Overview

The high-voltage withstand voltage test of electrical equipment is one of the most important items stipulated in the "Insulation Preventive Test". The withstand voltage test can be divided into AC withstand voltage test and DC withstand voltage test. and 0.1Hz very-low frequency test technology, of which 0.1Hz very-low frequency technology is the latest technology and is currently recommended by the International Electrotechnical Commission. According to the actual situation of my country's power system, the National Development and Reform Commission has formulated the industry standard of "Very-low frequency (0.1Hz) withstand voltage test method for XLPE insulated power cables of 35kV and below".

When the power frequency withstand voltage test is carried out on the large and medium-sized generators, motors, power cables, etc., because their insulating layers have a large capacitance, a large-capacity test transformer or resonant transformer is required. Such huge devices are not only cumbersome and expensive, but also very inconvenient to use. In order to solve this contradiction, the method of reducing the test frequency and thus the capacity of the test power supply is generally adopted internationally. The very-low frequency insulation withstand voltage test is actually an alternative method to the power frequency withstand voltage test. It has been proved from many years of theory and practice at home and abroad that replacing the power frequency withstand voltage test with the 0.1Hz very-low frequency withstand voltage test can not only have the same equivalence, but also the size of the equipment is greatly reduced, the weight is greatly reduced, and the theoretical capacity It is about one-fifth of the power frequency, and the operation is simple, which is the main reason why developed countries generally use this method。

Our company's new generation series of very-low frequency high voltage generators are core products independently developed by the latest technology, using 7-inch touch screen, imported high-speed AD acquisition circuit, and advanced production technology. It improves the quality stability of the instrument, reduces the volume and weight of the equipment, is easy to operate, and overcomes many shortcomings of similar domestic products (see Table 1). Disadvantages of high failure rate and large volume. Compared with other methods of withstand voltage test equipment, 0.1Hz very-low frequency has many advantages, as shown in Table 2。

Through years of practice, feedback from a large number of users shows that this series of very-low frequency and high-voltage technology leads the market and has the highest cost performance.！

Table 1 Performance comparison between mechanical and electronic 0.1Hz withstand voltage test equipment

Table 2 Performance comparison of various withstand voltage test equipment

Instrument characteristics

1.High degree of intelligence: using digital frequency conversion technology, microcomputer control, fully automated test processes such as boosting, bucking, and measurement。

2.Convenient operation: simple wiring, 7-inch large LCD touch screen, convenient operation, friendly human-computer interaction。

3.Comprehensive protection: multiple protections (overvoltage protection, high and low voltage side overcurrent protection), rapid action (action time ≤ 10ms), safe and reliable instrument。

4. Safe and reliable: low-voltage connection between controller and high-voltage generator, photoelectric control, safe and reliable use。

5.The high and low voltage closed-loop negative feedback control circuit is adopted, and the output has no capacity rise effect.。

6.Accurate sampling: The high-voltage current and voltage data are directly obtained by sampling the high-voltage side, so the data is true and accurate。

7.Complete configuration: 7-inch capacitive touch screen, LCD Chinese character display, automatic storage, automatic printing。

8. Wide test range: 0.1Hz, 0.05Hz and 0.02Hz multi-frequency selection, large test range。

9. Easy to carry: The instrument is small in size and light in weight, which is very conducive to outdoor operations。

   10.Multi-language display: Chinese and English switching function, other languages can be customized。

Technical parameter

1.Working power： 220V±5%，50Hz

Note:that a digital variable frequency generator

must be used, its output frequency is 50Hz, input voltage is 220V and power is larger than 3kW. 
 2.Output voltage：30kV

3.Output frequency：0.1Hz、0.05Hz、0.02Hz

4.Load capacity：0.1Hz-1.1uF、0.05Hz-2.2uF、0.02Hz-5.5uF

4.Measurement accuracy：3%

5.Voltage positive, negative peak error：≤3％

6.Voltage waveform distortion：≤5％

   7.Working temperature：-10℃～+40℃；humidity：≤85％RH