CN103630809A - Pulse discharge loop - Google Patents

Abstract

A pulse discharge circuit, comprising a pulse power supply (1), a discharge electrode, a current limiting resistor (4) and a measurement unit. The high voltage output end of the pulse power supply (1) is connected to the high voltage electrode (2) of the discharge electrode, the low voltage electrode (3) of the discharge electrode is connected to one end of the current limiting resistor (4), and the other end of the current limiting resistor (4) is connected to the pulse The ground terminals of the power supply are connected and grounded. The output voltage of the pulse power supply is measured on the high-voltage side of the discharge electrode with a high-voltage probe (5), and the current of the pulse circuit is measured between the current-limiting resistor and the ground wire through the Rogowski coil (6). The invention can generate milliampere-level nanosecond discharge pulses with a single and repeated frequency, and the amplitude of the discharge pulse is controlled by the current-limiting resistor (4), and can be used for simulating occasions of different forms of corona discharge.

Description

A pulse discharge circuit

technical field

The invention relates to the field of pulse discharge, in particular to a circuit capable of generating single-time and repetition frequency milliampere-level nanosecond pulse discharge.

Background technique

The corona discharge on the surface of the transmission line conductor will produce strong radio interference and audible noise, which will affect the surrounding electromagnetic environment. At present, the research on audible noise of transmission lines at home and abroad mainly focuses on on-site measurement and prediction formulas, but no in-depth research has been carried out on the generation mechanism of audible noise in transmission lines. Corona discharge consists of a series of single discharge pulses, the repetition rate of the discharge pulse is very high, and the characteristics of a single discharge pulse have certain randomness. The corona discharge signal obtained under the AC and DC corona test platform has certain randomness, and the characteristics such as the repetition rate of the discharge pulse, the amplitude, rising edge and pulse width of a single discharge pulse cannot be controlled, and these parameters often change at the same time . Therefore, it is difficult to study the correlation between individual discharge parameters and acoustic characteristics under the AC and DC corona test platform, and it is impossible to determine the influence of corona discharge parameters on the audible noise produced.

Document 1 (SF6 gas discharge characteristics under nanosecond pulse. High voltage technology, 38(7), 2012, Ran Huijuan, Wang Jue, Wang Tao, Yan Ping.) The discharge circuit proposed by the load salt water resistance adjusts the output voltage of the power supply, and the amplitude is 0- 200kV, the discharge gap, current limiting resistor and shunt are in the experimental chamber filled with SF6 gas. The connection between the power supply and the experimental chamber adopts a coaxial chamber. The current of this discharge circuit is on the order of tens to hundreds of amperes. The structure of the above-mentioned discharge circuit is complex and the current is relatively large, so it cannot simulate the corona discharge current at the milliampere level. At the same time, the design of the discharge chamber is not convenient for the measurement of the acoustic signal generated by the discharge.

Contents of the invention

The purpose of the present invention is to overcome the difficulties brought by the randomness and uncontrollability of corona discharge to the research on the generation mechanism of audible noise in the prior art, and propose a pulse discharge circuit. The pulse discharge circuit can generate milliampere-level nanosecond pulse discharge with a single and repetition frequency. The discharge amplitude and repetition frequency can be flexibly controlled by the circuit parameters, which can simulate corona discharge with different parameters, and realize the control of corona discharge parameters. controlling.

The invention includes four components: a pulse power supply, a discharge electrode, a current limiting resistor and a measuring unit. The high-voltage output end of the pulse power supply is connected to the high-voltage end of the discharge electrode, the low-voltage end of the discharge electrode is connected to one end of the current-limiting resistor, and the other end of the current-limiting resistor is connected to the ground end of the pulse power supply and grounded. The measurement unit includes a voltage measurement unit and a current measurement unit. The voltage measurement unit uses a high-voltage probe to measure on the high-voltage electrode side. The high-voltage probe is connected to the high-voltage side of the discharge electrode. The current-limiting resistor and the grounded insulated wire pass through the central hole of the Rogowski coil.

The pulse power supply is a nanosecond pulse power supply with continuously adjustable output pulse amplitude and repetition frequency. The high-voltage output end of the pulse power supply adopts cable output. The discharge electrodes include high-voltage electrodes, low-voltage electrodes, metal rods, insulating brackets and fixing screws. High-voltage electrodes and low-voltage electrodes and metal rods are made of copper or stainless steel, and insulating brackets are made of insulating materials. The high-voltage electrode and the low-voltage electrode have internal thread, which are connected with one end of the metal rod with external thread through the internal thread, and the other end of the metal rod has an internal screw hole, which can be connected with other devices; the two metal rods are fixed on the On both sides, the electrode spacing is adjusted through the first metal rod connected to the high-voltage electrode, and the first metal rod with the adjusted electrode spacing is fixed on the insulating support through fixing screws. The high-voltage electrode and the low-voltage electrode are pointed electrodes or plate electrodes, wherein the high-voltage electrode is in the form of a pointed electrode, and the low-voltage electrode is in the form of a plate electrode, or both the high-voltage electrode and the low-voltage electrode are in the form of a pointed electrode. The current-limiting resistor is a high-frequency, high-voltage non-inductive resistor, and its resistance is on the order of megohm; both ends of the current-limiting resistor have internal screw holes, which can be connected with other devices. The high-voltage output terminal of the pulse power supply is connected to the high-voltage electrode, the low-voltage electrode is connected to one end of the current-limiting resistor, and the other end of the current-limiting resistor is connected to the ground terminal of the pulse power supply and grounded. The high-voltage electrode and the low-voltage electrode are arranged oppositely. The axis is a horizontal line. The measurement unit includes a voltage measurement unit and a current measurement unit; the voltage measurement unit uses a high-voltage probe to measure on the high-voltage electrode side, and the current measurement unit measures the current between the current-limiting resistor and the ground wire through a Rogowski coil. The connecting wires in the pulse circuit are all high-voltage wires with insulating sheaths, and the connecting wires should be as short as possible.

Control the high-voltage pulse output by the pulse power supply to break down the discharge gap, and control the breakdown current of the loop through the current-limiting resistor to obtain a milliampere-level nanosecond pulse discharge current; the repetition frequency of the discharge pulse is controlled by the pulse power supply. Using a microphone to measure the domain waveform of the audible noise generated by gap breakdown, the correlation characteristics of different discharge parameters and their generated acoustic signals can be studied.

The positive effect of the invention is that the pulse discharge circuit can be used to flexibly change and control the discharge pulse parameters of the circuit, simulate corona discharge with different parameters, and lay a theoretical and experimental foundation for the mechanism research of corona discharge to produce audible noise.

Description of drawings

Fig. 1 is a kind of pulse discharge circuit schematic diagram of the present invention;

Fig. 2 is a schematic diagram of the structure of the discharge electrode in the pulse discharge circuit.

In the figure: 1 pulse power supply, 2 high voltage electrode, 3 low voltage electrode, 4 current limiting resistor, 5 voltage measurement unit, 6 current measurement unit, 7 metal rod connected with high voltage electrode, 8 metal rod connected with low voltage electrode, 9 insulation Bracket, 10 set screws.

Detailed ways

The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments.

As shown in FIG. 1 , the present invention includes a pulse power supply 1 , a discharge electrode, a current limiting resistor 4 , and measuring units 5 and 6 . The high-voltage output terminal of the pulse power supply 1 is connected to the high-voltage terminal 2 of the discharge electrode, the low-voltage terminal 3 of the discharge electrode is connected to one end of the current-limiting resistor 4, and the other end of the current-limiting resistor 4 is connected to the ground terminal of the pulse power supply 1 and grounded. The measuring unit 5 uses a high-voltage probe to measure the voltage on the high-voltage side of the discharge electrode, and the current measuring unit 7 measures the current between the current-limiting resistor and the grounding wire through a Rogowski coil. The pulse power supply 1 is a nanosecond pulse power supply with continuously adjustable output pulse amplitude and repetition frequency, and the high voltage output end of the pulse power supply adopts a cable output.

The composition structure of the discharge electrode is shown in Fig. 2 . The discharge electrodes include high-voltage electrodes 2, low-voltage electrodes 3, metal rods 7 and 8, insulating supports 9, and fixing screws 10. The discharge electrode and metal rod are made of copper or stainless steel, and the insulating support 9 is made of insulating material. The metal rods 7, 8 are respectively fixed on both sides of the insulating support 9. One end car of metal rod 7,8 has external thread, can be connected with the discharge electrode that has inner hole thread, and the other end of metal rod 7,8 has internal screw hole, can be connected with other devices. The first metal rod 7 connected to the high voltage electrode 2 can move inside the insulating support 9 to adjust the distance between the electrodes. After the distance between the high-voltage electrode 2 and the low-voltage electrode 3 is adjusted in place, the first metal rod 7 is fixed by the fixing screw 10 . The external thread at one end of the second metal rod 8 is connected and fixed with the insulating support 9 with internal thread. The discharge electrode is in the form of a pointed electrode or a plate electrode, wherein the high-voltage electrode 2 is a pointed electrode, the low-voltage electrode 3 is a plate electrode, and both the high-voltage electrode 2 and the low-voltage electrode 3 can also be in the form of a pointed electrode. The high-voltage electrode 2 and the low-voltage electrode 3 are arranged radially opposite each other on the same horizontal line. The current-limiting resistor 4 is a high-frequency, high-voltage non-inductive resistor with a resistance value in the order of megohms; both ends of the current-limiting resistor have internal screw holes, which can be connected with other devices. The high-voltage output terminal of the pulse power supply is connected to the high-voltage electrode 2, the low-voltage electrode 3 is connected to one end of the current limiting resistor 4, and the other end of the current limiting resistor 4 is connected to the ground terminal of the pulse power supply 1 and grounded. The measurement system includes a voltage unit 5 and a current measurement unit 6; the voltage measurement unit 5 uses a high-voltage probe to measure voltage on the high-voltage electrode side, and the current measurement unit 6 measures the current between the current-limiting resistor and the ground wire through a Rogowski coil. The connecting wires in the pulse circuit are all high-voltage wires with insulating sheaths.

The specific implementation of the present invention to obtain milliampere-level nanosecond pulse current is taken as an example. The output voltage amplitude of the pulse power supply is 0-30kV, the rising edge of the output pulse is about 30ns, the pulse width is about 100ns, and the repetition frequency is 2kHz. The high-voltage electrode in the discharge electrode is a pointed electrode, and the low-voltage electrode is a plate electrode. The high-voltage electrode and the low-voltage electrode are respectively connected to two metal rods fixed on both sides of the insulating support. The distance between the high-voltage and low-voltage electrodes is adjusted by the metal rod connected to the high-voltage electrode. After the adjustment is in place, it is fixed by the fixing screw above the insulating support. . The current-limiting resistance is a high-frequency and high-voltage non-inductive resistance of 1MΩ, with a pulse resistance of 30kV and a frequency of 10MHz. The high-voltage output end of the pulse power supply is connected to the metal rod connected to the high-voltage electrode through a high-voltage wire, and the metal rod connected to the low-voltage electrode is connected to one end of the current-limiting resistor through a high-voltage wire, and the other end of the current-limiting resistor is connected to the pulse power supply through a high-voltage wire. The ground terminal is connected and grounded, the ground wire adopts a copper braid, and finally connects with the laboratory ground. The voltage is measured on the high-voltage electrode side with a high-voltage probe, and the current is measured between the current-limiting resistor and the ground wire through the Rogowski coil.

The working process of the present invention is as follows: the pulse power supply is controlled to output a single pulse voltage of a certain amplitude. When the electrode does not break down, the current of the pulse loop is the displacement current. When the electrode breaks down, the loop current is the breakdown current. The breakdown current minus the displacement current is the required single milliampere nanosecond pulse current. When the pulse power supply outputs pulse voltage with repetition frequency, milliampere nanosecond pulse current with repetition frequency can be obtained. The amplitude of the pulse current can be adjusted by the output voltage amplitude of the pulse power supply and the current limiting resistor. The acoustic signal generated by the discharge can be collected by a microphone, the microphone is about 5cm away from the discharge gap, and the microphone is directly measured towards the discharge point. The time-domain waveforms of voltage, current and acoustic signals are collected by an oscilloscope, and the correlation characteristics between different discharge parameters and acoustic signals can be obtained through this loop and measurement system.

The invention can obtain milliampere-level nanosecond pulse current with single and repetition frequency, and the parameters are controllable, and can be used to simulate corona discharge with different parameters.

Claims (6)

1. a pulsed discharge loop, is characterized in that, described pulsed discharge loop comprises the pulse power, sparking electrode, current-limiting resistance and measuring unit; The described pulse power is exported high-voltage pulse by cable, the high-voltage output end of the pulse power is connected with the high-pressure side of sparking electrode, the low pressure end of sparking electrode is connected with one end of current-limiting resistance, and the other end of current-limiting resistance is connected with the earth terminal of the pulse power and ground connection.

2. pulsed discharge according to claim 1 loop, is characterized in that: described sparking electrode comprises high-field electrode (2), low-field electrode (3), two Metallic rod (7,8), insulating support (9) and gib screw (10); High-field electrode (2) and low-field electrode (3) have internal thread, are connected with being with externally threaded Metallic rod (7,8), and the other end of Metallic rod (7,8) has inner bolt hole; Two Metallic rod (7,8) are individually fixed in the both sides of insulating support (9), the first Metallic rod (7) that connects high-field electrode (2) can be inner mobile at insulating support (9), spacing between high-field electrode (2) and low-field electrode (3) regulates by the first Metallic rod (7) being connected with high-field electrode (2), fixing by gib screw (10); Radially positioned opposite is in the same horizontal line for described high-field electrode (2) and low-field electrode (3).

3. pulsed discharge according to claim 2 loop, is characterized in that: described high-field electrode (2), low-field electrode (3) and Metallic rod (7,8) adopt copper or stainless steel to make ,insulating support (9) adopts insulating material to make.

4. pulsed discharge according to claim 2 loop, is characterized in that: described high-field electrode (2) and low-field electrode (3) are sharp electrode or plate electrode form.

5. pulsed discharge according to claim 1 loop, is characterized in that: described current-limiting resistance is high-frequency and high-voltage noninductive resistance, and the frequency range of this noninductive resistance is 0-30MHz, and resistance to pulse voltage is 0-50kV; Described current-limiting resistance two ends are with inner bolt hole.

6. pulsed discharge according to claim 1 loop, is characterized in that: described measuring unit comprises voltage measurement unit and current measuring unit; Voltage measurement unit adopts high-voltage probe in sparking electrode high-pressure side measuring voltage, high-voltage probe is connected with sparking electrode high-pressure side, current measuring unit is measured electric current by Luo-coil between current-limiting resistance and ground wire, connects the insulated conductor of current-limiting resistance and ground connection through the center hole of Luo-coil.

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