The XZB series variable frequency series resonance withstand voltage test device adjusts the power supply frequency to achieve resonance between the reactor and the tested capacitor, thereby obtaining high voltage and large current on the tested object. Due to its low power consumption, light weight, and small size, it has been widely praised and applied both domestically and internationally, making it a new method and trend in high voltage testing.
The main functions and technical features of our company's frequency conversion resonance device are as follows:
1. The device has protection functions such as overvoltage, overcurrent, zero-position start, and system detuning (flashover). The overvoltage and overcurrent protection values can be set according to user needs. When the test object flashes over, the flashover protection operates and records the flashover voltage value for test analysis.
2. The entire device has a very light single-piece weight, making it convenient for on-site use.
3. The device has three working modes: fully automatic mode, manual mode, and automatic tuning with manual boosting mode; it is convenient for users to flexibly choose according to on-site conditions, improving test speed.
4. It can store and print data remotely. The stored data is numbered with digits, making it easy for users to identify and retrieve.
5. When the device automatically sweeps frequency, the starting frequency can be set arbitrarily within a specified range, and the sweep direction can be selected upward or downward. At the same time, the large LCD screen displays the sweep curve, making it convenient for users to intuitively see whether the resonance point has been found.
6. It adopts DSP platform technology, which can add or upgrade functions according to user needs, and the human-machine interface is more user-friendly.
7. The required power supply capacity is greatly reduced. Series resonance power uses the resonance reactor and the test object's capacitance to generate high voltage and large current. In the entire system, the power supply only needs to provide the active power consumption part of the system, so the power required for the test is only 1/Q of the test capacity.
8. The weight and volume of the equipment are greatly reduced. In the series resonance device, the bulky high-power voltage regulator and ordinary high-power power frequency test transformer are omitted. Moreover, the resonant excitation power supply only needs 1/Q of the test capacity, greatly reducing the system's weight and volume, generally 1/10-1/30 of ordinary test devices.
9. Effectively improve the output voltage waveform. The resonant power supply is a resonant filter circuit that can improve the waveform distortion of the output voltage, obtain a good sine wave, and effectively prevent mis-breakdown of the test object due to harmonic peaks.
10. Prevent large short-circuit currents from burning the fault point. In the series resonance state, when the insulation weakness of the test object is broken down, the circuit immediately detunes, and the loop current rapidly drops to 1/Q of the normal test current. However, when using parallel resonance or a test transformer for withstand voltage tests, the breakdown current immediately rises dozens of times. Comparing the two, the short-circuit current and breakdown current differ by hundreds of times. Series resonance can effectively find insulation weaknesses without the worry of large short-circuit currents burning the fault point.
11. No recovery overvoltage will occur. When the test object breaks down, due to the loss of resonance conditions, the high voltage immediately disappears, the arc is immediately extinguished, and the recovery voltage re-establishment process is very long, making it easy to disconnect the power supply before reaching the flashover voltage again. This voltage recovery process is an intermittent oscillation process of energy accumulation, with a long process and no recovery overvoltage.
Main technical parameters
1. Rated capacity: 75kVA
2. Rated voltage: 25kV; 75kV
3. Rated current: 3A; 1A
4. Measurement accuracy: system effective value class 1.5
5. Working frequency: 30-300Hz
6. Device output waveform: sine wave
7. Quality factor: device itself Q≥30 (f=45Hz)
8. Waveform distortion rate: output voltage waveform distortion rate ≤1%
9. Input power: single-phase 220V or three-phase 380V voltage, frequency 50Hz
10. Working time: continuous 60min allowed under rated load; overvoltage 1.1 times for 1 minute
11. Temperature rise: after continuous operation for 60min under rated load, temperature rise ≤65K
12. Protection functions: overvoltage, overcurrent, zero-position start, system detuning (flashover) and other protection functions.
13. Ambient temperature: -20℃ to 55℃
14. Relative humidity: ≤90%RH
15. Altitude: ≤3000 meters
