CATALOGUE

Oil-immersed test transformer

This series of products are suitable for power system, industrial and mining enterprises, transportation, posts and telecommunications departments, scientific research units, etc. The insulation strength test of various high-voltage electrical equipment, electrical components, insulation materials under power frequency AC or DC high voltage is carried out. Our company can customize any parameters of non-standard pressure products and equipment!

Product Manuals National Standard Product report

Regarding product purchases, technical maintenance, and other services, please feel free to call：400-8828-058

Product Introduction
Product Portfolio
Product video

Product Introduction

This series of products are suitable for power system, industrial and mining enterprises, transportation, posts and telecommunications departments, scientific research institutes and so on. The insulation strength test of various high-voltage electrical equipment, electrical components and insulation materials under power frequency AC or DC high voltage is carried out.
Product parameters

Selection of Test Transformer Capacity

Determining formula of transformer capacity Pn in nominal test: Pn=KV n 2_Ct *10-9

Type: Pn - Nominal test transformer capacity (kVA)

Vn - Valid Value of Rated Output High Voltage of Test Transformer (kV)

K - Safety factor. When the nominal voltage Vn is greater than 1MV, k = 2; when the nominal voltage is lower, K value may be higher.

Ct - Capacitance of Subject (pF)

_ - angular frequency, _ = 2 pi f, F - frequency of test power supply

The capacitance CT of the tested equipment can be measured by AC bridge. CT varies greatly, depending on the type of equipment. Typical data are as follows:

Simple rod or suspension insulator dozens of micro-methods

Simple Classified Casing 100-1000pF

Voltage transformer 200 ~ 500pF

Power Transformer 1000 kVA~1000 pF

1000 kVA 1000~10000 pF

250~300pF/m Insulation for High Voltage Power Cable and Oil-immersed Paper

Gas Insulation ~60pF/m

Closed Substation, SF6 Gas Insulation 100~10000pF

For different test voltage Vn, choose different (appropriate) safety factor K. The K values selected for different Vns are listed below for reference.

Vn = 50-100 kV k = 4

Vn = 150~300 kV k = 3

Vn > 300kV k = 2
Product features

High voltage test transformer adopts single frame core structure. The primary winding is on the core and the high-voltage winding is outside. This coaxial arrangement reduces the flux leakage and increases the coupling between windings. The shell of the product is made with an octagonal structure which matches the core well, and the overall shape is beautiful and generous. Its external structure is shown in Fig. 1, and its internal structure is shown in Fig. 2.

Figure 1: Single test transformer Figure 2: Internal structure of single test transformer

Schematic diagram of external structure

1-Short Circuit Rod D 2-Ball 3-High Pressure Casing

4-Transformer Handle 5-Oil Valve 6,7-Secondary Pressure Input a,x

8,9-Measuring Terminals E,F 10-Grounding Terminals of Transformer Shell

11-High Voltage Tail X 12-High Voltage Output A 13-High Voltage Silicon Reactor

14-Transformer Oil 15-Iron Core 16-Secondary Low Voltage Winding

17-Measuring Winding 18-Secondary High Voltage Winding

In the test transformer, A and X are low-voltage input terminals, E and F are instrument measurement terminals, A and X are high-voltage output.