CN116500330B - A detection device for secondary circuit current of superconducting transformer - Google Patents

Abstract

The invention provides a detection device for a secondary loop current of a superconducting transformer. The device has the function of measuring the secondary loop current of the superconducting transformer in real time, and comprises a shunt, a Hall sensor, a calibration coil, a Luo Ke coil, an induction coil, a compensation coil, a magnetic shielding device, a heater, a direct current power supply and a signal amplifier. The invention has the advantages of high precision, high response speed, low temperature drift, good linearity and strong anti-interference force, no magnetic saturation component is arranged in the detection device, the influence caused by magnetic flux saturation is reduced, the error caused by different installation positions of the Hall sensor in the traditional mode is reduced through the calibration coil, the interference caused by stray fields can be effectively avoided through the magnetic shielding device, and the information of the secondary loop current is accurately acquired.

Description

A detection device for secondary circuit current of superconducting transformer

Technical field

The invention relates to the field of superconducting technology, and in particular to a measuring device for secondary circuit current of a superconducting transformer.

Background technique

With the development of superconducting electrical technology and the implementation of large-scale superconducting magnet projects, the demand for testing superconducting strands and superconducting conductors has greatly increased; the CICC conductor performance testing platform is a simulation of superconducting conductors operating under large currents, strong magnetic fields, An experimental platform for testing various properties of superconducting conductors in extremely low temperature environments. Its working current is usually in the hundreds of kiloamps level. The traditional DC power module group occupies a large area, consumes high energy, and is inconvenient to move. In comparison, superconducting transformers have the advantages of small size, light weight, high efficiency, long life, and overload resistance, and are the preferred method for conductor measurement devices.

CICC conductors are generally connected in the secondary circuit of a superconducting transformer for measurement. In order to evaluate the true performance of the CICC conductor, it is necessary to obtain the current applied to the CICC conductor. Since the superconducting transformer works in an extremely low temperature environment and generates The current is relatively large, and traditional measurement technology will be affected by the installation location and measurement time, which will bring errors to the current measurement, thereby affecting the accuracy of CICC conductor performance evaluation.

Contents of the invention

In order to overcome the above technical problems, the present invention provides a measuring device for the secondary circuit current of a superconducting transformer, which uses the principle of a magnetically balanced Hall current sensor to provide high measurement accuracy, strong anti-interference ability, and the ability to work under extreme conditions. DC current testing device in low temperature environment, used to measure the current in the secondary circuit of superconducting transformer.

In order to achieve the above objects, the present invention adopts the following technical solutions:

A detection device for the secondary circuit current of a superconducting transformer, which includes a shunt, a Hall sensor, a calibration coil, a Roco coil, a Roco coil bobbin, an induction coil, a compensation coil, a compensation coil bobbin, and a magnetic shielding device. Heater, DC power supply, signal amplifier.

The calibration coil is wound through the Roco coil bobbin;

The Roco coil is wound on the Roco coil bobbin, and the Roco coil bobbin is wrapped in the secondary circuit of the superconducting transformer; the secondary circuit of the superconducting transformer is the circuit where the secondary coil of the superconducting transformer is located;

The induction coil is connected to the Roco coil, and the induction coil is placed in a magnetic shielding device;

The Hall sensor is placed in the center of the induction coil;

The heater is placed at the bottom of the magnetic shielding device;

The compensation coil is wound on the compensation coil frame, and the compensation coil frame is internally buckled on the Roco coil frame;

The input of the signal amplifier is connected to the Hall sensor, and the output is connected to the DC power supply control terminal;

The DC power supply and the compensation coil are connected to form a loop; the shunt is connected in series in the loop formed by the DC power supply and the compensation coil.

Furthermore, the material of the calibration coil is NbTi superconducting wire, and the coil is formed by winding multiple turns of a single NbTi superconducting wire. The calibration coil passes through the inside of the Roco coil frame and is used to calibrate the installation error of Hall sensors and other installations.

Furthermore, the Roco coil skeleton is annular in shape and can be divided into two semi-circular rings. The Roco coil skeleton is engraved with 360 equally spaced grooves for fixing the Roco coil.

Furthermore, the material of the Roco coil is NbTi superconducting wire. The coil is formed by wrapping a single NbTi superconducting wire around a Roco coil frame, and the Roco coil is installed on the secondary coil of the superconducting transformer.

Furthermore, the compensation coil bobbin is in an I-shape, with a rectangular parallelepiped on top and a bottom and a cylinder in the middle. There is a semi-annular Roco coil bobbin groove inside the bobbin for placing the Roco coil bobbin.

Furthermore, the material of the compensation coil is NbTi superconducting wire, and the single NbTi superconducting wire of the compensation coil is formed by being densely wound around the cylinder of the compensation coil skeleton in the radial direction.

Furthermore, the induction coil is made of NbTi superconducting wire, and the induction coil is made of a single NbTi superconducting wire and is shaped like a hollow cylinder.

Furthermore, the magnetic shielding device is a cylindrical shape with an upper opening and is made of oxygen-free copper.

Furthermore, the inner wall of the magnetic shielding device is cast with magnetic shielding material, and the material is made of lead-bismuth alloy.

Further, the heater is placed at the bottom of the magnetic shielding device, the induction coil is placed on the upper part of the heater, and the Hall sensor is placed inside the induction coil.

Further, the induction coil is connected to the Roco coil, and the connection method is a spot welding connection, and the joint resistance is less than 0.01 nanoohm.

Further, the shunt is connected in series in the loop between the DC power supply and the compensation coil, and is used to measure the output size of the DC power supply.

Further, the superconducting transformer, Hall sensor, calibration coil, Roco coil, Roco coil bobbin, induction coil, compensation coil, compensation coil bobbin, magnetic shielding device, and heater all work at an ambient temperature of less than 5K. Down.

Furthermore, the shunt, DC power supply, and signal amplifier all work at room temperature.

Beneficial effects:

The present invention provides a detection device for secondary circuit current of a superconducting transformer, which can accurately collect secondary current information and has the following advantages:

(1) There are no magnetic saturation components in this test device, which can further avoid the testing impact caused by magnet saturation.

(2) The calibration coil is added to this test device and method, which can reduce errors caused by different installation positions of traditional Hall sensors and improve measurement accuracy.

(3) This test device can effectively avoid interference from stray fields through the shielding device, further improving the anti-interference performance of the test device.

Description of the drawings

Figure 1 is a two-dimensional plan view of a detection device for secondary circuit current of a superconducting transformer according to the present invention;

Figure 2 is a three-dimensional view of the Roco coil skeleton of the device for detecting secondary circuit current of a superconducting transformer according to the present invention;

Figure 3 is a three-dimensional view of the assembly of the Roco coil bobbin and the compensation coil bobbin used in the detection device of the secondary circuit current of the superconducting transformer of the present invention.

In the picture: 1-magnetic shielding device, 2-Hall sensor, 3-compensation coil, 4-Roco coil, 5-superconducting transformer secondary coil, 6-shunt, 7-DC power supply, 8-signal amplifier, 9-superconducting transformer primary coil, 10-induction coil, 11-heater, 12-calibration coil, 13-Roco coil bobbin, 14-compensation coil bobbin.

Detailed ways

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts fall within the scope of protection of the present invention.

This embodiment provides a device for detecting the secondary circuit current of a superconducting transformer. The application of the device in accurately detecting the secondary circuit current of a superconducting transformer will be described below.

As shown in Figure 1, the detection device for the secondary circuit current of a superconducting transformer of the present invention includes a shunt 6, a Hall sensor 2, a superconducting transformer, a calibration coil 12, a Rocco coil 4, an induction coil 10, and a compensation coil. 3. Magnetic shielding device 1, heater 11, DC power supply 7, signal amplifier 8. The Roco coil 4 and the induction coil 10 form a whole. The Roco coil 4 is set in the secondary circuit of the superconducting transformer. The induction coil 10 is placed in the magnetic shielding device 1. The induction coil 10 and the Roco coil 4 are both of the same diameter. NbTi superconducting wires of different sizes, the induction coil 10 and the Roco coil 4 are connected by spot welding. The energized superconducting transformer secondary coil 5 generates forward magnetic flux and induces a current in the Roco coil 4. The current will generate an induced magnetic field in the induction coil 10 that is proportional to the current in the secondary coil 5 of the superconducting transformer.

Further, the Hall sensor 2, signal amplifier 8, DC power supply 7, shunt 6, and compensation coil 3 form a whole. The Hall sensor 2 is placed in the induction coil 10 to measure the size of the induced magnetic field and generate a Hall voltage proportional to the size of the magnetic field. The Hall voltage is amplified by the signal amplifier 8 and then input into the DC power supply 7 to generate a Hall voltage proportional to the Hall voltage. Current is input into the compensation coil 3, and the compensation coil 3 generates reverse magnetic flux.

Furthermore, the forward magnetic flux and the reverse magnetic flux will offset each other. When the magnetic flux flowing through the Roco coil 4 is not zero, the Hall sensor 2 will generate a deviation voltage signal, change the output current of the DC power supply 7, and adjust Imbalance of forward and reverse magnetic flux.

Furthermore, when the forward magnetic flux and the reverse magnetic flux are balanced, the magnetic flux flowing through the Roco coil 4 is zero, the output voltage of the Hall sensor 2 remains unchanged, and the output current of the DC power supply 7 remains unchanged. This time The size of the current output is proportional to the size of the secondary circuit current of the superconducting transformer, and the size of the current can be measured through the shunt 6 .

As shown in Figure 1, the Hall sensor 2, the heater 11, and the induction coil 10 are all placed in the magnetic shielding device 1. The magnetic shielding material is made of lead-bismuth alloy and is cast on the inner wall of the magnetic shielding device 1 with a thickness greater than 1 cm. .

Further, the heater 11 is located at the bottom of the magnetic shielding device 1, and the induction coil 10 is placed above the heater 11. Before the device is measured, the induction coil 10 is heated by the heater 11 to induce quench and eliminate the residual current of the induction coil 10.

As shown in Figure 1, the calibration coil 12 passes through the inside of the Roco coil 4. Its function is to pass a known current to the calibration coil 12 before each test starts, and read the voltage of the shunt 6 and convert it into the corresponding measurement current. By comparing the current of the compensation coil 3 with the measured current, the relevant error coefficient is solved, the corresponding test error is evaluated, and the error impression caused by the installation position of the Hall sensor 2 on the measurement is further reduced.

As shown in Figure 1, magnetic shielding device 1, Hall sensor 2, compensation coil 3, Roco coil 4, superconducting transformer secondary coil 5, superconducting transformer primary coil 9, induction coil 10, calibration coil 12, Roco The coil bobbin 13 and the compensation coil bobbin 14 both work in an environment with a temperature below 5K.

As shown in Figure 2, the Roco coil frame 13 is annular, made of oxygen-free copper, and can be divided into two semicircular rings. The rings are assembled using counter-pins, and 360 equal parts are engraved on the ring frame. Grooves, Roco coil 4 will be evenly wound inside these grooves.

As shown in Figure 3, the Roco coil bobbin 13 passes through the compensation coil bobbin 14. The compensation coil bobbin 14 is I-shaped, with a cuboid at the top and a bottom and a cylinder in the middle. The compensation coil 3 is closely wound on the bobbin in the radial direction. An L-shaped adapter is installed on the lower side of the coil bobbin 14 to fix the incoming and outgoing wires of the compensation coil 3. The material of the L-shaped adapter is oxygen-free copper.

The steps for using the superconducting transformer secondary circuit current detection device of the present invention are as follows:

Step 1. The superconducting transformer is not working, and the calibration coil 12 is energized. At the same time, the voltage value of the shunt 6 is collected and converted into the corresponding current. Repeat several sets of different currents, calculate the deviation between the measured current and the input current, and obtain the calibration coefficient;

Step 2. Turn off the calibration coil 12 input, set the superconducting transformer primary coil current, convert the voltage obtained through the shunt 6 into a current, and then multiply it by the calibration coefficient, which is the superconducting transformer secondary circuit current at this time.

In the description of this specification, reference to the description of "one embodiment", "example", "specific example", etc. means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one aspect of the present invention. in an embodiment or example. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

The above contents are only examples and descriptions of the structure of the present invention. Those skilled in the art may make various modifications or supplements to the described specific embodiments or substitute them in similar ways, as long as they do not deviate from the structure of the invention or Anything beyond the scope defined by the claims shall belong to the protection scope of the present invention.

Claims (13)

1. A detection device for the secondary circuit current of a superconducting transformer, characterized by: including a shunt, a Hall sensor, a calibration coil, a Roco coil, a Roco coil bobbin, an induction coil, a compensation coil, and a compensation coil bobbin. , magnetic shielding device, heater, DC power supply and signal amplifier; the calibration coil is wound through the Roco coil bobbin; the Roco coil is wound on the Roco coil bobbin, and the Roco coil bobbin is placed on the super In the secondary circuit of the superconducting transformer, the secondary circuit of the superconducting transformer is the circuit where the secondary coil of the superconducting transformer is located; the induction coil is connected to the Roco coil, and the induction coil is placed in a magnetic shielding device; The Er sensor is placed in the center of the induction coil; the heater is placed at the bottom of the magnetic shielding device; the compensation coil is wound on the compensation coil frame, and there is a semi-annular Rocco coil frame groove inside the compensation coil frame. It is used to place the Roco coil skeleton; the input of the signal amplifier is connected to the Hall sensor, and the output is connected to the control end of the DC power supply; the DC power supply is connected to the compensation coil to form a loop; the shunt is connected in series with the DC power supply. In the loop composed of power supply and compensation coil. 2. A detection device for secondary circuit current of a superconducting transformer according to claim 1, characterized in that: the material of the calibration coil is NbTi superconducting wire, and the calibration coil passes through the Roco coil frame. Installation error for calibrating Hall sensor. 3. A detection device for secondary circuit current of a superconducting transformer according to claim 1, characterized in that: the Roco coil skeleton is annular and is divided into two semicircular rings. There are 360 equally spaced grooves engraved on the Ke coil skeleton for fixing the Rock coil. 4. A detection device for secondary circuit current of a superconducting transformer according to claim 1, characterized in that: the material of the Roco coil is NbTi superconducting wire, and the Roco coil is installed on the secondary circuit of the superconducting transformer. on the stage coil. 5. A detection device for secondary circuit current of a superconducting transformer according to claim 1, characterized in that: the compensation coil skeleton is I-shaped, with a rectangular parallelepiped at the top and a bottom, and a cylinder in the middle. The compensation coil bobbin has a semi-annular Roco coil bobbin groove inside, which is used to place the Roco coil bobbin. 6. A detection device for secondary circuit current of a superconducting transformer according to claim 5, characterized in that: the compensation coil is made of NbTi superconducting wire, and the compensation coil is densely wound around the compensation coil frame in the radial direction. on the cylinder. 7. A detection device for secondary circuit current of a superconducting transformer according to claim 1, characterized in that: the induction coil is made of NbTi superconducting wire. 8. A detection device for secondary circuit current of a superconducting transformer according to claim 1, characterized in that: the magnetic shielding device is a cylindrical shape with an upper opening and is made of oxygen-free copper. 9. A detection device for secondary circuit current of a superconducting transformer according to claim 8, characterized in that: the inner wall of the magnetic shielding device is cast with magnetic shielding material, and the magnetic shielding material is lead-bismuth alloy. 10. A detection device for secondary circuit current of a superconducting transformer according to claim 8, characterized in that: the heater is placed at the bottom of the magnetic shielding device, the induction coil is placed on the upper part of the heater, and the induction coil is placed at the upper part of the heater. The sensor is placed inside the induction coil. 11. A detection device for secondary circuit current of a superconducting transformer according to claim 1, characterized in that: the shunt is used to measure the output size of the DC power supply. 12. A detection device for the secondary circuit current of a superconducting transformer according to claim 1, characterized in that: a superconducting transformer, a Hall sensor, a calibration coil, a Rocco coil, a Roco coil skeleton, and an induction coil. , compensation coil, compensation coil frame, magnetic shielding device, and heater all work at an ambient temperature less than 5K. 13. A detection device for secondary circuit current of a superconducting transformer according to claim 1, characterized in that: the shunt, DC power supply, and signal amplifier all operate at room temperature.