Background technology
Insulator is one of maximum and of paramount importance element of quantity in the electric power system, is the important component part of overhead transmission line, and crucial status is arranged in electric power system.Along with improving constantly of electric pressure, traditional porcelain insulator and glass insulator can not satisfy the requirement of external insulation, perhaps can bring a series of problems such as project cost height.
Series of advantages such as composite insulator is in light weight with it, intensity is high, be difficult for broken, pollution flashover voltage is high, need not zero value detection, be easy to make, transportation, installation and maintenance have been broken the dominant position of pottery, glass insulator, are being widely used in decades recently.
Selecting for use and designing, the key parameter of having recommended the relevant umbrella skirt construction of selecting principle, method and insulator for use to satisfy among the international standard IEC-815 for the regional porcelain insulator of filth.The product of at present main porcelain insulator producer all meets the requirement of IEC-815.The operating experience of filthy regional circuit also proves, based on the insulator of this standard application runnability of satisfaction guaranted substantially.
The DC compound insulator umbrella skirt construction comprise small one and large one and one big two little etc. multiple, many users and manufacturer are from the operating experience of traditional porcelain insulator, simply by stipulating that required creepage distance guarantees that the resistant of synthetic insulator dodges the wet performance of dodging, the value of umbrella skirt construction parameter is lacked scientific evidence.Because manufacturing process is simple, parameters such as umbrella stretches out by changing, umbrella spacing and umbrella inclination angle, producer almost can produce the synthetic insulator of the required any creepage distance of user under a certain given setting height(from bottom).Because the arc phenomenon of wafing under the direct voltage is serious, umbrella skirt construction to the arc path influence significantly makes the utilance difference of creepage distance, so under same structure height or the identical creepage distance condition, umbrella skirt construction different composite insulator contamination voltage difference is bigger.
Up to the present, research institution is not arranged both at home and abroad under direct voltage, composite insulator umbrella skirt construction parameter is carried out system research to the influence of direct current pollution flashover characteristic, therefore can not be optimized design to DC compound insulator umbrella skirt construction parameter, can not provide the umbrella skirt construction parameter of the optimum of direct current pollution flashover characteristic.
Embodiment
Describe in detail below in conjunction with the embodiment of the invention.
The present invention by the umbrella that changes the big umbellule of composite insulator stretch out, parameters such as umbrella spacing and umbrella inclination angle, the composite insulator umbrella skirt construction of direct current pollution flashover characteristic optimum is proposed.In conjunction with Fig. 1,2, the partial parameters of the composite insulator umbrella skirt construction that the present invention relates to is described as follows:
Full skirt diameter: the external diameter of insulator full skirt.
Umbrella stretches out: the radial distance between insulator full skirt outer and the sheath; Middle gamp umbrella shown in Fig. 1,2 stretches out P
1, the umbellule umbrella stretches out P
2
Umbrella spacing: the axial distance between the corresponding points on certain point and the adjacent same relative position same diameter full skirt on the insulator full skirt, the gamp umbrella interval S shown in Fig. 1,2
1
Adjacent umbrella spacing: the axial distance between the adjacent full skirt of the insulator lower edge, the adjacent umbrella umbrella interval S shown in Fig. 1,2
2
Insulation distance: the axial distance between the gold utensil of insulator two ends.
Creepage distance: between the gold utensil of insulator two ends, along the beeline of all full skirts and jacket surface.
Creepage coefficient CF: the ratio of insulator creepage distance and insulation distance.
As shown in Figure 1, embodiment 1 composite insulator comprises the gold utensil at plug, plug two ends and full skirt and the sheath that mandrel outer covers, and the full skirt part is rearranged adjacent gamp umbrella interval S by the gamp of some equal diameters and a umbellule between the per two adjacent gamps
1Be 97.5~102.5mm; The gamp umbrella stretches out P
1Stretch out P with the umbrella of umbellule
2Ratio be 1.3~2.0, and average umbrella stretches out P
AvBe 77~79mm; The creepage coefficient CF of this composite insulator is 3.5~4.5.Wherein, average umbrella stretches out P
AvBe that the gamp umbrella stretches out P
1Stretch out P with the umbrella of umbellule
2Average, i.e. P
Av=(P
1+ P
2)/2.
Shown in Figure 2, embodiment 2 composite insulators comprise the gold utensil at plug, plug two ends and full skirt and the sheath that mandrel outer covers, and the full skirt part is rearranged adjacent gamp umbrella interval S by the gamp of some equal diameters and two umbellules between the per two adjacent gamps
1Be 110~130mm; The gamp umbrella stretches out P
1Stretch out P with the umbrella of umbellule
2Ratio be 1.3~2.0, and average umbrella stretches out P
AvBe 65~67mm; The creepage coefficient CF of this composite insulator is 3.5~4.5.Wherein, the full skirt diameter of two umbellules can equate also can be unequal, and the full skirt diameter of two umbellules of embodiment 2 equates.Average umbrella stretches out P
AvBe that the gamp umbrella stretches out P
1The umbrella of umbellule stretches out P
2Average, i.e. P
Av=(P
1+ 2P
2)/3.
The invention will be further described below in conjunction with artificial pollution test result.
1, the average umbrella influence of stretching out
1) embodiment 1 composite insulator
Under the different umbrella spacing conditions, the average umbrella of the composite insulator of different umbrella skirt construction parameters stretches out P
Av(call U in the following text with 50% direct current pollution flashover voltage U
50%, unit K V) relation curve shown in Fig. 3 a, wherein, the gamp umbrella interval S of each curve correspondence
1Be respectively 90,100,110mm, gamp umbrella interval S
1With adjacent umbrella umbrella interval S
2Ratio be S
1: S
2=2: 1.
By Fig. 3 a as can be seen, average umbrella stretches out P
AvTo U
50%Obvious effect: work as P
AvDuring<78mm, the increase that pollution flashover voltage stretches out with the average umbrella of insulator and increasing gradually; Work as P
AvDuring=78mm, pollution flashover voltage is the value of reaching capacity substantially; Work as P
AvDuring>78mm, the increase with average umbrella stretches out though the decline degree is also not obvious, totally has downward trend.
2) embodiment 2 closes insulator
Under the different umbrella spacing conditions, the average umbrella of the composite insulator of different umbrella skirt construction parameters stretches out P
AvWith U
50%Relation curve shown in Fig. 3 b, wherein, the gamp umbrella interval S of each curve correspondence
1Be respectively 110,150mm, gamp umbrella interval S
1With adjacent umbrella umbrella interval S
2Ratio be S
1: S
2=3: 1.
By Fig. 3 b as can be seen, average umbrella stretches out P
AvTo U
50%Obvious effect: work as P
AvDuring<66mm, the increase that pollution flashover voltage stretches out with the average umbrella of insulator and increasing gradually, and the rising degree is apparent in view; Work as P
AvDuring=66mm, pollution flashover voltage is the value of reaching capacity substantially; Work as P
AvDuring>66mm, the increase with average umbrella stretches out though the decline degree is also not obvious, totally has downward trend.
Therefore, analyzed and can be drawn by Fig. 3 a, 3b: for embodiment 1 insulator and embodiment 2 insulators, average umbrella stretches out P
AvWhen value is respectively 77~79mm and 65~67mm left and right sides, pollution flashover characteristic optimum.2, the influence of umbrella spacing
1) embodiment 1 insulator
Figure is that embodiment 1 average umbrella stretches out P
AvWhen identical, gamp umbrella interval S
1With U
50%Relation curve.The marking explanation of curve bottom among Fig. 4 a, as :-▲-90/66mm, wherein P
1=90mm, P
2=66mm, the P of the curve correspondence of band " ▲ "
Av=(P
1+ P
2)/2=(90+66)/2=78mm; The P of remaining curve correspondence
AvAnalogize by corresponding mark.
By Fig. 4 a as seen, when gamp umbrella interval S
1During=100mm, composite insulator has pollution flashover characteristic preferably, and pollution flashover voltage is the highest, chooses gamp umbrella interval S
1Be 97.5-102.5, can meet design requirement.
2) embodiment 2 insulators
Fig. 4 b stretches out P for embodiment 2 average umbrellas
AvWhen identical, gamp umbrella interval S
1With U
50%Relation curve.The marking explanation of curve top among Fig. 4 b, as :-▲-90/54mm, wherein P
1=90mm, P
2=54mm, the P of the curve correspondence of band " ▲ "
Av=(P
1+ 2P
2)/3=(90+2 * 54)/3=66mm; The P of remaining curve correspondence
AvAnalogize by corresponding mark.
By Fig. 4 b as seen, when gamp umbrella interval S
1During=110~130mm, pollution flashover characteristic optimum.
3, the influence of creepage coefficient
The creepage coefficient of reference composite insulator and 50%U relation curve Fig. 5, when creepage coefficient CF was within 3.2~4.5, the pollution flashover characteristic was better relatively, and pollution flashover voltage can reach maximum.When creepage coefficient CF greater than 4.5 the time, creepage coefficient increases, pollution flashover voltage descends on the contrary.
Above-mentioned result of study shows: the umbrella skirt construction parameter of composite insulator is directly related with the direct current pollution flashover voltage, and present certain rules, reasonable optimizing designs composite insulator umbrella skirt construction parameter, can improve the direct current pollution flashover voltage of composite insulator largely.The design of umbrella skirt construction parameter optimization not only can improve the utilance of creepage distance, and the direct current pollution flashover voltage that also improves the unit insulation height largely is more than 25%.