The series resonance under UHV power can help many power workers conduct various power tests more conveniently.
Precautions to be taken when using a variable frequency series resonant device:
1. The variable frequency series resonant device is a high-voltage experimental equipment that requires the use of high-voltage experimental professionals. Before use, carefully read the instructions and repeat the operation practice.
2. There should be no less than 2 operators. The safety operating procedures for high-voltage testing should be strictly followed during operation.
3. In order to ensure the safety and accuracy of the experiment, it is not only necessary to understand the specifications of the product, but also to strictly follow the relevant national standards and regulations for the experiment.
4. Each connecting wire must not be misconnected, especially the ground wire. Otherwise, it may cause damage to the equipment.
5. When using this device, the output voltage is high voltage or ultra-high voltage. Be firmly grounded and pay attention to the operation of safety intervals.
6. The series resonance experimental system uses a resonant reactor to resonate with the sample to generate high voltage. Whether high voltage can occur mainly depends on whether the sample and resonant reactor resonate. Therefore, when dissecting the required high voltage on site, the experimenter should analyze whether the resonance conditions are disrupted and whether the circuit is connected. The voltage and current of the excitation transformer in the series resonance experimental system have certain requirements. When selecting alternatives, the voltage and current must be considered, and the capacity of the typical experimental transformer cannot be chosen.
The advantages of variable frequency series resonance in power system applications
The required power capacity is significantly reduced. The series resonant power supply uses resonant reactors and test capacitors for high voltage and high current resonance. In the entire system, the power supply only needs to provide a portion of the active power in the system, so the power required for the experiment is only 1/1 of the experimental capacity.
The total weight and volume of the equipment have been greatly reduced. In a series resonant power supply, not only are large high-power voltage regulating equipment and commonly used high-power experimental transformers eliminated, but the resonant excitation power supply only requires 1/Q of the experimental capacity, greatly reducing the system composition and volume, usually 1/3-1/5 of ordinary experimental equipment.
3. Improve the output voltage waveform. A resonant power supply is a resonant filtering circuit that can improve the waveform distortion of the output voltage, obtain a good sine wave waveform, and avoid the false breakdown of the sample by harmonic peaks.
4. Avoid burning nodes with large short-circuit currents In the series resonance state, when the insulation defect of the sample is punctured, the circuit will immediately de resonate and the ocean current will drop to 1/Q of the normal experiment. Parallel resonance can be used to test transformers, but the breakdown current will immediately increase by several tens of times. Compared with these two methods, the short-circuit current and breakdown current differ by hundreds of times. Therefore, series variable frequency resonance can effectively detect insulation defects without the problem of large short-circuit current burning.
5. The overvoltage has not been restored. When the sample is broken down, due to the loss of resonance conditions, the high voltage will immediately disappear, the arc will immediately dissipate, and the reconstruction process of restoring voltage is relatively long. It is very simple to disconnect the power before reaching the flash voltage again. The voltage recovery process is an intermittent vibration process of energy accumulation, which is a long process, and overvoltage recovery will not occur.
