What are the characteristics of a dry type test transformer

Dry-type insulation, lighter than oil immersion change, but poor overload resistance, poor heat dissipation ability, easy to leak;

Product Features: 1. The dry-type test transformer is small in size, light in weight, compact in structure, no oil seepage, and maintenance-free;

2. The wiring is simple and intuitive, and it is easy to use;

3. The NRGTB dry-type test transformer has good insulation reliability and beautiful appearance;

4. The dry-type test transformer has overvoltage protection function. (The operation part can be customized with over-voltage protection and over-current protection, that is, double protection function).

The dry-type transformer is mainly composed of an iron core composed of silicon steel sheet and an epoxy resin cast coil, an insulating cylinder is placed between the high and low voltage coils to increase electrical insulation, and the coil is supported and constrained by a cushion block, and the fasteners of its parts overlap have anti-loosening properties.

Its advantages can be broadly divided into the following points:

Safe, fireproof, pollution-free, can run directly in the load center;

Adopting domestic advanced technology, high mechanical strength, strong anti-short circuit ability, small partial discharge, good thermal stability, high reliability and long service life;

Low loss, low noise, obvious energy-saving effect, maintenance-free;

Good heat dissipation performance, strong overload capacity, and increased capacity operation when forced air cooling;

Good moisture-proof performance, suitable for operation in high humidity and other harsh environments;

Dry-type transformers can be equipped with a complete temperature detection and protection system. The intelligent signal temperature control system can automatically detect and display the respective working temperature of the three-phase winding, automatically start and stop the fan, and have alarm, trip and other function settings;

Small size, light weight, less floor space, low installation cost.

Weifang Hengxin Electric has been producing dry-type transformers for nearly 20 years and has rich experience in production and research and development. Welcome customers to communicate.

Advantages of dry-type transformers.

1. Good fire performance, no flammable resin, no toxic gas, flame retardant and self-extinguishing characteristics.

2. Low loss and low noise.

3. No pollution, maintenance-free.

4. Good insulation performance, no partial discharge, strong resistance to lightning impact.

5. Good mechanical strength, strong resistance to temperature changes and short circuit.

6. Moisture resistant, can operate under high humidity.

7. The installation is economical, it can be installed with the load center, and no special foundation is required.

8. Small size and light weight.

9. Automatic temperature monitoring and protection.

Disadvantages of dry-type transformers.

1. The cost is high, the ability to resist harsh environments is relatively poor, and it can only be installed indoors under normal circumstances.

2. If the dry-type transformer coil is broken, it will be scrapped directly.

3. The dry-type transformer is durable, and the probability of winding failure is small. But once it fails, the whole setting changes, i.e. the limb is used to complete the change of the high voltage and low voltage windings.

Dry-type transformer: relies on air convection for cooling, generally used for local lighting, electronic circuits. Transformers such as machinery and equipment, in the power system, general steam turbine transformers, boiler transformers, ash removal transformers, dust removal transformers, desulfurization transformers, etc. are dry-type transformers, with a conversion ratio of 6000V 400V and 10KV 400V, which are used for loads with rated voltage of 380V.

The analysis report on market demand and investment strategic planning of dry-type transformer industry shows that China has become the largest country in the world in terms of dry-type transformer production and sales. Before the foreign high and low voltage electrical products, occupy some important domestic markets, but the dry-type transformer from the end of the 20th century, almost no import from abroad, in the domestic key projects and major projects, it is difficult to find a trace of foreign dry change.

At present, the pace of urban and rural power grid construction is accelerating, and China's power generation and electricity consumption are increasing day by day. Generally speaking, for every 1kW of additional power generation, 11kW of total transformer capacity needs to be added; Among them, the Satons distribution transformer accounts for about 1 3-1 2 of the total capacity of all transformers. It is estimated that dry-type distribution transformers account for about 1 5-1 4 of all distribution transformers.

Driven by the investment in power grid construction, the transformer industry is booming, and the output will maintain a growth rate of about 20% after 2010. According to the historical experience and the change of transformer voltage level structure, the proportion of distribution transformers is about 40%, and according to the proportion of 40%, China's new dry-type transformer output will reach about 200 million kva this year.

In the past 20 years, with the development of the world economy, dry transformer has achieved rapid development in the world, especially in the distribution transformer, the proportion of dry transformer is increasing, according to statistics, in developed countries such as Europe and the United States, it has accounted for 40 50% of the distribution transformer. In China, it accounts for about 50%. From the point of view of output, China since 1989 after the second urban network transformation meeting, the output of dry-type transformers has increased significantly, from the 90s of the 20th century, the annual rate of about 20% increase, the total output in 1999 has approached 10,000 MVA (the value has greatly exceeded 10 years ago, **4,005 MVA), and the total output in 2002 reached 20,000 MVA, in 2004 has reached 32,000 MVA.

Such a growth rate is also unprecedented in the world.

From the above data, it can be seen that China has become one of the countries with the largest dry variable production and sales in the world, and has been at the world's leading level in terms of factory scale, product capacity, voltage, etc.

The performance and function of the dry-type transformer are mainly reflected in the stability of the voltage can be adjusted, and the basic stability of the voltage can be guaranteed in the circuit, so that the circuit can be kept smooth, and lay a solid foundation for the safe operation of various electrical appliances. What are the components of dry-type transformers and their roles in circuits? Let's take a look with Tongyida :

The main structure of the dry-type transformer:

1.Core. The core is the main part of the magnetic circuit in a dry-type transformer.

Usually made of hot-rolled or cold-rolled silicon steel sheets with high silicon content, thickness, and coated with insulating paint on the surface, the iron core is divided into two parts: the core column and the transverse piece, and the core column is sleeved with windings; The transverse piece is used to close the magnetic circuit, and the basic form of the core structure has two types: heart type and shell type.

2.Winding. The winding is the circuit part of the dry-type transformer, which is wound with double wire (paper pack) insulated flat wire or enameled round wire.

The basic principle of dry-type transformer is the principle of electromagnetic induction, and now the single-phase double-winding dry-type transformer is used as an example to illustrate its basic working principle: when the voltage & is added to the primary side winding, the current flows, and the alternating magnetic flux is generated in the iron core, and these magnetic fluxes are called the main magnetic flux, under its action, the windings on both sides induce the electric potential 1,2 respectively, and the induced electric potential formula is: e=where:

e -- the effective value of the induced potential.

f -- frequency.

n -- number of turns.

Dry-type transformer characteristics and applications:

Features of dry-type transformers:

1.Safe, fireproof, pollution-free, can run directly in the load center;

2.Adopting domestic advanced technology, high mechanical strength, strong anti-short circuit ability, small partial discharge, good thermal stability, high reliability and long service life;

3.Low loss, low noise, obvious energy-saving effect, maintenance-free;

4.Good heat dissipation performance, strong overload capacity, and increased capacity operation when forced air cooling;

5.Good moisture-proof performance, suitable for operation in high humidity and other harsh environments;

6.Dry-type transformers can be equipped with a complete temperature detection and protection system. The intelligent signal temperature control system can automatically detect and display the respective working temperature of the three-phase winding, automatically start and stop the fan, and have alarm, trip and other function settings;

7.Small size, light weight, less floor space, low installation cost.

Dry-type transformers are widely used in local lighting, high-rise buildings, airports, docks, CNC machinery and equipment and other places. Cooling methods are divided into natural air cooling (AN) and forced air cooling (AF).

The dry-type test transformer adopts the new process and new material of coil epoxy vacuum casting molding and CD-type core. Compared with the oil invasion test transformer with the same capacity and voltage, it has the advantages of light weight, small size, beautiful appearance, stable performance, easy to use and carry, and no oil leakage. And effectively weaken the magnetic flux leakage, improve the dielectric strength and moisture resistance.

It is especially suitable for power system and power users to test the insulation performance of various electrical equipment on site, DC withstand voltage and leakage current test. It is the preferred product to replace the current bulky oil-induced transformer.

A brief description of dry-type test transformers.

Test transformer, English name: dry-type transformer test.

The dry-type test transformer outputs AC and DC high voltage, and provides high voltage for all kinds of high voltage tests. Dry-type test transformers are used for on-site testing of the insulation properties of various electrical equipment.

The dry-type test transformer is the introduction of the latest foreign advanced technology, the use of advanced production equipment, the use of coil epoxy vacuum casting molding, and the new process and new material of CD type core, compared with the same capacity, the same voltage of oil-immersed test transformer, with the advantages of light weight, small size, beautiful appearance, stable performance, easy to use and carry, no oil leakage and so on. And effectively weaken the magnetic flux leakage, improve the dielectric strength and moisture resistance. It is especially suitable for power system and power users to test the insulation performance, DC withstand voltage and leakage current test of various electrical equipment on site.

It is the preferred product to replace the current bulky oil-immersed transformer.

Aliases: high-voltage test transformer, power high-voltage test transformer, ultra-light high-voltage test transformer, cascade high-voltage test transformer, AC and DC high-voltage generator, high-voltage booster, high-voltage withstand voltage machine, high-voltage withstand voltage meter.

High Voltage Test Controller Features:

1. Zero-back protection device.

2. Eliminate residual voltage device.

3. High-voltage working sound and light alarm device.

4. Overcurrent protection device.

5. Small size, light weight, new security function.

Dry-type test transformers are generally used in series resonance withstand voltage tests. The main features are as follows:

1. In terms of insulation structure layout, according to the positioner oil"The distance effect"The principle is that multi-level insulation is adopted, and the inner insulation of the transformer is divided into multiple oil channels, so as to improve the degree of insulation and reduce the volume.

2. Epoxy resin is used to seal, because epoxy resin will produce a large number of bubbles when pouring under normal conditions, and the discharge phenomenon occurs at the high-voltage lead part. The metal parts are used to fix the lead pen and equalize the pressure, so that the discharge phenomenon is eliminated.

4. Compact structure, novel appearance, small volume and weight.

5. The iron core is a single-frame core type, using DQ type, cold-rolled to silicon steel sheets, and using new special materials to tighten the factor, replacing the traditional core-piercing screw. The coil is a concentric cylindrical multi-layer tower structure.

Two types of dry-type test transformers.

The dry-type test transformer mainly has the following characteristics:

1.The secondary voltage is high, and the current is generally small. Short-term work. Light weight, small size, beautiful appearance, stable performance, easy to use and carry, no oil leakage. Generally, it is larger than the loss of ordinary transformers.

2.It has a zeroing protection device, a residual pressure elimination device, a high-voltage working sound and light alarm device and an overcurrent protection device.

3.The magnetic flux leakage is weakened, the dielectric strength and moisture-proof performance are improved, and the ability of the transformer to withstand the impact of the test short-circuit current is enhanced. It is suitable for power systems and power users to test the insulation performance, DC withstand voltage and leakage of various electrical equipment on site.

4.Cabling is simple and intuitive, making it easy to use.

The dry-type test transformer has an overvoltage protection function. (The operation part can be customized with over-voltage protection and over-current protection, that is, double protection function).

6.The dry-type test transformer outputs AC and DC high voltage, providing high voltage for a variety of high voltage tests. The dry-type test transformer produced by Dingsheng Electric Power Company is used to check the insulation performance of various electrical equipment on site.

7.The dry-type test transformer has good insulation reliability and beautiful appearance.

8.The dry-type test transformer is small in size, light in weight, compact in structure, no oil leakage, and maintenance-free.

The input voltage of dry-type test transformer series products is 200V, and the input voltage can be changed according to the needs of electromagnetic induction, and the display high voltage can be continuously adjusted from zero volt to the rated maximum value.

For DC withstand voltage and leakage voltage test, as long as the high-voltage silicon stack is screwed on the high-voltage display terminal, the input voltage can be changed, so as to obtain DC high-voltage display of different values.

SGB: Test Transformer JS: Time Relay TY: Self-Coupling Voltage Regulator FM: Alarm.

LJ: Overcurrent Relay DDD: Indicator C: AC Contactor AQ: Start button.

K: Main power switch K: Time relay power switch AT: stop button &nb test transformer sp;CL: high-voltage silicon stack.

A K: Voltage regulator back to zero limit switch RD: Fuse A: Display voltmeter KV: Display voltmeter.