CN201655513U

CN201655513U - Transformer high-voltage coil shunting tap structure

Info

Publication number: CN201655513U
Application number: CN2010201097162U
Authority: CN
Inventors: 张中
Original assignee: Jiangsu Sunel Transformer Co Ltd
Current assignee: Jiangsu Sunel Transformer Co., Ltd.
Priority date: 2010-02-09
Filing date: 2010-02-09
Publication date: 2010-11-24
Anticipated expiration: 2020-02-09

Abstract

The utility model discloses a transformer high-voltage coil shunting tap structure. A high-voltage coil body comprises six shunting sections which are divided into four H1 shunting sections and two H2 shunting sections, wherein the H1 shunting sections are divided into a first shunting section, a second shunting section, a third shunting section and a fourth shunting section; the H2 shunting sections are divided into a fifth shunting section and a sixth shunting section; a ninth tap is pulled out by the first shunting section; the first shunting section and the second shunting section are intertwined with each other to pull out an eighth tap and a seventh tap; the second shunting section and the third shunting section are intertwined with each other to pull out a sixth tap; the third shunting section and the fourth shunting section are intertwined with each other to pull out a fifth tap and a fourth tap; the fourth shunting section and the fifth shunting section are intertwined with each other to pull out a third tap; the fifth shunting section and the sixth shunting section are intertwined with each other to pull out a second tap; and a first tap is pulled out by the sixth shunting section. The transformer high-voltage coil shunting tap structure can obviously improve the short-circuit resistance of an axial split type on-load voltage-regulating transformer of 500 thousand volt grade.

Description

Transformer high-voltage coil shunting tap structure

Technical field

The utility model belongs to field transformer, relates in particular to a kind of transformer high-voltage coil shunting tap structure, is applicable to 50 ten thousand volts axial split on-load tap-changing transformers.

Background technology

Since 21 century, in East China of China, areas such as North China, southwest, northwest, many newly-built power plant day by day trend towards adopting low pressure winding division formula on-load tap-changing transformer as startup in order to save capital construction investment.The outstanding feature of this kind transformer is: two branches of division winding can independent operating and standby mutually, also can parallel running; And when a certain branch was short-circuited fault, the load of another non-fault branch still can be kept operation under near 90% voltage; In addition, the short-circuit impedance of this kind transformer higher (usually between 18%～23%), limiting short-circuit current effectively.Replace two with on-load tap-changing transformer electric pressure, that total capacity is identical with this kind transformer, can save transformer equipment cost 30～40%; Simultaneously, the Generator Set of current each power plant is selected 600MW and above capacity more and more, the secondary side voltage of generator step-up transformer has upgraded to 500,000 volts mostly, so each power plant is urgent day by day to the demand of 50 ten thousand volts on-load voltage regulation transformer with split windings.But because the electric pressure height, technological difficulties are many, and the manufacturing cost of domestic traditional transformer production producer is still apparently higher than international well-known manufacturers such as Japanese Toshiba and ABB, the market competitiveness relatively a little less than.

50 ten thousand volts division formula on-load tap-changing transformer has two kinds of structural shapes in theory---low pressure axis of winding division formula and the radial division formula of low pressure winding; The loop construction arrangement mode of low pressure axis of winding dual low voltage transformer by iron core is from the inside to surface: stablize that winding (if having) → up and down divides multilayer and around the special high-tension coil of being entangled with the middle part inlet wire of mode shunting tap of drum type brake low pressure winding → body band; The loop construction of the radial dual low voltage transformer of low pressure winding is similar to common three coil transformers, and its arrangement mode by iron core is from the inside to surface: stablize the inboard winding of winding (if having) → low pressure → high pressure pressure regulation winding → end inlet wire high-tension coil → low pressure outside winding.Two kinds of structural shapes all are feasible in theory, and electric property but has very big difference.When partly passing through impedance behavior, both division impedances have very big-difference same, and the coefficient of causing a split is totally different, and the former bundle factor (promptly divide impedance and pass through the ratio of impedance) is about 3.5, and the latter's bundle factor is 4.5～5.5.The critical defect of radial dual low voltage transformer is on operation characteristic, when the high-pressure side is in non-specified tap (when especially being in limit tap), the impedance of partly passing through of partly passing through impedance and high pressure winding-low pressure outside winding of the inboard winding of high pressure winding-low pressure has evident difference, both differ when limit tap can exceed 20%, this means in the capacity allocation of passing through between when operation two low pressure branches significantly unevenly, one of them branch is with obvious overload; Be similar to two unmatched transformers connected in parallel operations of impedance, this is quite disadvantageous.In addition, when adopting the radial splitted construction of low pressure, high-tension coil has to adopt the end outlet structure, because high-tension coil is 50 ten thousand volts, therefore insulation system will be quite complicated, and the high-tension coil head end will need bigger insulation distance and cause the significantly increase and cost heightens of material usage such as iron core to the iron yoke; Therefore, in the 50 ten thousand volts division formula on-load tap-changing transformer design of states such as Japan, be not adopt the radial splitted construction of low pressure winding.And, be not have the problems referred to above, and owing to radial minimizing of going up coil number and clearance for insulation has tangible cost advantage for low pressure axis of winding dual low voltage transformer; But the Short Circuit withstand performance of axial split formula transformer is its weak link.How to design novel high-tension coil special construction, reduce the horizontal leakage field that causes because of the ampere-turn imbalance between the high and low pressure coil as far as possible, thereby under the prerequisite that keeps big cost advantage, significantly improve the Short Circuit withstand performance of axial split formula transformer, this is the key problem in technology point in the 50 ten thousand volts axial split formula on-load tap-changing transformers designs just.

Usually, as 50 ten thousand volts axial split formula on-load tap-changing transformers of the startup of large power plant, its typical high-pressure side tapping voltage is 500 (525) kV ± 8 * 1.25%.In common designing technique, consider the symmetry of high-tension coil structure and the economy of design, the way of taking is ± 8 * 1.25% tap to be arranged to be positioned at the body tap section of high-tension coil end, because the neutral point of 50 ten thousand volts transformers is defined as dead earth or through little reactance grounded, so its insulation level is not higher than 60 kilovolts of level insulation against ground levels, so be fully feasible from this structure of angle of insulation.Method for designing according to routine, when ± 8 * 1.25% tap adopts positive-negative voltage-regulation, at least need to make 8 tap sections, extract 9 taps out, as everyone knows, body tap hop count is many more, and then the ampere-turn imbalance is serious more between the coil during limit tap state, laterally leakage field is big more, and the Short Circuit withstand performance of transformer is poor more.

Summary of the invention

The purpose of this utility model provides a kind of transformer high-voltage coil shunting tap structure that can obviously improve transformer Short Circuit withstand performance.

A kind of technical scheme of the present utility model is, a kind of transformer high-voltage coil shunting tap structure, and the high-tension coil body comprises 6 tap sections, wherein is divided into 4 H ₁Tap section and 2 H ₂The tap section, described H ₁The number of turn of tap section is H ₂1.5 times of the number of turn of tap section, described H ₁The tap section is divided into the first tap section, the second tap section, the 3rd tap section and the 4th tap section, described H ₂The tap section is divided into the 5th tap section and the 6th tap section, the described first tap section is extracted the 9th tap out, be entangled with between the first tap section and the second tap section and extract the 8th tap and the 7th tap out, be entangled with between the described second tap Duan Yudi, the three tap sections and extract the 6th tap out, be entangled with between the 3rd tap Duan Yudi four tap sections and extract the 5th tap and the 4th tap out, be entangled with between the 4th tap Duan Yudi five tap sections and extract the 3rd tap out, be entangled with between described the 5th tap Duan Yudi six tap sections and extract second tap out, described the 6th tap section is extracted first tap out.

The number of turn with each tap is 2N, described each H ₁Every section number of turn of tap section is 3N, each H ₂Every section number of turn of tap section is 2N.

The number of turn with each tap is 12 circles, described each H ₁Every section number of turn of tap section is 18 circles, each H ₂Every section number of turn of tap section is 12 circles.

The tap section of the utility model 50 ten thousand volts axial split formula on-load tap-changing transformers be set to the high-tension coil body with 6 tap sections, significantly reduce the reactance height in tap zone, thereby obviously improved the Short Circuit withstand performance, guaranteed the reliability and the economy of 50 ten thousand volts axial split formula on-load tap-changing transformers.

Description of drawings

Fig. 1 is a structural representation of the present utility model;

Fig. 2 is H ₁Section coil winding schematic diagram;

Fig. 3 is H ₂Section coil winding schematic diagram.

Embodiment

Below contrast accompanying drawing,, the utility model made further specifying by the description of embodiment.

As shown in Figure 1, a kind of transformer high-voltage coil shunting tap structure, the high-tension coil body comprises 6 tap sections, wherein is divided into 4 H ₁Tap section 1 and 2 H ₂Tap section 2, described H ₁The number of turn of tap section 1 is H ₂1.5 times of the number of turn of tap section 2, described H ₁Tap section 1 is divided into the first tap section 1-1, the second tap section 1-2, the 3rd tap section 1-3 and the 4th tap section 1-4, described H ₂Tap section 2 is divided into the 5th tap section 2-1 and the 6th tap section 2-2, the described first tap section 1-1 extracts the 9th tap T9 out, be entangled with between the first tap section 1-1 and the second tap section 1-2 and extract the 8th tap T8 and the 7th tap T7 out, be entangled with between described second tap section 1-2 and the 3rd tap section 1-3 and extract the 6th tap T6 out, be entangled with between the 3rd tap section 1-3 and the 4th tap section 1-4 and extract the 5th tap T5 and the 4th tap T4 out, be entangled with between the 4th tap section 1-4 and the 5th tap section 2-1 and extract the 3rd tap T3 out, be entangled with between described the 5th tap section 2-1 and the 6th tap section 2-2 and extract the second tap T2 out, described the 6th tap section 2-2 extracts the first tap T1 out.

With 50 ten thousand volts axial split on-load tap-changing transformers as an example, at first reasonably adjust the number of turn of specified tap, make the number of turn of each tap can be taken as deviation that even number and voltage ratio check in allowed limits, because axial split formula on-load tap-changing transformer is as the startup in power plant, its range of capacity is generally between 31.5MVA to 75MVA, capacity is less relatively, so the turn ratio of high-tension coil is more, the number of turn that can select each tap is an even number.

If the number of turn Wtap=2N of each tap then is divided into 4 H with 6 tap sections ₁Section and 2 H ₂Section, wherein H ₁Every section number of turn of section is taken as 3N, i.e. 1.5 tap numbers of turn; H ₂Every section number of turn of section is taken as 2N, is 1 tap number of turn.With H ₁Section and H ₂What Duan Jinhang was special is entangled with, and 9 shunting taps that can accomplished ± 8 * 1.25% taps (T1～T9), as shown in Figure 1.

Among Fig. 1, per minute connects the number of turn and is taken as 12 circles and makes example, H ₁Every section number of turn of section is taken as 18, i.e. 1.5 tap numbers of turn; H ₂Every section number of turn of section is taken as 12.Respectively lift one's head rationally in each grade outlet for making, it is example that Fig. 2,3 is 24 grades with stay shelves number, cooperates the H among Fig. 1 ₁Section and H ₂Every section number of turn of section, the reality that has provided the actual winding method of the special section of being entangled with and every section is around the number of turn.

For keeping the radial consistency of tap section, H ₂Section should be chosen the bigger wire gauge of thickness, reduces the interlayer mat thickness in the line segment, H as far as possible ₁Section and H ₂Duan Junying chooses highly relative specification less than the normal reach lead, reaches the purpose that reduces axial short circuit mechanical force to reduce the uneven region height of ampere-turn.In addition, because H ₂Every section number of turn of section all is taken as even number, if adopt traditional appointment way of being entangled with the unit in pairs, then internal side diameter is not easy tap greatly and at outside diameter along the potential difference of stay, therefore should adopt modified model shown in Figure 1 to be entangled with winding.

Claims

1. transformer high-voltage coil shunting tap structure, it is characterized in that: the high-tension coil body comprises 6 tap sections, wherein be divided into 4 H1 tap sections (1) and 2 H2 tap sections (2), the number of turn of described H1 tap section (1) is 1.5 times of the number of turn of H2 tap section (2), described H1 tap section (1) is divided into the first tap section (1-1), the second tap section (1-2), the 3rd tap section (1-3) and the 4th tap section (1-4), described H2 tap section (2) is divided into the 5th tap section (2-1) and the 6th tap section (2-2), the described first tap section (1-1) is extracted the 9th tap (T9) out, be entangled with between the first tap section (1-1) and the second tap section (1-2) and extract the 8th tap (T8) and the 7th tap (T7) out, be entangled with between described second tap section (1-2) and the 3rd tap section (1-3) and extract the 6th tap (T6) out, be entangled with between the 3rd tap section (1-3) and the 4th tap section (1-4) and extract the 5th tap (T5) and the 4th tap (T4) out, be entangled with between the 4th tap section (1-4) and the 5th tap section (2-1) and extract the 3rd tap (T3) out, be entangled with between described the 5th tap section (2-1) and the 6th tap section (2-2) and extract second tap (T2) out, described the 6th tap section (2-2) is extracted first tap (T1) out.

2. transformer high-voltage coil shunting tap structure according to claim 1 is characterized in that: the number of turn with each tap is 2N, and every section number of turn of described each H1 tap section is 3N, and every section number of turn of each H2 tap section is 2N.

3. transformer high-voltage coil shunting tap structure according to claim 1 and 2 is characterized in that: the number of turn with each tap is 12 circles, and every section number of turn of described each H1 tap section is 18 circles, and every section number of turn of each H2 tap section is 12 circles.