Wuhan UHV specializes in producingseries resonant devices (also known as variable frequency series resonant devices). Next, we will share with you the principle of variable frequency series resonant devices.

Working principle of series resonance test device:

A device that uses tuned inductors and load capacitors to generate power frequency series resonance and obtain power frequency test voltage.  

Composed of a variable frequency power supply, excitation transformer, reactor, and capacitive voltage divider. The capacitor and reactor of the test sample form a series resonant connection; The voltage divider is connected in parallel to the test sample to measure the resonant voltage on the test sample and provide an overvoltage protection signal; The frequency modulation power output is coupled to the series resonant circuit through an excitation transformer, providing excitation power for series resonance.  

The series resonance test device is a generation of equipment specifically designed for AC withstand voltage testing of capacitive test samples. It is widely used for AC withstand voltage testing of various high-voltage cross-linked cables, transformers, generators, GIS switches, motors, and SF6 switch frequency conversion frequency modulation series resonance series resonance AC withstand voltage testing complete sets of instruments and equipment.  

The series resonant voltage withstand device mainly consists of a frequency converter controller, excitation transformer, high-voltage reactor, high-voltage voltage divider, etc. Variable frequency controllers are divided into two categories: desktop controllers with 20KW and above, and portable box controllers with 20KW and below; It consists of a controller and a filter. The main function of a variable frequency controller is to convert a 380V or 200V AC power frequency sine wave with fixed amplitude and frequency into a sine wave with adjustable amplitude and frequency. And provide power for the entire equipment. The function of the excitation transformer is to raise the voltage output by the variable frequency power supply to the appropriate test voltage. The high-voltage reactor L is an important component of the resonant circuit. When the power frequency is equal to 1/(2 π√ LCX), it undergoes series resonance with the test sample CX.