High voltage test transformer four media classification

There are four types of high voltage test transformers according to the medium:

YD oil-immersed high-voltage test transformer: large capacity, cheap, easy maintenance, mainstream products.

YDQ inflatable high voltage test transformer: arc extinguishing, light weight.

GTB dry high voltage test transformer: light weight, light weight, can be put down, expensive.

YD (C) series high-voltage test transformer: small capacity, low voltage, light weight, easy to transport and install.

YD oil-immersed high voltage test transformer:


The high-voltage test transformer is the basic test equipment used by the majority of users of power plants, power supply bureaus, and research institutes to conduct AC voltage withstand tests. It has passed the standards of the National Quality Supervision Bureau and is used for various electrical products, electrical components, and insulation materials. Such as the insulation strength test under the specified voltage, assessment of the product's insulation level, found that the insulation of the test product defects, measure the ability of over-voltage.

The oil-immersed test transformer is suitable for power systems, industrial and mining enterprises, transportation, post and telecommunication departments, scientific research units, etc., and conducts insulation strength tests for various high-voltage electrical equipment, electrical components, and insulating materials at power frequency or DC high voltage. The oil-immersed test transformer uses a single frame core type core structure. The primary winding is wound on the core and the high voltage winding is on the outside. This coaxial arrangement reduces the leakage flux and therefore increases the coupling between the windings.

The iron core of this series is a single-phase core type, which is made of high-quality cold-rolled oriented silicon steel sheet. The fastening method uses steel as a clamp. The high-voltage coil is a cylindrical multilayer tower, which is made of high-quality polyester enameled wire and high-voltage insulation material. The low voltage coil is outside and the instrument coil is a separate winding, which is generally 100V. The housing is octagonal and the test transformer above 10KVA is equipped with a movable iron wheel. With light weight, small size, easy movement, superior performance and so on.

working principle

1, AC, AC and DC test transformer: The power frequency power input to the operation box (or console), the auto-regulator regulator voltage input to the primary winding of the test transformer. According to the principle of electromagnetic induction, power frequency high voltage can be obtained in the secondary (high voltage) winding. This high frequency high voltage can obtain DC high voltage after rectification and capacitance filtering of the high voltage silicon stack. Its amplitude is 1.4 times of the effective value of the high voltage of the power frequency. It is only necessary to draw out the shorting bar when using direct current, and to insert shorting bar when using alternating current.

2. Tap test transformer: In order to meet the contradiction between a relatively high voltage of a transformer and a relatively low current, a high voltage winding is divided into two windings, one is a winding with a larger current and the other is Smaller current windings, and then two windings in series, lead to the 3, cascade test transformers: In order to obtain a higher voltage test transformer, a higher voltage may also be obtained by a cascade method. Figure 2 shows the basic wiring diagram of a three-stage cascade test transformer. Among them, the capacity and voltage relationship of the three transformers satisfy: P1=2P2=3P3, U(total)=1U+2U+3U.

Main Specifications:

> Rated capacity: 1 ~ 300KVA> Single rated output voltage: (AC) 50, 100, 150, 200, 300KV (DC) 70, 140, 210, 280KV> Rated input voltage: 200V, 400V> Transformation ratio: 500/ 1,1000/1, 1500/1, 2000/1, 3000/1> Ratio error: ≤±1.5%> Impedance voltage: <10%

YDQ inflatable high voltage test transformer:


Inflatable AC and DC test transformers Along with the development of China's power industry, the voltage rating of test transformers is also increasing, and traditional oil-immersed test transformers are increasingly unable to meet the site work in terms of volume and weight. The request. Inflatable test transformer reduces the volume and weight, and it is more convenient for customers to carry it to the site for testing. With the advancement of China's basic scientific research, the application of new materials and new processes, the new medium sulfur hexafluoride gas has been pushed to the power equipment. Application areas. Due to its excellent insulation performance, arc extinguishing performance and non-flammability, SF6 gas has been widely used as a new insulating medium.


1. The design concept, material selection and process flow of YDQ series products are all new. Therefore, it is not only small in size, light in weight, and beautiful in appearance, but also has achieved various technical indicators. > Standard requirements. YDQ series products are made of high quality cold-rolled DQ-151 oriented silicon steel sheet stacked into a multi-stage cylindrical frame core, and a high-strength tower coil is directly and continuously wound on a special high-strength insulating tube using a QZ type wire. The housing is sized to fit in SF6 gas. 2. The difference between YDQ (JZ) products and YDQ products lies in cleverly assembling high-voltage rectifier silicon stacks in high-voltage bushings through the insertion and extraction of short-circuit rods. The YDQ can be converted to high-frequency AC output or high-voltage DC output. 3. The difference between YDQ (C) products and YDQ products is in the casing structure.

main feature:

> The product is small in size and light in weight (40%-65% lighter than transformers of the same grade oil immersion tester).> Clean, no oil, no maintenance required. > Not affected by adverse weather conditions, the site can be tested without stopping. > The dielectric strength is significantly higher than that of the oil-immersed test transformer, with minimal corona.

Technical Parameters:

>Voltage level:10-600KV>Capacity range:1-600KVA>No-load current:<7%>Impulse voltage:<8%>Voltage rating:<5PC

Dry high voltage test transformer:


GTB dry test transformer has the characteristics of light weight, small size, beautiful appearance, stable performance, easy to carry, etc. It is especially suitable for on-site operation and use. It is a new AC/DC dual-purpose high-voltage test transformer that is replaced at home. This series of products is suitable for on-site testing of the insulation performance of various electrical equipment in the power system and various power users, high-voltage power supplies in various voltage systems or devices for DC high voltage and low current of electrical products.


This series of transformers, using advanced production equipment, uses a new process of coil winding epoxy vacuum casting and CD core, compared with similar products oil-immersed transformers, significantly reduce the weight, reduce the volume, improve the quality of the insulation Strength and humidity resistance, and effectively weaken the magnetic flux leakage and greatly enhanced.

Technical indicators:

> Impedance voltage: 12% dry test transformer> Output voltage waveform: power frequency, sine wave> Surface temperature rise: <55°C

> No-load loss: 0.2%~0.35%

> Allow continuous travel time: 1/hour> Continuous run time: continuous
String high voltage test transformer:


The main characteristics and functions of the series-excited high-voltage transformer are the same as those of the YDJ/TDM series, which differs from the above-mentioned transformer in that it has a great advantage over the high-voltage test transformer in that the entire test set consists of several single test transformers. The bench test transformer has a small capacity, low voltage and light weight, which is convenient for transportation and installation. Since it can be connected in series to a single test transformer output voltage several times higher, it can be divided into several sets of single test transformers and used alone.


In the basic schematic diagram of the cascade test transformer, the low voltage power supply is applied to the primary winding a1x1 of the test transformer I. The output voltage of the single test transformer I, II and III is V. The field windings A1, C1 supply the primary winding of the second stage test transformer II; the second stage test transformer II field windings A2, C2 supply the primary winding of the third stage test transformer III. The boxes of the second-stage test transformer II and the third-stage test transformer III are respectively located at a high potential of 1V and 2V to the ground, so that the cabinet is insulated from the ground and the casing of the test transformer I is grounded.

Use caution

1. The test transformer should be used together with the operation box (table). For the operation method of the operation box (table), please refer to the instruction manual of the operation box (table) for details.

2, transformer shell, high pressure tail must be grounded. To ensure safety, sufficient distance must be maintained between testers and other tested equipment and test transformers.

3. The output of the test transformer should generally be connected in series with current limiting resistors to protect the safety of the equipment.

YDJ series oil-immersed test transformer overview:

YDJ series oil-immersed test transformer has the characteristics of small size, light weight, compact structure, complete functions, strong versatility and easy to use. Especially suitable for power system, industrial and mining enterprises, research departments and other high voltage electrical equipment, electrical components, insulation materials under high frequency or DC high voltage insulation strength test. It is an indispensable and important equipment in high pressure test.


1. Good material selection, reliable quality and good year stability;

2, the voltage margin is large, the sound of electricity is small, and the discharge is small;

3, the use of new insulation materials, small size and light weight.


1. Rated voltage: AC50~400kVDC70~420kV;

2, rated capacity: 1 ~ 400kVA;

3, product categories: AC, AC and DC, AC series, AC and DC series.