Main Technical Characteristics and Application Advantages of Series Resonance in Power System Applications

   1. The required power supply capacity is greatly reduced.Series resonant powersource uses a resonant reactor and the capacitance of the test object to generate high voltage and large current through resonance. In the entire system, the power supply only needs to provide the active power consumption part of the system. Therefore, the power required for the test is only 1/Q of the test capacity.

       2. The weight and volume of the equipment are greatly reduced. In the series resonant power supply, not only the bulky high-power voltage regulating device 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, generally 1/10-1/30 of the ordinary test device.

       3. Improve the waveform of the output voltage. The resonant power supply is a resonant filter circuit that can improve the waveform distortion of the output voltage, obtain a good sine waveform, and effectively prevent the harmonic peak from causing false breakdown of the test object.

       4. Prevent large short-circuit current 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. In contrast, when using parallel resonance or test transformer method for withstand voltage test, the breakdown current immediately rises dozens of times. Comparing the two, the short-circuit current and breakdown current differ by hundreds of times. Therefore, series resonance can effectively find insulation weaknesses without the worry of large short-circuit current burning the fault point.

       5. 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 extinguished immediately, 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 will occur.

Main functions and technical characteristics of the frequency conversion resonant device:

       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 acts and can record the flashover voltage value for test analysis.

       2. The single-piece weight of the entire device is very light, making it convenient for on-site use.

       3. The device has three working modes, allowing users to flexibly choose according to on-site conditions and improve test speed. The working modes are: fully automatic mode, manual mode, and automatic tuning with manual boosting mode.

       4. It can store and print data remotely. The stored data numbers are numeric, which conveniently helps users identify and search.

       5. When the device automatically sweeps frequency, the starting frequency can be arbitrarily set within the specified range, and the sweep direction can be selected upward or downward. At the same time, the large LCD screen displays the sweep curve, allowing users to intuitively understand whether the resonance point has been found.

       6. It adopts DSP platform technology, which can conveniently add or upgrade functions according to user needs, and also makes the human-machine interface more user-friendly.