1. A direct current support capacitor impact discharge test device is characterized by comprising a first wiring board and a second wiring board which are arranged in parallel, a discharge gap and a discharge trigger device which are arranged on the first wiring board and the second wiring board,

a plurality of mounting through holes are arranged on the first wiring board and the second wiring board at intervals along the length direction of the first wiring board and the second wiring board, the size of each mounting through hole is matched with the outer diameter of a binding post on the direct current supporting capacitor, the distance between the mounting through holes is consistent with the distance between the binding posts on the direct current supporting capacitor,

the discharge gap comprises a first discharge block and a second discharge block, the bottoms of the first discharge block and the second discharge block are respectively arranged in the middle of the first wiring board and the second wiring board, the adjacent parts of the top ends of the first discharge block and the second discharge block are respectively provided with a conductive inclined plane, the two conductive inclined planes and the two inner side surfaces of the first discharge block and the second discharge block form a bottomless Y-shaped groove,

the discharge triggering device comprises a fixed plate, a movable plate and a conductive cylinder, the fixed plate is horizontally arranged and fixed above the discharge block, a long through hole is arranged in the center of the fixed plate, the length direction of the long through hole is parallel to that of the Y-shaped groove, the long through hole is positioned right above the Y-shaped groove, the movable plate is slidably and horizontally arranged between the fixed plate and the discharge block, the diameter and the length of the conductive cylinder are adaptive to the width and the length of the long through hole, the conductive cylinder is supported by the movable plate and stays in the long through hole in an initial test state,

in the test, the first wiring board and the second wiring board are inserted into the mounting through hole through the wiring terminal and fixed at the top end of the direct current supporting capacitor, and current starts from one electrode of the direct current supporting capacitor, sequentially passes through the wiring terminal, the first wiring board, the first discharging block, the conductive inclined plane, the conductive cylinder, the conductive inclined plane, the second discharging block, the second wiring board and the wiring terminal and returns to the other electrode of the direct current supporting capacitor.

2. The direct current support capacitor impact discharge test device of claim 1, wherein the bottom of the first conductive block or the second conductive block is provided with a bayonet for mounting a current sensor.

3. The direct current support capacitor impact discharge test device according to claim 1, wherein the mounting through holes on the first wiring board and/or the second wiring board are strip-shaped through holes, and the length direction of the strip-shaped through holes is perpendicular to the arrangement direction of the wiring posts on the direct current support capacitor.

4. The apparatus of claim 1, wherein the fixed plate is fixed to the top of the conductive block by a bolt, the bottom of the fixed plate is provided with a groove adapted to the size of the movable plate, and the movable plate is supported by the first and second conductive blocks and stays in the groove.

5. The apparatus of claim 1, wherein the conductive cylinder, the first discharge block and the second discharge block are made of tungsten copper.

Background

With the development of power electronic IGBT converter technology, the requirement on the safety performance of a direct current support capacitor of a key component is higher and higher. Two electrodes of the direct current support capacitor are respectively connected with a plurality of binding posts which are arranged at intervals, and the binding posts of the two electrodes form two parallel columns which are arranged at the top end of the capacitor. The direct current support capacitor has the characteristics of large capacity, high design field intensity, large current resistance, low impedance, low inductance, high stability and the like, and is widely applied to the fields of flexible direct current transmission, photovoltaic inverters, high-voltage frequency converters, electric locomotives and the like. Due to the high standard requirements of safety performance, particularly the non-repetitive peak discharge current generated under the condition of system switching or module failure is very large, direct current support capacitor (hereinafter referred to as capacitor) impact discharge tests are specified in the relevant standards to verify the reliability of the direct current support capacitor. The test requires that the two poles of the capacitor are directly short-circuited to discharge at a direct voltage, thereby generating an oscillating discharge current which specifies the highest peak current, and the type test specifies that each capacitor is subjected to 5 such discharges, but no specific test embodiment is given. The maximum peak current specified in the corresponding specification is very high, usually requiring several hundred kiloamperes, even on the order of mega amperes. This requires that the loop impedance of the discharge device itself is very small, and at the same time, the influence factors such as vibration force and high temperature generated under such a large impact current should be considered, which imposes very strict requirements on the triggering mode, material and structure of the discharge device. At present, the common copper plate short circuit or mechanical discharge switch mode can not meet the test requirements.

Disclosure of Invention

The invention aims to provide a direct current support capacitor impact discharge test device which is large in peak discharge current, small in impedance, safe in trigger discharge mode, simple in manufacturing process and low in cost.

The technical scheme for achieving the aim comprises the following contents.

A DC support capacitor impact discharge test device comprises a first wiring board and a second wiring board which are arranged in parallel, a discharge gap and a discharge trigger device which are arranged on the first wiring board and the second wiring board,

a plurality of mounting through holes are arranged on the first wiring board and the second wiring board at intervals along the length direction of the first wiring board and the second wiring board, the size of each mounting through hole is matched with the outer diameter of a binding post on the direct current supporting capacitor, the distance between the mounting through holes is consistent with the distance between the binding posts on the direct current supporting capacitor,

the discharge gap comprises a first discharge block and a second discharge block, the bottoms of the first discharge block and the second discharge block are respectively arranged in the middle of the first wiring board and the second wiring board, the adjacent parts of the top ends of the first discharge block and the second discharge block are respectively provided with a conductive inclined plane, the two conductive inclined planes and the two inner side surfaces of the first discharge block and the second discharge block form a bottomless Y-shaped groove,

the discharge triggering device comprises a fixed plate, a movable plate and a conductive cylinder, the fixed plate is horizontally arranged and fixed above the discharge block, a long through hole is arranged in the center of the fixed plate, the length direction of the long through hole is parallel to that of the Y-shaped groove, the long through hole is positioned right above the Y-shaped groove, the movable plate is slidably and horizontally arranged between the fixed plate and the discharge block, the diameter and the length of the conductive cylinder are adaptive to the width and the length of the long through hole, the conductive cylinder is supported by the movable plate and stays in the long through hole in an initial test state,

in the test, the first wiring board and the second wiring board are inserted into the mounting through hole through the wiring terminal and fixed at the top end of the direct current supporting capacitor, and current starts from one electrode of the direct current supporting capacitor, sequentially passes through the wiring terminal, the first wiring board, the first discharging block, the conductive inclined plane, the conductive cylinder, the conductive inclined plane, the second discharging block, the second wiring board and the wiring terminal and returns to the other electrode of the direct current supporting capacitor.

Further, a bayonet for mounting the current sensor is arranged at the bottom of the first conductive block or the second conductive block.

Furthermore, the mounting through holes in the first wiring board and/or the second wiring board are strip-shaped through holes, and the length direction of the strip-shaped through holes is perpendicular to the arrangement direction of the wiring posts on the direct-current support capacitor. The strip-shaped through holes are beneficial to adjusting the distance between the two wiring boards so as to adapt to different discharge voltages.

Further, the fixed plate is fixed on the top ends of the conductive blocks through bolts, a groove matched with the movable plate in size is formed in the bottom of the fixed plate, and the movable plate is supported by the first conductive block and the second conductive block to stay in the groove.

Furthermore, the conductive cylinder, the first discharge block and the second discharge block are made of tungsten copper.

When the direct-current support capacitor impact discharge test device is used, the two wiring boards are firstly installed on the wiring terminals on the two electrodes of the capacitor respectively, the two wiring boards are enabled to be parallel, then the distance between the two wiring boards can be adjusted according to discharge voltage, the discharge trigger device is installed again, when the capacitor is charged to test voltage required by the test, the movable plate is pulled out from the lower part of the fixed plate through remote control, the conductive cylinder falls into the Y-shaped groove from the strip through hole, the conductive cylinder is communicated with the two conductive inclined planes, and discharge is realized.

The invention has the beneficial effects that:

the discharging gap is arranged in the middle of the parallel wiring boards, the two conductive inclined planes are symmetrically arranged, and the conductive cylinder is in contact with the two conductive inclined planes, so that the self impedance of the discharging device is greatly reduced, the peak value of the discharging current is greatly improved, the discharging device can be guaranteed to be resistant to impact vibration force, and the reliability is high; the discharge trigger device is arranged at the top end of the discharge block, so that discharge energy is conveniently dispersed upwards, and the capacitor shell and the current sensor are protected from arc ablation; the movable plate is drawn out from the lower part of the fixed plate, so that circuit conduction can be realized, and the operation is simple, safe and reliable; the discharge device has simple structure and low manufacturing cost.

Obviously, the fixed plate and the movable plate are both made of insulating materials, and the movable plate can be pulled out from the lower part of the fixed plate by using an additionally arranged mechanical device or manually pulling wires, because the discharge times specified according to a type test are few, the movable plate is pulled out manually most conveniently.

Drawings

FIG. 1 is a state diagram illustrating the use of an embodiment of the present invention;

fig. 2 is a schematic structural diagram of a discharge triggering device according to an embodiment of the present invention.

In the drawings, 1. a first wiring board; 2. a second wiring board; 3. a first discharge block; 4. a second discharge block; 4-1. bayonet; a Y-shaped groove; 6. a discharge triggering device; 6-1, fixing a plate; 6-2. a movable plate; 6-3, a conductive cylinder; 7. mounting a through hole; 8. a DC support capacitor; 8-1, a binding post.

Detailed Description

The present invention will be described in detail with reference to examples.

Referring to fig. 1, a dc support capacitor impact discharge test device comprises a first wiring board 1, a second wiring board 2 arranged in parallel, and a discharge gap and discharge trigger device 6 arranged on the first and second wiring boards,

four mounting through holes 7 are arranged on the first wiring board and the second wiring board at intervals along the length direction of the first wiring board and the second wiring board, the size of each mounting through hole 7 is matched with the outer diameter of a binding post 8-1 on the DC support capacitor 8, the distance between every two mounting through holes 7 is consistent with the distance between every two binding posts 8-1 on the DC support capacitor 8, the mounting through holes 7 on the first wiring board 1 are strip-shaped through holes, the length direction of the strip-shaped through holes is vertical to the arrangement direction of the mounting through holes 7,

the discharge gap comprises a first discharge block 3 and a second discharge block 4, the bottoms of the first discharge block and the second discharge block are respectively arranged in the middle of the first wiring board and the second wiring board, the adjacent parts of the top ends of the first discharge block and the second discharge block are respectively provided with a conductive inclined plane, the two conductive inclined planes and the two inner side surfaces of the first discharge block and the second discharge block form a bottomless Y-shaped groove 5, the bottom of the second discharge block 4 is provided with a bayonet 4-1 for installing a current sensor,

the discharge triggering device 6 comprises a fixed plate 6-1, a movable plate 6-2 and a conductive cylinder 6-3, the fixed plate 6-1 is fixed at the top end of the conductive block through a bolt, a long through hole is arranged in the center of the fixed plate 6-1, the length direction of the long through hole is parallel to the length direction of the Y-shaped groove 5, the long through hole is positioned right above the Y-shaped groove 5, a groove matched with the movable plate 6-2 in size is arranged at the bottom of the fixed plate 6-1, the movable plate 6-2 can be slidably mounted in the groove under the support of the first and second discharge blocks, the diameter and the length of the conductive cylinder 6-3 are matched with the width and the length of the long through hole, the conductive cylinder 6-3 is supported by the movable plate 6-2 and stays in the long through hole in an initial test state, in, The material of the two discharge blocks is tungsten copper.

When the direct current support capacitor impact discharge test device is used, firstly, two wiring boards are respectively arranged on wiring posts 8-1 on two electrodes of a capacitor, the two wiring boards are parallel, then the position of a first wiring board 1 is adjusted along the length direction of a strip-shaped through hole according to discharge voltage so as to adjust the intermittence of two discharge blocks, a fixed plate 6-1 is fixed at the top ends of the conductive blocks, a movable plate 6-2 is inserted into a groove at the bottom of the fixed plate 6-1 so as to block the strip-shaped through hole of the fixed plate 6-1, a conductive cylinder 6-3 is placed into the strip-shaped through hole to complete the initial state setting of a test, when the capacitor is charged to the test voltage required by the test, the movable plate 6-2 is drawn out from the groove of the fixed plate 6-1 through remote control, and the conductive cylinder 6-3 falls into a Y-shaped groove 5 from the strip-shaped through hole, the conductive cylinder 6-3 is communicated with the two conductive inclined planes to realize discharge and complete a discharge test, then the movable plate 6-2 is inserted into the groove, the conductive cylinder 6-3 is taken out of the Y-shaped groove 5 and placed into the long through hole, and the next discharge test is continued.