■ Product Introduction

High voltage withstand test of electrical equipment is one of the important items stipulated in insulation preventive test. Withstand voltage test can be divided into AC withstand voltage test and DC withstand voltage test, ac withstand voltage test can be divided into power frequency, frequency conversion and 0.1Hz ultra-low frequency test technology. This series of ultra-low frequency high voltage generator is the core product independently developed by American technology. It adopts 7-inch touch screen, ARM7 single chip microcomputer, high-speed AD acquisition circuit, and is equipped with background management software. It overcomes many shortcomings of similar domestic products (see Table 1), and its cost performance is much higher than that of similar imported products. It is especially suitable for electrical equipment with large insulation equivalent capacitance (such as: Power cables, power capacitors, large and medium-sized generators and motors, etc.) withstand voltage test, in line with the requirements of "General Technical Conditions for Ultra-low frequency High Voltage Generators DL/ T8494-2004", a new national power industry standard issued in 2004.

■ Product advantages

Ultra low frequency insulation withstand voltage test is actually an alternative method of power frequency withstand voltage test. In the large and medium-sized generators, motors, power cables and other test products of power frequency voltage test, because of their insulation layer presents a large capacity, so need a large capacity of the test transformer or resonant transformer. Such equipment is bulky, expensive and 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 widely adopted in the world. Many years of theory and practice at home and abroad have proved that replacing power frequency voltage test with 0.1Hz ultra-low frequency voltage test can not only have the same equivalence, but also greatly reduce the volume and weight of the equipment. The theoretical capacity is about 1/500th of the power frequency, and the operation is simple.

According to the actual situation of China's power system, the National Development and Reform Commission has formulated the industry standard "Ultra-Low Frequency (0.1Hz) Voltage Withstand Test Method of 35kV and below XLPE insulated power Cables". In 2004, the power industry standard "General Technical Conditions of Ultra-Low Frequency High Voltage Generator DL/T 8494-2004" was promulgated. This test method is being popularized in our country.

Although the DC withstand voltage test equipment has the advantages of small volume, light weight and low cost, but the DC withstand voltage test is also very destructive to the insulation of the tested products. (See Table 2) Therefore, AC withstand voltage test is constantly being popularized.

The company developed a new generation of this series of 0.1Hz ultra-low frequency high voltage generator "using power electronic components and ARM7 microcontroller technology, further reduce the volume and weight of the equipment, fool operation, more stable performance, to overcome the first generation of mechanical booster short service life, high failure rate, large volume shortcomings.

1. Rated output voltage: See Table 3

2. Output frequency: 0.1Hz, 0.05Hz, 0.02Hz

3. Load capacity: 0.1Hz maximum 1.1µF

0.05 Hz maximum (including 2.2 F

0.02 Hz maximum (including 5.5 F

4. Measurement accuracy: 3%

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

6. Voltage waveform distortion: ≤ 5%

7. Conditions of use: indoor and outdoor; Temperature: -10℃ ~ +40℃; Humidity: ≤ 85% RH

8. Power fuse: See Table 3

9 power supply: voltage 220V±5%, 50±5Hz

Note: if the portable generator is used for power supply, it is required that the output voltage and frequency of the generator be stable (generally, the power is more than 3kW, the frequency is 50Hz, and the voltage is 220V±5%

10. The capacitance of the tested product shall not exceed the maximum rated capacitance of the instrument. See Table 3 for the value.