Series Resonant Test DevicePrimarily designed for AC withstand voltage tests of cross-linked cables, hydraulic generators, main transformers, busbars, GIS, etc., it boasts a wide range of applicability and is the ideal voltage withstand equipment for high-voltage testing departments at the provincial, municipal, and county levels, as well as for power installation and maintenance engineering units.
Series Resonant Test DevicePrimarily composed of variable-frequency control power supplies, excitation transformers, reactors, capacitor voltage dividers, and compensating capacitors (optional).
Advantages of series resonance application in power systems:
1. The required power capacity is significantly reduced. Series resonance power supplies utilize resonance reactors and the capacitive resonance of the test item to generate high voltage and current. In the entire system, the power supply only needs to provide the active power consumption part. Therefore, the power required for the test is only 1/Q of the test capacity.
2. The weight and volume of the equipment are 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 requires only 1/Q of the test capacity, leading to a substantial reduction in system weight and volume, typically 1/10 to 1/30 of a standard test setup.
3. Improve the output voltage waveform. The resonant power supply is a resonant filter circuit that can improve the distortion of the output voltage waveform, achieving a good sine wave. It effectively prevents the harmonic peak from causing false breakdown in the test items.
4. Prevent large short-circuit currents from burning fault points. In series resonance, when the insulation weakness of the test item is punctured, the circuit immediately detunes, and the circuit current rapidly drops to 1/Q of the normal test current. In contrast, during withstand voltage tests using parallel resonance or a test transformer, the puncture current immediately rises several tens of times. Compared to this, the difference between short-circuit current and puncture current can be hundreds of times. Therefore, series resonance can effectively locate insulation weaknesses without the隐患 of large short-circuit currents causing burn faults.
5. There will be no voltage recovery. When the sample is punctured, the high voltage disappears immediately due to the loss of resonance conditions, and the arc is extinguished at once. Moreover, the process of re-establishing the voltage is lengthy, making it easy to disconnect the power supply before reaching the flashover voltage again. This voltage recovery process is an intermittent oscillation of energy accumulation, which is lengthy and does not result in any overvoltage recovery.
Frequency Converter Series Resonant Test Device: Main Functions and Technical Features
1. The device features protective functions such as overpressure, overcurrent, zero-point startup, and system detuning (arc-over). The overpressure and overcurrent protection values can be adjusted according to customer requirements. The arc-over protection will activate during the arc-over of the test sample to safeguard it.
2. The entire unit is extremely lightweight, making it convenient for on-site use.
3. The device features three operating modes, allowing users to flexibly select based on on-site conditions to enhance testing speed.
Operation modes: Full Automatic, Manual, and Auto-Tuning Manual Boost Mode.
4. Stores and allows remote printing of data. Stored data is numbered, conveniently aiding users in identification and retrieval.
5. The frequency starting point can be arbitrarily set within the specified range during automatic sweep operation, and the LCD large screen displays the scan curve, making it easy for users to visually determine if the resonance point has been found.
6. Utilizes DSP platform technology, allowing for easy addition or removal of features and upgrades based on user needs, and also makes the human-machine exchange interface more user-friendly.
