodiments of the specification:

example one

As shown in fig. 1 and fig. 2 (fig. 2 is obtained by rotating the x-axis of fig. 1 by 180 ° clockwise), a switching device double-pulse test laminated busbar includes: the flexible printed circuit board comprises a dielectric substrate 10, a first copper-clad plate 11, a second copper-clad plate 12, a first flexible coil 21 and a second flexible coil 22; the dielectric substrate 10 adopts a rectangular PCB, the first copper-clad plate 11 and the second copper-clad plate 12 are two identical rectangular copper-clad plates, the first copper-clad plate 11 covers the upper surface of the rectangular PCB, and the second copper-clad plate 12 covers the lower surface of the rectangular PCB.

As shown in fig. 3, four mounting holes are formed in the middle of the dielectric substrate 10 along the Y-axis direction, and the four mounting holes are arranged in a straight line along the Y-axis direction and respectively include a first mounting hole 101, a second mounting hole 102, a third mounting hole 103, and a fourth mounting hole 104.

As shown in fig. 1, 2, 5 and 7 (fig. 7 can be obtained by rotating fig. 5 clockwise by 180 ° about the x-axis), the third mounting hole 103 and the fourth mounting hole 104 are used for mounting the first flexible coil 21, and the first mounting hole 101 and the second mounting hole 102 are used for mounting the second flexible coil 22. The first flexible coil 21 and the second flexible coil 22 both adopt rogowski coils.

As shown in fig. 4, the vertical direction of the middle position of the first copper-clad plate 11 is provided with a first upper-surface insulation groove 111 and a second upper-surface insulation groove 112, the length of the first upper-surface insulation groove 111 is greater than that of the second upper-surface insulation groove 112, the sum of the lengths of the first upper-surface insulation groove 111 and the second upper-surface insulation groove 112 is smaller than the width of the first copper-clad plate 11, the first upper-surface insulation groove 111 has an upward opening, and the second upper-surface insulation groove 112 has a downward opening.

As shown in fig. 5, when the first copper-clad plate 11 covers the upper surface of the dielectric substrate 10, the first mounting hole 101, the second mounting hole 102, and the third mounting hole 103 are located inside the first insulating groove 111 on the upper surface, and the fourth mounting hole 104 is located inside the second insulating groove 112 on the upper surface.

As shown in fig. 6, a first lower surface insulation groove 121 and a second lower surface insulation groove 122 are formed in the middle of the second copper clad laminate 12 in the vertical direction, the length of the first lower surface insulation groove 121 is greater than that of the second lower surface insulation groove 122, the sum of the lengths of the first lower surface insulation groove 121 and the second lower surface insulation groove 122 is less than the width of the second copper clad laminate 12, the opening of the first lower surface insulation groove 121 faces upward, and the opening of the second lower surface insulation groove 122 faces downward.

As shown in fig. 7, when the second copper-clad plate 12 is covered on the lower surface of the dielectric substrate 10, the first mounting hole 101 is located inside the second insulating groove 122 on the lower surface, and the second mounting hole 102, the third mounting hole 103, and the fourth mounting hole 104 are located inside the first insulating groove 121 on the lower surface.

The working principle of the laminated busbar is as follows: as shown in fig. 1, fig. 2, fig. 5 and fig. 7, when a double-pulse test of a switching device is performed, current flows through the copper clad laminate between the first insulation groove 111 on the upper surface of the first copper clad laminate 11 and the second insulation groove 112 on the upper surface of the first copper clad laminate, so that the current detection is completed through the first flexible coil 21; at the lower surface of the low-inductance laminated busbar, the current flows through the copper-clad plate between the first insulation groove 121 at the lower surface of the second copper-clad plate 12 and the second insulation groove 122 at the lower surface, so that the current passes through the second flexible coil 22 to complete the detection of the current.

Example two

As shown in fig. 8, a switching device double pulse test system includes: the circuit comprises a support capacitor C, a solid-state switch KT, a laminated busbar, a switch tube Q1, a switch tube Q2, a fast recovery diode D1, a fast recovery diode D2, an inductive load L, a first switch K1 and a second switch K2; the positive electrode of the supporting capacitor C is connected with one end of a solid-state switch KT, the other end of the solid-state switch KT is connected with the left end of a first copper-clad plate 11 of a laminated busbar, the right end of the first copper-clad plate 11 is connected with a collector of a switch tube Q1, an emitter of the switch tube Q1 is connected with a collector of a switch tube Q2, an emitter of the switch tube Q2 is connected with the right end of a second copper-clad plate 12, and the left end of the second copper-clad plate 12 is connected with the negative electrode of the supporting capacitor C; the switching tube Q1 and the switching tube Q2 form a half-bridge structure, the fast recovery diode D1 is connected with two ends of the switching tube Q1 in an anti-parallel mode, and the fast recovery diode D2 is connected with two ends of the switching tube Q2 in an anti-parallel mode; after the first switch K1 and the second switch K2 are connected in series, the non-series end of the first switch K1 is connected to the common connection point of the solid-state switch KT and the first copper-clad plate 11, the non-series end of the second switch K2 is connected to the common connection point of the supporting capacitor C and the second copper-clad plate 12, one end of the inductive load L is connected to the middle point of the half-bridge structure, and the other end of the inductive load L is connected to the common series point of the first switch K1 and the second switch K2.

Fig. 9 is a diagram of a double-pulse waveform of the double-pulse test, and the working principle of the double-pulse test system is as follows:

opening the first switch K1, closing the second switch K2, and testing the switch tube Q1 and the fast recovery diode D2; applying a double-pulse waveform to the grid electrode of the switching tube Q1, wherein the switching tube Q1 is conducted in a time period of t1, and the current path is as follows: the positive electrode of the supporting capacitor C → the solid-state switch KT → the first copper-clad plate 11 of the laminated busbar → the switch tube Q1 → the inductive load L → the second switch K2 → the negative electrode of the supporting capacitor C, and the first flexible coil 21 arranged on the first copper-clad plate 11 of the laminated busbar collects the current signal of the current path; in the time period t2, the switching tube Q1 is turned off, at this time, the fast recovery diode D2 continues current, and the current path is: the right end of the inductive load L → the second switch K2 → the second copper-clad plate 12 of the laminated busbar → the fast recovery diode D2 → the left end of the inductive load L, and the second flexible coil 22 arranged on the second copper-clad plate 12 of the laminated busbar collects current signals of a current path; in the time period t3, the switching tube Q1 is turned on, and a reverse voltage is applied to the fast recovery diode D2 to rapidly turn off the fast recovery diode D2, and the current path in the time period t3 is the same as that in the time period t 1.

The process of closing the first switch K1 and opening the second switch K2 and testing the switch tube Q2 and the fast recovery diode D1 is similar to the process of testing the switch tube Q1 and the fast recovery diode D2, and is not described in detail.

The above embodiments are only used to illustrate the technical solution of the present invention, and not to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, it should be understood by those skilled in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; such modifications or substitutions do not depart from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. The utility model provides a female row of switching device dipulse test stromatolite which characterized in that includes: the flexible coil current sensor comprises a dielectric substrate (10), a first flexible coil current sensor (21), a second flexible coil current sensor (22), a first copper-clad plate (11) and a second copper-clad plate (12) which cover the upper surface and the lower surface of the dielectric substrate (10); the first flexible coil current sensor (21) and the second flexible coil current sensor (22) are fixed on the medium substrate (10), the through holes of the first flexible coil current sensor (21) and the second flexible coil current sensor (22) are in the same direction, the first copper-clad plate (11) penetrates through the first flexible coil current sensor (21), and the second copper-clad plate (12) penetrates through the second flexible coil current sensor (22).

2. The laminated busbar according to claim 1, wherein the dielectric substrate (10) is provided with a first mounting hole (101), a second mounting hole (102), a third mounting hole (103) and a fourth mounting hole (104); the first copper-clad plate (11) and the second copper-clad plate (12) are both provided with a first insulation groove and a second insulation groove, and the sum of the lengths of the first insulation groove and the second insulation groove is smaller than the width of the copper-clad plates; on the upper surface of the dielectric substrate (10), a first mounting hole (101), a second mounting hole (102) and a third mounting hole (103) are positioned inside the first insulating groove, and a fourth mounting hole (104) is positioned inside the second insulating groove; on the lower surface of the dielectric substrate (10), a first mounting hole (101) is positioned inside the second insulating groove, and a second mounting hole (102), a third mounting hole (103) and a fourth mounting hole (104) are positioned inside the first insulating groove; the first flexible coil current sensor (21) penetrates through the third mounting hole (103) and the fourth mounting hole (104) to be mounted on the medium substrate (10), and the second flexible coil current sensor (22) penetrates through the first mounting hole (101) and the second mounting hole (102) to be mounted on the medium substrate (10).

3. The laminated busbar according to claim 1, wherein the first flexible coil current sensor (21) and the second flexible coil current sensor (22) are mounted perpendicular to the dielectric substrate (10).

4. Laminated busbar according to claim 1, wherein the first flexible coil current sensor (21) and the second flexible coil current sensor (22) are implemented as Rogowski coils.

5. The laminated busbar according to claim 1, wherein the dielectric substrate (10) is a PCB.

6. The laminated busbar according to claim 2, wherein the first mounting hole (101), the second mounting hole (102), the third mounting hole (103), and the fourth mounting hole (104) are aligned in a straight line along the Y-axis direction.

7. The laminated busbar according to claim 2, wherein the length of the first insulation groove is greater than the length of the second insulation groove.

8. The laminated busbar according to claim 2, wherein the first insulation groove and the second insulation groove are U-shaped grooves.

9. A switching device double pulse test system using the laminated busbar according to any one of claims 1 to 8, comprising: the circuit comprises a support capacitor C, a solid-state switch KT, a first switch K1 and a second switch K2; the positive electrode of the supporting capacitor C is connected with one end of a solid-state switch KT, the other end of the solid-state switch KT is connected with a first copper-clad plate (11) of the laminated busbar, and the negative electrode of the supporting capacitor C is connected with a second copper-clad plate (12); after the first switch K1 and the second switch K2 are connected in series, the non-series end of the first switch K1 is connected to the common connection point of the solid-state switch KT and the first copper-clad plate (11), and the non-series end of the second switch K2 is connected to the common connection point of the support capacitor C and the second copper-clad plate (12).

10. The switching device double pulse test system of claim 9, further comprising: a switching tube Q1, a switching tube Q2 and an inductive load L; a half-bridge structure is formed by the switching tube Q1 and the switching tube Q2, a collector of the switching tube Q1 is connected with a first copper-clad plate (11), and an emitter of the switching tube Q2 is connected with a second copper-clad plate (12); one end of the inductive load L is connected to the midpoint of the half-bridge structure, and the other end of the inductive load L is connected to the common point of the first switch K1 and the second switch K2 in series.