CN108680777A - A kind of surge voltage generating means - Google Patents

Abstract

The invention discloses an impulse voltage generating device, which includes a host computer, a body, a DC high-voltage power supply, and an impact generating circuit; the DC high-voltage power supply includes a transformer, a silicon stack, and an output terminal; the host computer is fixed inside the body It is characterized in that the DC high-voltage power supply adopts a closed structure to fix the transformer and the silicon stack inside the body, and the output terminal transmits the DC voltage to the impact generating circuit; the structure of the impact generating circuit It is a modular structure composed of several levels of modules, and the modules of each level are fixed and connected in series by supporting insulators and fixed brackets. Through the technical solution, the transmission of overvoltage in a high-voltage environment can be improved, and its safety performance can be improved.

Description

A surge voltage generator

technical field

The invention relates to the field of impulse voltage, in particular to an impulse voltage generating device.

Background technique

The following statements merely provide background information related to the present disclosure and do not necessarily constitute prior art.

The transformer for power system is a kind of power grid primary voltage/current conversion to 100/3V, A special transformer with a secondary voltage of 100V or a secondary current of 5A and 1A is used for power metering, voltage/current measurement and relay protection of the power grid. The primary winding is connected to the power grid, and the secondary winding is connected to the measuring instrument and protection respectively. The connection of devices, etc., is the primary and secondary contact unit of the power system. Since the power system is continuously subjected to various overvoltages such as lightning and operation during operation, various overvoltages will be transmitted to the secondary winding through the voltage/current transformer, causing secondary equipment failure or damage, and affecting the safety of electrical equipment run.

In order to reduce the harm of the transmission overvoltage to secondary equipment, GB/T20840.2 "Part 2 of Transformer: Current Transformer Part: Supplementary Technical Requirements for Current Transformer", GB/T20840.3 "Part 3 of Transformer: Electromagnetic Type Supplementary Technical Requirements for Pressure Transformers" and GB/T20840.5 "Part 5 of Transformers: Supplementary Technical Requirements for Capacitive Pressure Transformers" and other national standards stipulate the test method for overvoltage transmission of voltage/current transformers, which require that there will be a certain wave The shock wave of the front time, wave tail time and amplitude is applied to the voltage/current transformer, and the peak value of the overvoltage transmitted shall not exceed 1.6kV. For the voltage/current transformer used in the open substation, the standard stipulates that the applied shock wave is A Class shock wave, the peak voltage is (Um is the highest voltage of the equipment), the wave front time is 0.50×(1±20%) μs, and the half-peak time is ≥50 μs. This kind of shock wave can be realized by using a traditional voltage generator. As for the voltage/current transformer used in GIS, since it will suffer from high-frequency very fast transient overvoltage (Very Fast Transient Overvoltage, VFTO), the standard stipulates that the applied shock wave is a type B shock wave, and the voltage peak value is The wave front time is 10×(1±20%) ns, and the wave tail time is >100 ns. The reference waveform of the transmitted overvoltage is shown in Figure 1. It is difficult to produce such a short wave front time by increasing the inductance of the test circuit of the traditional impulse voltage generator. The impact of the impact makes it difficult to realize the transfer overvoltage test of the voltage transformer used in GIS under high voltage at this stage.

Contents of the invention

In order to overcome the deficiencies of the prior art, the technical purpose achieved by the present invention is to provide an impulse voltage generating device capable of improving the safety performance of overvoltage transmission in a high voltage environment.

In order to achieve the above-mentioned technical purpose, the content of the technical solution adopted in the present invention is specifically as follows:

An impulse voltage generating device, which includes a host computer, a body, a DC high-voltage power supply, and an impact generating circuit; the DC high-voltage power supply includes a transformer, a silicon stack, and an output terminal; the host computer is fixed inside the body; it is characterized in that , the DC high-voltage power supply adopts a closed structure to fix the transformer and silicon stack inside the body, and the output terminal transmits DC voltage to the impact generating circuit;

The structure of the impact generating circuit is a modular structure composed of modules of several levels, and the modules of each level are fixed and connected in series through supporting insulators and fixed brackets;

The modules at each level include:

High voltage pulse capacitor;

protection resistors or inductors; and,

Charging resistance or inductance;

One end of the high-voltage pulse capacitor is connected to the protective resistor or inductance through a metal flange; the other end of the high-voltage pulse capacitor is connected to the charging resistor or inductance through a metal flange.

In order to realize the transmission of overvoltage in a high-voltage environment, in this technical solution, the inventor proposed the above-mentioned structure. More specifically, due to the structure of this solution, the protection resistor or inductance and the high-voltage pulse capacitor in the impulse voltage generating device generate The isolation function can suppress the overvoltage and realize the transmission of the overvoltage, thereby reducing the harm of the transmission overvoltage to the secondary equipment and improving the safety of the equipment.

It should be noted that the closed structure corresponds to the open structure, which means that the entire device adopts a metal tank-type closed structure filled with insulating gas. Under this structure, the internal components of the device can withstand repeated switching between vacuum and positive pressure without damage.

Furthermore, the reason why the shock generation circuit adopts a modular structure is that the structure of the charging and discharging circuit is symmetrical, which can achieve the technical effect of reducing the influence of parasitic parameters of the device. The modular structure is through the reasonable layout design of the pulse capacitor and the ignition switch, so that the switch and the capacitor form a whole, and then the modules of each level are fixed and connected in series through supporting insulators and fixed brackets. The structure of the module is very compact, and the connection line between the capacitor and the switch is very short, which can effectively reduce the discharge loop inductance and stray parameters, and the distance between each stage is also very small, in some embodiments, about 20-30cm.

Preferably, the body is in a pot structure.

More preferably, the interior of the body is filled with sulfur hexafluoride gas.

It should be noted that the main body is set in a tank structure. Compared with other structures, the tank structure is filled with SF6 gas, and its internal components are fixed by supporting insulators, insulating plates and steel structures, so it has a small size, The connection is short, the movement is more convenient, and the technical performance is relatively high. It can effectively carry out the technical effects of shockproof, windproof, dustproof, rainproof and anti-aging, easy to clean, overall structure, compact and beautiful.

It should be noted that the function of filling the body with sulfur hexafluoride gas is to enhance the insulation performance of the device. SF6 is the heat dissipation medium, and its dielectric strength is 8.9kV/mm. The impulse voltage generator using SF6 gas insulation is the most ideal solution at present. As an excellent insulator, SF6 has excellent electrical properties. It can effectively reduce the insulation distance and volume required for the device when used in the impulse voltage generating device. Noise test requirements.

More preferably, it also includes a host computer, and the host computer, DC high-voltage power supply and impact generating circuit are fixed inside the body through support insulators, insulating plates and steel structures.

It should be noted that the function of fixing the above components inside the main body through supporting insulators, insulating plates and steel structures is to effectively prevent shock, wind, dust, rain and aging, and improve the service life of the equipment.

Preferably, the output end transmits the DC voltage to the impulse generating circuit through a pot insulator.

It should be noted that the function of the pot insulator is to make the charging and discharging circuit structure symmetrical and reduce the influence of parasitic parameters of the device. In order to meet the miniaturization design requirements, it has the function of reducing the volume of the device. The modular structure is through the reasonable layout design of the pulse capacitor and the ignition switch, so that the switch and the capacitor form a whole, and then the modules of each level are fixed and connected in series through supporting insulators and fixed brackets. The structure of the module is very compact, and the connection line between the capacitor and the switch is very short, which can effectively reduce the discharge loop inductance and stray parameters, and the distance between each stage is also very small, in some embodiments, about 20-30cm.

More preferably, the modules at each level also include:

Shock resistance;

The wave-modulating resistor includes a wave front resistor and a discharge resistor. When the impulse voltage is generated and the device operates but the sample is not discharged, all the energy of the device is consumed in the discharge resistor; and when the sample is discharged, all the energy of the device is consumed In discharge resistance and wave front resistance.

It should be noted that, in some embodiments, the sample is a capacitor. When the impulse voltage generating device operates and the test product is not discharged, the capacitor is in a charged state, and the test product is discharged and the capacitor is fully charged and then discharged.

It should be noted that under different circumstances, the energy on different components can avoid flashover along the surface, and by reasonably selecting the length and diameter of the resistance wire without considering heat dissipation, a pulsating impulse voltage source can be realized and the low voltage can be converted into The technical effect of pulsed high voltage.

Further, each level of module also includes a spark ball gap switch, and the spark ball gap switch adopts a multi-pole ignition device structure.

It should be noted that the spark ball gap switch adopts a multi-pole ignition device structure, and the multi-pole ignition device structure adopts a forced trigger mode, which does not need to adjust the ball gap distance, is easy to operate, and improves the synchronization range of triggering.

Furthermore, the spark ball gap switch is two hollow balls; the material of the hollow balls is copper or aluminum.

It should be noted that the spark ball gap switch adopts a hollow ball structure, and its function is to realize equipotential uniform discharge and maintain simultaneity. In addition, considering the material economy and universality (easy to obtain) and its electrical conductivity, mechanical strength, weather resistance, and price factors, it is usually a hollow sphere of copper or aluminum.

In some embodiments, the diameter of a single hollow ball is not less than twice the distance between two hollow balls when charging at full voltage, and the hollow balls of the spark ball gap switch in each stage of the module are separated by are all on the same vertical line.

It should be noted that the diameter of a single hollow ball is not less than twice the distance between the two hollow balls when charging at full voltage, which can avoid corona, reduce the dispersion of spark gap discharge voltage, and improve synchronization performance. . Ball diameter usually depends on the maximum voltage value during charging. The diameter of the ball should not be less than 1 to 2 times the distance between the two balls when charging at full voltage.

It should be noted that the hollow ball gaps of the spark ball gap switches in each level of modules are on the same vertical line, so that the two hollow ball gaps (midpoints) in all the spark ball gap switches of each level, the front The ultraviolet rays generated during the discharge of the first-stage ball gap can irradiate the second-stage ball gap to promote its discharge, thereby improving the synchronization performance.

Furthermore, the triggering mode of the spark ball gap switch is realized by a low-inductance three-electrode field distortion gas switch filled with nitrogen, and the gas switch is completely isolated from the external gas.

It should be noted that with this structure, the derivatives generated by the ignition discharge can be avoided from affecting the insulation performance of the sulfur hexafluoride gas, thereby completely isolating the interior of the ignition voltage and spacing of the spark ball gap switch and the fluctuation of the impulse voltage generation device can be avoided. discharge phenomenon.

Compared with prior art, the beneficial effect of the present invention is:

1. The impulse voltage generating device of the present invention, the protective resistance or inductance in the device structure and the isolation effect of the high-voltage pulse capacitor can suppress the overvoltage, realize the transmission of the overvoltage, thereby reducing the harm of the transmission overvoltage to the secondary equipment , which improves the safety of the equipment; compared with the traditional impulse voltage generator test circuit, under the condition of a large inductance test circuit, it can still generate a Class B shock wave with a wave front time of 10ns and a wave tail time > 100ns, which can meet the requirements of 1000kV and The following high voltage level GIS uses a voltage/current transformer to transmit overvoltage test;

2. In the impulse voltage generating device of the present invention, the entire device adopts a metal tank-type closed structure, and the inside is filled with insulating gas; under this structure, the internal components of the device can withstand repeated vacuum and positive pressure without damage; no outlet sleeve is provided Tank-type structure, no outlet bushing and transition barrel, directly connected to the voltage/current transformer for GIS, the test circuit is shielded by a metal flange, which further shortens the circuit and reduces the influence of stray parameters;

3. In the impulse voltage generating device of the present invention, the reason why the impulse generating circuit adopts a modular structure is to make the structure of the charging and discharging circuit symmetrical, which can achieve the technical effect of reducing the influence of the parasitic parameters of the device;

4. In the impulse voltage generating device of the present invention, the body is configured as a tank structure. Compared with other structures, the tank structure is filled with SF6 gas, and its internal components are fixed by supporting insulators, insulating plates and steel structures , has the advantages of small size, short connection, convenient movement, and relatively high technical performance. It can effectively perform technical effects such as shockproof, windproof, dustproof, rainproof and anti-aging, easy to clean, overall structure, compact and beautiful;

5. The impulse voltage generating device of the present invention is filled with sulfur hexafluoride gas in the body, and SF6, as an excellent insulator, has excellent electrical properties, and can effectively reduce the insulation distance and At the same time, SF6 gas has the characteristics of flame retardant and explosion-proof, which can meet the test requirements of small size, light weight, safety and no noise;

6. In the impulse voltage generating device of the present invention, the output end transmits the DC voltage to the impact generating circuit through the basin-type insulator, and the function of the basin-type insulator is to make the structure of the charging and discharging circuit symmetrical and reduce the influence of the parasitic parameters of the device;

7. In the impulse voltage generating device of the present invention, the spark ball gap switch adopts a multi-pole ignition device structure, and the multi-pole ignition device structure adopts a forced trigger mode, which does not need to adjust the ball gap distance, is simple to operate, and improves the synchronization range of triggering;

8. In the impulse voltage generating device of the present invention, the hollow ball gaps of the spark ball gap switches in each level of modules are all on the same vertical line, so that the two hollow ball gaps ( Midpoint), the ultraviolet rays generated during the discharge of the previous stage of the ball gap can irradiate the latter stage of the ball gap to promote its discharge, thereby improving the synchronization performance.

The above description is only an overview of the technical solution of the present invention. In order to better understand the technical means of the present invention, it can be implemented according to the contents of the description, and in order to make the above and other purposes, features and advantages of the present invention more obvious and understandable , the following preferred embodiments are specifically cited below, and are described in detail as follows in conjunction with the accompanying drawings.

Description of drawings

Fig. 1 is a schematic diagram of the circuit principle of a preferred embodiment of the impulse voltage generating device of the present invention;

Fig. 2 is a schematic cross-sectional view of a structural design of a preferred embodiment of the impulse voltage generating device of the present invention;

Fig. 3 is a test waveform diagram of transmission overvoltage measurement in a preferred embodiment of the impulse voltage generating device of the present invention;

The reference signs are as follows:

1. Resistance; 2. Pulse capacitor; 3. Support insulator.

Detailed ways

In order to further elaborate the technical means and effects that the present invention adopts for reaching the intended invention purpose, below in conjunction with the accompanying drawings and preferred embodiments, the specific implementation, structure, features and effects of the present invention are described in detail as follows:

Example 1

An impulse voltage generating device, which includes a body, a DC high-voltage power supply, and an impact generating circuit; the DC high-voltage power supply includes a transformer, a silicon stack, and an output terminal; the DC high-voltage power supply adopts a closed structure to fix the transformer and the silicon stack Inside the body, the output terminal transmits a DC voltage to the impact generating circuit;

The structure of the impact generating circuit is a modular structure composed of modules of several levels, and the modules of each level are fixed and connected in series through supporting insulators and fixed brackets;

The modules at each level include:

High voltage pulse capacitor;

protection resistors or inductors; and,

Charging resistance or inductance;

One end of the high-voltage pulse capacitor is connected to the protective resistor or inductance through a metal flange; the other end of the high-voltage pulse capacitor is connected to the charging resistor or inductance through a metal flange.

In order to realize the transfer of overvoltage under high voltage environment, in this technical solution, due to the structure of this solution, the protection resistance or inductance in the impulse voltage generating device and the isolation effect of high-voltage pulse capacitor can suppress overvoltage and realize the overvoltage. The transmission of voltage, thereby reducing the harm of the transmission overvoltage to the secondary equipment, and improving the safety of the equipment. The closed structure corresponds to the open structure, which means that the whole device adopts a metal tank-type closed structure filled with insulating gas. Under this structure, the internal components of the device can withstand repeated switching between vacuum and positive pressure without damage.

The reason why the shock generation circuit adopts a modular structure is that the structure of the charging and discharging circuit is symmetrical, which can achieve the technical effect of reducing the influence of parasitic parameters of the device. The modular structure is through the reasonable layout design of the pulse capacitor and the ignition switch, so that the switch and the capacitor form a whole, and then the modules of each level are fixed and connected in series through supporting insulators and fixed brackets. The structure of the module is very compact, and the connection line between the capacitor and the switch is very short, which can effectively reduce the discharge loop inductance and stray parameters, and the distance between each stage is also very small, in some embodiments, about 20-30cm.

Example 2

This embodiment provides a specific implementation of the solution of the present invention, wherein the example of connection structure and number is a preferred example, and does not mean to be limited to this example.

As shown in Figure 1, it is a schematic diagram of the circuit principle of a preferred embodiment of the impulse voltage generating device of the present invention; it specifically includes a DC high-voltage power supply (10kV power supply) and an impulse generation circuit (protective resistance or inductance, charging resistance or inductance, high-voltage pulse capacitance, spark ball gap switch, etc.).

As shown in Figure 2 is a schematic cross-sectional view of the structure design of a preferred embodiment of the impulse voltage generating device of the present invention; specifically, it is a single-stage module in the structure of the impulse generating circuit body, including a resistor 1, a pulse capacitor 2, and a supporting insulator 3.

The device includes a host computer, a charging power supply, an impact generating circuit, a sealed tank, and a metal flange; the charging power supply adopts a DC high-voltage power supply composed of a transformer, a voltage regulating device, a silicon stack, and a first protection resistor or inductance; the DC high-voltage The first protection resistor or inductance of the power supply can protect the impact generating circuit and transformer, prevent voltage overcurrent phenomenon, and have the function of voltage equalization at the same time. The shock generating circuit is composed of a high-voltage pulse capacitor, a spark ball gap switch, a charging resistor or inductance, a second protection resistor or inductance, and a modulation resistor. The main body structure of the impact generating circuit adopts a modular structure, and each level of modules is fixed and connected in series through supporting insulators and fixed brackets. Each level of modules includes a pulse capacitor, a spark ball gap switch, and a second protection resistor or inductance, a charging resistor or inductance, a trigger pulse introduction interface and an inflated joint; the spark ball gap switch adopts a multi-pole ignition device structure, and its spark ball gap switch adopts a multi-pole ignition device structure; the high-voltage pulse The capacitor adopts an insulating shell pulse capacitor insulated by oil paper, and each end is connected to a resistor or inductor through a metal flange as a pole; the wave modulation resistor includes a wave front resistor and a discharge resistor, and its allowable temperature rise is 150°C: when the impulse voltage occurs, the device operates But when the sample is not discharging, all the energy of the device is consumed in the discharge resistor, and when the sample is discharged, all the energy of the device is consumed in the discharge resistor and wave front resistance.

The basic principle of this device is to charge high-voltage pulse capacitors in parallel and then discharge them in series to obtain high-voltage output. It has the characteristics of small size, strong controllability, low internal sense, and fast discharge. After the original element compresses the energy, a high-voltage pulse is obtained on the load. The specific test method is as follows:

Step 1: First, set the voltage and current amplitude required for the charging power supply and trigger the spark ball gap switch through the host computer, as well as the rising time and holding time of the charging voltage. The voltage is boosted and rectified to DC high voltage, and the charging power supply works in a constant voltage output state;

Step 2: After clicking the start button of the upper computer, the charging power supply will charge the high-voltage pulse capacitor through the protection resistor or inductance and the charging resistor or inductance. When the current value of each resistor in the impact circuit is zero, the charging process is completed. The potential difference on each spark ball gap switch is the voltage value U of the charging power supply. At this time, the voltage enters the holding state until the voltage holding time expires and the power supply automatically stops. Before the test, adjust the distance between the spark ball gap switches to slightly greater than U so that the switch does not discharge. When the action is required, click the trigger button of the host computer to send a pulse voltage to the needle of the spark ball gap switch. A small spark is generated and then causes the discharge of the spark ball gap switch;

Step 3: The impact generation circuit controls the charging current through the protection resistor or inductance at the beginning of charging, and plays an isolation role through the charging resistor or inductance after the spark ball gap switch is turned on, so that the high-voltage pulse capacitor forms a series topology to improve the output of the generator voltage and carry out the discharge process.

Step 4: When the voltage at both ends of the first-stage spark ball-gap switch exceeds the self-breakdown voltage of the air gap during the discharge process of the impact generation circuit or when a trigger voltage U is given to the first-stage spark ball-gap switch through the trigger button of the host computer, the first-stage spark ball-gap switch The first-stage spark ball gap switch is turned on; when the voltage across the second-stage spark ball-gap switch reaches 2U, the second-stage spark ball-gap switch undergoes self-breakdown conduction; when the third-stage spark ball-gap switch reaches 3U At this time, the third-stage spark ball gap switch has self-breakdown conduction.

As shown in Figure 3, the test waveform diagram of the overvoltage measurement of the generator is given. Due to the increase of the inductance of the test circuit of the traditional impulse voltage generator, it is difficult to generate a shock wave with such a short front time, which leads to the current GIS application. The transfer overvoltage test of voltage transformer is difficult to realize under high voltage. It can be seen from the figure that when the parameters of the impulse voltage generating device of the present invention are fixed, the size of the load resistance affects the waveform and the amplitude of the pulse voltage. The smaller the load resistance, the smaller the amplitude of the pulse voltage, and the faster the waveform drop time. When the load capacitance value is smaller, the amplitude of the pulse voltage is higher, and the discharge drop time is shorter, which shows the feasibility of the device.

The above-mentioned embodiment is only a preferred embodiment of the present invention, and cannot be used to limit the protection scope of the present invention. Any insubstantial changes and substitutions made by those skilled in the art on the basis of the present invention belong to the scope of the present invention. Scope of protection claimed.

Claims (10)

1. An impulse voltage generating device, which includes a host computer, a body, a DC high-voltage power supply, and an impact generation circuit; the DC high-voltage power supply includes a transformer, a silicon stack and an output terminal; the host computer is fixed inside the body; its The feature is that the DC high-voltage power supply adopts a closed structure to fix the transformer and the silicon stack inside the body, and the output terminal transmits the DC voltage to the impact generating circuit; The structure of the impact generating circuit is a modular structure composed of modules of several levels, and the modules of each level are fixed and connected in series through supporting insulators and fixed brackets; The modules at each level include: High voltage pulse capacitor; protection resistors or inductors; and, Charging resistance or inductance; One end of the high-voltage pulse capacitor is connected to the protective resistor or inductance through a metal flange; the other end of the high-voltage pulse capacitor is connected to the charging resistor or inductance through a metal flange. 2. The impulse voltage generating device according to claim 1, characterized in that, the body is in the form of a pot. 3. The impulse voltage generating device according to claim 2, wherein the inside of the main body is filled with sulfur hexafluoride gas. 4. The impulse voltage generating device according to claim 2, characterized in that it also includes a host computer, and the host computer, DC high-voltage power supply and impulse generating circuit are fixed on the Inside the body. 5 . The impulse voltage generating device according to claim 1 , wherein the output terminal transmits the DC voltage to the impulse generating circuit through a pot insulator. 5 . 6. The surge voltage generating device according to claim 1, characterized in that, the modules of each stage further comprise: Shock resistance; The wave-modulating resistor includes a wave front resistor and a discharge resistor. When the impulse voltage is generated and the device operates but the sample is not discharged, all the energy of the device is consumed in the discharge resistor; and when the sample is discharged, all the energy of the device is consumed In discharge resistance and wave front resistance. 7 . The impulse voltage generating device according to claim 6 , wherein each stage of the module further includes a spark ball gap switch, and the spark ball gap switch adopts a multi-pole ignition device structure. 8 . 8. The impulse voltage generating device according to claim 7, wherein the spark ball gap switch is two hollow balls; the hollow balls are made of copper or aluminum. 9. The impulse voltage generating device according to claim 8, wherein the diameter of a single hollow sphere is not less than twice the distance between two hollow spheres when charging at full voltage, and each of the hollow spheres The hollow ball separation parts of the spark ball gap switch in the stage module are all on the same vertical line. 10. The impulse voltage generating device according to claim 7, characterized in that, the triggering mode of the spark ball gap switch is realized by a low-inductance three-electrode field distortion gas switch filled with nitrogen, and the gas switch is in contact with the external gas Complete isolation.