Principle of series resonance withstand voltage test device

According to the principle of series resonance and the output characteristics of the excitation transformer, the series resonance circuit was excited. By adjusting the output frequency of the variable frequency controller, the inductance L and sampling C in the circuit resonate, and the resonant voltage is added to the sampling voltage.

Test object of series resonant device

The frequency conversion series resonance test device is the most effective method for on-site inspection of the quality of cross-linked cable laying and accessory installation. The frequency conversion resonance device produced by Dingsheng Power Company meets the requirements of IEC and national standards, and can meet the on-site AC withstand voltage requirements of 10 kV-500 kV series parallel cables.

Principle analysis of series resonance withstand voltage test device

In an AC circuit with resistor R, inductor L, and capacitor C, the voltage across the circuit is usually different from the current phase. If we adjust the parameters or power frequency of circuit components (L or C), they can be in the same phase, and the entire circuit is purely resistive. When the circuit reaches this state, it is called resonance. In resonance state, the total impedance of the circuit reaches an extreme value or an approximate value. The purpose of studying resonance is to understand this objective phenomenon, fully utilize the characteristics of resonance in science and application technology, and prevent its harm. According to the different circuit connections, there are two types of DAXZ series series series resonance and parallel resonance. In a series circuit composed of resistors, inductors, and capacitors, when the capacitance reactance XC is equal to the inductance reactance XL, i.e. XC=XL, the phase of the voltage U and current I in the circuit are the same, and the circuit exhibits pure resistance, which is called series resonance (also known as voltage resonance). When series resonance occurs, the total impedance of the circuit Z=R2 XC-XL2=R is minimized, and the current reaches its maximum value.