DE112022000188T5 - A single power supply, multiple electrode arc ignition device and ignition method - Google Patents

Abstract

The invention discloses a single power supply multiple electrode arc ignition device and an ignition method, wherein the ignition device includes a DC voltage source, an air switch, an LC resonant circuit, a high voltage pack and a multiple electrode ignition group. The multiple electrode ignition group includes 2n arc ignition branches connected in parallel, which are connected between the connection point of the positive electrode and the connection point of the negative electrode. Each arc ignition branch contains a capacitor bank and a horn electrode, with the positive pole of the horn electrode connected to the positive electrode connection point of the multiple electrode ignition group, and the negative pole of the horn electrode first connected in series with the capacitor bank and then to the negative electrode connection point of the multiple electrode ignition group is connected. The ignition device and method proposed by the invention realize the simultaneous generation of arcs by multiple electrodes using a single power supply. The arc generated by this is not periodically extinguished and remains stable, which can fully meet the experimental requirements. The power of each electrode is the same, and the power of the igniter is increased by the extension electrodes, effectively solving the problem of lack of multiple electrode ignition group required by the arc ignition method in the cable burning test.

Description

Technical area

The invention relates to the technical field of AC arc testing devices and, more particularly, to a single power supply, multiple electrode arc ignition device and an ignition method.

background

In the development process of the electricity industry, cables play a crucial role in every link of energy production, transmission, conversion, distribution and consumption, and are one of the important infrastructures for social production and people's lives. However, while the cable exerts its normal operating benefits, problems such as overload, short circuit and leakage may occur due to line faults, and even fires may occur. In recent years, large-scale power outages caused by cable fires have occurred frequently, causing serious adverse social impacts. According to statistics from the Chinese Fire Department, electrical fires accounted for about 30% of all fires in China in recent years. When the direct causes of electrical fires were distributed among major fires, major fires and especially large fires from 2006 to 2015, the proportion of fires caused by power line failures was as high as 72%. More than 2/3 of general urban fires are caused by the burning of wires and cables, and cable fires caused by arc flashes account for a significant proportion of all cable fires.

Cable fire simulation is the basis for predicting the risk of cable fires, and it is also the most direct and effective means of evaluating cable fire characteristics, which can prevent cable fires more effectively. The traditional method of simulating the fire source of cable burning is mainly external open flame ignition, including the gas burner method, radiant heating method, electric heating method and fuel oil ignition method. However, these external open flame ignitions are significantly different from arc ignition. Therefore, fire simulations or cable fire tests based on these methods are difficult to meet the requirements of in-depth quantitative analysis of the fire behavior of cable arc faults.

In the prior art, compared with the external open flame ignition method, the arc fire source generated by the arc ignition method can more realistically simulate a cable fire caused by an arc generated by a cable fault. The arc temperature is very high and the holding temperature of the middle part can reach over 5000°C. In addition, the arc power can be precisely controlled by the power supply and can be used at any time as long as there is a power supply, achieving good sustainability. The arc generating device only requires metal electrodes and is therefore easy to move.

At the same time, no other chemical impurities are introduced during the combustion process, which is convenient for quantitative testing and analysis of combustion properties, the results of which have important guiding significance for understanding the fire behavior of cables in the event of arc flashes.

Similar to the mechanism of generating the fault arcs, the arc generation principle in the arc ignition method is to apply a high voltage between two metal electrodes, and the air closest to the two electrodes is first decomposed to form a large number of positive and negative plasmas, which leads to an arc discharge. Driven by arc air convection and electromagnetic field force, the arc rises upwards. As the arc is lengthened, the resistance that the arc passes through increases and the heat dissipation to the air also increases. When the energy delivered by the current to the arc is equal to the heat delivered by the arc to the environment, the arc reaches a steady state.

However, under normal circumstances, the arc is relatively small, with a diameter of the order of millimeters, resulting in a very concentrated fire source and a small area, causing the heat to be quickly released to the cable and the environment, making it difficult does to ignite the cable. To solve the above problems, multiple arc generating devices can be used, or a multi-electrode arc generator can be constructed to generate an arc with a larger area.

" (Chen HR, Liu ZD, Huang SJ, Pan HJ, Qiu MB (2015) Study of the mechanism of multi-channel discharge in semiconductor processing by WEDM. Mater Sci Semicond Process 32:125-130), Das schematische Diagramm des experimentellen Aufbaus für diese Studie ist in 1 dargestellt. Die Figur umfasst die Impulsstromversorgung V, den Spaltkondensator C_j2, den Isolationskondensator C_j1, den Rückkopplungskondensator C_f und den Kompensationskondensator C₀, wobei j = 1,2, ... , m. Unter diesen wird die Spaltkapazität C_j2 als Ersatzschaltbildelement des Spalts zwischen der Schneidwerkzeugelektrode und dem Werkstück verwendet, wobei angenommen wird, dass die Spaltkapazitäten gleich sind. Der Isolationskondensator C_j1 wird verwendet, um die gegenseitige Beeinflussung zwischen parallelen Entladeschaltungen zu eliminieren und wird auf den gleichen Wert eingestellt. Der Rückkopplungskondensator C_f kann verwendet werden, um die Entladeenergie der parallelen Entladeschaltung gleichmäßig zu variieren, so dass alle Spaltkondensatoren mit der gleichen kapazitiven Ladung geladen werden können. Wenn die Entladeschleife eine Entladung erzeugt, kann der Kompensationskondensator C₀ den Isolationskondensator aufladen, wodurch die Ausgleichswiederherstellungszeit der Entladeschleife verkürzt wird. Außerdem kann der Kompensationskondensator C₀ auch den Entladestrom erhöhen und die Entfernungsrate des Funkens verbessern. Verglichen mit dem Rückkopplungskondensator und dem Isolationskondensator ist die Spaltkapazität sehr klein, sodass beim Entladen eines Spalts die Spannung zwischen anderen Spalten immer noch auf einem hohen Wert gehalten werden kann, wodurch mehrere parallele Entladungsschaltungen gebildet werden und die Verlängerung der Entladungszeiten eines einzelnen Impulsgenerators in jedem Entladungszyklus realisiert wird. Auf dem Gebiet der Multi-Arc-Entladungsforschung gibt es ein chinesisches Erfindungspatent (200510090547.6) „

" („Multi-Arc-Schweißsystem“), wie in 2 gezeigt. Das System umfasst einen positiven Stromversorgungsausgang 32 , einen negativen Stromversorgungsausgang 34 , einen Mittelabgriff 82 , einen Magnetkern 120 , einen ersten Anschluss 32a , einen zweiten Anschluss 32b , einen ersten Spulenabschnitt 112 , einen zweiten Spulenabschnitt 110, einen ersten Lichtbogen A1, einen zweiten Lichtbogen A2, eine erste Elektrode 10 , eine zweite Elektrode 12 , einen ersten Induktor 402 , einen zweiten Induktor 410 , eine erste Freilaufdiode 404 und eine zweite Freilaufdiode 412. Das positive Ausgangsende einer einzelnen Stromversorgung ist mit der Drosselspule 100 verbunden, und der Mittelabgriff 82 der Drosselspule 100 ist in zwei Anschlüsse geteilt, um zwei Zweige zu bilden, wobei jeder Zweig mit einer Elektrode und einem Induktor in Reihe geschaltet ist, und dann parallel zu einer Freilaufdiode geschaltet. Basierend auf diesem Verfahren bleibt der Lichtbogen auf dem anderen Zweig für eine gewisse Zeit bestehen, wenn eine Elektrode und das Werkstück zerstört werden, und die Haltezeit wird durch den Induktivitätswert des Induktors bestimmt.The existing research on multi-electrode ignition devices worldwide mainly focuses on EDM. “

" (Chen HR, Liu ZD, Huang SJ, Pan HJ, Qiu MB (2015) Study of the mechanism of multi-channel discharge in semiconductor processing by WEDM. Mater Sci Semicond Process 32:125-130), The schematic diagram of the experimental The structure for this study is in 1 shown. The figure includes the pulse power supply V, the gap capacitor C _j2 , the isolation capacitor C _j1 , the feedback capacitor C _f and the compensation capacitor C ₀ , where j = 1.2, ..., m. Among them, the gap capacitance C _j2 is used as an equivalent circuit element of the Gap between the cutting tool electrode and the workpiece is used, assuming that the gap capacities are equal. The isolation capacitor C _j1 is used to eliminate the mutual interference between parallel discharge circuits and is set to the same value. The feedback capacitor C _f can be used to uniformly vary the discharge energy of the parallel discharge circuit so that all gap capacitors can be charged with the same capacitive charge. When the discharge loop generates a discharge, the compensation capacitor C ₀ can charge the isolation capacitor, thereby shortening the discharge loop balance recovery time. In addition, the compensation capacitor C ₀ can also increase the discharge current and improve the spark removal rate. Compared with the feedback capacitor and the isolation capacitor, the gap capacitance is very small, so when discharging one gap, the voltage between other gaps can still be kept at a high value, thereby forming multiple parallel discharge circuits and extending the discharge times of a single pulse generator in each discharge cycle is realized. In the field of multi-arc discharge research, there is a Chinese invention patent (200510090547.6) "

" (“Multi-Arc Welding System”), as in 2 shown. The system includes a positive power supply output 32, a negative power supply output 34, a center tap 82, a magnetic core 120, a first terminal 32a, a second terminal 32b, a first coil section 112, a second coil section 110, a first arc A1, a second arc A2 , a first electrode 10, a second electrode 12, a first inductor 402, a second inductor 410, a first freewheeling diode 404 and a second freewheeling diode 412. The positive output end of a single power supply is connected to the reactor 100, and the center tap 82 of the reactor 100 is divided into two terminals to form two branches, each branch connected in series with an electrode and an inductor, and then connected in parallel with a freewheeling diode. Based on this method, when one electrode and the workpiece are destroyed, the arc remains on the other branch for a certain time, and the holding time is determined by the inductance value of the inductor.

Both the above-mentioned documents and the Chinese invention patent (200510090547.6) can realize multi-electrode ignition under the condition that a single power supply is used. The invention uses a pulse power supply to realize spark ignition and uses a capacitor as an energy storage element. After the failure of a particular electrode, the energy of the remaining electrodes is provided by the capacitor. By changing the capacitance of the capacitor, the number of ignition electrodes can be increased and the scalability is high. However, the breakdown frequency of the electrode in this device is limited by the current pulse cycle and the capacitance of the capacitor, and the energy release time is extremely short, so it cannot continuously release heat and has poor stability, and therefore cannot be used as an ignition source for cable fire tests .

The Chinese invention patent (200510090547.6) forms two loops by connecting the center tap of the reactor coil. Inductance elements are connected in series on each branch, and the duration of the arc is extended by the inductance in order to realize multiple arc ignition. This method is affected by the structure of the center tap of the reactor and cannot further increase the number of ignition electrodes, and the scalability is poor. In addition, in this scheme, the inductance elements connected in series in the circuit increase the reactive component in the output power of the power supply and reduce the output efficiency of the power supply. Although this scheme can generate an arc, the arc is still generated and extinguished periodically and cannot burn stably, which does not meet the requirements of the cable burn test.

Summary of the invention

The object of the present invention is to provide a single power supply multi-electrode arc ignition device and an ignition method to solve the shortcomings of the prior art, which involves the simultaneous generation of arcs that are not periodically extinguished by multiple electrodes Using a single power supply is realized to meet the experimental requirements. The active power of each electrode in the device is equal and the reactive power of all electrodes is 0, which improves the power output efficiency. The increase in ignition performance is achieved by lengthening the electrodes. Therefore, the problem of lack of multi-electrode ignition devices required by the arc ignition method in the cable burning test is effectively solved.

• Eine Lichtbogenzündvorrichtung mit einer einzigen Stromversorgung und mehreren Elektroden, die eine Stromversorgung, ein Hochspannungspaket, einen Schalter, der das Hochspannungspaket und die Stromversorgung verbindet, und eine Mehrfach-Elektroden-Zündgruppe umfasst, worin der Anschlusspunkt der positiven Elektrode der Mehrfach-Elektroden-Zündgruppe elektrisch mit der Hochspannungsseite des Hochspannungspakets verbunden ist und der Anschlusspunkt der negativen Elektrode der Mehrfach-Elektroden-Zündgruppe geerdet ist.
• die Mehrfach-Elektroden-Zündgruppe umfasst 2n parallel geschaltete Lichtbogenzündungszweige, die zwischen dem Anschlusspunkt der positiven und dem Anschlusspunkt der negativen Elektrode angeschlossen sind.

The above technical purpose of the present invention is achieved through the following technical solutions:

• A single power supply multi-electrode arc ignition device comprising a power supply, a high voltage package, a switch connecting the high voltage package and the power supply, and a multi-electrode ignition group, wherein the connection point of the positive electrode of the multiple electrode ignition group is electrical is connected to the high voltage side of the high voltage pack and the connection point of the negative electrode of the multi-electrode ignition group is grounded.
• The multiple-electrode ignition group includes 2n arc ignition branches connected in parallel, which are connected between the connection point of the positive electrode and the connection point of the negative electrode.

The (2i-1)th arc ignition branch includes a capacitor bank and a horn electrode, wherein the positive pole of the horn electrode in the (2i-1)th arc ignition branch is connected to the connection point of the positive electrode of the multi-electrode ignition group and the negative pole of the horn electrode in the (2i-1)th arc ignition branch is first connected in series with the capacitor bank and then connected to the negative electrode connection point of the multi-electrode ignition group.

The 2i-th arc ignition branch includes an induction coil group and a horn electrode, wherein the positive pole of the horn electrode in the 2i-th arc ignition branch is connected to the connection point of the positive electrode of the multi-electrode ignition group, and the negative pole of the horn electrode in the (2i)-th Arc ignition branch is first connected in series with the induction coil group and then connected to the negative electrode connection point of the multi-electrode ignition group.

The capacitance group on the (2i-1)th arc ignition branch has the same impedance modulus as the induction coil group on the 2ith arc ignition branch, where i=1,2,···,n, and n is half of the total number of arc ignition branches in the multiple Electrode ignition group is.

The arc ignition branch is in an open state when the horns electrode in one of the arc ignition branches is not broken, and the voltage across the horns electrodes in this case is less than the breakdown voltage of the electrodes.

The horn electrode is broken in the branch and the arc ignition branch is in a conducting state when the voltage across the horn electrode in the (2i-1)th arc ignition branch is greater than the electrode breakdown voltage, and the voltage across the horn electrode at this time drops the electrode voltage, where the electrode voltage is equal to the voltage determined by the resistance of the electrode arc after the horn electrode is turned on. The voltage across the horn electrode in the 2i-th arc ignition branch at this time is the sum of the electrode voltage of the horn electrode in the (2i-1)-th arc ignition branch and the voltage of the capacitor bank, and the voltage of the capacitor bank in the (2i-1)-th arc ignition branch is compensated the electrode voltage of the horns electrode, so that the horns electrode in the 2i-th arc ignition branch is broken if the voltage across the horns electrode in the 2i-th arc ignition branch is greater than the breakdown voltage of the horns electrode.

The number of the capacitor bank in the multi-electrode ignition group is the same as the number of the induction coil group, which is half of the total number of arc ignition branches, n times the sum of the capacitance values of all capacitor banks is less than or equal to the first set value, and the sum the inductance values of all inductance coil groups is greater than or equal to n times the second set value.

$$P_{2i}=R_{2i}\times I_{2i}{}^2$$

worin
P_2i-1 die Wirkleistung an dem (2i-1)-ten Lichtbogenzündzweig ist,
P_2i die Wirkleistung an dem 2i-ten Lichtbogenzündzweig ist,
R_2i-1 der charakteristische Lichtbogenwiderstand auf dem (2i-1)-ten Lichtbogenzündungszweig ist,
R_2i der charakteristische Lichtbogenwiderstand auf dem 2i-ten Lichtbogenzündungszweig ist,
I_2i-1 der Eingangsstrom des (2i-1)-ten Lichtbogenzündungszweigs ist, der die folgende Beziehung erfüllt: $$I_{2i-1}=\frac{R_{2i}+j\omega L}{\left(R_{2i}+R_{2i-1}\right)+j\left(\omega L-\frac{1}{\omega C}\right)}$$

und I_2i der Eingangsstrom des 2i-ten Lichtbogenzündungszweigs ist, der die folgende Beziehung erfüllt: $$I_{2i-1}=\frac{R_{2i}+j\omega L}{\left(R_{2i}+R_{2i-1}\right)+j\left(\omega L-\frac{1}{\omega C}\right)}$$

worin L der Induktivitätswert der Induktivitätsspulengruppe und C der Kapazitätswert der Kondensatorbank ist. Die induktive Reaktanz der Induktionsspulengruppe ist unter der Bedingung gleich ω und $\frac{1}{\sqrt{LC}}$

gleich der kapazitiven Reaktanz der Kondensatorbank, und die Lichtbogenkennwiderstände sind auf jedem Lichtbogenzündzweig bei gleichem Material und gleicher Größe der Hörnerelektrode gleich, also R_2i-1 = R_2i, sodass die Eingangsstromamplituden in jedem Lichtbogenzündungszweig gleich sind und die folgende Beziehung erfüllen: $$\frac{I_s}{n}=I_{2i}+I_{2i-1}$$

worin I_S der Ausgangsstrom der Stromversorgung ist.If all arc ignition branches are in the conductive state, the active power on the (2i-1)th arc ignition branch and the active power on the 2ith arc ignition branch each satisfy the following relationship: $$P_{2i-1}=R_{2i-1}\times I_{2i-1}{}^2$$

$$P_{2i}=R_{2i}\times I_{2i}{}^2$$

wherein
P _2i-1 is the active power on the (2i-1)th arc ignition branch,
P _2i is the active power on the 2i-th arc ignition branch,
R _2i-1 is the characteristic arc resistance on the (2i-1)th arc ignition branch,
R _2i is the characteristic arc resistance on the 2i-th arc ignition branch,
I _2i-1 is the input current of the (2i-1)th arc ignition branch, which satisfies the following relationship: $$I_{2i-1}=\frac{R_{2i}+j\omega L}{\left(R_{2i}+R_{2i-1}\right)+j\left(\omega L-\frac{1}{\omega C}\right)}$$

and I _2i is the input current of the 2i-th arc ignition branch satisfying the following relationship: $$I_{2i-1}=\frac{R_{2i}+j\omega L}{\left(R_{2i}+R_{2i-1}\right)+j\left(\omega L-\frac{1}{\omega C}\right)}$$

where L is the inductance value of the inductance coil group and C is the capacitance value of the capacitor bank. The inductive reactance of the induction coil group is equal to ω and $\frac{1}{\sqrt{LC}}$

equal to the capacitive reactance of the capacitor bank, and the arc resistances are the same on each arc ignition branch with the same material and the same size of the horn electrode, i.e. R _2i-1 = R _2i , so that the input current amplitudes in each arc ignition branch are the same and satisfy the following relationship: $$\frac{I_s}{n}=I_{2i}+I_{2i-1}$$

where I _S is the output current of the power supply.

The active power is the same in each arc ignition branch, and the reactive power generated by the capacitor bank in the (2i-1)th arc ignition branch is equal to the reactive power absorbed by the induction coil group in the 2ith arc ignition branch, that is, the power of the power supply is the sum of the active power output to each arc ignition branch.

Preferably, the power supply in the device is a DC voltage source, and the output voltage and the maximum output current of the DC voltage source are adjustable, the setting range of the output voltage being 0 to 50 V and the setting range of the maximum output current being 0 to 50 A.

Preferably, the device also includes an inverter device, the output terminal of the DC voltage source is connected to the switch of the power supply and the input terminal of the inverter device through the connection high voltage package, and the output terminal of the inverter device is connected to the low voltage side of the high voltage package.

Further, the inverter device converts the DC voltage and the DC current output from the DC voltage source into a sinusoidal AC voltage and a sinusoidal AC current, the frequency of which is the frequency of the power supply itself.

Furthermore, the inverter device also includes a voltage and current feedback control unit that uses the sinusoidal AC voltage and current to adjust the DC voltage and current output from the control DC voltage source to obtain a constant sinusoidal AC current.

Furthermore, the inverter device is an LC oscillator circuit.

Preferably, the high voltage package contains a horizontal output transformer whose transformation ratio is not less than 500.

Preferably, the capacitor bank includes two series-connected high-voltage polystyrene film capacitors capable of withstanding a voltage level of 50 kV, and the capacitance of each high-voltage polystyrene film capacitor is twice the capacitance of the capacitor bank.

Preferably, the induction coil group includes five series-connected high-voltage coils with large inductance capable of withstanding a voltage level of 20 kV, and each high-voltage coil is made of amorphous ferromagnetic material in which the wires are wound with high-voltage tape for more than 5 turns. The horn electrodes are preferably rod-shaped and made of copper, stainless steel or tungsten alloy, the diameter of which ranges from 2 mm to 4 mm, and the internal distance of the bottom of the horn electrode is 0.7 cm - 1 cm and that of the top is 1.2 cm - 2cm.

• Schritte 1 Bestimmung der Anzahl der Lichtbogen-Zündungszweige in der Mehrfach-Elektroden-Zündgruppe und Regulierung der Ausgangsspannung und des Ausgangsstroms der Gleichspannungsquelle entsprechend den Daten der für das simulierte Kabelverbrennungsexperiment erforderlichen Leistung;
• Schritte 2 Invertieren der von der Gleichspannungsquelle ausgegebenen konstanten Spannung und des konstanten Stroms unter Verwendung der LC-Oszillatorschaltung zur Erzeugung von sinusförmigen Wechselspannungen und -strömen;
• Schritte 3 Hochsetzen von sinusförmiger Wechselspannung und -strom durch Verwendung eines horizontalen Ausgangstransformators;
• Schritte 4 Die Lichtbogenbildung durch Erregen der Mehrfach-Elektroden-Zündgruppe mit dem verstärkten Wechselspannungsstrom.

A method of arc ignition using a single power supply and multiple electrodes, comprising the steps of:

• Steps 1 Determine the number of arc ignition branches in the multi-electrode ignition group and regulate the output voltage and output current of the DC voltage source according to the data of the power required for the simulated cable burning experiment;
• Steps 2 Inverting the constant voltage and current output from the DC voltage source using the LC oscillator circuit to generate sinusoidal AC voltages and currents;
• Steps 3 Step up sinusoidal AC voltage and current by using a horizontal output transformer;
• Steps 4 Arc formation by energizing the multi-electrode ignition group with the increased AC current.

Preferably, in Step 1, the arrangement and size of the horn electrodes must be adjusted according to the data of the power required for the simulated cable combustion experiment.

The arrangement of the horn electrodes includes the horizontal distance between each electrode, the vertical distance between each electrode and the experimental ignition object.

The size of the horn electrodes includes the diameter of the electrode, the internal distance between the two electrodes at the bottom of the electrode, the internal distance between the two electrodes at the top of the electrode, and the vertical height between the top of the electrode and the bottom of the Electrode, where the lower end of the electrode is the initial discharge end in the arcing process, and the upper end is the final stable combustion end in the arcing process.

The advantageous effect of the present invention is that, compared to the prior art, capacitor banks on odd-numbered arc ignition branches and inductance coil groups on even-numbered arc ignition branches are connected in series, which are used to extend the arc duration to realize multiple arc ignition, and at the same time the Total reactive power on all arc ignition branches made zero by resonance, improving power delivery efficiency.

1. 1. Die Erfindung verwirklicht die gleichzeitige Zündung mehrerer Elektroden, und die Zündzeitdifferenz zwischen den Elektroden ist extrem klein. Darüber hinaus kann der gezündete Lichtbogen weiterbrennen, hat eine starke Stabilität und erfüllt die Anforderungen der Feuerwiderstandsleistungsprüfung des Testkabels.
2. 2. Die Erfindung verwirklicht die durchschnittliche Verteilung der Leistung jeder Elektrode, und die Leistung jeder Elektrode ist nach Lichtbogenbildung gleich und stabil, wodurch zuverlässige Versuchsergebnisse sichergestellt werden.
3. 3. Bei der vorliegenden Erfindung sind an zwei benachbarte Lichtbogenzündzweige jeweils Induktivitätsgruppen bzw. Kondensatorbänke in Reihe geschaltet. Durch Ändern der Impedanz der Kondensatorbank und der Induktivitätsgruppe kann die Blindleistung aufgehoben werden, wodurch die von der Stromversorgung abgegebene Blindleistung reduziert, die Effizienz der Stromversorgung effektiv verbessert und die Arbeitseffizienz der gesamten Zündvorrichtung erhöht wird.
4. 4. Die Anzahl der Lichtbogenzündungszweige in der vorliegenden Erfindung kann gemäß den experimentellen Leistungsanforderungen erhöht werden, und die Skalierbarkeit ist stark.
5. 5. Die Erfindung verwirklicht auch die Steuerbarkeit der Lichtbogenleistung, und die Lichtbogenleistung kann durch Einstellen der Ausgangsspannung der Gleichspannungsquelle gesteuert werden, die flexibel ist.

The present invention also has the following advantageous effect:

1. 1. The invention realizes the simultaneous ignition of multiple electrodes, and the ignition time difference between the electrodes is extremely small. In addition, the ignited arc can continue to burn, has strong stability, and meets the requirements of the fire resistance performance test of the test cable.
2. 2. The invention realizes the average distribution of the power of each electrode, and the power of each electrode is equal and stable after arcing, thereby ensuring reliable experimental results.
3. 3. In the present invention, inductance groups or capacitor banks are connected in series to two adjacent arc ignition branches. By changing the impedance of the capacitor bank and the inductor group, the reactive power can be canceled, thereby reducing the reactive power output from the power supply, effectively improving the efficiency of the power supply and increasing the work efficiency of the entire ignition device.
4. 4. The number of arc ignition branches in the present invention can be increased according to the experimental performance requirements, and the scalability is strong.
5. 5. The invention also realizes the controllability of the arc power, and the arc power can be controlled by adjusting the output voltage of the DC power source, which is flexible.

Short description of the drawing

• 1 is the schematic diagram of the experimental device of “multi-channel EDM method based on capacitive coupling” in background.
• 2 is the schematic diagram of the experimental device of Chinese invention patent (200510090547.6) “Multi-arc welding system” in background.
• 3 Fig. 10 is a structural illustration of the single power supply, multi-electrode arc ignition device of the present invention, wherein the reference numerals are as follows:
  • 10-power supply; 20 switches; 30-high voltage package; 40-multi-electrode ignition group; 50- positive electrode connection point; 60- negative electrode connection point.
• 4 is the schematic structural diagram of the single power supply multi-electrode arc lighting device in Embodiment 1 of the present invention.
• 5 is the schematic diagram of two-electrode ignition of the arc ignition device with a single power supply and multiple electrodes in Embodiment 1 of the present invention.
• 6 is the voltage and current waveform at the time of ignition of two electrodes of the single power supply multi-electrode arc lighting device Embodiment 1 of the present invention.
• 7 is the voltage and current waveform of two electrodes of the steady state arc ignition device with a single power supply and multiple electrodes Embodiment 1 of the present invention.
• 8th is the schematic diagram of four-electrode ignition of the arc ignition device with a single power supply and multiple electrodes in Embodiment 2 of the present invention.
• 9 is the schematic flow diagram of the single power supply, multiple electrode ignition method of the present invention.

Detailed description of the preferred embodiments

The technical means and effects of the present invention are further explained below in connection with the accompanying drawings. The following examples serve only to more clearly illustrate the technical solutions of the present invention, but not to limit the scope of the present application.

An arc ignition device with a single power supply and multiple electrodes, as in 3 shown includes power supply 10, high voltage package 30, switch 20 which connects the high voltage package 30 to the power supply 10, and multiple electrode ignition group 40 which is the core component of the arc ignition device. The positive electrode connection point 50 of the multi-electrode ignition group 40 is electrically connected to the high-voltage side of the high-voltage pack 30, and the negative electrode connection point 60 of the multi-electrode ignition group 40 is grounded.

The multiple-electrode ignition group includes 2n arc ignition branches connected in parallel, which are connected between the connection point of the positive electrode and the connection point of the negative electrode, where n is a natural number. In this preferred embodiment, the arc ignition branches are preferably 2 and 4, respectively. It is noted that the technician in this field can select the number of arc ignition branches according to experimental conditions and performance requirements, but the number of arc ignition branches must be an even number. The selection in this preferred embodiment is a non-limiting preferred selection.

The (2i-1)th arc ignition branch includes a capacitor bank and a horn electrode, wherein the positive pole of the horn electrode in the (2i-1)th arc ignition branch is connected to the connection point of the positive electrode of the multi-electrode ignition group and the negative pole of the horn electrode in the (2i-1)th arc ignition branch is first connected in series with the capacitor bank and then connected to the negative electrode connection point of the multi-electrode ignition group.

The 2i-th arc ignition branch includes an induction coil group and a horn electrode, wherein the positive pole of the horn electrode in the 2i-th arc ignition branch is connected to the connection point of the positive electrode of the multi-electrode ignition group, and the negative pole of the horn electrode in the (2i)-th Arc ignition branch is first connected in series with the induction coil group and then connected to the negative electrode connection point of the multi-electrode ignition group.

In this preferred embodiment, the arc ignition device includes at least one discharge electrode group. Each discharge electrode group includes two discharge electrodes that cooperate with each other, and each discharge electrode is electrically connected to the output end of the high-voltage generator. The power supply supplies power to the discharge electrode group under the control of the switch, and the arc is generated according to the principle of high voltage discharge and used for ignition.

The capacitance group on the (2i-1)th arc ignition branch has the same impedance modulus as the induction coil group on the 2ith arc ignition branch, where i=1,2,···,n, and n is half of the total number of arc ignition branches in the multiple Electrode ignition group is.

The arc ignition branch is in an open state when the horns electrode in one of the arc ignition branches is not broken, and the voltage across the horns electrodes in this case is less than the breakdown voltage of the electrodes.

The horn electrode is broken in the branch and the arc ignition branch is in a conducting state when the voltage across the horn electrode in the (2i-1)th arc ignition branch is greater than the electrode breakdown voltage, and the voltage across the horn electrode at this time drops the electrode voltage, where the electrode voltage is equal to the voltage determined by the resistance of the electrode arc after the horn electrode is turned on. The voltage across the horn electrode in the 2i-th arc ignition branch at this time is the sum of the electrode voltage of the horn electrode in the (2i-1)-th arc ignition branch and the voltage of the capacitor bank, and the voltage of the capacitor bank in the (2i-1)-th arc ignition branch is compensated the electrode voltage of the horns electrode, so that the horns electrode in the 2i-th arc ignition branch is broken if the voltage across the horns electrode in the 2i-th arc ignition branch is greater than the breakdown voltage of the horns electrode.

In this preferred embodiment, the electrode voltage obtained by experiments is about 10K to 20K times the branch current, and the voltage at both ends of the horn electrode drops to the electrode voltage very quickly, and the timing of the sudden drop coincides with it together the time of failure. Therefore, the device proposed by the present invention realizes the simultaneous ignition of multiple electrodes, and the ignition time difference between the electrodes is extremely small. The number of the capacitor bank in the multi-electrode ignition group is the same as the number of the induction coil group, which is half of the total number of arc ignition branches, n times the sum of the capacitance values of all capacitor banks is less than or equal to the first set value, and the sum the inductance values of all inductance coil groups is greater than or equal to n times the second set value.

um die Durchbruchspannung der nächsten Elektrode zu erreichen. Das heißt, der Reaktanzwert der reaktiven Komponente beträgt etwa 60 kΩ. Bei einer Frequenz von 20 kHz beträgt der entsprechende Kapazitätswert 80 pF, dh zwei 160 pF sind in Reihe geschaltet, und der entsprechende Induktivitätswert beträgt 0,5 mH. Es sei angemerkt, dass der erste Einstellwert in dieser bevorzugten Ausführungsform vorzugsweise 160 pF und der zweite Einstellwert vorzugsweise 0,35 mH beträgt. Dies ist eine nicht einschränkende bevorzugte Wahl, und Fachleute können bevorzugte Werte des ersten Einstellwerts und des zweiten Einstellwerts gemäß tatsächlichen Anwendungsparametern auswählen.In this preferred embodiment, the breakdown voltage of the electrode is about 25 kV peak-to-peak and the resistance at the electrode after conduction is about 15 kΩ. If the peak-to-peak value of the incoming current is 0.4 A, the electrode voltage has a peak-to-peak value of 6 kV, and the voltage required $U_{AnscHlusspunkt}=\sqrt{U_{LicHtbOGen}^2+U_{blindleistunG}^2}=20\text{kV}\text{,}$

to reach the breakdown voltage of the next electrode. That is, the reactance value of the reactive component is about 60 kΩ. At a frequency of 20 kHz, the corresponding capacitance value is 80 pF, that is, two 160 pF are connected in series, and the corresponding inductance value is 0.5 mH. It should be noted that in this preferred embodiment, the first setting value is preferably 160 pF and the second setting value is preferably 0.35 mH. This is a non-limiting preferred choice, and those skilled in the art can select preferred values of the first setting value and the second setting value according to actual application parameters.

$$P_{2i}=R_{2i}\times I_{2i}$$

worin
P_2i-1 die Wirkleistung an dem (2i-1)-ten Lichtbogenzündzweig ist,
P_2i die Wirkleistung an dem 2i-ten Lichtbogenzündzweig ist,
R_2i-1 der charakteristische Lichtbogenwiderstand auf dem (2i-1)-ten Lichtbogenzündungszweig ist,
R_2i der charakteristische Lichtbogenwiderstand auf dem 2i-ten Lichtbogenzündungszweig ist,
I_2i-1 der Eingangsstrom des (2i-1)-ten Lichtbogenzündungszweigs ist, der die folgende Beziehung erfüllt: $$I_{2i-1}=\frac{R_{2i}+j\omega L}{\left(R_{2i}+R_{2i-1}\right)+j\left(\omega L-\frac{1}{\omega C}\right)}$$

und I_2i der Eingangsstrom des 2i-ten Lichtbogenzündungszweigs ist, der die folgende Beziehung erfüllt: $$I_{2i}=\frac{R_{2i}-j\omega L}{\left(R_{2i}+R_{2i-1}\right)+j\left(\omega L-\frac{1}{\omega C}\right)}$$

worin L der Induktivitätswert der Induktivitätsspulengruppe und C der Kapazitätswert der Kondensatorbank ist. Die induktive Reaktanz der Induktionsspulengruppe ist unter der Bedingung gleich ωund $\frac{1}{\sqrt{LC}}$

gleich der kapazitiven Reaktanz der Kondensatorbank, und die Lichtbogenkennwiderstände sind auf jedem Lichtbogenzündzweig bei gleichem Material und gleicher Größe der Hörnerelektrode gleich, also R_2i-1 = R_2i , sodass die Eingangsstromamplituden in jedem Lichtbogenzündungszweig gleich sind und die folgende Beziehung erfüllen: $$\frac{I_S}{n}=I_{2i}+I_{2i-1}$$

worin I_S der Ausgangsstrom der Stromversorgung ist.If all arc ignition branches are in the conductive state, the active power on the (2i-1)th arc ignition branch and the active power on the 2ith arc ignition branch each satisfy the following relationship: $$P_{2i-1}=R_{2i-1}\times I_{2i-1}{}^2$$

$$P_{2i}=R_{2i}\times I_{2i}$$

wherein
P _2i-1 is the active power on the (2i-1)th arc ignition branch,
P _2i is the active power on the 2i-th arc ignition branch,
R _2i-1 is the characteristic arc resistance on the (2i-1)th arc ignition branch,
R _2i is the characteristic arc resistance on the 2i-th arc ignition branch,
I _2i-1 is the input current of the (2i-1)th arc ignition branch, which satisfies the following relationship: $$I_{2i-1}=\frac{R_{2i}+j\omega L}{\left(R_{2i}+R_{2i-1}\right)+j\left(\omega L-\frac{1}{\omega C}\right)}$$

and I _2i is the input current of the 2i-th arc ignition branch satisfying the following relationship: $$I_{2i}=\frac{R_{2i}-j\omega L}{\left(R_{2i}+R_{2i-1}\right)+j\left(\omega L-\frac{1}{\omega C}\right)}$$

where L is the inductance value of the inductance coil group and C is the capacitance value of the capacitor bank. The inductive reactance of the induction coil group is equal to ωand $\frac{1}{\sqrt{LC}}$

equal to the capacitive reactance of the capacitor bank, and the arc resistances are the same on each arc ignition branch with the same material and the same size of the horn electrode, i.e. R _2i-1 = R _2i , so that the input current amplitudes in each arc ignition branch are the same and satisfy the following relationship: $$\frac{I_S}{n}=I_{2i}+I_{2i-1}$$

where I _S is the output current of the power supply.

The active power is the same in each arc ignition branch, and the reactive power generated by the capacitor bank in the (2i-1)th arc ignition branch is equal to the reactive power absorbed by the induction coil group in the 2ith arc ignition branch, that is, the sum of the reactive power in the entire arc device is 0 , thereby realizing the mutual cancellation of reactive power. The power of the power supply is the sum of the active power output to each arc ignition branch, which effectively improves the power efficiency, thereby improving the work efficiency of the entire ignition device.

In particular, the power supply in the device is a DC voltage source, and the output voltage and the maximum output current of the DC voltage source are adjustable, the setting range of the output voltage being 0 to 50 V and the setting range of the maximum output current being 0 to 50 A.

Specifically, the device also includes an inverter device, the output terminal of the DC voltage source is connected to the switch of the power supply and the input terminal of the inverter device through the connection high voltage package, and the output terminal of the inverter device is connected to the low voltage side of the high voltage package.

Further, the inverter device converts the DC voltage and the DC current output from the DC voltage source into a sinusoidal AC voltage and a sinusoidal AC current, the frequency of which is the frequency of the power supply itself. In the preferred embodiment this frequency is 20 kHz.

Furthermore, the inverter device also includes a voltage and current feedback control unit that uses the sinusoidal AC voltage and current to adjust the DC voltage and current output from the control DC voltage source to obtain a constant sinusoidal AC current.

In particular, the inverter device is an LC oscillator circuit.

It should be noted that the use of an LC oscillator circuit as an inverter device in the preferred embodiment of the present invention is a non-limiting preferred choice, and those skilled in the art can select different inverter devices according to device design requirements and experimental conditions.

In particular, the high-voltage package contains a horizontal output transformer, the transformation ratio of which is not less than 500.

Specifically, the capacitor bank includes two high-voltage polystyrene film capacitors connected in series, which can withstand a voltage level of 50 kV, and the capacitance of each high-voltage polystyrene film capacitor is twice the capacitance of the capacitor bank.

It is noted that in order to avoid the breakdown phenomenon that may damage the reactive components when the withstand voltage is low, the withstand voltage level of the capacitor selected in this preferred embodiment is 50 kV. This is a non-limiting preferred choice, and the selection of the withstand voltage level and the number of series-connected capacitors determined according to different withstand voltage levels are all within the scope of the present invention.

In particular, the induction coil group includes five series-connected high-voltage coils with large inductance that can withstand a voltage level of 20 kV, and each high-voltage coil is made of amorphous ferromagnetic material, wherein the wires are wound with high-voltage tape for more than 5 turns. Note that in order to avoid the breakdown phenomenon that may damage the reactive components when the withstand voltage is low, the preferred embodiment selects the withstand voltage level of the inductor to be 20 kV. This is a non-limiting preferred choice, and the selection of the withstand voltage level and the number of series connected inductors determined according to different withstand voltage levels are all within the scope of the present invention.

Specifically, the horn electrodes are rod-shaped and made of copper, stainless steel or tungsten alloy, whose diameter ranges from 2mm to 4mm, and the inner distance of the bottom of the horn electrode is 0.7cm-1cm and that of the top is 1.2cm- 2cm.

example 1

The arc ignition device with a single power supply and multiple electrodes in the preferred embodiment of the present invention is in 4 shown, including a DC voltage source 1, an air switch 2, an LC oscillation circuit 3, a high voltage pack 4, and a multi-electrode ignition group multiple-electrode ignition system 5.

The DC voltage source 1 was electrically connected to the input end of the LC resonant circuit 3 via the air switch 2, so that the DC voltage source 1 provided a constant input voltage and a constant current to the LC resonant circuit 3. The LC oscillation circuit 3 inverted the DC voltage and DC current input from the DC voltage source 1 into a 20 kHz AC voltage and AC current and output them to the low voltage side of the high voltage package 4 . The high-voltage package 4 amplified the AC voltage transmitted from the LC oscillator circuit 3, and the high-voltage side of the high-voltage package 4 outputted the amplified AC voltage to the multi-electrode firing group 5. The positive electrode connection point of the multi-electrode ignition group 5 was connected to the high-voltage side of the high-voltage pack 4, and the negative electrode connection point of the multi-electrode ignition group 5 was grounded.

The output voltage and the maximum output current of the DC voltage source 1 were adjustable, with the setting range of the output voltage being 0 to 50 V and the setting range of the maximum output current being 0 to 50 A.

The connection point of the LC oscillation circuit 3 included a feedback that could control the output of a constant current.

The high-voltage package 4 was a horizontal output transformer, and the transformation ratio was not less than 500 to ensure that the voltage output from the high-voltage side of the transformer could smoothly penetrate the horn electrodes in the multi-electrode ignition group 5, so that a stable arc can be generated smoothly could.

The multi-electrode ignition group included an even number of horn electrodes, a high-voltage capacitor bank and a large induction coil group, where the number of the high-voltage capacitor bank and the large induction coil group was equal. As in 5 shown, the multi-electrode ignition group contains two arc ignition branches, that is, the multi-electrode ignition group contained two sets of arc electrodes. The two arc ignition branches each included the A horn electrode 6 and the B horn electrode 7, the first high-voltage capacitor bank 8 and the first large induction coil group 9.

The electrode of the A horn electrode 6 and the B horn electrode 7 were connected to one another and electrically connected to the high-voltage side of the high-voltage package 4. Further, the negative electrode of the A horn electrode 6 is electrically connected to a connection point of the first high-voltage capacitor bank 8, and the negative electrode of the B horn electrode 7 was electrically connected to a connection point of the first large inductance coil group 9.

Furthermore, the other connection point of the first large inductance coil group 9 was electrically connected to the other connection point of the first high-voltage capacitor bank 8 and grounded.

Furthermore, the capacity of the first high-voltage capacitor bank 8 should be less than or equal to 160 pF, and the inductance of the first large inductance coil group 9 should be greater than or equal to 0.35 mH.

Furthermore, the first high-voltage capacitor bank consisted of two high-voltage polystyrene film capacitors connected in series, which could withstand a voltage level of 50 kV, and the capacity of each high-voltage polystyrene film capacitor was twice the capacity of the capacitor bank, thereby realizing voltage division, to ensure that the capacitor has not been broken. Furthermore, the first large induction coil group 9 consisted of five large ßen induction coils that withstood a high voltage in series. The high-voltage, high-inductance coils were made of amorphous ferromagnetic material, and the wire was wound with high-voltage tape for more than 5 turns.

When the A horn electrode 6 and the B horn electrode 7 were not broken, each arc ignition branch was in an open state, and the voltages at both terminal points of the A horn electrode 6 and the B horn electrode 7 were the terminal voltages. When the A horn electrode 6 is first broken, the voltage on the electrode suddenly dropped, and the peak-to-peak value of the terminal voltage fell from the original 30 kV to below 5 kV. At this time, the first arc ignition branch was in one conductive state and the current flowed through the reactive element on the first arc ignition branch - the first high-voltage capacitor bank 8. The two connection points of the reactive elements on the first arc ignition branch generated a voltage of about 30 kV, thereby reducing the voltage drop caused by the conduction of the A-horn electrode 6 caused was compensated for so that the two connection points of the B horn electrode 7, which had not collapsed, still held high voltage. Then the B horn electrode 7 was broken and the second arc ignition branch was switched on. When both arc ignition branches were switched on, the first high-voltage capacitor bank 8 and the first large inductance coil group 9 came into resonance, so that the reactive power emitted and received canceled each other out. Therefore, the power supply only output useful power, thereby improving the power supply efficiency and also improving the work efficiency of the ignition device.

6 is a waveform diagram of the terminal voltage and current at the moment of ignition of two electrodes in the preferred embodiment of the present invention. It can be seen from the figure that there were two obvious drops in the electrode terminal voltage, which means that the two electrodes were on respectively. According to the simulation calculation, it was concluded that the ignition time difference between the two electrodes was about 5 μs, and the simultaneous breakdown of the two electrodes was essentially realized.

7 is a waveform diagram of the terminal voltage and current of two electrodes in the steady state in the preferred embodiment of the present invention. It was seen from the figure that the output waveform of the power source was sinusoidal. The terminal voltage and current phase were similar, basically in the same phase. It was seen that the arc generated by the ignition device proposed by the present invention was close to pure resistance, that is, the reactive power was close to zero. In addition, the waveforms of current and voltage were stable, so stable long-term arc output could be realized.

Example 2

As in 8th shown, the multi-electrode ignition group contained four arc ignition branches, that is, the multiple-electrode ignition group contained four sets of arc electrodes. The four arc ignition branches each contained the A horn electrode 6, B horn electrode 7, C horn electrode 10, D horn electrode 11 and also included the first large induction coil group 9 and the second large induction coil group 12 and the first high voltage capacitor bank 8 and the second high voltage capacitor bank 13.

The positive electrodes of the A horn electrode 6, B horn electrode 7, C horn electrode 10 and D horn electrode 11 were connected to one another and electrically connected to a connection point on the high-voltage side of the high-voltage package 4.

Furthermore, the negative electrode of the A horn electrode 6 was electrically connected to a connection point of the first high-voltage capacitor bank 8, the negative electrode of the B horn electrode 7 was electrically connected to a connection point of the first large induction coil group 9, and the negative electrode of the C horn electrode 10 was electrically connected to a connection point the second high-voltage capacitor bank 13 is connected and the negative electrode of the D-horn electrode 11 is electrically connected to a connection point of the second large induction coil group 12.

Furthermore, the other electrodes of the first large induction coil group 9, the first high voltage capacitor bank 8, the second large induction coil group 12 and the second high voltage capacitor bank 13 were all electrically connected and grounded. Furthermore, the structures were the first Large induction coil group 9 and the second large induction coil group 12 and the structures of the first high-voltage capacitor bank 8 and the second high-voltage capacitor bank 13 are each the same.

In this preferred embodiment, the adopted circuit structure was the same as that in Embodiment 1. However, since there were two high-voltage capacitor banks and two large-scale inductor groups, the double capacitance of the high-voltage capacitor bank should be less than or equal to 160 pF, which means that the capacitance of the high-voltage capacitor bank should be less than or equal to 80pF, and the inductance value of the large induction coil group should be greater than or equal to twice 0.35 mH, which means that the inductance value of the large induction coil group should be greater than 0.7 mH.

Similarly, if the number of arc electrodes included in the ignition device is 2n, then the number of high-voltage capacitor groups and large induction coil groups is each n. Here, the capacitance value of the high-voltage capacitor bank should be less than or equal to 160/npF, and the inductance value of the Large induction coil group must be greater than or equal to 0.35 nmH.

Furthermore, the shape and material of the claw electrodes were all the same, they were all rod-shaped and the material was copper, stainless steel or tungsten alloy. Their diameters ranged from 2 mm to 4 mm, the internal distance of the bottom of the horn electrode was 0.7 cm-1 cm and that of the top was 1.2 cm-2 cm.

• Schritte 1 Bestimmung der Anzahl der Lichtbogen-Zündungszweige in der Mehrfach-Elektroden-Zündgruppe und Regulierung der Ausgangsspannung und des Ausgangsstroms der Gleichspannungsquelle entsprechend den Daten der für das simulierte Kabelverbrennungsexperiment erforderlichen Leistung;

As in 9 As shown, a single power supply, multiple electrode ignition method includes the following steps:

• Steps 1 Determine the number of arc ignition branches in the multi-electrode ignition group and regulate the output voltage and output current of the DC voltage source according to the data of the power required for the simulated cable burning experiment;

Furthermore, in Step 1, the arrangement and size of the horn electrodes need to be adjusted according to the data of the power required for the simulated cable combustion experiment.

The arrangement of the horn electrodes includes the horizontal distance between each electrode, the vertical distance between each electrode and the experimental ignition object.

• Schritte 2 Invertieren der von der Gleichspannungsquelle ausgegebenen konstanten Spannung und des konstanten Stroms unter Verwendung der LC-Oszillatorschaltung zur Erzeugung von sinusförmigen Wechselspannungen und -strömen;
• Schritte 3 Hochsetzen von sinusförmiger Wechselspannung und -strom durch Verwendung eines horizontalen Ausgangstransformators;
• Schritte 4 Die Lichtbogenbildung durch Erregen der Mehrfach-Elektroden-Zündgruppe mit dem verstärkten Wechselspannungsstrom.

The size of the horn electrodes includes the diameter of the electrode, the internal distance between the two electrodes at the bottom of the electrode, the internal distance between the two electrodes at the top of the electrode, and the vertical height between the top of the electrode and the bottom of the Electrode, where the lower end of the electrode is the initial discharge end in the arcing process, and the upper end is the final stable combustion end in the arcing process.

• Steps 2 Inverting the constant voltage and current output from the DC voltage source using the LC oscillator circuit to generate sinusoidal AC voltages and currents;
• Steps 3 Step up sinusoidal AC voltage and current by using a horizontal output transformer;
• Steps 4 Arc formation by energizing the multi-electrode ignition group with the increased AC current.

1. (1) zunächst die Mehrelektroden-Zündgruppe entsprechend der Versuchsgröße anordnen;
2. (2) Schalter der Gleichspannungsquelle einschalten, und die Ausgangsspannung des Netzteils entsprechend den experimentellen Erfordernissen einstellen;
3. (3) 2 bis 5 Sekunden warten, um sicherzustellen, dass der Ausgang der Gleichspannungsquelle stabil ist, den Luftschalter öffnen, um die Gleichspannungsquelle mit der LC-Oszillatorschaltung zu verbinden, und die Lichtbogenbildung durch die Mehrfach-Elektroden-Zündgruppe erregen.
4. (4) den Luftschalter nach einem einzelnen Experiment ausschalten, die Ausgangsspannung der Gleichspannungsquelle anpassen, um die Lichtbogenleistung zu ändern, die Anordnung von Mehrfach-Elektroden-Zündgruppen oder die Größe von Hörnerelektrode ändern, und den Luftschalter für das nächste Experiment wieder einschalten.
5. (5) nach Versuchsende zuerst den Luftschalter und dann die Gleichspannungsquelle ausschalten, und die Experimentierplattform evakuieren, nachdem die Experimentiergeräte abgekühlt sind und keine Brandgefahr vor Ort besteht.

In this preferred embodiment, the specific implementation process of the single power supply, multiple electrode ignition method was as follows:

1. (1) first arrange the multi-electrode ignition group according to the experimental size;
2. (2) Turn on the switch of the DC voltage source, and adjust the output voltage of the power supply according to the experimental needs;
3. (3) Wait 2 to 5 seconds to ensure that the output of the DC voltage source is stable, open the air switch to connect the DC voltage source to the LC oscillator circuit, and excite the arcing through the multi-electrode ignition group.
4. (4) Turn off the air switch after a single experiment, adjust the output voltage of the DC power source to change the arc power, change the arrangement of multi-electrode ignition groups or the size of horn electrode, and turn on the air switch again for the next experiment.
5. (5) After the end of the experiment, first turn off the air switch and then the DC voltage source, and evacuate the experimental platform after the experimental equipment has cooled down and there is no risk of fire on site.

1. 1. Die Erfindung verwirklicht die gleichzeitige Zündung mehrerer Elektroden, und die Zündzeitdifferenz zwischen den Elektroden ist extrem klein. Darüber hinaus kann der gezündete Lichtbogen weiterbrennen, hat eine starke Stabilität und erfüllt die Anforderungen der Feuerwiderstandsleistungsprüfung des Testkabels.
2. 2. Die Erfindung verwirklicht die durchschnittliche Verteilung der Leistung jeder Elektrode, und die Leistung jeder Elektrode ist nach Lichtbogenbildung gleich und stabil, wodurch zuverlässige Versuchsergebnisse sichergestellt werden.
3. 3. Bei der vorliegenden Erfindung sind an zwei benachbarte Lichtbogenzündzweige jeweils Induktivitätsgruppen bzw. Kondensatorbänke in Reihe geschaltet. Durch Ändern der Impedanz der Kondensatorbank und der Induktivitätsgruppe kann die Blindleistung aufgehoben werden, wodurch die von der Stromversorgung abgegebene Blindleistung reduziert, die Effizienz der Stromversorgung effektiv verbessert und die Arbeitseffizienz der gesamten Zündvorrichtung erhöht wird.
4. 4. Die Anzahl der Lichtbogenzündungszweige in der vorliegenden Erfindung kann gemäß den experimentellen Leistungsanforderungen erhöht werden, und die Skalierbarkeit ist stark.
5. 5. Die Erfindung verwirklicht auch die Steuerbarkeit der Lichtbogenleistung, und die Lichtbogenleistung kann durch Einstellen der Ausgangsspannung der Gleichspannungsquelle gesteuert werden, die flexibel ist.

Compared with the prior art, the advantageous effects of the present invention are as follows:

1. 1. The invention realizes the simultaneous ignition of multiple electrodes, and the ignition time difference between the electrodes is extremely small. In addition, the ignited arc can continue to burn, has strong stability, and meets the requirements of the fire resistance performance test of the test cable.
2. 2. The invention realizes the average distribution of the power of each electrode, and the power of each electrode is equal and stable after arcing, thereby ensuring reliable experimental results.
3. 3. In the present invention, inductance groups or capacitor banks are connected in series to two adjacent arc ignition branches. By changing the impedance of the capacitor bank and the inductor group, the reactive power can be canceled, thereby reducing the reactive power output from the power supply, effectively improving the efficiency of the power supply and increasing the work efficiency of the entire ignition device.
4. 4. The number of arc ignition branches in the present invention can be increased according to the experimental performance requirements, and the scalability is strong.
5. 5. The invention also realizes the controllability of the arc power, and the arc power can be controlled by adjusting the output voltage of the DC power source, which is flexible.

The applicant of the present invention explained and described the implementation examples of the present invention in detail in connection with the accompanying drawings. However, those skilled in the art should understand that the above implementation examples are only preferred embodiments of the present invention. The detailed description is only intended to assist readers in better understanding the present invention, but is not intended to limit the scope of the present invention. On the contrary, any improvement or modification based on the present invention is intended to be within the scope of the present invention.

Claims (15)

A single power supply multi-electrode arc ignition device comprising a power supply, a high voltage package, a switch connecting the high voltage package and the power supply, and a multi-electrode ignition group, wherein the connection point of the positive electrode of the multiple electrode ignition group is electrically connected the high-voltage side of the high-voltage package is connected and the connection point of the negative electrode of the multiple-electrode ignition group is grounded, characterized in that the multiple-electrode ignition group 2n comprises arc ignition branches connected in parallel, which are connected between the connection point of the positive electrode and the connection point of the negative electrode are; wherein the (2i-1)-th arc ignition branch comprises a capacitor bank and a horn electrode, wherein the positive pole of the horn electrode in the (2i-1)-th arc ignition branch is connected to the connection point of the positive electrode of the multiple-electrode ignition group and the negative pole of the Horn electrode in the (2i-1)th arc ignition branch is first connected in series with the capacitor bank and then connected to the negative electrode connection point of the multi-electrode ignition group; and the 2i-th arc ignition branch comprises an induction coil group and a horn electrode, wherein the positive pole of the horn electrode in the 2i-th arc ignition branch is connected to the connection point of the positive electrode of the multi-electrode ignition group, and the negative pole of the horn electrode in the (2i) th arc ignition branch is first connected in series with the induction coil group and then connected to the negative electrode connection point of the multi-electrode ignition group; and the capacitance group on the (2i-1)th arc ignition branch has the same impedance module as the inductor tion coil group on the 2i-th arc ignition branch, where i = 1,2,···,n, and n is half of the total number of arc ignition branches in the multiple-electrode ignition group. Arc ignition device with a single power supply and multiple electrodes Claim 1 , characterized in that the arc ignition branch is in an open state when the horn electrode in one of the arc ignition branches is not broken, and the voltage across the horn electrodes in this case is lower than the breakdown voltage of the electrodes. Arc ignition device with a single power supply and multiple electrodes Claim 1 or 2 , characterized in that the horn electrode in the branch is broken and the arc ignition branch is in a conductive state when the voltage across the horn electrode in the (2i-1)th arc ignition branch is greater than the electrode breakdown voltage, and the voltage across the horn electrode drops to the electrode voltage at this time, the electrode voltage being equal to the voltage determined by the resistance of the arc of the electrode after the horn electrode is turned on; the voltage across the horn electrode in the 2i-th arc ignition branch at this time is the sum of the electrode voltage of the horn electrode in the (2i-1)-th arc ignition branch and the voltage of the capacitor bank, and the voltage of the capacitor bank in the (2i-1)-th arc ignition branch is the Electrode voltage of the horns electrode is compensated so that the horns electrode in the 2i-th arc ignition branch is broken if the voltage across the horns electrode in the 2i-th arc ignition branch is greater than the breakdown voltage of the horns electrode. Arc ignition device with a single power supply and multiple electrodes Claim 1 , characterized in that the number of the capacitor bank in the multiple-electrode ignition group is the same as the number of the induction coil group, which is half of the total number of arc ignition branches, n times the sum of the capacitance values of all capacitor banks less than or equal to the first setpoint is, and the sum of the inductance values of all inductance coil groups is greater than or equal to n times the second set value. Arc ignition device with a single power supply and multiple electrodes Claim 1 , characterized in that when all arc ignition branches are in the conductive state, the active power on the (2i-1)th arc ignition branch and the active power on the 2ith arc ignition branch each satisfy the following relationship: $$P_{2i-1}=R_{2i-1}\times I_{2i-1}{}^2$$

$$P_{2i}=R_{2i}\times I_{2i}{}^2$$

where P _2i-1 is the active power on the (2i-1)th arc ignition branch, P _2i is the active power on the 2ith arc ignition branch, R _2i-1 is the characteristic arc resistance on the (2i-1)th arc ignition branch, R _2i is the characteristic arc resistance on the 2i-th arc ignition branch, I _2i-1 is the input current of the (2i-1)-th arc ignition branch, which satisfies the following relationship: $$I_{2i-1}=\frac{R_{2i}+j\omega L}{\left(R_{2i}+R_{2i-1}\right)+j\left(\omega L-\frac{1}{\omega C}\right)}$$

and I _2i is the input current of the 2i-th arc ignition branch satisfying the following relationship: $$I_{2i}=\frac{R_{2i}-j\omega L}{\left(R_{2i}+R_{2i-1}\right)+j\left(\omega L-\frac{1}{\omega C}\right)}$$

where L is the inductance value of the inductance coil group and C is the capacitance value of the capacitor bank, the inductive reactance of the induction coil group under the condition equal to ω and $\frac{1}{\sqrt{LC}}$

same as that capacitive reactance of the capacitor bank, and the arc resistances on each arc ignition branch are the same with the same material and the same size of the horn electrode, i.e. R _2i-1 = R _2i , so that the input current amplitudes in each arc ignition branch are the same and satisfy the following relationship: $$\frac{I_S}{n}=I_{2i}+I_{2i-1}$$

where I _S is the output current of the power supply; the active power in each arc ignition branch is the same, and the reactive power generated by the capacitor bank in the (2i-1)th arc ignition branch is equal to the reactive power absorbed by the induction coil group in the 2ith arc ignition branch, that is, the power of the power supply is the sum of the active power output each arc ignition branch. Arc ignition device with a single power supply and multiple electrodes Claim 1 , characterized in that the power supply in the device is a DC voltage source, and the output voltage and the maximum output current of the DC voltage source are adjustable, the setting range of the output voltage being 0 to 50 V and the setting range of the maximum output current being 0 to 50 A. Arc ignition device with a single power supply and multiple electrodes Claim 6 , characterized in that the device also includes an inverter device, the output terminal of the DC voltage source is connected to the switch of the power supply and the input terminal of the inverter device through the connection high-voltage package, and the output terminal of the inverter device is connected to the low-voltage side of the high-voltage package, the inverter device being the of converts the DC voltage output from the DC voltage source and the DC current into a sinusoidal AC voltage and a sinusoidal AC current, the frequency of which is the frequency of the power supply itself. Arc ignition device with a single power supply and multiple electrodes Claim 7 , characterized in that the inverter device also includes a voltage and current feedback control unit that uses the sinusoidal AC voltage and current to adjust the DC voltage and current output from the control DC voltage source to obtain a constant sinusoidal AC current. Arc ignition device with a single power supply and multiple electrodes Claim 8 , characterized in that the inverter device is an LC oscillator circuit. Arc ignition device with a single power supply and multiple electrodes Claim 1 , characterized in that the high-voltage package contains a horizontal output transformer whose transformation ratio is not less than 500. Arc ignition device with a single power supply and multiple electrodes Claim 4 , characterized in that the capacitor bank includes two series-connected high-voltage polystyrene film capacitors capable of withstanding a voltage level of 50 kV, and the capacitance of each high-voltage polystyrene film capacitor is twice the capacity of the capacitor bank. Arc ignition device with a single power supply and multiple electrodes Claim 4 , characterized in that the induction coil group comprises five series-connected high-voltage coils with large inductance capable of withstanding a voltage level of 20 kV, and each high-voltage coil is made of amorphous ferromagnetic material, wherein the wires are wound with high-voltage tape with more than 5 turns. Arc ignition device with a single power supply and multiple electrodes Claim 3 , characterized in that the horn electrodes are rod-shaped and made of copper, stainless steel or tungsten alloy, the diameter of which ranges from 2 mm to 4 mm, and the internal distance of the bottom of the horn electrode is 0.7 cm-1 cm and that of the top is 1.2 cm-2 cm. Method of arc ignition with a single power supply and multiple electrodes by using the in one of the Claims 1 until 13 described arc ignition device is realized with a single power supply and multiple electrodes, characterized in that the method comprises the steps: Steps 1 Determination of the number of arc ignition branches in the multi-electrode ignition group and regulation of the output voltage and the output current of the DC voltage source according to the data the power required for the simulated cable burning experiment; Steps 2 Inverting the constant voltage and current output from the DC voltage source using the LC oscillator circuit to generate sinusoidal AC voltages and currents; Steps 3 Step up sinusoidal AC voltage and current by using a horizontal output transformer; Steps 4 Arc formation by energizing the multi-electrode ignition group with the increased AC current. Procedure for arc ignition Claim 14 , characterized in that in Steps 1, the arrangement and size of the horn electrodes must be adjusted according to the data of the power required for the simulated cable burning experiment, the arrangement including the horizontal distance between each electrode, the vertical distance between each electrode and the experimental ignition object , and the size is the diameter of the electrode, the internal distance between the two electrodes at the bottom of the electrode, the internal distance between the two electrodes at the top of the electrode and the vertical height between the top of the electrode and the bottom of the electrode wherein the lower end of the electrode is the initial discharge end in the arcing process, and the upper end is the final stable combustion end in the arcing process.

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