Variable Frequency Resonant Voltage Withstand Test Device

Product Introduction

The TPXB-D type voltage-adjustable variable-frequency series resonance voltage-withstanding device is primarily designed and manufactured for AC voltage withstand tests of 11kV/30MW hydraulic turbines. The reactors are designed in two separate units.

The TPXB-D type variable frequency series resonance voltage withstand device is mainly composed of a variable frequency control power supply, excitation transformer, reactor, and capacitor voltage divider.

The advantages of TPXB-D type tuning inverter series resonant voltage withstand device in power system applications:

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

2. The weight and volume of the equipment have been significantly reduced. In series resonance power supplies, not only are the bulky high-power voltage regulators and the standard high-power power frequency test transformers eliminated, but the resonant excitation power supply only requires 1/Q of the test capacity, resulting in a substantial reduction in system weight and volume, typically 1/10 to 1/30 of conventional test equipment.

3. Enhanced Output Voltage Waveform: The resonant power supply, a resonant filter circuit, improves the waveform distortion of the output voltage, achieving a superior sine waveform. It effectively prevents the mis-breakdown of the test item due to harmonic peak values.

4. Prevent large short-circuit currents from burning out fault points. In series resonance, when the insulation weakness of the test item is pierced, the circuit immediately detunes, and the loop current rapidly drops to 1/Q of the normal test current. In contrast, during withstand voltage tests using parallel resonance or the test transformer method, the piercing current immediately rises several times. Compared to this, the difference between short-circuit current and piercing current is hundreds of times. Therefore, series resonance can effectively locate insulation weaknesses without the concern of large short-circuit currents causing burnout faults.

There will be no voltage recovery. 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 limit.