CN115436680B - A small resistance signal resistor for self-integrating Rogowski coil - Google Patents

Abstract

The invention relates to a coaxial small-resistance resistor, in particular to a small-resistance signal resistor for a self-integration rogowski coil, which solves the technical problems of complex structure and high cost of the existing signal resistor. The small-resistance signal resistor for the self-integration rogowski coil is characterized in that: the connecting device comprises a first connector, an adapter flange, a connecting assembly, an inner core, N patch resistors and a second connector, wherein N is more than or equal to 2; one end of the connecting component is connected with the first connector, and the other end of the connecting component is connected with the second connector; one end of the adapter flange is coaxially connected with the first connector, and the other end of the adapter flange is sleeved on the inner wall of the second connector; the inner core is sleeved on the connecting component; the other end of the inner core, the adapter flange and the second connector form an accommodating cavity; the N chip resistors are uniformly arranged in the accommodating cavity along the circumference; the signal resistor has small volume and can meet the requirement of a large pulse power device on the rogowski coil.

Description

A small resistance signal resistor for self-integrating Rogowski coil

Technical Field

The invention relates to a coaxial small-resistance resistor, in particular to a small-resistance signal resistor used for a self-integrating Rogowski coil.

Background Art

With the continuous development and wide application of pulse power technology, it is very important to accurately measure large pulse currents. In pulse power devices, Rogowski coil current detectors are often used to measure pulse currents of hundreds of kA. Rogowski coils can be divided into two types according to the integration method: self-integration and external integration. For large pulse currents with a pulse width of less than hundreds of ns, self-integration Rogowski coils are often used. Self-integration Rogowski coils usually use coaxial small resistance resistors as signal resistors. They can be divided into two types according to the use method: one is a special signal resistor fixed to the Rogowski coil, which is mostly used for Rogowski coils that can move freely. The other is a universal signal resistor that can be matched with different Rogowski coils, which is mostly used for Rogowski coils fixed to pulse power devices. The resistance value of the signal resistor directly affects the output signal size of the Rogowski coil, and the two are generally proportional. In the measurement of pulse currents of hundreds of kA, due to the large amplitude of the current to be measured, in order to avoid insulation failure of the Rogowski coil port or damage to the measurement circuit components (including but not limited to signal resistors, attenuators, oscilloscopes, etc.), the signal resistor value is generally several Ω or even less than 1Ω. The signal resistor itself has inductance, which will have a certain impact on the output of the Rogowski coil. Under the same inductance, the smaller the signal resistor value, the greater the impact of the inductance, so it is necessary to minimize the impact of the inductance. Generally, the method of reducing the inductance value is used to reduce the impact of the inductance. The following three solutions are usually used: one is to use multiple small resistors in parallel to reduce the inductance; the second is to reduce the inductance by making the signal resistor structure more compact; the third is to directly use a coaxial body resistor.

In the prior art, Chinese patent CN104502664A discloses "a low-resistance non-inductive self-integrating Rogowski coil integrating resistor and its manufacturing method", which introduces a signal resistor of a loop device made of a cylindrical metal support, and uses a compact structure to reduce inductance. Chinese patent CN106154013B discloses "a composite Rogowski coil integrating resistor and its manufacturing method", which introduces a signal resistor composed of an external integrating resistor, a self-integrating resistor, and an integrating capacitor, which uses a compact structure to reduce inductance, and uses capacitor compensation to reduce the influence of inductance. A Chinese patent of the China Shipbuilding Industry System Engineering Research Institute, with publication number CN113917214A, discloses "a self-integrating Rogowski coil disc-shaped integrating resistor and its manufacturing method", which uses a disc-shaped PCB board and a plurality of patch resistors arranged radially in a ring on the PCB board to make a signal resistor, and uses a plurality of resistors in parallel to reduce inductance. Another Chinese patent publication number is CN212341315U, which discloses "a coaxial disc-shaped water resistor for self-integrating Rogowski coils". The disc-shaped signal resistor for self-integrating Rogowski coils is made by using two inner and outer stainless steel tubes as two poles and an electrolyte charged inside. The inductance is reduced by making a coaxial body resistor. The four signal resistors introduced in the above materials are only applicable to specific return structures. The article "A compact coaxial non-inductive resistor" published by the National University of Defense Technology in "Electronic Components and Materials", 1997, 16 (5) uses a large number of stainless steel cylindrical small resistors to make a compact signal resistor, and uses multiple small resistors in parallel and a compact structure to reduce inductance. The article "Response of Rogowski coil signal resistor to nanosecond pulse large current" published by the National University of Defense Technology in "High Power Laser and Particle Beam", 2009, 21 (10) uses 50 metal film resistors in parallel to form a signal resistor, and uses multiple resistors in parallel to reduce inductance. The two types introduced in the materials of the National University of Defense Technology are both universal signal resistors.

For large-scale pulse power devices, there may often be dozens or hundreds of Rogowski coils installed, so a large number of signal resistors need to be prepared at the same time, but the number is not enough to reduce the cost through mass production, which requires a signal resistor with simple structure and low cost. In addition, in large-scale pulse power devices, the peripheral structures of these Rogowski coils are different, and the space left for installing signal resistors is limited, which requires the radial size of the signal resistor to be as small as possible to accommodate more Rogowski coil structures. Among the two general-purpose signal resistors mentioned above, "a compact coaxial non-inductive resistor" has the smallest radial size, but the structure is complex, the production cycle is long, and the cost is high; while the signal resistor introduced in "The response of Rogowski coil signal resistor to nanosecond pulse large current" has a large radial size, which is not conducive to installation in some small spaces.

Summary of the invention

The purpose of the present invention is to solve the technical problems of the complex structure and high cost of existing signal resistors, and to provide a small-resistance signal resistor for a self-integrating Rogowski coil.

In order to solve the above technical problems, the technical solution adopted by the present invention is:

A small resistance signal resistor for a self-integrating Rogowski coil, which is special in that it includes a first connector, a transfer flange, a connection component, an inner core, N chip resistors and a second connector, N≥2;

One end of the connecting component is connected to the first inner pin of the first connector, and the other end of the connecting component is connected to the second inner pin of the second connector;

One end of the adapter flange is coaxially connected to the first connector, and the other end is sleeved on the inner wall of the second connector;

The inner core is sleeved on the connecting assembly; one end of the inner core is connected to the first inner pin of the first connector, and the other end of the inner core forms a receiving cavity with the adapter flange and the second connector;

N chip resistors are evenly arranged in the accommodating cavity along the circumference, and two ends of the chip resistors are respectively connected to the outer wall of the inner core and the inner wall of the transfer flange;

The first connector is used to connect to the output port of the self-integrating Rogowski coil, and the second connector is used to connect to an oscilloscope; or, the first connector is used to connect to the oscilloscope, and the second connector is used to connect to the output port of the self-integrating Rogowski coil.

Furthermore, the inner core is a cylindrical structure; a plurality of blind grooves adapted to one end of the chip resistor are arranged on the outer wall of the inner core;

An annular step is provided on the inner wall of the transfer flange corresponding to the other end of the chip resistor;

One end of the chip resistor is located in the blind groove and connected to the bottom of the blind groove; the other end of the chip resistor is located on the annular step and connected to the inner wall of the annular step.

Furthermore, the value of N is 6.

Further, the connecting assembly is a connecting rod;

The first connector is an N-50KF connector;

The second connector is an N-J connector.

Compared with the prior art, the technical solution of the present invention has the following beneficial effects:

(1) The present invention is a low-resistance signal resistor for a self-integrating Rogowski coil, which uses a first connector, a transfer flange, a connection assembly, an inner core, N chip resistors and a second connector, and connects the first inner pin of the first connector with the second inner pin of the second connector through the connection assembly, and the inner core is sleeved on the connection assembly, so that the signal resistor of the present invention has the advantages of small size, simple and compact structure, and high bandwidth upper limit. The two connectors are connected through the transfer flange to shield external electromagnetic interference, which can meet the demand for self-integrating Rogowski coils in large pulse power devices.

(2) The low-resistance signal resistor used for the self-integrating Rogowski coil of the present invention is evenly distributed in the accommodating cavity formed by the inner core, the adapter flange and the second connector. Under the premise of ensuring small volume and high power, the component structure of the signal resistor is simplified and the difficulty of the manufacturing process is reduced.

(3) The present invention is used for the small-resistance signal resistor of the self-integrating Rogowski coil, and can also use common components sold in the market, so that the overall cost is low and it is easier to mass produce.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic structural diagram of a small-resistance signal resistor for a self-integrating Rogowski coil according to the present invention.

2 is a schematic diagram of the installation structure of the chip resistor inside the adapter flange in an embodiment of the small-resistance signal resistor for the self-integrating Rogowski coil of the present invention.

FIG3 is a schematic diagram of the working process of an embodiment of a small-resistance signal resistor for a self-integrating Rogowski coil of the present invention, wherein i(t) is the induced current in the self-integrating Rogowski coil and V(t) is the voltage signal.

The accompanying drawings in the figure are as follows:

1-first connector, 11-first inner needle, 2-adapter flange, 3-connection assembly, 4-inner core, 5-chip resistor, 6-second connector, 61-second inner needle, 7-self-integrating Rogowski coil, 8-output connector, 9-signal transmission cable, 10-oscilloscope.

DETAILED DESCRIPTION

The technical solution of the present invention will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the technical solution in 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.

As shown in FIG1 , a small-resistance signal resistor for a self-integrating Rogowski coil includes a first connector 1, a transfer flange 2, a connecting component 3 (connecting rod), an inner core 4, N chip resistors 5 and a second connector 6, where N is greater than or equal to 2.

One end of the connecting component 3 is connected to the first inner pin 11 of the first connector 1, and the other end of the connecting component 3 is connected to the second inner pin 61 of the second connector 6; one end of the adapter flange 2 is coaxially connected to the first connector 1, and the other end is sleeved on the inner wall of the second connector 6; one end of the adapter flange 2 is connected to the first connector 1 by a screw, and the other end is connected to the second connector 6 by a thread. The adapter flange 2, the first connector 1 and the second connector 6 together constitute the outer shell of the signal resistor of the present invention, which plays a role in shielding external electromagnetic interference.

The inner core 4 is sleeved on the connecting assembly 3; one end of the inner core 4 is connected to the first inner pin 11 of the first connector 1, and the other end of the inner core 4 forms a receiving cavity with the adapter flange 2 and the second connector 6;

N chip resistors 5 are evenly arranged along the circumference in the accommodating cavity, and the two ends of the chip resistors 5 are respectively connected to the outer wall of the inner core 4 and the inner wall of the adapter flange 2. The N chip resistors 5 are evenly distributed between the inner core 4 and the adapter flange 2 in an angular direction relative to the axis of the inner core, one end of the chip resistor 5 is welded to the outer wall of the inner core 4, and the other end is welded to the inner wall of the adapter flange 2, forming the resistor body part of the signal resistor of the present invention.

The first connector 1 is used to connect to the output port of the self-integrating Rogowski coil 7, and the second connector 6 is used to connect to the oscilloscope 10; or, the first connector 1 is used to connect to the oscilloscope 10, and the second connector 6 is used to connect to the output port of the self-integrating Rogowski coil 7.

In this embodiment, the inner core 4 is preferably a cylindrical structure; a plurality of blind grooves matching one end of the chip resistor 5 are provided on the outer wall of the inner core 4 for clamping the electrode. An annular step is provided on the inner wall of the adapter flange 2 corresponding to the other end of the chip resistor 5; one end of the chip resistor 5 is located in the blind groove and connected to the bottom of the blind groove; the other end of the chip resistor 5 is located on the annular step and connected to the inner wall of the annular step. The value of N is 6, the blind groove is a rectangular groove, and the number is 6; the 6 chip resistors 5 are evenly arranged between the inner core 4 and the adapter flange 2. The connecting component 3 is a connecting rod; the first connector 1 is an N-50KF connector; the second connector 6 is an N-J connector.

First, weld the connecting rod to the inner pin of the N-50KF connector, put the inner core 4 on the outside of the connecting rod, connect one end of the inner core 4 to the inner pin of the N-50KF connector, and connect the inner core 4 to the connecting rod by soldering.

Then, connect the adapter flange 2 to the N-50KF connector by screws.

As shown in Figure 2, six chip resistors 5 are placed symmetrically and sideways between the inner core 4 and the adapter flange 2. One end of the chip resistor 5 is placed in the blind groove on the top of the inner core 4, and the other end is placed on the step on the adapter flange 2 for supporting the chip resistor 5. The electrodes at both ends of the chip resistor 5 are welded to the inner core 4 and the adapter flange 2 respectively.

Then, remove the inner pins of the N-J connector from the N-J connector and solder them to the connecting rod.

Finally, the N-J connector is threadedly connected to the adapter flange 2 to complete the assembly of the small-resistance signal resistor for the self-integrating Rogowski coil.

The signal resistor of the present invention comprises an N-50KF connector, a transfer flange 2, a connecting rod, an inner core 4, 6 chip resistors 5, and an N-J connector. The inner pins of the two connectors are connected by a connecting rod, and the inner core 4 is welded on the connecting rod. The outer shells of the two connectors are connected by a transfer flange 2 to shield external electromagnetic interference. The chip resistors 5 are symmetrically distributed between the inner core 4 and the outer shell, so that the signal resistor of the present invention has the advantages of small size, simple structure, low cost, and high bandwidth upper limit.

The working process of the above embodiment is as follows:

As shown in Figure 3, the signal resistor of the present invention is connected to the output port of the output end connector 8 of the self-integrating Rogowski coil 7. The port where the signal resistor is connected to the output port of the output end connector 8 connected to the self-integrating Rogowski coil 7 is called the input port of the signal resistor, and the other end is called the output port of the signal resistor.

The signal resistor in the present invention has no direction, and both the first connector 1 and the second connector 6 can be used as input ports. In other embodiments, the output connector 8 is not necessarily an N-type connector, and its connection with the signal resistor can use other connectors as a transfer. The self-integrating Rogowski coil 7 and the signal resistor of the present invention together form a complete current measurement probe, and the parameters such as the sensitivity and front response of the probe are closely related to the resistance value R of the signal resistor.

Assume that the above-mentioned current measuring probe is to be used to measure the current I(t) to be measured, and the induced current in the self-integrating Rogowski coil 7 is i(t). When i(t) flows through the signal resistor, a voltage signal V(t) is generated on the signal resistor, and V(t)=i(t)·R.

The voltage signal V(t) is transmitted to the oscilloscope 10 through the signal transmission cable 9 and recorded by the oscilloscope 10. The voltage signal V(t) is proportional to the current I(t) to be measured, and the amplitude of the current I(t) to be measured can be inferred by measuring the amplitude of the voltage signal V(t).

Claims (4)

1. A small-resistance signal resistor for a self-integrating Rogowski coil, characterized by comprising a first connector (1), a transfer flange (2), a connecting component (3), an inner core (4), N chip resistors (5) and a second connector (6), N ≥ 2; One end of the connecting component (3) is connected to the first inner needle (11) of the first connector (1), and the other end of the connecting component (3) is connected to the second inner needle (61) of the second connector (6); One end of the adapter flange (2) is coaxially connected to the first connector (1), and the other end is sleeved on the inner wall of the second connector (6); The inner core (4) is sleeved on the connecting assembly (3); one end of the inner core (4) is connected to the first inner needle (11) of the first connector (1), and the other end of the inner core (4) forms a receiving cavity with the adapter flange (2) and the second connector (6); N chip resistors (5) are evenly arranged along the circumference in the accommodating cavity, and two ends of the chip resistors (5) are respectively connected to the outer wall of the inner core (4) and the inner wall of the adapter flange (2); The first connector (1) is used to connect to the output port of the self-integrating Rogowski coil (7), and the second connector (6) is used to connect to the oscilloscope (10); or the first connector (1) is used to connect to the oscilloscope (10), and the second connector (6) is used to connect to the output port of the self-integrating Rogowski coil (7). 2. A small resistance signal resistor for a self-integrating Rogowski coil according to claim 1, characterized in that: The inner core (4) is a cylindrical structure; a plurality of blind grooves adapted to one end of the chip resistor (5) are arranged on the outer wall of the inner core (4); An annular step is provided on the inner wall of the adapter flange (2) corresponding to the other end of the chip resistor (5); One end of the chip resistor (5) is located in the blind groove and connected to the bottom of the blind groove; the other end of the chip resistor (5) is located on the annular step and connected to the inner wall of the annular step. 3. A small resistance signal resistor for a self-integrating Rogowski coil according to claim 2, characterized in that the value of the N chip resistors (5) is 6. 4. A small-resistance signal resistor for a self-integrating Rogowski coil according to any one of claims 1 to 3, characterized in that: The connecting component (3) is a connecting rod; The first connector (1) is an N-50KF connector; The second connector (6) is an N-J connector.