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Huazheng Manufacture Ultra low Frequency Generator VLF Hipot Tester
Product Features
☆ Advanced technology: By adopting digital frequency conversion technology and microcomputer control, the test procedures of boosting, voltage reduction, measurement, protection, etc. are fully automated. The instrument has the electronic calendar function, and the time can still be maintained after powering down.
☆ Convenient operation: Simple wiring, and fully automatic operation.
☆ Comprehensive protection: Multi-protection (over-voltage protection, over-current protection on high- and low-voltage side), rapid action (action time ≤ 20 ms), the instrument is safe and reliable.
☆ Safe and reliable: The controller and the high-voltage generator are in low-voltage connection and under photoelectric control, which are safe and reliable to use.
☆ By adopting high- and low-voltage closed-loop negative feedback control circuit, the output has no capacitive rise effect.
☆ Complete configuration: 8-inch industrial touch screen, manual storage, and manual printing.
☆The instrument has the data communication function. It can be connected to a computer through a USB port for uploading test data to the computer.
The instrument has the help documentation function, through which the directions for use, wiring and notes of the instrument can be known without viewing the instruction book.
The instrument has the system setting function, through which the current time can be modified.
Large test range: Multi-frequency selection of 0.1Hz, 0.05Hz and 0.02Hz, a large test range.
Small size and light weight: Very conducive to outdoor operations.
Technical Parameters Of VLFS Series Products
Technical parameters ain parameters of series products are shown in Table 1
Model★ M |
Peak Voltage |
Measuring Range |
Weight |
Purpose |
HZYDP-30KV |
30kV |
≤1.1μF @ 0.1Hz |
Controller: 4kg Booster: 25kg |
Cables, generators with voltage of 10kV and below |
≤2.2μF @ 0.05Hz | ||||
≤5.5μF @ 0.02Hz | ||||
HZYDP-40KV |
40kV |
≤1.5μF @ 0.1Hz |
Controller: 5kg Booster: 35kg |
Cables, generators with voltage of 20kV and below |
≤3.0μF @ 0.05Hz | ||||
≤7.5μF @ 0.02Hz | ||||
HZYDP-50KV |
50kV |
≤1.5μF @ 0.1Hz |
Controller: 5kg Booster: 35kg |
Cables, generators with voltage of 20kV and below |
≤3.0μF @ 0.05Hz | ||||
≤7.5μF @ 0.02Hz | ||||
HZYDP-80KV |
80kV |
≤1.1μF @ 0.1Hz |
Controller: 5kg Booster: 45kg |
Cables, generators with voltage of 35kV and below |
≤2.2μF @ 0.05Hz | ||||
≤5.5μF @ 0.02Hz |
Table 1 Main Technical Parameters of VLFS Series Ultra-low Frequency High-voltage Generator
★ Power supply: 220V±10%, 50±5%Hz
Note: When a portable generator is used for supplying power, it is required that output voltage and frequency of the generator shall be stable (generally it is required that power shall be greater than 3 kW, the frequency shall be 50 Hz, and voltage shall be 220V±5%), otherwise some assistance measures shall be used to stabilize output of the generator.
★ Output voltage precision:
Degree of instability for peak value of output high voltage: ≤1%
Degree of instability for frequency of output voltage: ≤3%
Distortion rate of output voltage waveform: ＜5%
★ The instrument has the function of not burning the booster and the mainframe in case of power failure and sudden shutdown during the operation.
★ Service environment: Temperature: －100C～＋400C, humidity: ≤85%RH
★Description of testing range:
1. The capacitance of the tested product shall not exceed the maximum rated capacitance of the instrument, and the value is as shown in Table 1;
2. If the capacitance of the tested product is too low, the waveform would be affected. If it is lower than 0.05µF, the instrument would not output normally, so that the auxiliary device (optional) provided by the company can be adopted.
3. For capacitance estimation of common electrical equipment, see Table 2 and Table Table 2 Single-phase to Ground Capacitance of Different Types of Generators
Turbo-generator |
Hydro Generator |
||||||
Generator capacity (MW) |
200 |
300 |
600 |
85 |
125-150 |
300 |
400 |
Single phase to ground capacitance (µF) |
0.198 |
0.18-0.26 |
0.31-0.34 |
0.69 |
1.8-1.9 |
1.7-2.5 |
2.0-2.5 |
Advantages Of 0.1 Hz Ultra-low Frequency Withstand Voltage Technology
The ultra-low frequency insulation withstand voltage test is actually an alternative method of the power frequency withstand voltage test. When conducting power frequency withstand voltage tests on test products such as large- and medium-sized generators, motors, power cables, etc., as their insulating layers exhibit relatively large capacitance, test transformers or resonance transformers with very large capacity are required. Such huge equipment is not only cumbersome and expensive, but also very inconvenient to use. In order to solve this conflict, the method of reducing the test frequency thereby reducing the test power capacity is generally adopted in the world. Many years of theory and practice at home and abroad have proved that replacing the power frequency withstand voltage test with a 0.1 Hz ultra-low frequency withstand voltage test can not only have the same equivalence, but also the size of equipment is greatly reduced, the weight is greatly reduced, the capacity is about 1/500 of the power frequency theoretically, and it is simple to operate. This is the main reason why developed countries generally adopt this method.
According to the actual situation of the power system in our country, the National Development and Reform Commission has formulated the industry standard Ultra-low Frequency (0.1 Hz) Withstand Voltage Test Method for XLPE Insulated Power Cable of 35kV and Below. In 2004, the power industry standard General Technical Specification of Ultra-low Frequency High-voltage Generator DL/T 849.4-2004 was issued, and this latest test method is promoted in our country at present.
Although the DC withstand voltage test equipment has the advantages of small size, light weight, low cost, etc., the DC withstand voltage test is also the most destructive to insulation of the tested product. Therefore, the latest national regulations on preventive test of electrical equipment have expressly stipulated that DC high voltage is no longer used for conducting withstand voltage tests on electrical equipment, and the AC withstand voltage tests are recommended.
The new generation of VFLS series 0.1 Hz ultra-low frequency high-voltage generator researched and developed by FARSEE adopts the latest power electronic components and the latest microcomputer technology, which further reduces the size and weight of equipment, and with the fully automatic operation, it is more stable in performance, which overcomes the shortcomings of short service life, high fault rate and large size for the first generation of boosters. Through years of practice, a large number of user feedbacks show that: The 0.1 Hz ultra-low frequency high-voltage technology of Farsee Company is in the lead in the country, and it is the most cost-effective!
Attached table: Comparison on Performance of Various Withstand Voltage Test Equipment
Comparison Content |
Power Frequency Withstand Voltage |
Frequency Conversion Withstand Voltage |
0.1 Hz Withstand Voltage |
DC Withstand Voltage |
Equivalence |
Good |
Good |
Good |
Poor |
Insulation destructiveness |
Low |
Low |
Low |
High |
Operation safety |
Relatively low |
Relatively low |
High |
Relatively low |
Test wiring |
Complicated |
Most complicated |
Simplest |
Complicated |
Equipment size |
Maximum |
Relatively large |
Small |
Minimum |
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