60KV/1.1μF智能/全自动VLF Hipot Tester装置-扬州达瑞

60KV/1.1μF Intelligent/Automatic Very Low Frequency Withstand Voltage Test Device

Product Features

1. The design indicators fully comply with the power industry standard "General Technical Conditions for Special Test Instruments for Power Equipment, Part 4: General Technical Conditions for Very Low Frequency High Voltage Generators", and are very convenient to use.

2. Current, voltage, and waveform data are directly obtained through high-voltage side sampling, so the data is true and accurate.

3. Overvoltage protection: When the output exceeds the set voltage limit, the instrument will stop protection, with an action time of less than 20 milliseconds.

4. Overcurrent protection: Designed with dual protection for high and low voltage. The high-voltage side can stop protection according to the set value; the low-voltage side will stop protection when the current exceeds the rated current, with an action time of less than 20 milliseconds.

5. The very low frequency high voltage generator combines modern digital frequency conversion advanced technology, adopts microcomputer control, and fully automates voltage boosting, voltage reduction, measurement, and protection, and allows manual intervention during automatic voltage boosting.

6. Fully electronic, so it is small in size and light in weight, with a large screen LCD display, clear and intuitive, and can display output waveforms, and the printer outputs test reports.

7. The high-voltage output protection resistor is designed inside the booster, so no external protection resistor is needed.

8. Because the very low frequency high voltage generator adopts a high and low voltage closed-loop negative feedback control circuit, there is no capacitive rise effect in the output.

 

Product Parameters

1. Power supply: 220V±10%, 50±5%Hz

Note: If using a portable generator for power supply, it is required that the generator output voltage and frequency are stable (generally, power greater than 3kW, frequency 50Hz, voltage 220V±5%), otherwise some auxiliary measures should be taken to stabilize the generator output.

2. Output voltage accuracy: 

Output high voltage peak instability: ≤1%

Output voltage frequency instability: ≤3%

Output voltage waveform distortion rate: <5%

3. Operating environment: Temperature: -10℃～+40℃; Humidity: ≤85%RH

Product Principle

Such huge equipment is not only bulky and expensive but also very inconvenient to use. To solve this contradiction, the test frequency is reduced, thereby reducing the capacity of the test power supply. Theory and practice from many years at home and abroad have proven that replacing power frequency withstand voltage test with 0.1Hz very low frequency withstand voltage test not only has the same equivalence but also greatly reduces the size and weight of the equipment, with a capacity about one five-hundredth of power frequency, and the test procedure is greatly simplified, with more advantages compared to power frequency tests. This is why developed countries generally adopt this method. China's Ministry of Electric Power has commissioned the Wuhan High Voltage Research Institute to draft the industry standard "Very Low Frequency (0.1Hz) Withstand Voltage Test Method for 35kV and Below Cross-linked Polyethylene Insulated Power Cables". This method is being promoted in China. This instrument is developed based on this need in China. It can be widely used in AC withstand voltage tests of cables, large high-voltage rotating motors, and power capacitors.

Capacitance of cross-linked polyethylene insulated single-core power cables (μF/km)

Selection Table

Product Introduction

The very low frequency high voltage generator is mainly used for withstand voltage testing of polyethylene insulated power cables, and can also be used for insulation withstand voltage testing of large power transformers. Using very low frequency high voltage to test the withstand voltage of power cables is a new method.

When performing power frequency AC withstand voltage tests on large generators, cables, and other test objects, due to their large capacitance in the insulation layer, large test transformers or resonant transformers are required. Such huge equipment is not only bulky and expensive but also very inconvenient to use. To solve this contradiction, the power department has adopted reducing the test frequency, thereby reducing the current and the capacity of the test power supply. Theory and practice from many years at home and abroad have proven that using a test power supply with 0.1Hz or lower frequency to replace power frequency AC withstand voltage test can not only achieve the same test effect but also greatly reduce the size and weight of the power supply equipment, about one five-hundredth of power frequency. The test procedure is greatly simplified, with more advantages than power frequency tests.

Note: The above information and technical parameters are compiled and released by Yangzhou Darui Electric Co., Ltd.