Variable frequency resonance? Wuhan UHV specializes in the production of series resonance, with a wide range of product selection and professional electrical testing. To find series resonance, choose Wuhan UHV.
Variable frequency resonance uses the method of adjusting the frequency of the power supply to achieve resonance between the reactor and the tested capacitor, obtaining high voltage and high current on the tested object. It is a new method and trend in current high-voltage testing, and has been widely used both domestically and internationally.
The frequency conversion resonance adopts a dedicated SPWM digital waveform generation chip with a frequency resolution of 16 bits, and the frequency fineness can reach 0.1Hz between 20-300Hz. It adopts an orthogonal asynchronous fixed carrier modulation method to ensure good output waveform throughout the entire frequency range; The power section adopts advanced IPM modules to ensure instrument stability and safety with minimal weight.
The frequency conversion resonant device consists of a frequency and voltage regulation power supply, an excitation transformer, a reactor, and a capacitive voltage divider.
Widely used in industries such as power, metallurgy, petroleum, chemical, etc., suitable for high-capacity and high-voltage capacitive test samples, such as generators, transformers, etc GIS、 Handover and preventive tests for high-voltage cross-linked cables, transformers, bushings, etc. Our company has independently developed variable frequency and voltage regulation software technology in the field of variable frequency series resonance high voltage testing, leading the domestic high voltage testing industry. Using this technology, we have designed and manufactured a complete set of variable frequency series parallel resonance testing devices using 16 bit fine variable frequency, 10KHz carrier frequency, SPWM, and imported original IPM modules, which fully comply with the relevant national regulations and requirements for high voltage testing.
Working principle of frequency conversion resonance
By adjusting the output frequency of the variable frequency controller, resonance occurs between the inductance L of the reactor in the circuit and the capacitance C of the test sample, and the resonance voltage is the voltage applied to the test sample. The power supply is provided through the frequency modulation controller, and the test voltage is initially boosted by the excitation transformer to apply high voltage to the reactor L and the test sample CX. By changing the output frequency of the frequency modulation controller, the circuit is in series resonance state; The resonant frequency of the circuit depends on the capacitance CX of the test sample and the inductance L of the reactor. Adjust the output voltage of the variable frequency controller to achieve the required voltage value of the high voltage on the test sample.
Characteristics of Variable Frequency Resonant Products
1. Cables with voltage levels of 35kV and below are widely used and require a large amount of testing work. Therefore, this type of voltage withstand test device is small in size and light in weight, giving rise to portable cable voltage withstand test systems
2. This system requires that the weight of components that can be moved on-site by a single person should not exceed 30kg, and the weight of components that can be moved on-site by two people should not exceed 60kg, which is suitable for on-site handling
3. The power supply adopts 220V single-phase power supply or 380V single power supply, which is convenient for on-site power supply
4. The reactor part adopts dry-type epoxy casting, which is beautiful and reliable, suitable for the requirements of various types of cables
5. Oil immersed reactors are used for the withstand voltage test of cables with voltage levels of 110kV and above. When the individual weight exceeds 100kg, our company's dedicated small electric crane can be optionally equipped
