AC/DC voltage withstand test device

Compared with ordinary control boxes, the operation box of the AC/DC withstand voltage test device produced by Shengxu Electric has the advantages of fast maintenance, accurate measurement, high functionality, small size, light weight, and beautiful appearance.

　　AC/DC voltage withstand test deviceNotes:

1. Connect the working circuit according to the experiment you conducted. The shell of the test transformer and the shell of the operating system must be reliably grounded, and the x-end (high-voltage tail) of the high-voltage winding of the test transformer and the F-end of the measuring winding must be reliably grounded.

2. When conducting a cascade test, the X end of the low voltage winding, the F end for measuring winding resistance, and the X end (high voltage tail) of the high voltage winding of the second and third stage test transformers are all connected to the outer shell of the current stage test transformer. The outer shells of the second and third stage test transformers must be grounded through insulation brackets.

3. Before turning on the power, the voltage regulator of the operating system must be set to zero before the power can be turned on, closed, and the boost can begin.

4. Starting from scratch, increase the pressure of the rotating regulator handwheel uniformly. The boosting methods include: fast boosting method, which is the 20S step-by-step boosting method; Slow boost method, i.e. 60S step-by-step boost method; The extremely slow boost method is available for selection. Starting from zero, the voltage is raised to 75% of your desired rated test voltage using a certain boosting method and speed. Then, at a rate of 2% per second, the rated test voltage is raised from zero to your desired rated test voltage using a certain boosting method and speed. Pay close attention to the readings of the measuring instruments and the condition of the test sample. If any abnormality is found in the indication of the measuring instrument or the condition of the test object during the boosting process or the testing process, the voltage should be immediately reduced, the power should be cut off, and the situation should be investigated.

5. After the experiment is completed, the voltage regulator should be returned to zero at a constant speed within a few seconds, and then the power should be cut off.

6. This product may be used beyond its rated parameters. Unless necessary for testing, full voltage power on or off is never allowed.

7. When using this product for high-voltage testing, in addition to being familiar with this instruction, it is also necessary to strictly follow the relevant national standards and operating procedures. Reference can be made to GB311-83 "Insulation Coordination and High Voltage Testing Techniques for High Voltage Transmission and Transformation Equipment"; Preventive Testing Regulations for Electrical Equipment, etc.

AC/DC voltage withstand test deviceSupporting products:

1. Operating System:

XZC series operation box: Capacity: 1KVA-5KVA, Input voltage: 0.22KV

KZT series console: Capacity: 10K/A-300KVA Input voltage: 0.22KV, 0.38KV

2. Protective digital microampere meter SWB-II

3. Resistance capacitance AC/DC voltage divider FYQ-50, 100, 150, 220KV

4. High voltage DC discharge rod FZ-70, 140, 210KV

5. High voltage silicon stack: 2DL-150, 300, 450KV

6. Insulation bracket 50, 100, 200, 300KV

7. High voltage filtering capacitor 0.01UF, 40-100KV

8. Equal pressure ball

9. Protecting Ball Gap: Q-50, 100, 150, 200, 250, 500

10. Standard oil test cup 400ml

11. Medium oil cup

12. Folding trolley models 150 and 300

13. Water resistance

14. High voltage tester 10KV, 35KV

15. High Voltage Phaser 10KV, 35KV/110KV, 220KV

16. Various multimeters, megohmmeters, and test wires

Capacity selection of test transformer:

The formula for determining the capacity Pn of a standard test transformer is Pn=KVn2 ω ct × 10-9.

Where:

Pn - nominal test transformer capacity (KVA)

Vn - Effective value of rated output high voltage of the test transformer (KV)

K - Safety factor. K≥1， When the nominal voltage Vn is ≥ 1MV, K=2， When the nominal voltage is low, the K value can be higher,

CT - capacitance of the test sample (PF)

ω - angular frequency, 2 μ f - frequency of the test power supply.

The capacitance CT of the tested equipment can be measured by an AC bridge. The variation of Ct is significant and can be determined by the type of device. The typical data is as follows:

Simple rod or suspension insulators with a thickness of tens of micrometers

Simple graded casing 100-1000PF

Voltage Transformer 200-500PF

Voltage transformer<1000KVA -1000PF

>1000KVA 1000-10000PF

High voltage power cables and oil immersed paper insulation 250-300PF/m

Gas Insulation-60PF/m

Enclosed substation, SF6 gas insulated 100-10000PF

For different test voltages Vn, choose different (appropriate) safety factors K. The following lists the K values selected for different Vns for reference.

Vn=50-100KV K=4

Vn=150-300KV K=3

Vn>300KV K=2

Selection of AC/DC test transformers:

Note: This series of products includes 200V series taps, which can be cascaded with two or three units to form high voltages of AC 100KV, 150KV, 200KV, 300KV, DC 140KV, 210 KV, 280 KV, 420 KV. And according to user needs, 5-15 KV medium voltage taps can be extracted from the high-voltage winding for AC withstand voltage testing of the high-voltage machine. And special specifications of test transformers can be customized.