CN111952114A - Three-stage speed control method for voltage sharing of double-break vacuum switch - Google Patents
Three-stage speed control method for voltage sharing of double-break vacuum switch Download PDFInfo
- Publication number
- CN111952114A CN111952114A CN202010645812.7A CN202010645812A CN111952114A CN 111952114 A CN111952114 A CN 111952114A CN 202010645812 A CN202010645812 A CN 202010645812A CN 111952114 A CN111952114 A CN 111952114A
- Authority
- CN
- China
- Prior art keywords
- speed
- stage
- operating mechanism
- arc
- vacuum switch
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Images
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
- H01H33/00—High-tension or heavy-current switches with arc-extinguishing or arc-preventing means
- H01H33/60—Switches wherein the means for extinguishing or preventing the arc do not include separate means for obtaining or increasing flow of arc-extinguishing fluid
- H01H33/66—Vacuum switches
- H01H33/666—Operating arrangements
Landscapes
- High-Tension Arc-Extinguishing Switches Without Spraying Means (AREA)
Abstract
The invention belongs to the field of vacuum switch voltage sharing, and relates to a three-stage speed control method for voltage sharing of a double-break vacuum switch. According to the invention, by controlling the opening speed of the vacuum switch operating mechanism and according to a three-stage speed regulation and control method, the arc forms of the arc at the arc current rising stage and the arc extinguishing stage are changed, so that the medium strength recovery process after the arc is influenced, the effect of balancing the recovery voltage of the double-fracture vacuum switch is achieved, the use of the voltage-sharing capacitor of the vacuum switch is reduced, and the service life of the operating mechanism is prolonged.
Description
Technical Field
The invention belongs to the field of vacuum switch voltage sharing, and relates to a three-stage speed control method for voltage sharing of a double-break vacuum switch.
Background
The vacuum switch is difficult to develop towards higher voltage levels due to the saturation effect between the insulation strength and the distance between the contacts. The multi-fracture vacuum switch with a plurality of fractures connected in series can make up for the defect, but the voltage sharing problem caused by the vacuum switch becomes a difficult point for research. In recent years, the recovery voltage is usually equalized by adopting an external voltage equalizing resistor and an external voltage equalizing capacitor, but external voltage equalizing measures bring various disadvantages, for example, the heat capacity required by a small voltage equalizing resistor is large, the normal on-off of a switch is influenced, and the ferromagnetic resonance is generated between an overlarge voltage equalizing capacitor and inductive reactance in a circuit, so that the equipment safety is damaged. Research on the influence of internal voltage-sharing measures such as magnetic fields, speed and the like on voltage sharing of the vacuum switch is rapidly developing. Correspondingly, the recovery voltage of the vacuum switch through speed equalization also puts higher requirements on the speed regulation method. Firstly, an excessively fast breaking speed may impair the service life of the device. Secondly, the breaking speed of the switch is not as fast as possible, the multi-fracture switches need to be matched with each other, and the whole double-fracture switch cannot be broken down due to breakdown of one arc extinguish chamber. Finally, speed regulation is intended to vary the post-arc medium recovery speed, which in turn is related to the arc morphology, requiring speed regulation to be coordinated with the arc morphology. Against this background, the present invention proposes a three-stage speed control method for equalizing recovery voltage of a double-break vacuum switch.
Disclosure of Invention
The invention aims to solve the technical problem that the form of an electric arc at an arc current rising stage and an arc extinguishing stage is changed by controlling the opening speed of a vacuum switch operating mechanism according to a three-stage speed regulation method, so that the medium strength recovery process after the arc is influenced, and the effect of balancing the recovery voltage of a double-break vacuum switch is realized.
The technical scheme of the invention is as follows:
the speed is regulated and controlled by controlling the arc forms of the arc current rising stage and the arc extinguishing stage, so that the medium recovery strength after the arc is changed, and the balance of the voltage bearing capacity is realized. The double-fracture vacuum switch also involves the speed matching between the two fractures, the maximum breaking capacity of a single fracture is not pursued, and the breaking capacity of the two fractures can be improved. The speed is reduced at the final stage of breaking, so that the effects of reducing the shaking of the contact, stabilizing the voltage and reducing the action dispersion of the mechanism are achieved, the collision loss of the equipment can be reduced, and the service life of the equipment is prolonged.
1. The first stage is as follows: speed control of the arc current rise phase (I first phase).
The first phase is from the beginning of the contact action, the arc current begins to rise, and the end is at the maximum of the arc current. The medium recovery phase refers to the process of the contact gap recovering from a highly conductive state during arcing to an insulating state. When the mechanism starts to open the gate, the contact area of the contact gradually decreases, the contact resistance increases, and a molten metal bridge is formed. As the breaking proceeds, the metal bridge collapses, emitting a large amount of molten vapor. These metal vapors enter the narrow contact gap, forming a bridge arc. As the breaking continues, the bridge arc is transformed into a concentrated arc, anode spots are generated, and the concentrated arc is transformed into a diffused arc after the current is reduced until the arc is extinguished. The high opening speed can quickly convert the strong arc mode into the diffusion mode, reduce the erosion of the arc to the contact, reduce the number of inter-electrode plasmas, and influence the recovery strength of the subsequent medium as shown in the formula (1).
Wherein S is the sheath thickness, VRFor transient sheath pressure drop, V0For initial sheath voltage drop, e is the ionic charge, n0As the density of the plasma, it is,0is the dielectric constant in vacuum. When the breaking speed is faster, the plasma density n between fractures is higher0The smaller the sheath thickness, the greater the ability to assume a recovery voltage. The electromagnetic force expression of the operating mechanism of the double-break vacuum switch is as follows:
wherein, Δ WmFor the magnetic energy converted from electric energy in the action process of the operating mechanism, delta is an air gap value, psi is an operating mechanism coil flux linkage, psisIs made of magnetismThe chain stability value, i, is the value of the current through the coil. The electromagnetic force is converted into the kinetic energy of the mechanism, and the speed expression of the operating mechanism in the first stage is obtained as shown in the formula (2).
Wherein v isIThe opening speed of the operating mechanism in the first stage is shown, and m is the mass of the movable iron core of the operating mechanism.
2. And a second stage: speed control in the arc extinguishing phase (II second phase).
The second phase of the speed control is from the peak of the arc current until the arc column is apparently extinguished. The arc extinguishing stage of the vacuum circuit breaker is a stage in which the arc column is rapidly contracted after the peak value of the current passes, and the moment when the arc column obviously disappears can be observed in a high-speed camera.
Since the initial plasma density plays a crucial role in the post-arc dielectric recovery process, the higher the initial density, the lower the resistance to the recovery voltage. The speed control method in the arc quenching stage can be obtained by researching the influence of the breaking speed on the plasma concentration after the arc quenching.
Suppose that:
firstly, the extinguishing of the electric arc can uniformly disperse metal steam to the horizontal direction between fractures;
the gap is a cylinder;
and the speed of the metal vapor emitted in each direction is the same.
By applying the particle conservation law as shown in the formula (3), the method can obtain
The left side of the equation represents the reduction of the metal vapor in the fracture gap per unit time, ρ represents the metal vapor density per unit volume at a certain time, and V is the volume of the fracture gap. Represents the increased vapor flux density in the arc chamber per unit time, S represents the total area of the gap at the break, and the right side of the equation represents the increased amount of metal vapor emanating from the gap into the arc chamber.
Along with the proceeding of the arc quenching stage, the volume of the fracture gap is increased, the density of steam in the fracture gap is reduced, correspondingly, the density of gas in the arc extinguishing chamber is increased, a density balance value exists between the fracture gap and the gas, the balance value corresponds to the optimal on-off speed of the arc quenching stage, as shown in formula (5),
-∮r·dSrthe amount of metal vapor that is emitted out of the gap is shown to eventually increase to a constant value as the interruption progresses, and the left side of the equation correspondingly decreases to a constant value. Rho0Representing the initial metal vapor density in the gap, and Δ ρ representing the decreased density, the metal vapor mass decreases and the velocity increases, causing the density to decrease. The speed of the arc quenching phase is obtained because there must be a value that balances the inter-fracture steam density and the density of the steam inside the arc extinguishing chamber.
2.1 acquisition of the arc column shrinkage speed
The optimal arc shape can be obtained by a camera, and the optimal contraction speed of the arc can be obtained by multiple times of sampling. According to the relation between the electric arc contraction speed and the opening speed, the optimal second-stage speed can be obtained.
2.2 acquisition of Circuit breaker actuator speed
The opening speed of the operating mechanism can be obtained by a displacement sensor. The opening speed of each operating mechanism corresponds to the contraction speed of an electric arc. The breaking speed of the mechanism has a certain relation with the contraction speed of the arc column. The contraction speed of the arc column can be obtained by shooting through a high-speed camera and establishing a coordinate system. The breaking speed of the mechanism can be obtained by a displacement sensor. The relation between the two can be obtained by performing three times of fitting through MATLAB as shown in formula (6).
Wherein k isnIs a constant value vIIV is the breaking speed of the mechanism and v is the contraction speed of the arc column. And the mechanism breaking speed of the second stage can be obtained by analyzing the influence of the arc form on the voltage distribution.
3. And a third stage: and (III) controlling the speed at the later stage of breaking (III).
The breaking mechanism which does not pass through speed regulation has high breaking speed, so that the fracture can reciprocate when the maximum opening distance is reached, the service life of equipment can be damaged, the arc voltage can be unstable, and the medium recovery process after the arc is influenced. The speed control of the third stage is mainly embodied in the buffer action, and the speed is kept at the speed shown in the formula (7) on the premise of ensuring that the speeds of the first stage and the second stage meet the requirement.
Wherein v isI、vII、vIIIFirst, second and third stage speeds, t1、t2The time of the first stage and the second stage, L is the maximum opening distance of the operating mechanism, and T is the existing time of the arc current. Through speed regulation and control for breaking the maximum opening distance of later stage fracture with comparatively gentle speed, stabilize arc voltage, extension equipment life.
The invention has the beneficial effects that: according to the invention, by controlling the opening speed of the vacuum switch operating mechanism and according to a three-stage speed regulation and control method, the arc forms of the arc at the arc current rising stage and the arc extinguishing stage are changed, so that the medium strength recovery process after the arc is influenced, the effect of balancing the recovery voltage of the double-fracture vacuum switch is achieved, the use of the voltage-sharing capacitor of the vacuum switch is reduced, and the service life of the operating mechanism is prolonged.
Drawings
Fig. 1 is a three-stage velocity control timing diagram during the opening of a vacuum switch.
Fig. 2 is a graph of the relationship between the opening speed of the vacuum switch operating mechanism and the shrinkage speed of the arc column.
Figure 3 is a bar graph of the percent recovery voltage assumed by the five experimental high-side fractures.
Detailed Description
Example 1
The laboratory synthesis loop system was 50kV, 30 kA. The experimental current source generates peak current of 5kA, the voltage source generates peak voltage of 8kV, the frequency modulation capacitor is 5000pF, the opening capacitor of the vacuum switch operating mechanism adopts 10000mH and 450V, and the charging voltage is 180V. The maximum opening distance L between the vacuum switch contacts is 6 mm. The experiment adopts the electric capacity voltage-sharing, and voltage-sharing electric capacity is 5000 pF. In order to reduce the use of the voltage-sharing capacitor, a three-stage speed control method is adopted for opening the vacuum switch.
The first stage is as follows: the switching-off loop of the operating mechanism of the vacuum switch is an RLC series discharge loop, and the current discharges to the switching-off coil to generate a stable flux linkage psisThe inductance L is 13mH, and the mass of the core is 15 kg.
Therefore, the opening speed of the first-stage vacuum switch operating mechanism is 0.95 m/s.
And a second stage: the radius of the vacuum switch contact is 29mm, and the frame number of the high-speed camera is 10000 frames/second. 25 pictures of the vacuum arc column from generation to disappearance can be obtained, so that the second stageDuration t2Is 2.5 ms. The vacuum arc contraction speeds of shooting and sampling by a high-speed camera are respectively as follows: 100m/s, 210m/s, 290m/s, 300m/s, 305 m/s. The corresponding opening speed of the vacuum switch operating mechanism is 0.35m/s, 0.55m/s, 0.75m/s, 0.85m/s and 0.95 m/s. The breaking speed v of the vacuum switch can be obtained by fitting a cubic polynomial by using MATLABIIAnd the arc column contraction velocity v.
vII＝5.328×10-7v3-3.165×10-4v2+0.06v-3.0108
The obtained curve chart of the relation between the opening speed of the vacuum switch operating mechanism and the contraction speed of the arc column is shown in figure 2. The second stage velocity v can be obtainedIIMore preferably 0.9 m/s.
And a third stage: the half-wave period of the sine wave of the current source of the synthetic loop is 10ms, and the action time T of the operating mechanism is 10-T0. When t is0When the time is 3ms, the operating mechanism starts the opening action, and the contact of the vacuum switch is pulled open. From the above, the velocity in the first stage is vI＝0.95m/s、t12ms, second stage velocity bit vII＝0.9m/s、t22.5 ms. The third stage speed from the third stage speed formula is:
after the three-stage speed is calculated, the IGBT can be controlled to be switched on and off by the pulse signal output by the single chip microcomputer so as to realize speed regulation and control. The regulated voltage distribution can be measured by a high-voltage probe. Five groups of experiments are carried out, and the opening speed of the first four groups of experiment operating mechanisms is as follows: 0.65m/s, 0.75m/s, 0.85m/s and 0.95m/s, the speed is not regulated and controlled, and the fifth group of experiment speeds adopts a three-stage speed regulation and control method, wherein v is respectivelyI＝0.95m/s、vII＝0.9m/s、vIII0.74 m/s. The voltage profiles of the comparative two sets of experiments are shown in figure 3.
In five experiments, the recovery voltage percentage born by the fracture of the high-voltage side of the vacuum switch is as follows: 64.4%, 62.8%, 58.6%, 54.3%, 52.5%. Compared with the voltage distribution when the speed regulation is not carried out, the speed regulation and control play a role in balancing the recovery voltage of the double-break vacuum switch, and the use of the voltage-sharing capacitor of the vacuum switch can be reduced. The speed of the operating mechanism in the third stage of opening is low, the shaking of a contact is reduced, the collision loss of equipment is reduced, and the service life of the equipment is prolonged.
Claims (1)
1. A three-stage speed control method for voltage sharing of a double-break vacuum switch is characterized by comprising the following steps:
the first stage is as follows: the first stage of the control of the opening speed of the operating mechanism of the double-break vacuum switch is from the moment of the action of a contact of the operating mechanism to the moment of the peak value of the arc current; the operating mechanism of the first-stage double-fracture vacuum switch has the following action speed:
wherein, Δ WmFor the magnetic energy converted from electric energy in the action process of the operating mechanism, delta is an air gap value, psi is an operating mechanism coil flux linkage, psisFor flux linkage stability values, i is the value of the current through the coil, vIThe opening speed of the operating mechanism in the first stage is shown, and m is the mass of a movable iron core of the operating mechanism;
and a second stage: the opening speed of the vacuum switch operating mechanism is controlled in the second stage from the peak moment of the arc current to the disappearance moment of the arc column of the arc current;
2.1 acquisition of the arc column shrinkage speed
The contraction speed of the arc column can be shot by a high-speed camera, a coordinate system is established, and the optimal contraction speed of the arc is obtained through multiple times of sampling;
2.2 acquisition of Circuit breaker actuator speed
The opening speed of each operating mechanism is obtained through a displacement sensor, and the opening speed of each operating mechanism corresponds to the contraction speed of one electric arc; the breaking speed of the operating mechanism is obtained through a displacement sensor, and the three-time fitting is carried out through MATLAB to obtain the relation between the two as shown in the formula (6);
wherein k isnIs a constant value vIIThe breaking speed of the operating mechanism is shown, and v is the contraction speed of the arc column;
and a third stage: the opening speed of the vacuum switch operating mechanism is controlled in the third stage from the moment when the arc column of the arc current disappears to the moment when the arc current passes zero, and the action speed of the operating mechanism in the third stage is as follows:
wherein v isI、vII、vIIIFirst, second and third stage speeds, t1、t2The time of the first stage and the second stage, L is the maximum opening distance of the operating mechanism, and T is the existing time of the arc current.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010645812.7A CN111952114B (en) | 2020-07-07 | 2020-07-07 | Three-stage speed control method for voltage sharing of double-break vacuum switch |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010645812.7A CN111952114B (en) | 2020-07-07 | 2020-07-07 | Three-stage speed control method for voltage sharing of double-break vacuum switch |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN111952114A true CN111952114A (en) | 2020-11-17 |
| CN111952114B CN111952114B (en) | 2022-04-12 |
Family
ID=73340180
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202010645812.7A Active CN111952114B (en) | 2020-07-07 | 2020-07-07 | Three-stage speed control method for voltage sharing of double-break vacuum switch |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN111952114B (en) |
Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2008084718A (en) * | 2006-09-28 | 2008-04-10 | Mitsubishi Electric Corp | Operation circuit of switch, and power switch using it |
| CN102364655A (en) * | 2011-11-17 | 2012-02-29 | 武汉大学 | Dynamic voltage sharing device of multi-break vacuum circuit breaker and parameter selection method for dynamic voltage sharing device |
| EP2538429A1 (en) * | 2011-06-24 | 2012-12-26 | Tavrida Electric Holding AG | Method and apparatus for controlling circuit breaker operation |
| CN104465210A (en) * | 2014-11-19 | 2015-03-25 | 大连理工大学 | Double-break vacuum circuit breaker optimum clearance fit control method |
| CN204303672U (en) * | 2014-12-22 | 2015-04-29 | 苏州施源特电气有限公司 | A kind of transmission mechanism for double-fracture breaker |
| CN104810200A (en) * | 2015-05-19 | 2015-07-29 | 成都恒科瑞恩智能电气科技有限公司 | Super-quick vacuum switch device |
| CN110941935A (en) * | 2019-11-01 | 2020-03-31 | 国网宁夏电力有限公司电力科学研究院 | Simulation method and system for electric arc of double-break circuit breaker |
-
2020
- 2020-07-07 CN CN202010645812.7A patent/CN111952114B/en active Active
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2008084718A (en) * | 2006-09-28 | 2008-04-10 | Mitsubishi Electric Corp | Operation circuit of switch, and power switch using it |
| EP2538429A1 (en) * | 2011-06-24 | 2012-12-26 | Tavrida Electric Holding AG | Method and apparatus for controlling circuit breaker operation |
| CN102364655A (en) * | 2011-11-17 | 2012-02-29 | 武汉大学 | Dynamic voltage sharing device of multi-break vacuum circuit breaker and parameter selection method for dynamic voltage sharing device |
| CN104465210A (en) * | 2014-11-19 | 2015-03-25 | 大连理工大学 | Double-break vacuum circuit breaker optimum clearance fit control method |
| CN204303672U (en) * | 2014-12-22 | 2015-04-29 | 苏州施源特电气有限公司 | A kind of transmission mechanism for double-fracture breaker |
| CN104810200A (en) * | 2015-05-19 | 2015-07-29 | 成都恒科瑞恩智能电气科技有限公司 | Super-quick vacuum switch device |
| CN110941935A (en) * | 2019-11-01 | 2020-03-31 | 国网宁夏电力有限公司电力科学研究院 | Simulation method and system for electric arc of double-break circuit breaker |
Non-Patent Citations (2)
| Title |
|---|
| YIFAN FU ETAL.: "Investigation on the Influence of Non-Synchronous Magnetic Field Control on the Dynamic Voltage Distribution of Vacuum Circuit Breakers in Series", 《INVESTIGATION ON THE INFLUENCE OF NON-SYNCHRONOUS MAGNETIC FIELD CONTROL ON THE DYNAMIC VOLTAGE DISTRIBUTION OF VACUUM CIRCUIT BREAKERS IN SERIES》 * |
| 廖敏夫: "双断口真空开关的动态介质恢复特性分析", 《真空科学与技术学报》 * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN111952114B (en) | 2022-04-12 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Bo et al. | Investigation on arc dwell and restriking characteristics in DC high-power relay | |
| CN111627748B (en) | Double-break heterogeneous arc extinguishing chamber based on speed regulation | |
| Song et al. | Experimental investigation on the initial expansion process in a drawn vacuum arc and the influence of axial magnetic field | |
| CN111952114B (en) | Three-stage speed control method for voltage sharing of double-break vacuum switch | |
| CN109698682A (en) | A kind of nanosecond forward position high voltage pulse generator | |
| Yan et al. | Experimental investigation on anode spots and anode plumes in high-current vacuum arc under different contact materials | |
| CN109449761A (en) | Trigger switch trigger switch synchronous with the two-stage high power repetition that compact electromagnetic drives | |
| Zhou et al. | Operational characteristics of a surface breakdown triggered vacuum switch with six gap rod electrode system | |
| Liu et al. | Effect of TMF and AMF components on expansion process in different ignition modes of vacuum arc between spiral-type TMF contacts | |
| Ding et al. | Effect of parallel circuit parameters on the instability of a low-current vacuum arc | |
| Abid et al. | Effect of filling pressure on post-arc gap recovery of N 2 | |
| CN209056763U (en) | Trigger switch trigger switch synchronous with the two-stage high power repetition that compact electromagnetic drives | |
| US1861128A (en) | High-power circuit-breaker | |
| Frohlich et al. | Fundamental research on vacuum interrupters at technical universities in Germany and Austria | |
| CN111466006B (en) | Gas-insulated high-voltage or medium-voltage circuit breaker | |
| CN112490063A (en) | Direct-acting type rapid direct-current circuit breaker | |
| CN111999611B (en) | Test device and method for improving breakdown voltage of vacuum arc-extinguishing chamber | |
| Xiu et al. | Transition Process of Vacuum Arc to Diffusion Stage Under Transverse Magnetic Field | |
| Yao et al. | Opening velocity characteristics for vacuum interrupters with cup-type axial magnetic field contacts | |
| RU2207647C1 (en) | Switching device | |
| Wang et al. | Comparison of vacuum arc current transfer characteristics of a novel AMF-TMF contact under different opening velocities | |
| RU77502U1 (en) | VACUUM CIRCUIT BREAKER | |
| CN111863521B (en) | SF6 quick circuit breaker | |
| Yuan et al. | Interruption process and droplets emission in vacuum arc for aviation intermediate-frequency power supply system | |
| CN111834915B (en) | Method and system for back-flushing extinguishing arc plasma |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |