VLF Intelligent Very Low Frequency High Voltage Generator - Yangzhou Darui

VLF Intelligent Very Low Frequency High Voltage Generator

Darui Electric recommends

Product Introduction

    This product combines modern digital frequency conversion advanced technology, adopts microcomputer control, and fully automates voltage boosting, voltage reduction, measurement, and protection. It also allows manual intervention during the automatic voltage boosting process. Due to full electronic design, it is small in size and light in weight, with a large-screen LCD display that is clear and intuitive, capable of displaying output waveforms, and a printer for outputting test reports. 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," making it very convenient to use. Currently, both domestic and international methods use mechanical modulation and demodulation to generate very low frequency signals, resulting in non-standard sine waveforms, large measurement errors, spark discharge in the high-voltage part, bulky equipment, and the need for high-power high-voltage resistors for discharge shaping in the second and fourth quadrants of the sine wave, leading to high overall power consumption. This product overcomes these shortcomings and also has the following special features:

★ Current, voltage, and waveform data are directly sampled from the high-voltage side, ensuring data authenticity and accuracy.

★ Overvoltage protection: When the output exceeds the set voltage limit, the instrument will shut down for protection, with an action time of less than 20 milliseconds.

★ Overcurrent protection: Designed with dual protection at high and low voltage sides. The high-voltage side can perform shutdown protection according to the set value; the low-voltage side will shut down for protection when the current exceeds the rated current, with action times both less than 20 milliseconds.

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

★ Due to the adoption of high and low voltage closed-loop negative feedback control circuit, there is no capacitive rise effect in the output.

Product Features

Very low frequency insulation withstand voltage test is actually an alternative to power frequency withstand voltage test. We know that when performing power frequency withstand voltage tests on large generators, cables, and other test objects, due to their large insulation capacitance, large-capacity 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 problem, the power sector has adopted a method of reducing the test frequency, thereby reducing the capacity of the test power supply. Theory and practice from many years at home and abroad have proven that using 0.1Hz very low frequency withstand voltage test instead of power frequency withstand voltage test not only has the same equivalence but also greatly reduces the size and weight of the equipment. Theoretically, the capacity is about one five-hundredth of that at power frequency. The test procedure is greatly simplified, offering more advantages compared to power frequency tests. This is why developed countries widely 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, and this instrument is developed based on this need. It can be widely used for AC withstand voltage testing of cables, large high-voltage rotating motors, and power capacitors.

Very Low Frequency Series Products