Laser-triggered calibration Rogowski coil system

Abstract

The invention relates to a laser-triggered calibration Rogowski coil system, which is characterized in that a Rogowski coil to be calibrated and a standard Pearson coil are coaxially arranged, the centers of the two coils are positioned in an electric loop which is triggered and conducted by laser, and the current calibration coefficient of the Rogowski coil is obtained by comparing the current of the conducted electric loop which is simultaneously detected. According to the system for calibrating the Rogowski coil through laser triggering, due to the fact that a laser triggering device replaces a North Star High Voltage trigger, the overall scheme is simple in design and low in cost, and calibration is more convenient and faster; plasma conduction is generated based on laser ionization environment gas, compared with traditional electric trigger calibration, the trigger success rate is high, the requirements for parameters such as air pressure, environment gas, trigger electrode distance and trigger voltage are lower, especially the trigger voltage is lower, and the safety performance of the whole system is effectively improved; according to the invention, the Rogowski coil and the Pearson coil are coaxially arranged, so that the current deviation of the current flowing through the two coils is small, and the calibration precision is higher.

Description

Technical Field

[0001] The invention relates to the field of measurement technology, and in particular to a laser triggered calibration Rogowski coil system. Background Art

[0002] High voltage and high current are one of the main characteristics of pulse current sources in the field of pulse power and fusion. Accurately measuring the high voltage and high current parameters on the experimental device in the loop of high-power pulse current source is a key technology in the experiments in the field of pulse power and fusion. Its measurement results are an important basis for the analysis and evaluation of the results of physical experiments related to pulse power and fusion technology research. At present, the measurement of pulsed large current mainly uses two methods: Pearson coil and Rogowski coil; Pearson coil is accurate in measurement, but it is expensive. At the same time, the limited size of Pearson coil cannot meet the measurement of large-scale experimental devices; Rogowski coil has the advantages of fast instantaneous response ability, simple processing, low cost, and no special requirements for the size and shape of the measured device, but it needs to be calibrated with the standard Pearson coil to obtain the true measured current value. Traditional calibration of Rogowski coil usually uses a high-power trigger switch developed by North Star High Voltage in the United States to realize the loop conduction to generate alternating current to realize Rogowski coil calibration. This calibration system is complex, costly, has a low success rate of triggering conduction, a large threshold voltage required for triggering, and a long calibration process. Summary of the invention

[0003] To solve the above problems, a laser triggered Rogowski coil calibration system is proposed. The laser trigger is used to generate alternating current to quickly calibrate the Rogowski coil. The system has a simple structure, low price, fast and convenient calibration, high precision, and is suitable for calibration of Rogowski coils of different sizes. It has important application value in the fields of pulsed power systems and fusion physics.

[0004] The technical solution of the present invention is: a laser-triggered Rogowski coil calibration system, comprising a laser, an insulating cavity, a low-voltage electrode, a high-voltage electrode, a lens, a capacitor, a current-limiting resistor, an oscilloscope, a Rogowski coil to be calibrated and a standard Pearson coil;

[0005] The insulating cavity is in a cylindrical structure, the low-voltage electrode and the high-voltage electrode pair are respectively arranged at the upper and lower ends of the center plane in the cylindrical cavity, the Rogowski coil to be calibrated which is sleeved outside the insulating cavity is coaxial with the standard Pearson coil on the connecting rod and the centers thereof are both on the connecting line of the low-voltage electrode and the high-voltage electrode pair;

[0006] The low voltage electrode is connected to one of the electrodes of the capacitor, and the high voltage electrode is connected to the other electrode of the capacitor through a current limiting resistor;

[0007] The laser emitted by the laser enters the insulating cavity through a lens installed in the middle section of the cylindrical surface of the insulating cavity, and is focused on the middle space in the insulating cavity between the low-voltage electrode and the high-voltage electrode facing each other. The laser ionizes and breaks down the ambient gas in the insulating cavity to generate plasma. The generated plasma forms a stable plasma channel between the low-voltage electrode and the high-voltage electrode, so that the low-voltage electrode and the high-voltage electrode are conductive, so that the capacitor storage voltage is quickly discharged through the plasma channel, and the current reaches a maximum. The Rogowski coil to be calibrated outside the insulating cavity and the standard Pearson coil on the connecting rod simultaneously measure the current signal during the high-voltage discharge process of the capacitor. The oscilloscope simultaneously monitors the magnitude of the current signals collected by the Rogowski coil and the Pearson coil. The Rogowski coil current calibration coefficient can be obtained by comparing the collected currents.

[0008] Preferably, the insulating cavity has a cylindrical structure, a low-voltage electrode mounting port is provided at the center of the top circular surface, an ambient gas input port is provided on the side of the top circular surface mounting port, a lens mounting port is provided in the middle section of the cylindrical surface, a high-voltage electrode mounting port is provided at the center of the bottom circular surface, and an ambient gas output port is provided on the side of the bottom circular surface mounting port.

[0009] Preferably, the laser triggered calibration Rogowski coil system also includes a high-voltage power supply, the low-voltage electrode is connected to one of the electrodes of the capacitor through a wire, the high-voltage electrode passes through a vertical connecting rod fixed at the center below the bottom circular surface of the insulating cavity, and is then connected to the other electrode of the capacitor through a current limiting resistor; the high-voltage power supply charges the capacitor through a switch and a power supply current limiting resistor.

[0010] Preferably, the Rogowski coil is sleeved on the end of the insulating cavity where the high-voltage electrode is located, and the Pearson coil is sleeved on the connecting rod.

[0011] A laser-triggered Rogowski coil calibration method is provided, wherein a Rogowski coil to be calibrated is coaxially arranged with a standard Pearson coil, and the centers of both coils are in an electrical circuit that is triggered by the laser and turned on. The current calibration coefficient of the Rogowski coil is obtained by comparing the currents of the turned-on electrical circuits that are detected simultaneously.

[0012] Furthermore, the two ends of the fully charged capacitor are respectively connected to the low-voltage electrode and the high-voltage electrode placed in the insulating cavity, and the laser emitted by the laser is focused through a lens on the middle space in the insulating cavity facing the low-voltage electrode and the high-voltage electrode. The laser ionizes and breaks down the ambient gas in the insulating cavity to generate plasma. The generated plasma forms a stable plasma channel between the low-voltage electrode and the high-voltage electrode, so that the low-voltage electrode and the high-voltage electrode are conductive, so that the capacitor storage voltage is quickly discharged through the plasma channel, and the current reaches a maximum. The Rogowski coil to be calibrated and the standard Pearson coil outside the insulating cavity simultaneously measure the current signal of the capacitor during the high-voltage discharge process. The oscilloscope simultaneously monitors the magnitude of the current signals collected by the Rogowski coil and the Pearson coil. The Rogowski coil current calibration coefficient can be obtained by comparing the collected currents.

[0013] The beneficial effects of the present invention are as follows: the laser-triggered calibration Rogowski coil system of the present invention uses a laser-triggered calibration Rogowski coil system. Since the laser trigger device replaces the North Star High Voltage trigger, the overall solution design is simple, the cost is low, and the calibration is more convenient and quick; based on laser ionization to generate plasma conduction, compared with traditional electrical trigger calibration, the present invention has a high trigger success rate and lower requirements on parameters such as air pressure, ambient gas, trigger electrode spacing, and trigger voltage, especially a lower trigger voltage, which effectively improves the safety performance of the entire system; the present invention adopts the coaxial placement of the Rogowski coil and the Pearson coil in terms of structure. This design method makes the current deviation of the current flowing through the two coils smaller and the calibration accuracy higher. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 This is a schematic diagram of the structure of the laser triggered calibration Rogowski coil system of the present invention;

[0015] Figure 2 A schematic diagram of the structure of an insulating cavity in the laser triggered calibration Rogowski coil system of the present invention;

[0016] Figure 3 This is a diagram of the experimental results of the Rogowski coil calibration system under the laser triggered 1KV voltage of the present invention. DETAILED DESCRIPTION

[0017] The present invention is described in detail below in conjunction with the accompanying drawings and specific embodiments. This embodiment is implemented based on the technical solution of the present invention, and provides a detailed implementation method and specific operation process, but the protection scope of the present invention is not limited to the following embodiments.

[0018] like Figure 1 , 2As shown, a laser triggered calibration Rogowski coil system of the present invention comprises: a laser 1, an insulating cavity 2, a low voltage electrode 3, a high voltage electrode 4, a lens 5, a capacitor 6, a connecting rod 7, two current limiting resistors 8-1 and 8-2, a high voltage power supply 9, an oscilloscope 10, a Rogowski coil to be calibrated 11 and a standard Pearson coil 12;

[0019] The insulating cavity 2 is a cylindrical structure, a low-voltage electrode 3 mounting port 16 is provided at the center of the top circular surface 13, an ambient gas input port 17 is provided on the side of the mounting port 16 of the top circular surface 13, a lens 5 mounting port 18 is provided in the middle of the cylindrical surface 14, a high-voltage electrode 4 mounting port 19 is provided at the center of the bottom circular surface 15, and an ambient gas output port 20 is provided on the side of the mounting port 19 of the bottom circular surface 15;

[0020] The low-voltage electrode 3 is connected to one of the electrodes of the capacitor 6 through a wire, and the high-voltage electrode 4 passes through a vertical connecting rod 7 fixed at the center of the bottom circular surface 15 of the insulating cavity 2, and is then connected to the other electrode of the capacitor 6 through a current-limiting resistor 8-2; the high-voltage power supply 9 charges the capacitor 6 through a switch and a current-limiting resistor 8-1;

[0021] Ambient gas is injected into the insulating cavity 2 through the ambient gas inlet 17, and the ambient gas in the insulating cavity 2 is output from the insulating cavity 2 through the ambient gas outlet 20;

[0022] The Rogowski coil 11 is sleeved on the end of the high-voltage electrode 4 outside the insulating cavity 2, and the Pearson coil 12 is sleeved on the connecting rod 7. The Rogowski coil 11 is coaxial with the Pearson coil 12 and their centers are both on the connecting line directly opposite the low-voltage electrode 3 and the high-voltage electrode 4.

[0023] A closed-loop charging circuit switch, the capacitor 6 is charged by a high-voltage power supply 9. After charging is completed, the high-voltage power supply 9 is turned off. The laser emitted by the laser 1 enters the insulating cavity 2 through the lens 5 and is focused on the middle space in the insulating cavity 2 between the low-voltage electrode 3 and the high-voltage electrode 4 facing each other. The laser ionizes and breaks down the ambient gas in the insulating cavity 2 to generate plasma. The generated plasma forms a stable plasma channel between the low-voltage electrode 3 and the high-voltage electrode 4, so that the low-voltage electrode 3 and the high-voltage electrode 4 are conductive, so that the voltage stored in the capacitor 6 is quickly discharged through the plasma channel, and the current reaches the maximum. The Rogowski coil 11 to be calibrated outside the insulating cavity and the standard Pearson coil 12 on the connecting rod simultaneously measure the current signal of the capacitor 6 during the high-voltage discharge process. The oscilloscope 10 simultaneously monitors the current signal size collected by the Rogowski coil 11 and the Pearson coil 12. The Rogowski coil current calibration coefficient can be obtained by comparing the collected currents.

[0024] like Figure 3This is the experimental result diagram of the Rogowski coil calibration system under the laser-triggered 1KV voltage of the present invention. The present invention can well generate plasma through laser to trigger the conduction between electrodes, realize the current in the loop to flow through the Pearson coil and the Rogowski coil, and complete the calibration of the Rogowski coil and the Pearson coil measurement current according to the current size of the Pearson coil. The present invention has a simple design structure, low price, fast and convenient calibration, high precision, and is suitable for calibration of Rogowski coils of different sizes. It has important application value in the field of pulse power systems and fusion physics.

[0025] The above-mentioned embodiments only express the specific implementation of the present invention, and the description thereof is relatively specific and detailed, but it cannot be understood as limiting the scope of the invention patent. It should be pointed out that for ordinary technicians in this field, several modifications and improvements can be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be based on the attached claims.

Claims

1. A laser-triggered Rogowski coil calibration system, characterized in that: It includes a laser, an insulating cavity, a low-voltage electrode, a high-voltage electrode, a lens, a capacitor, a current-limiting resistor, an oscilloscope, a Rogowski coil to be calibrated, and a standard Pearson coil; The insulating cavity is in a cylindrical structure, the low-voltage electrode and the high-voltage electrode pair are respectively arranged at the center ends of the upper and lower surfaces in the cylindrical cavity, the Rogowski coil to be calibrated which is sleeved outside the insulating cavity is coaxial with the standard Pearson coil on the connecting rod and the centers thereof are both on the connecting line of the low-voltage electrode and the high-voltage electrode pair; The low voltage electrode is connected to one of the electrodes of the capacitor, and the high voltage electrode is connected to the other electrode of the capacitor through a current limiting resistor; The laser emitted by the laser enters the insulating cavity through a lens installed in the middle section of the cylindrical surface of the insulating cavity, and is focused on the middle space in the insulating cavity between the low-voltage electrode and the high-voltage electrode facing each other. The laser ionizes and breaks down the ambient gas in the insulating cavity to generate plasma. The generated plasma forms a stable plasma channel between the low-voltage electrode and the high-voltage electrode, so that the low-voltage electrode and the high-voltage electrode are conductive, so that the capacitor storage voltage is quickly discharged through the conductive channel, and the current reaches a maximum. The Rogowski coil to be calibrated outside the insulating cavity and the standard Pearson coil on the connecting rod simultaneously measure the current signal during the high-voltage discharge process of the capacitor. The oscilloscope simultaneously monitors the magnitude of the current signals collected by the Rogowski coil and the Pearson coil. The Rogowski coil current calibration coefficient can be obtained by comparing the collected currents.

2. The laser-triggered calibration Rogowski coil system according to claim 1, characterized in that: The insulating cavity is in a cylindrical structure, with a low-voltage electrode mounting port at the center of the top circular surface, an ambient gas input port at the side of the top circular surface mounting port, a lens mounting port at the middle of the cylindrical surface, a high-voltage electrode mounting port at the center of the bottom circular surface, and an ambient gas output port at the side of the bottom circular surface mounting port.

3. The laser-triggered calibration Rogowski coil system according to claim 2, characterized in that: It also includes a high-voltage power supply, the low-voltage electrode is connected to one of the electrodes of the capacitor through a wire, the high-voltage electrode passes through a vertical connecting rod fixed at the center below the bottom circular surface of the insulating cavity, and is then connected to the other electrode of the capacitor through a current-limiting resistor; the high-voltage power supply charges the capacitor through a switch and a power supply current-limiting resistor.

4. The laser-triggered calibration Rogowski coil system according to claim 3, characterized in that: The Rogowski coil is sleeved on the end of the insulating cavity where the high-voltage electrode is located, and the Pearson coil is sleeved on the connecting rod.

5. A laser-triggered Rogowski coil calibration method, characterized in that: The Rogowski coil to be calibrated is coaxially arranged with the standard Pearson coil, and the centers of the two coils are both in the electrical loop triggered by the laser. The current calibration coefficient of the Rogowski coil is obtained by comparing the currents of the electrical loops detected simultaneously.

6. The laser-triggered Rogowski coil calibration method according to claim 1, characterized in that: The two ends of the fully charged capacitor are respectively connected to the low-voltage electrode and the high-voltage electrode placed in the insulating cavity. The laser emitted by the laser is focused through a lens on the middle space in the insulating cavity facing the low-voltage electrode and the high-voltage electrode. The laser ionizes and breaks down the ambient gas in the insulating cavity to generate plasma. The generated plasma forms a stable plasma channel between the low-voltage electrode and the high-voltage electrode, so that the low-voltage electrode and the high-voltage electrode are conductive, so that the capacitor storage voltage is quickly discharged through the plasma channel, and the current reaches the maximum. The Rogowski coil to be calibrated outside the insulating cavity and the standard Pearson coil on the connecting rod simultaneously measure the current signal of the capacitor during the high-voltage discharge process. The oscilloscope simultaneously monitors the magnitude of the current signals collected by the Rogowski coil and the Pearson coil. The Rogowski coil current calibration coefficient can be obtained by comparing the collected currents.

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