Overview of resonance test equipment:
During the calibration of the capacitive voltage transformer (CVT), the test frequency must be carried out under the condition of 50Hz. At the same time, the geographical conditions on the site are complicated. The traditional experimental device has been difficult to meet the requirements of on-site handling and testing. XZB-H can The resonant booster device is the first adjustable resonant device used for on-site verification in China, and has been widely used in the on-site verification of domestic capacitive voltage transformers of 500kV and below.
Advantages of series resonant power supply in power system applications:
1. The required power capacity is greatly reduced. The series resonant power supply uses the resonance of the resonant reactor and the capacitor to be tested to generate high voltage and large current. In the entire system, the power supply only needs to provide the active part of the system. Therefore, the power required for the test is only the test capacity. 1/Q.
2. The weight and volume of the equipment are greatly reduced. In the series resonant power supply, not only the bulky high-power voltage regulator and the ordinary high-power power frequency test transformer are omitted, but also the resonant excitation power supply only needs 1/Q of the test capacity, which greatly reduces the weight and volume of the system. 1/5-1/10 of ordinary test equipment.
3. Improve the output voltage waveform. The resonant power supply is a resonant filter circuit, which can improve the waveform distortion of the output voltage, obtain a good sine waveform, and effectively prevent the false breakdown of the test product by the harmonic peak.
4. Prevent large short-circuit current fault points. In the series resonance state, when the insulation weakness of the test product is broken down, the circuit is immediately detuned, and the loop current quickly drops to 1/Q of the normal test current. When the parallel resonance or test transformer is used for the withstand voltage test, the breakdown current immediately rises several dozen times. Compared with the two, the short-circuit current and the breakdown current are hundreds of times different. Therefore, the series resonance can effectively find the insulation weakness, and there is no worry of large short-circuit current fault points.
5. There will be no recovery overvoltage. When the test product breaks down, due to the loss of resonance conditions, the high voltage disappears immediately, the arc is extinguished immediately, and the reestablishment process of the recovery voltage is very long, and it is easy to disconnect the power before reaching the flashover voltage again. This voltage recovery The process is an intermittent oscillating process of energy accumulation. The process is long and there is no recovery overvoltage.
