Frequency modulation resonance withstand voltage test device

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ZLJXZFrequency modulation resonance withstand voltage test deviceApplied in industries such as power, metallurgy, petroleum, and chemical engineering, it is suitable for the handover and preventive testing of high-capacity capacitive samples, such as generators, power transformers, and high-voltage cross-linked cables. The TPXZB-210/60 cable AC withstand voltage test equipment can meet the AC withstand voltage test of 35kV cross-linked cables with a length of 1km. Can meet the AC withstand voltage test of 10kV cross-linked cable with a length of 2km. Can meet the AC withstand voltage test of 10kV voltage level power transformers.

ZLJXZFrequency modulation resonance withstand voltage test deviceTechnical Specifications:

Environmental temperature: -10~45 ℃

Environmental humidity: ≤ 90%

Altitude: ≤ 2000M

Power input: 220V ± 10% single-phase 50Hz output 0-2220V (≤ 10KW)

380V ± 10% three-phase 50Hz output 0-400V

Rated test capacity: 0-8000KVA (optional)

Resonant voltage: 0-1000KV (optional)

Frequency adjustment range: 0.1-300Hz

System measurement accuracy: Level 0.5

Frequency regulation division rate: 0.01Hz

Instability: ≤ 0.05%

Output waveform: sine wave

Waveform distortion rate: ≤ 0.5%

Noise: ≤ 60dB

Reactor Q value: 30-200 (optional)

ZLJXZ frequency modulation resonance withstand voltage working environment:

1. Environmental temperature: -150C -400C;

2. Relative humidity: ≤ 90% RH;

3. Altitude: ≤ 1000 meters;

Subject and Test Requirements

1. 64/110kV/300mm2 cable, length 0.2km, capacitance ≤ 0.03uF, test frequency 30-300Hz, test voltage 128kV.

2. 26/35kV/300mm2 cable, length 1.2km, capacitance ≤ 0.228uF, test frequency 30-300Hz, test voltage 52kV.

3. 8.7/10KV/300mm2 cable, length 4km, capacitance ≤ 1.2uF, test frequency 30-300Hz, test voltage 22kV.

4. 110kV substation GIS equipment, 35kV transformer, distribution equipment AC withstand voltage, test frequency 30-300Hz, test voltage 184kV.

Advantages of series resonance:

1. The required power capacity is greatly reduced. Series resonant power supply generates high voltage and high current through resonance between resonant reactor and tested capacitor. In the entire system, the power supply only needs to provide the active consumption part of the system. Therefore, the required power supply for the test is only 1/Q of the test capacity

2. The weight and volume of the equipment have been greatly reduced. In a series resonant power supply, not only is the bulky high-power voltage regulating device and ordinary high-power power frequency test transformer eliminated, but the resonant excitation power supply only requires 1/Q of the test capacity, greatly reducing the weight and volume of the system, usually 1/3-1/5 of ordinary test devices

3. Improve the waveform of the output voltage. A resonant power supply is a resonant filtering circuit that can improve the waveform distortion of the output voltage, obtain a good sine waveform, and effectively prevent the accidental breakdown of the test sample by harmonic peaks.

4. Prevent large short-circuit currents from burning the fault point. In the series resonance state, when the weak point of the insulation of the test sample is broken down, the circuit immediately disengages and the loop current rapidly drops to 1/Q of the normal test current. However, when conducting voltage withstand tests in parallel resonance or test transformer mode, the breakdown current immediately increases by several tens of times. Compared with the short-circuit current, the breakdown current differs by hundreds of times. So, series resonance can effectively identify insulation weaknesses without the concern of large short-circuit currents burning the fault point.

5. There will be no overvoltage recovery. When the test sample breaks down, due to the loss of resonance conditions, the high voltage immediately disappears, the arc can be extinguished, and the process of re establishing the recovery voltage is long. It is easy to disconnect the power supply before reaching the flashover voltage again. This voltage recovery process is an intermittent oscillation process of energy accumulation, which is long and does not result in any recovery overvoltage.