WO2018032717A1

WO2018032717A1 - Ultra-high voltage electroceramics external-insulation lead-out bushing

Info

Publication number: WO2018032717A1
Application number: PCT/CN2017/070402
Authority: WO
Inventors: 虞育号
Original assignee: 江苏智达高压电气有限公司
Priority date: 2016-08-15
Filing date: 2017-01-06
Publication date: 2018-02-22
Also published as: CN106128659B; CN106128659A

Abstract

Disclosed is an ultra-high voltage electroceramics external-insulation lead-out bushing, which can be applied to such a device as an ultra-high voltage GIS, a tubular busbar and a circuit breaker. The bushing comprises a ceramic bushing, a grounding flange (1) and a conductive rod (3) arranged in the centre of the ceramic bushing. A cylindrical grounding electrode (4) is provided between the conductive rod (3) and the grounding flange (1). The ceramic bushing at least has two adjacent sub-bushings (5, 6). The sub-bushings (5, 6) are fixed to each other as a whole via a transition member (7). A cylindrical intermediate electrode (8) penetrating the sub-bushing (6) therebelow is provided between the grounding electrode (4) and the conductive rod (3). The intermediate electrode (8) is isolated from the grounding electrode (4) and the conductive rod (3). This solution can significantly improve the electrical performance of the bushing, and in particular, improve the wet flashover voltage, the bending strength, etc. of the bushing, while reducing manufacturing difficulties and manufacturing costs of the ultra-high voltage ceramic bushing.

Description

一种特高压电瓷外绝缘出线套管UHV electric porcelain outer insulation outlet bushing

技术领域Technical field

本发明涉及一种特高压套管，尤其是一种可用于母线、GIS、断路器及其相近设备上的瓷外套出线套管。The invention relates to an ultra-high voltage bushing, in particular to a porcelain jacket outlet bushing which can be used for a busbar, a GIS, a circuit breaker and the like.

背景技术Background technique

目前550kV及以上特高压断路器及GIS用出线套管，外绝缘有电瓷和复合两种，对于以电瓷为外绝缘的出线套管，瓷套基本都是塔型结构(也称锥形)，对于750kV产品，高度在7m以上。由于电瓷套管制造过程中，其成型及烧成阶段的工艺特点，烧制的电瓷元件高度不超过2m，所以550kV及以上的瓷套是由若干个单节瓷套通过无机粘接二次烧成，瓷件越高，烧成难度越高，制造成本也越高。At present, the 550kV and above UHV circuit breakers and GIS outlet bushings are made of electric porcelain and composite. For the outlet bushings with electric porcelain as the outer insulation, the porcelain sleeves are basically tower-type structures (also called cones). For 750kV products, the height is above 7m. Due to the process characteristics of the forming and firing stages in the manufacturing process of the electric porcelain bushing, the height of the fired electric porcelain component does not exceed 2 m, so the porcelain sleeve of 550 kV and above is subjected to secondary bonding by a plurality of single-section porcelain sleeves. The higher the porcelain, the higher the difficulty of firing and the higher the manufacturing cost.

现有高压电瓷出线套管如图1所示，出线上下都胶装有法兰(下法兰1，上法兰2)，出线套管是用导电杆3将断路器或GIS等设备的特高压、大电流穿越接地法兰(下法兰1)，将电能引入、引出***。导电杆3与接地法兰之间形成一个高压电极，中间的绝缘介质是SF6气体，为了满足及提高电气性能，使出线套管通过相应的电气性能试验，接地法兰(下法兰1)内侧设置有一个接地电极4，而相应的，导电杆3就是高压电极，导电杆3与接地电极4之间形成一个比较均匀的同轴电场，其最大场强出现在导电杆3的表面，同轴电场计算方法：The existing high-voltage electric porcelain outlet bushing is shown in Figure 1. The outer and lower rubbers are equipped with flanges (lower flange 1, upper flange 2). The outlet bushings are made of conductive rods 3 to make circuit breakers or GIS equipment. High voltage and high current pass through the grounding flange (lower flange 1) to introduce and withdraw electrical energy into the system. A high-voltage electrode is formed between the conductive rod 3 and the grounding flange, and the insulating medium in the middle is SF6 gas. In order to meet and improve the electrical performance, the outlet bushing passes the corresponding electrical performance test, and the inner side of the grounding flange (the lower flange 1) A grounding electrode 4 is disposed, and correspondingly, the conductive rod 3 is a high voltage electrode, and a relatively uniform coaxial electric field is formed between the conductive rod 3 and the grounding electrode 4, and the maximum field strength appears on the surface of the conductive rod 3, coaxial Electric field calculation method:

E＝U/[r1×ln(r2/r1)]E=U/[r1×ln(r2/r1)]

E——导电杆表面场强；E——the surface field strength of the conductive rod;

U——试验电压；U——test voltage;

r1——导电杆截面半径；R1——the cross-section radius of the conductive rod;

r2——接地电极内屏蔽半径；R2——the shielding radius in the grounding electrode;

为了寻求规律，我们选用750kV套管的工频电压和雷电冲击电压，并选取不同r1、r2进行对比计算，数据如下：In order to seek the law, we select the power frequency voltage and lightning impulse voltage of the 750kV bushing, and select different r1 and r2 for comparison calculation. The data are as follows:

根据以上计算结果对比，为了降低场强，通常的做法是增大r1及r2，因此瓷套的直径就会比较大。另外，由于接地电极不会做得太高，一般不会超过瓷套高度的20％(太高会导致接地电极与瓷套外绝缘表面间电位差过大而击穿)，所以外绝缘的电压分布是很不均匀的，下端不到20％的瓷套高度占外绝缘电压分布的50％以上，而在淋雨状态下，宝塔状的外形使得下端的雨水又非常密集，因此下端非常容易发生湿闪络。According to the above calculation results, in order to reduce the field strength, the usual practice is to increase r1 and r2, so the diameter of the porcelain sleeve will be relatively large. In addition, since the grounding electrode will not be made too high, it will generally not exceed 20% of the height of the porcelain sleeve (too high will cause the connection The potential difference between the ground electrode and the outer insulating surface of the porcelain sleeve is too large and breaks down, so the voltage distribution of the outer insulation is very uneven, and the height of the porcelain sleeve of less than 20% of the lower end accounts for more than 50% of the external insulation voltage distribution. In the rainy state, the shape of the pagoda makes the rain at the lower end very dense, so the lower end is very prone to wet flashover.

发明内容Summary of the invention

本发明所要解决的技术问题是，克服现有技术的不足，提供一种特高压电瓷外绝缘出线套管，通过对瓷套进行分段并增设中间电极，改善外绝缘的电位分布，提高湿闪络电压及污秽条件下的闪络电压，提高设备安全性。The technical problem to be solved by the present invention is to overcome the deficiencies of the prior art and provide a UHV electric porcelain outer insulation outlet bushing. By segmenting the porcelain sleeve and adding an intermediate electrode, the potential distribution of the outer insulation is improved, and the wet flash is improved. The flashover voltage under the voltage and pollution conditions improves the safety of the device.

为了解决以上技术问题，本发明提供的一种特高压电瓷外绝缘出线套管，包括瓷套、接地法兰和设置于瓷套中央的导电杆，所述导电杆与接地法兰之间设置有筒状的接地电极,其特征在于：所述瓷套至少具有两个相邻的子套管，子套管之间通过过渡件固定为一体，接地电极与导电杆之间设置有贯穿下方子套管的筒状中间电极，所述中间电极与接地电极和导电杆之间为绝缘。In order to solve the above technical problem, the present invention provides an ultra-high voltage electric porcelain outer insulation outlet bushing, which comprises a porcelain sleeve, a grounding flange and a conductive rod disposed at a center of the porcelain sleeve, and the conductive rod and the grounding flange are disposed between The cylindrical grounding electrode is characterized in that: the porcelain sleeve has at least two adjacent sub-casings, and the sub-casings are integrally fixed by a transition piece, and a sub-sleeve is disposed between the grounding electrode and the conductive rod A cylindrical intermediate electrode of the tube, the intermediate electrode being insulated from the ground electrode and the conductive rod.

为了进一步解决以上技术问题，本发明还具有如下特征：In order to further solve the above technical problems, the present invention also has the following features:

1、过渡件呈板状结构，子套管分别通过法兰固定在过渡件的两侧。1. The transition piece has a plate-like structure, and the sub-casings are respectively fixed on both sides of the transition piece by flanges.

2、所述过渡件为金属材质，过渡件的***设置有均压环。2. The transition piece is made of metal material, and a pressure equalizing ring is arranged on the periphery of the transition piece.

3、所述中间电极的上端通过所述过渡件固定，中间电极的下端延伸至接地电极下端或接地电极下端以下。3. The upper end of the intermediate electrode is fixed by the transition piece, and the lower end of the intermediate electrode extends to the lower end of the ground electrode or below the lower end of the ground electrode.

4、导电杆与中间电极之间形成同轴电场，中间电极与接地电极之间形成同轴电场。4. A coaxial electric field is formed between the conductive rod and the intermediate electrode, and a coaxial electric field is formed between the intermediate electrode and the ground electrode.

5、所述瓷套内部填充有绝缘气体。5. The porcelain sleeve is filled with an insulating gas inside.

6、所述绝缘气体为六氟化硫。6. The insulating gas is sulfur hexafluoride.

本发明特高压瓷出线套管，将瓷套分成两段(也可以是两段以上),中间用过渡板联接，在过渡板上安装与接地电极和导电杆绝缘的筒状中间电极，使导电杆与中间电极之间、中间电极与接地电极之间分别形成同轴电场，电容量分别为C1、C2。通过调整、优化导电杆截面半径r1、接地电极内屏蔽半径r2、中间电极内屏蔽半径r3，以及中间电极和接地电极的高度，使C1、C2基本相等。这样，通过电容分压就可以将瓷套中间法兰的电位钳制在0.5倍的Un(设备额定电压)，可以明显改善外绝缘的电位分布，提高湿闪络电压及污秽条件下的闪络电压。The ultra-high pressure porcelain outlet sleeve of the invention divides the porcelain sleeve into two sections (which may also be two or more sections), and is connected by a transition plate in the middle, and a cylindrical intermediate electrode insulated from the ground electrode and the conductive rod is mounted on the transition plate to make the conductive A coaxial electric field is formed between the rod and the intermediate electrode and between the intermediate electrode and the ground electrode, and the capacitances are C1 and C2, respectively. By adjusting and optimizing the cross-section radius r1 of the conductive rod, the shielding radius r2 in the grounding electrode, the shielding radius r3 in the intermediate electrode, and the heights of the intermediate electrode and the grounding electrode, C1 and C2 are substantially equal. In this way, the potential of the intermediate flange of the porcelain sleeve can be clamped to 0.5 times of Un (equal rated voltage) by capacitor partial pressure, which can significantly improve the potential distribution of the outer insulation and improve the flashover voltage under the conditions of wet flashover voltage and pollution. .

此外，由于过渡板的遮挡作用，上瓷套的雨水经由过渡板直接落地，不会淋落在下瓷套的伞盘上，相当于降低了雨量，也有利于湿闪络电压的提高。In addition, due to the shielding effect of the transition plate, the rainwater of the porcelain sleeve directly falls through the transition plate, and does not fall on the umbrella disk of the lower porcelain sleeve, which is equivalent to reducing the rainfall and also improving the wet flashover voltage.

在同样的瓷套内径及导电杆直径的前提下，增加中间电极后，导电杆表面的场强降低接近一半，显著提高内绝缘的电气性能，或者在保持内绝缘性能相同时，可明显减小瓷套直径。Under the premise of the same inner diameter of the porcelain sleeve and the diameter of the conductive rod, after increasing the intermediate electrode, the field strength of the surface of the conductive rod is reduced by nearly half, which significantly improves the electrical performance of the inner insulation, or can be significantly reduced while maintaining the same internal insulation performance. Porcelain sleeve diameter.

在同样瓷套高度及瓷套直径的前提下，本发明在提高湿闪络电压及内绝缘电气性能的同时，瓷套的生产难度大大降低。由于可以通过单节瓷套进行分解及组装，套管的安装和运输也更加方便、安全，上下瓷件借助过渡板联结，对瓷套抗弯受力时的力的分解有很好的改善，提高套管的抗弯性能。此创新结构尤其适合于750kV及以上特高压产品，可靠性显著提高的同时，制造成本也能明显下降。 Under the premise of the same porcelain sleeve height and porcelain sleeve diameter, the invention improves the wet flashover voltage and the internal insulation electrical performance, and the production difficulty of the porcelain sleeve is greatly reduced. Because it can be disassembled and assembled by a single-section porcelain sleeve, the installation and transportation of the casing is also more convenient and safe. The upper and lower porcelain pieces are connected by the transition plate, which greatly improves the decomposition of the force when the porcelain sleeve is subjected to bending resistance. Improve the bending resistance of the casing. This innovative structure is especially suitable for UHV products of 750kV and above. The reliability is significantly improved and the manufacturing cost can be significantly reduced.

附图说明DRAWINGS

图1为现有特高压电瓷外绝缘出线套管结构示意图。FIG. 1 is a schematic structural view of a conventional UHV electric porcelain outer insulation outlet bushing.

图2为本发明特高压电瓷外绝缘出线套管结构示意图。2 is a schematic view showing the structure of an ultra-high voltage electric porcelain outer insulation outlet bushing according to the present invention.

图中标号示意如下：The figures in the figure are as follows:

1-下法兰，2-上法兰，3-导电杆，4-接地电极，5-上瓷套，6-下瓷套，7-过渡板，8-中间电极，9-均压环。1-lower flange, 2-upper flange, 3-conducting rod, 4-grounding electrode, 5-upper porcelain sleeve, 6-lower porcelain sleeve, 7-transition plate, 8-intermediate electrode, 9-pressure equalizing ring.

具体实施方式detailed description

下面结合实施例对本发明作进一步详细描述。但是本发明不限于所给出的例子。The present invention will be further described in detail below with reference to the embodiments. However, the invention is not limited to the examples given.

如图2所示，本实施例特高压电瓷外绝缘出线套管，具有上瓷套5和下瓷套6，上下瓷套通过中间法兰固定在过渡板7上，过渡板7上安装有均压环，瓷套内充有六氟化硫(绝缘气体)。上瓷套5的顶端设置上法兰2，下瓷套6的底端设置下法兰1(下法兰1接地，因此下法兰1也称作接地法兰)，接地电极4(可借助过渡板)安装在下法兰1上，该接地电极4与下法兰1等电位。过渡板上固定有中间电极8，该中间电极8位于导电杆3和接地电极4之间，并且中间电极8与导电杆3和接地电极4绝缘。中间电极8、过渡板7和中间法兰为等电位。中间电极、接地电极、导电杆三者同轴，当导电杆通电后，导电杆与中间电极之间形成同轴电场，电容量为C1；中间电极与接地电极之间形成同轴电场，电容量为C2。As shown in FIG. 2, the ultra-high voltage electric porcelain outer insulation outlet sleeve of the embodiment has an upper porcelain sleeve 5 and a lower porcelain sleeve 6, and the upper and lower porcelain sleeves are fixed on the transition plate 7 through the intermediate flange, and the transition plate 7 is mounted with The pressure ring and the porcelain sleeve are filled with sulfur hexafluoride (insulating gas). The top end of the upper porcelain sleeve 5 is provided with an upper flange 2, and the bottom end of the lower porcelain sleeve 6 is provided with a lower flange 1 (the lower flange 1 is grounded, so the lower flange 1 is also referred to as a ground flange), and the ground electrode 4 can be used The transition plate) is mounted on the lower flange 1, and the ground electrode 4 is equipotential to the lower flange 1. An intermediate electrode 8 is fixed on the transition plate, the intermediate electrode 8 is located between the conductive rod 3 and the ground electrode 4, and the intermediate electrode 8 is insulated from the conductive rod 3 and the ground electrode 4. The intermediate electrode 8, the transition plate 7, and the intermediate flange are equipotential. The intermediate electrode, the grounding electrode and the conductive rod are coaxial. When the conductive rod is energized, a coaxial electric field is formed between the conductive rod and the intermediate electrode, and the capacitance is C1; a coaxial electric field is formed between the intermediate electrode and the ground electrode, and the capacitance is formed. For C2.

通过调整导电杆直径、中间电极内径及高度、接地电极内径及高度，使两部分的电容值C1和C2接近相等，通过仿真计算验证电场场强在绝缘允许范围之内。By adjusting the diameter of the conductive rod, the inner diameter and height of the middle electrode, the inner diameter and height of the grounding electrode, the capacitance values C1 and C2 of the two parts are nearly equal, and the field strength of the electric field is verified within the allowable range of insulation by simulation calculation.

例如以下计算实例：For example, the following calculation example:

导电杆直径Conductor rod diameter	中间电极直径Intermediate electrode diameter	中间电极高度Middle electrode height	接地电极直径Ground electrode diameter	接地电极高度Ground electrode height	C1C1	C2C2
180mm180mm	385mm385mm	5000mm5000mm	530mm530mm	2100mm2100mm	1316pF1316pF	1317pF1317pF

除上述实施例外，本发明还可以有其他实施方式。凡采用等同替换或等效变换形成的技术方案，均落在本发明要求的保护范围。 Other than the above-described embodiments, the present invention may have other embodiments. Any technical solution formed by equivalent replacement or equivalent transformation falls within the protection scope of the present invention.

Claims

一种特高压电瓷外绝缘出线套管，包括瓷套、接地法兰和设置于瓷套中央的导电杆，所述导电杆与接地法兰之间设置有筒状的接地电极,其特征在于：所述瓷套至少具有两个相邻的子套管，子套管之间通过过渡件固定为一体，接地电极与导电杆之间设置有贯穿下方子套管的筒状中间电极，所述中间电极与接地电极和导电杆之间为绝缘。An ultra-high voltage electric porcelain outer insulation outlet sleeve comprises a porcelain sleeve, a grounding flange and a conductive rod disposed at a center of the porcelain sleeve, and a cylindrical ground electrode is disposed between the conductive rod and the ground flange, wherein: The porcelain sleeve has at least two adjacent sub-casings, and the sub-casings are integrally fixed by a transition piece, and a cylindrical intermediate electrode penetrating through the lower sub-casing is disposed between the ground electrode and the conductive rod, the middle The electrode is insulated from the ground electrode and the conductive rod.
根据权利要求1所述的特高压电瓷外绝缘出线套管，其特征在于：所述过渡件呈板状结构，子套管固定在过渡件的两侧。The UHV electric porcelain outer insulation outlet sleeve according to claim 1, wherein the transition piece has a plate-like structure, and the sub-casing is fixed on both sides of the transition piece.
根据权利要求2所述的特高压电瓷外绝缘出线套管，其特征在于：所述过渡件为金属材质，过渡件的***设置有均压环。The UHV electric porcelain outer insulation outlet sleeve according to claim 2, wherein the transition piece is made of a metal material, and a pressure equalizing ring is disposed on a periphery of the transition piece.
根据权利要求2所述的特高压电瓷外绝缘出线套管，其特征在于：子套管分别通过法兰固定在过渡件的两侧。The UHV electric porcelain outer insulation outlet bushing according to claim 2, wherein the sub-casings are respectively fixed to both sides of the transition piece by flanges.
根据权利要求1所述的特高压电瓷外绝缘出线套管，其特征在于：所述中间电极的上端通过所述过渡件固定，中间电极的下端延伸至接地电极下端或接地电极下端以下。The UHV electric porcelain outer insulation outlet bushing according to claim 1, wherein an upper end of the intermediate electrode is fixed by the transition piece, and a lower end of the intermediate electrode extends to a lower end of the ground electrode or a lower end of the ground electrode.
根据权利要求1-5任一项所述的特高压电瓷外绝缘出线套管，其特征在于：导电杆与中间电极之间形成同轴电场，中间电极与接地电极之间形成同轴电场。The ultra-high voltage electric porcelain outer insulation outlet bushing according to any one of claims 1 to 5, wherein a coaxial electric field is formed between the conductive rod and the intermediate electrode, and a coaxial electric field is formed between the intermediate electrode and the ground electrode.
根据权利要求1-6任一项所述的特高压电瓷外绝缘出线套管，其特征在于：所述瓷套内部填充有绝缘气体。The UHV electric porcelain outer insulation outlet bushing according to any one of claims 1 to 6, wherein the porcelain sleeve is filled with an insulating gas.
根据权利要求7所述的特高压电瓷外绝缘出线套管，其特征在于：所述绝缘气体为六氟化硫。 The UHV electric porcelain outer insulation outlet bushing according to claim 7, wherein the insulating gas is sulfur hexafluoride.