HZBP 10kv-500kv Variable Frequency AC Resonant Hipot Test System for Electricl Equipment

The HZBP series variable frequency AC resonant hipot test system is primarily designed for AC withstand voltage tests of cross-linked cables, hydro generators, main transformers, busbars, GIS, and other high-voltage equipment. It offers a wide range of applications and serves as an ideal withstand voltage testing device for high-voltage testing departments at the regional, city, and county levels, as well as for power installation, repair, and testing units.

The system is primarily composed of a variable frequency control power supply, excitation transformer, reactor, capacitive divider, and an optional compensation capacitor.

Suitable for the commissioning and preventive testing of large-capacity, high-voltage capacitive test samples. The device features over-voltage, over-current, zero start, and system detuning (flash-over) protection functions. The entire device is lightweight, making it convenient for on-site use.

1. Significantly Reduced Power Supply Capacity. Series resonant power sources use resonant reactors and the test sample's capacitance to generate high voltage and high current. In the entire system, the power supply only needs to provide the active power consumption, so the required power supply capacity is only 1/Q of the test capacity.
2. Greatly Reduced Weight and Volume. The series resonant power source eliminates the need for bulky high-power voltage regulators and ordinary high-power power frequency test transformers. The resonant excitation power supply only needs 1/Q of the test capacity, significantly reducing the system's weight and volume, typically to 1/10 to 1/30 of conventional test devices.
3. Improved Output Voltage Waveform. The resonant power source acts as a resonant filter circuit, improving the output voltage waveform distortion, achieving a good sine wave, and effectively preventing harmonic peak values from causing false breakdowns of the test sample.
4. Prevention of Large Short-Circuit Currents. In a series resonant state, if the test sample's insulation weak point is broken down, the circuit immediately detunes, and the loop current quickly drops to 1/Q of the normal test current. In contrast, with parallel resonance or test transformer methods, the breakdown current immediately increases dozens of times, resulting in short-circuit and breakdown currents differing by hundreds of times. Therefore, series resonance effectively identifies insulation weak points without the risk of large short-circuit currents damaging the fault point.
5. No Recovery Over-voltage. When the test sample breaks down, the high voltage immediately disappears due to the loss of resonance, the arc extinguishes instantly, and the reestablishment process of the recovery voltage is very long, making it easy to disconnect the power before reaching flash-over voltage again. This recovery process is a kind of energy accumulation intermittent oscillation process, which is long and does not generate any recovery over-voltage.