Variable Frequency Series Resonant Voltage Withstand Test

Introducing the Tuned Sensing Variable Frequency Series Resonant Voltage Withstand Device

The Tuning Sensing Variable Frequency Series Resonant Voltage Withstand Device is primarily designed for...11kV/30MWDesign and manufacturing of AC withstand voltage test for hydro-turbine generators. The reactors are designed in two separate units.

The Variable Frequency Series Resonant Voltage Stabilizing Device primarily consists of a variable frequency control power supply, excitation transformer, reactor, and capacitor voltage divider.

The advantages of the tuning-type variable frequency series resonance voltage withstand device in power system applications:

1The required power capacity is significantly reduced. Series resonant power supplies utilize resonant inductors and the capacitive resonance of the test item to generate high voltage and high current. In the entire system, the power supply only needs to provide the active power consumption part of the system, thus the power required for the test is only a fraction of the test capacity.1/Q。

2The weight and volume of the equipment have been significantly reduced. In series resonance power supplies, not only has the bulky high-power voltage regulator and the ordinary high-power power frequency transformer been eliminated, but also the resonant excitation power supply only requires a test capacity of1/QReducing the system's weight and volume significantly, typically much less than that of a standard testing device.1/10-1/30。

3Enhanced Output Voltage Waveform. The resonant power supply, being a resonant filter circuit, improves the waveform distortion of the output voltage, achieving a good sine waveform. It effectively prevents mis-blowouts on the test sample due to harmonic peak values.

4Prevent large short-circuit currents from burning the fault points. In the series resonance state, when the insulation weakness of the test item is pierced, the circuit immediately detunes, and the circuit current rapidly drops to the normal test current level.1/QWhen performing withstand voltage tests using parallel resonance or test transformers, the breakdown current immediately increases by several tens of times. Compared to this, the short-circuit current differs from the breakdown current by several hundred times. Therefore, series resonance can effectively locate insulation weaknesses without the concern of large short-circuit currents causing burnout faults.

5No voltage recovery will occur. When the sample is punctured, due to the loss of resonance conditions, the high voltage disappears immediately, the arc is extinguished at once, and the process of re-establishing the voltage is very long, making it easy to disconnect the power source before reaching the flashover voltage again. This voltage recovery process is an intermittent oscillation of energy accumulation, with a long duration and no voltage recovery exceeding the original level.