By hvhipot 
In a series circuit composed of resistors, inductors, and capacitors, when the capacitive reactance XC is equal to the inductive 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 resistive behavior. This phenomenon is called series resonance. When a series resonance occurs in the circuit, the impedance Z=√ R ^ 2+(XC-XL) ^ 2=R, the total impedance in the circuit is minimized, and the current will reach its maximum value.
The conditions for generating series resonance:
XL=XC
Due to the high voltage generated by series resonance in L and C, it may cause damage to the breakdown of coils or capacitors. Therefore, in power engineering, series resonance should be avoided as much as possible, and it is particularly important to use series resonance testing devices to detect power systems.
In a sinusoidal AC circuit with R, L, and C components, the voltage and current at both ends of the circuit are generally different phases If the parameter values of circuit components are changed or the frequency of the power supply is adjusted, the voltage and current of the circuit can be in phase, causing the impedance of the circuit to exhibit resistance properties. A circuit in this state is called resonance According to different connection forms of circuits, resonance phenomena can be divided into series resonance and parallel resonance. In a series circuit of R, L, and C, when XL=XC in the circuit, the impedance angle ∧=0, that is, the power supply voltage and current are in phase, this phenomenon is called series resonance.
HV Hipot Electric Co., Ltd. specializes in the production of series resonance (also known as variable frequency series resonance complete equipment) and has been engaged in the electrical measurement industry for many years. Its products have first-class quality and welcome customers to come and purchase.