CN106992509A - A kind of laminated bus guide rod and suppressing method for being used to suppress VFTO - Google Patents

Abstract

The invention discloses a laminated busbar guide rod for suppressing VFTO, which comprises: an internal resistance layer, an inductance layer and an external resistance layer. The internal resistance layer has a central hollow area on the inside and an inductance layer on the outside, which is the same as the internal resistance layer. The above-mentioned external resistance layers are commonly used to absorb traveling wave energy after the formation of the ultra-fast transient overvoltage VFTO, increase the active power loss of the busbar guide rod, and reduce the amplitude and frequency of the VFTO; the inside of the inductance layer is the internal resistance layer, and the outside It is an external resistance layer, including: a magnetic ring and a high-conductivity medium, which are used to transmit current normally under power frequency conditions. The beneficial effects of the present invention are: by changing the wave impedance of the bus bar, the active power loss of the section of the bus bar is increased, and the development of the traveling wave is suppressed, so as to achieve the purpose of reducing the amplitude and frequency of the VFTO, which helps to improve the safety of the primary equipment Reliable operation, reducing the risk of insulation damage to primary equipment, and will also help the safe use of secondary testing equipment, and improve the reliable operation of intelligent equipment such as electronic transformers.

Description

A laminated bus bar guide rod and suppression method for suppressing VFTO

technical field

The invention relates to the field of power grid operation and maintenance, and more specifically, to a laminated bus bar guide rod and a suppression method for suppressing VFTO.

Background technique

Very Fast Transient Over-voltage VFTO (Very Fast Transient Over-voltages, VFTO) refers to the transient overvoltage within the wave front time of 3 to 100ns, mainly due to the operation of the isolating switch in the gas insulated switchgear GIS (Gas Insulated Switchgear, GIS) and other factors. When operating the isolating switch of GIS, due to the slow moving speed of the contacts, several expected wear and heavy breakdowns between the contacts are caused. During the closing process, the voltage between the contacts decreases, and then a breakdown similar to reclosing occurs, and VFTO with a higher voltage amplitude appears. In addition, during the opening process, due to the slow moving speed of the contacts, re-breakdown occurs between the contacts, and a scene similar to reclosing will also occur, so VFTO with a higher voltage amplitude will also occur. Due to the steep wave front and high amplitude, VFTO is likely to cause damage to GIS, winding equipment, transformers and secondary equipment. The upper limit frequency of VFTO can reach 5MHz to 40MHz, which will cause harm to GIS internal insulation supports, basin insulators and other components, especially to transformers and reactors connected to GIS through oil and gas bushings. With the increase of GIS voltage level, the lower the relative insulation margin of primary equipment, the greater the risk of harm caused by the existence of VFTO. In addition, the harm of VFTO to the secondary system is also very serious. The construction of the smart grid has enabled more and more analog signals to be digitized, allowing the secondary weak current system to be moved closer to the primary equipment, and a large number of monitoring equipment are also installed near the primary equipment. During operation, it was found that the overvoltage generated by the operation of the isolating switch is one of the main causes of secondary faults, especially the secondary equipment installed near the primary equipment has a high failure rate.

As one of the characteristics of the primary equipment of the smart grid, the failure of the electronic transformer is high, which often occurs in the secondary system, including the front circuit, the acquisition card and the data processing unit, resulting in crash, garbled code or damage. An important influencing factor is caused by the electromagnetic interference generated by the operation of the isolating switch, including the instantaneous ground potential rise of the primary equipment ground terminal caused by the operation of the isolating switch.

Therefore, a busbar guide rod is needed to solve the problem of suppressing VFTO.

Contents of the invention

The invention provides a laminated busbar guide rod used for suppressing VFTO to solve the problem of suppressing VFTO.

In order to solve the above problems, according to one aspect of the present invention, a laminated busbar guide bar for suppressing ultra-fast transient overvoltage VFTO is provided, the laminated busbar guide bar includes: an internal resistance layer, an inductance layer and external resistive layer,

The internal resistance layer, the inner side is the central hollow area, and the outer side is the inductance layer, which is used together with the external resistance layer to absorb traveling wave energy after the VFTO is formed, increase the active loss of the busbar guide rod, and reduce the amplitude and frequency;

The inductance layer has an internal resistance layer on the inside and an external resistance layer on the outside, including: a magnetic ring and a high-conductivity medium for normal transmission of current under power frequency conditions.

Preferably, the high-conductivity medium is symmetrically embedded in the magnetic ring.

Preferably, the magnetic ring is ferrite material, and the high conductivity medium is molybdenum oxide.

Preferably, both the internal resistance layer and the external resistance layer are composed of non-inductive damping resistors connected in series.

Preferably, the non-inductive damping resistor is electrically connected to the conductive rod tube through an insert or a spring piece.

According to another aspect of the present invention, a kind of method of suppressing VFTO is provided, said method comprises:

Under the condition of power frequency, the current is transmitted through the inductive layer, and the inductive layer includes: a high-conductivity medium and a magnetic ring;

After the VFTO is formed, the traveling wave energy is absorbed through the internal resistance layer and the external resistance layer, which increases the active power loss of the bus bar and reduces the amplitude and frequency of the VFTO.

Preferably, the high-conductivity medium is symmetrically embedded in the magnetic ring.

Preferably, the magnetic ring is ferrite material, and the high conductivity medium is molybdenum oxide.

Preferably, both the internal resistance layer and the external resistance layer are composed of non-inductive damping resistors connected in series.

Preferably, the non-inductive damping resistor is electrically connected to the conductive rod tube through an insert or a spring piece.

The beneficial effects of the present invention are:

The technical solution of the present invention designs a stacked bus bar conductive bar that consumes electron flow energy to suppress VFTO. By changing the wave impedance of the bus bar, the active power loss of the section of the bus bar is increased, and the development of traveling waves is suppressed, thereby Reaching the purpose of reducing the amplitude and frequency of VFTO will help to improve the safe and reliable operation of primary equipment, reduce the risk of insulation damage to primary equipment, and will also help the safe use of secondary detection equipment and improve the intelligence of electronic transformers. reliable operation of equipment. At the same time, the design can not only transform the existing GIS pipeline, but also play a guiding role in the design of the new GIS pipeline, and the design principle can be applied to the arrester bushing to reduce the damage of the lightning wave to the primary equipment insulation.

Description of drawings

A more complete understanding of the exemplary embodiments of the present invention can be had by referring to the following drawings:

FIG. 1 is a top view of a laminated bus guide bar for suppressing VFTO according to an embodiment of the present invention;

Figure 2 is a schematic diagram of VFTO formation;

Fig. 3 is a front view of a laminated busbar guide rod for suppressing VFTO according to an embodiment of the present invention;

4 is a side view of a laminated bus bar guide for VFTO suppression according to an embodiment of the present invention; and

Fig. 5 is a schematic diagram of a laminated busbar guide rod for suppressing VFTO according to an embodiment of the present invention;

Fig. 6 is an equivalent circuit diagram of a laminated bus guide bar for suppressing VFTO according to an embodiment of the present invention;

FIG. 7 is a flowchart of a suppression method 700 according to an embodiment of the present invention.

detailed description

Exemplary embodiments of the present invention will now be described with reference to the drawings; however, the present invention may be embodied in many different forms and are not limited to the embodiments described herein, which are provided for the purpose of exhaustively and completely disclosing the present invention. invention and fully convey the scope of the invention to those skilled in the art. The terms used in the exemplary embodiments shown in the drawings do not limit the present invention. In the figures, the same units/elements are given the same reference numerals.

Unless otherwise specified, the terms (including scientific and technical terms) used herein have the commonly understood meanings to those skilled in the art. In addition, it can be understood that terms defined by commonly used dictionaries should be understood to have consistent meanings in the context of their related fields, and should not be understood as idealized or overly formal meanings.

FIG. 1 is a top view of a laminated bus bar guide for suppressing VFTO according to an embodiment of the present invention. As shown in Figure 1, the laminated bus bar guide rod for suppressing VFTO includes: a central hollow area 1, a magnetic ring 2, an external resistance layer 3, an internal resistance layer 4 and a high-conductivity medium 5, the magnetic ring and The high conductivity medium constitutes the inductance layer. Preferably, the internal resistive layer has a central hollow area on the inner side and an inductive layer on the outer side, and is used together with the external resistive layer to absorb traveling wave energy after the formation of the ultra-fast transient overvoltage VFTO and increase the active power of the busbar guide rod. Loss, reducing the amplitude and frequency of VFTO.

Preferably, the inductive layer has an internal resistance layer on the inside and an external resistance layer on the outside, which are used for normal transmission of current under power frequency conditions. Preferably, the high-conductivity medium is symmetrically embedded in the magnetic ring. Preferably, the magnetic ring is ferrite material, and the high conductivity medium is molybdenum oxide. Preferably, both the internal resistance layer and the external resistance layer are composed of non-inductive damping resistors connected in series, and the non-inductive damping resistors are electrically connected to the conductive rod through inserts or spring sheets. 2 is a front view of a laminated bus bar guide for suppressing VFTO according to an embodiment of the present invention. 3 is a side view of a laminated bus bar guide for VFTO suppression according to an embodiment of the present invention.

Figure 4 is a schematic diagram of VFTO formation. As shown in Figure 4, it is the schematic diagram formed by VFTO. There are two busbars in GIS, the wave impedances are Z1 and Z2, respectively, and the charges G1 and G2 are respectively charged. on distribution. Due to the good insulation performance in the GIS, the energy loss is very weak during the redistribution process of the busbar charge, and the traveling wave is refracted and reflected at both ends of the busbar to form a fast and steep overvoltage with a high amplitude and a frequency of 5 to 40MHz, that is, the formation of VFTO .

5 is a schematic diagram of a laminated bus bar guide for suppressing VFTO according to an embodiment of the present invention. As shown in Figure 5, in GIS, the wave impedance of a section of busbar conductive rod is changed in the form of laminated busbar guide rod, that is, the form of inductance L paralleled with resistance R, and the traveling wave forms a higher voltage in the residual inductance section, and its two ends Resistors absorb traveling wave energy under high voltage. The magnetic ring is cut into two incomplete semicircles, and a high-conductivity medium is embedded between the two semicircles. Consistent with the characteristics of the magnetic ring, the resistance value of this high-conductivity medium is extremely small under power frequency conditions, and its inductive reactance value is extremely large as the frequency increases, that is, the current is transmitted through this high-conductivity medium under normal conditions, and the After VFTO, because its inductive reactance is too large, it enters the resistance rod with small impedance. Because of its small energy, it is absorbed by the resistance rod to produce a very small active loss, which can reduce the amplitude and frequency. The embedded high-conductivity medium is different from the material of the magnetic ring, and the amplitude of the inductance change of the two is different. Generally, the magnetic ring is made of ferrite material, while the high-conductivity medium is made of molybdenum oxide and other materials. Improvement effect.

6 is an equivalent circuit diagram of a laminated bus guide bar for suppressing VFTO according to an embodiment of the present invention. As shown in Fig. 6, the inductive material L and the resistance R of the laminated busbar guide rod are realized by distributed parameter elements. L1 represents the inductance of the magnetic ring; L2 represents the inductance of the high-conductivity medium; R1 represents the resistance of the internal resistance rod; R2 represents the resistance of the external resistance rod. The inductive substance L increases the round-trip time of the traveling wave, that is, reduces the VFTO frequency, and at the same time increases the voltage at the R terminal of the resistor, so that the traveling wave charge flows through R to generate energy consumption. The parameters of the inductive substance L and the resistance R are determined according to the simulation calculation results of suppressing VFTO. In the calculation of the transient process, the nonlinearity of the perceptual substance L must be considered. In the embodiment of the present invention, the resistance of R1 is 10Ω, and the resistance of L2 is 1Ω at power frequency of the high-conductivity medium. As the frequency increases, the impedance shows an increasing trend, and when the frequency reaches 1MHz, the resistance value is 100Ω. The magnetic ring is an ordinary magnetic ring without special requirements. According to the simulation and actual measurement results, this design method can absorb more than 30% of the VFTO amplitude in the original GIS pipeline, and its effect of suppressing VFTO is far better than the current magnetic ring.

In addition, the design principle of the high-conductivity medium plus magnetic ring of the present invention can not only be used to absorb VFTO in GIS, but also can be used to absorb lightning waves in the arrester bushing, that is, the conductive rod inside the bushing is magnetized with high-conductivity medium Structural design of ring-added resistors when stacked.

FIG. 7 is a flowchart of a suppression method 700 according to an embodiment of the present invention. As shown in FIG. 7 , the suppression method 700 is used to suppress VFTO. The method 700 starts from step 101. In step 701, under power frequency conditions, the current is transmitted through the inductance layer, and the inductance layer includes: high Conductive medium and magnetic ring. Preferably, the high-conductivity medium is symmetrically embedded in the magnetic ring. Preferably, the magnetic ring is ferrite material, and the high conductivity medium is molybdenum oxide.

Preferably, in step 702, after the VFTO is formed, the traveling wave energy is absorbed by the internal resistance layer and the external resistance layer, so as to increase the active power loss of the bus guide bar and reduce the amplitude and frequency of the VFTO. Preferably, both the internal resistance layer and the external resistance layer are composed of non-inductive damping resistors connected in series. Preferably, the non-inductive damping resistor is electrically connected to the conductive rod tube through an insert or a spring piece.

The laminated busbar guide rod for suppressing VFTO in this embodiment of the present invention corresponds to the VFTO suppressing method 700 in another embodiment of the present invention, and will not be repeated here.

The invention has been described with reference to a small number of embodiments. However, it is clear to a person skilled in the art that other embodiments than the invention disclosed above are equally within the scope of the invention, as defined by the appended patent claims.

Generally, all terms used in the claims are to be interpreted according to their ordinary meaning in the technical field, unless explicitly defined otherwise therein. All references to "a/the/the [means, component, etc.]" are openly construed to mean at least one instance of said means, component, etc., unless expressly stated otherwise. The steps of any method disclosed herein do not have to be performed in the exact order disclosed, unless explicitly stated.

Claims (10)

1. a kind of laminated bus guide rod for being used to suppress VFTO, it is characterised in that the laminated bus guide rod includes：It is internal Resistive layer, inductor layer and external electrical resistance layer,

Vacancy section centered on the internal resistance layer, inner side, outside is inductor layer, is provided commonly for the external electrical resistance layer in spy After fast transient overvoltage VFTO is formed, traveling wave energy is absorbed, increases the active loss of bus guide rod, VFTO amplitude and frequency is reduced Rate；

The inductor layer, inner side is internal resistance layer, and outside is external electrical resistance layer, including：Magnet ring and height lead medium, in work Normal transmission electric current under the conditions of frequency.

2. bus guide rod according to claim 1, it is characterised in that the height is led medium and is symmetrically embedded in magnet ring.

3. bus guide rod according to claim 2, it is characterised in that the magnet ring is Ferrite Material, the height leads Jie Matter is molybdenum oxide.

4. bus guide rod according to claim 1, it is characterised in that the internal resistance layer and external electrical resistance layer are by nothing Sense damping resistance is composed in series.

5. bus guide rod according to claim 4, it is characterised in that the noninductive damping resistance passes through inserts or spring leaf It is electrically connected with conductive rod tube.

6. a kind of method for suppressing VFTO using bus guide rod as claimed in claim 1, it is characterised in that methods described bag Include：

Under the conditions of power frequency, electric current is transmitted by inductor layer, the inductor layer includes：Height leads medium and magnet ring；

After VFTO is formed, traveling wave energy is absorbed by internal resistance layer and external electrical resistance layer, increases the active damage of bus guide rod Consumption, reduces VFTO amplitude and frequency.

7. according to the method described in claim 1, it is characterised in that the height is led medium and is symmetrically embedded in magnet ring.

8. method according to claim 7, it is characterised in that the magnet ring is Ferrite Material, the height leads medium and is Molybdenum oxide.

9. method according to claim 6, it is characterised in that the internal resistance layer and external electrical resistance layer are by noninductive resistance Buffer resistance is composed in series.

10. method according to claim 9, it is characterised in that the noninductive damping resistance by inserts or spring leaf with Conductive rod tube electrical connection.