CN201663043U

CN201663043U - 220,000 volts autotransformer with on-load voltage regulation

Info

Publication number: CN201663043U
Application number: CN2010201310341U
Authority: CN
Inventors: 张中
Original assignee: Jiangsu Sunel Transformer Co Ltd
Current assignee: Jiangsu Sunel Transformer Co., Ltd.
Priority date: 2010-02-08
Filing date: 2010-02-08
Publication date: 2010-12-01
Anticipated expiration: 2020-02-08

Abstract

The utility model discloses a 220,000 volts autotransformer with on-load voltage regulation, comprising an iron core, a high-tension coil, a medium-tension coil and a low-tension coil; from the iron core to the low-tension coil, the arrangement mode of coils: the iron core - the high-tension coil - a medium-tension coil branch A - a medium-tension coil branch B - the low-tension coil is adopted; and the medium-tension coil branch A and the medium-tension coil branch B are connected with each other in series. In the utility model, the adoption of the 220,000 volts autotransformer with on-load voltage regulation and lower cost can realize the effects of superhigh impedance and low loss.

Description

22 ten thousand volts self-coupling on-load voltage-regulating transformers

Technical field

The utility model belongs to field transformer, relates in particular to a kind of 22 ten thousand volts self-coupling on-load voltage-regulating transformers.

Background technology

According to national standard " GB/T6451-2008 oil-immersed power transformer technical parameter and requirement ", for the conventional impedance self-coupling on-load voltage-regulating transformer of electric power system 22 ten thousand volts commonly used, the impedance voltage percentage under its high pressure-middle pressure, middle pressure-low pressure, three kinds of operational modes of high pressure-low pressure is followed successively by 8～10%, 18～24%, 28～34% usually.

Along with 22 ten thousand volts power system development, the separate unit capacity of transformer increases day by day, by original 120MVA be main flow to rise to 180-240MVA be main flow, under the conventional impedance voltage percentage, the short circuit current of low-pressure side is quite big, makes the specification of low-pressure side circuit breaker select to have any problem.In this case, generally adopt series reactor is set on low-voltage circuit, come limiting short-circuit current with the short-circuit impedance that improves entire system.In recent years, because the development of transformer technology and electrical network user improve day by day to the requirement that reduces the converting equipment maintenance workload, take the lead in adopting the cancellation series reactor by Guangdong Province's power department, and incorporate its impedance into transformer in the lump, promptly design the ultra-high-impedance transformer and replace original conventional impedance transformer and add series reactor, and succeed in actual applications.So in nearest 2-3, especially in part Jiangsu, developed coastal province, east and Zhejiang area, the demand of jumbo ultra-high-impedance self-coupling on-load voltage-regulating transformer sharply increases, this is a new problem and challenge for high-power transformer manufacturer.

The present big capacity ultra-high-impedance of 22 ten thousand volts self-coupling on-load voltage-regulating transformer in the national grid bid, its capacity is generally 180-240MVA, typical impedance voltage percentage under its high pressure-middle pressure, middle pressure-low pressure, three kinds of operational modes of high pressure-low pressure is followed successively by 12～14%, 44～48%, 62～68%, this ultra-high-impedance be arranged on guarantee between high pressure and the medium voltage side can the prerequisite of more low-yield loss electric energy transmitting under, obviously controlled the short circuit current of low-pressure side greatly.

In the many decades before the earlier 2000s, the conventional coil arrangement architecture of domestic 220,000 volts of conventional impedance self-coupling on-load voltage-regulating transformers is: from iron core, that 1. coil arrangement from inside to outside is followed successively by in proper order is unshakable in one's determination → and 2. intermediate voltage winding (also claiming common winding) → 4. high-tension coil (also claiming series coil) → 5. high pressure voltage regulation coil of low-voltage coil → 3..This structure can realize conventional impedance voltage smoothly.Consider that the coil near core side is the coil of minimum voltage, this kind traditional structure also is fairly simple reliable on insulation system.But, realize ultra-high-impedance if still adopt above-mentioned conventional coil arrangement architecture, the problem that has two aspects: one, if increase simply main insulating structure between low-voltage coil and the intermediate voltage winding realize in-double high impedance between low, then in-when impedance increases between low, high-between impedance then because the synchronous increase of coil mean radius and increasing thereupon, be difficult in the realization-accurately realize ultra-high-impedance between low the time high-between higher resistance; They are two years old, for main performance for transformer---load loss and the no-load loss, this way that increases the main insulating structure between low-voltage coil and the intermediate voltage winding simply is very uneconomic, because because the increase of the mean radius of high pressure and intermediate voltage winding, for realizing equal drain performance target, this will consume more copper cash and silicon steel sheet that more dominance can grade.Therefore, be necessary very much to study a kind of self-coupling on-load voltage-regulating transformer of new coil arrangement architecture, under lower material cost, realize target capabilities such as ultra-high-impedance, low-loss.

Summary of the invention

The purpose of this utility model be to provide that a kind of cost is low, low-loss and can realize 22 ten thousand volts self-coupling on-load voltage-regulating transformers of ultra-high-impedance.

A kind of technical scheme of the present utility model is, a kind of 22 ten thousand volts self-coupling on-load voltage-regulating transformers, comprise iron core, high-tension coil, intermediate voltage winding and low-voltage coil, its improvement is: adopt the iron core-high-tension coil-A-of intermediate voltage winding branch high pressure voltage regulation coil-such coil arrangement mode of the B-of intermediate voltage winding branch low-voltage coil from iron core to low-voltage coil, the described intermediate voltage winding A of branch connects with the B of intermediate voltage winding branch.

The utility model adopts and adopts the iron core-high-tension coil-A-of intermediate voltage winding branch high pressure voltage regulation coil-such coil arrangement mode of the B-of intermediate voltage winding branch low-voltage coil from iron core to low-voltage coil, make high-tension coil be positioned at the most inboard of close iron core, so the mean radius of high-tension coil diminishes, conductor length shortens, resistance just diminishes, thereby copper loss diminishes, and cost has also reduced; Simultaneously, the described intermediate voltage winding A of branch connects with the B of intermediate voltage winding branch, with the radial mode that is split into two series branches of intermediate voltage winding, the shape that has changed the leakage field group has promptly increased the equivalent leakage field area of leakage field group, thereby realized ultra-high-impedance, the utility model adopts the radial division of one-sided coil back series connection to add whole inverted peculiar methods, thereby makes 22 ten thousand volts self-coupling on-load voltage-regulating transformers realize ultra-high-impedance and low-loss at lower cost.

Description of drawings

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

Embodiment

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

As shown in Figure 1, a kind of 22 ten thousand volts self-coupling on-load voltage-regulating transformers, comprise iron core 1, high-tension coil 2, intermediate voltage winding 3 and low-

voltage coil

4,4 adopt the such coil arrangement mode of the iron core 1-high-tension coil 2-intermediate voltage winding A 3-1-of the branch high pressure voltage regulation coil 5-intermediate voltage winding B 3-2-of branch low-voltage coil 4 from iron core 1 to low-voltage coil, and the described intermediate voltage winding A 3-1 of branch connects with the B3-2 of intermediate voltage winding branch.

The most inboard owing to high-tension coil is placed on, as long as handle insulation system well, for realizing that ultra-high-impedance and low-loss are quite favourable; And the high pressure voltage regulation coil placed between A of intermediate voltage winding branch and the B of branch, the high impedance in can utilizing fully between the pressure-low pressure in requisition for main insulating structure, significantly improved the economy of transformer device structure.

Computational analysis comparing result according to many products, for capacity at 180000kVA to 22 ten thousand volts self-coupling on-load voltage-regulating transformers between the 240000kVA, the special coil structure that adopts the utility model to describe, with respect to conventional impedance transformer, corresponding to same load loss and no-load loss performance, the separate unit product cost only increases about 10%.But the Short Circuit withstand performance of considering the ultra-high-impedance transformer is better than conventional impedance transformer greatly, and the current specification of having saved the series reactor in the low-pressure side circuit and having reduced circuit breaker, simplified the structure of electric power system, obviously reduced and safeguarded whole maintenance workload, in fact significantly reduced the transforming plant primary cost of investment, its economy is self-evident.

Claims

1. ten thousand volts self-coupling on-load voltage-regulating transformer, comprise iron core (1), high-tension coil (2), intermediate voltage winding (3) and low-voltage coil (4), it is characterized in that: adopt iron core (1)-high-tension coil (2)-A of intermediate voltage winding branch (3-1)-high pressure voltage regulation coil (5)-B of intermediate voltage winding branch (3-2)-such coil arrangement mode of low-voltage coil (4) from iron core (1) to low-voltage coil (4), the described intermediate voltage winding A of branch (3-1) connects with intermediate voltage winding branch B (3-2).