Power frequency series resonance equipment based on PLC

LAI Bai-le， KONG De-peng， LUO Jie
（Education College of Science＆Technology， Zhejiang University of Technology， Hangzhou 310014， China）

Abstract： In order to solve the problems of the size of the transformer and regulator getting very large and inconvenient in the power frequency withstand voltage test， the technology of PLC and resonance was investigated in the power frequency series resonance equipment. After the analysis of the resonant state，the relationship between the quality factor and sample's capacity was established. A method was presented to control the regulator by PLC. The method was evaluated on the theory of resonance，it changes the inductance of the reactor to make the circuit in the resonant state，and controls the contact of the regulator by PLC. As a result，the power frequency withstand voltage test of samples will come true under a low voltage. The experimental results show that equipment of large capacity can accomplish the power frequency withstands voltage test under a small capacity by using the power frequency series resonance equipment，in addition，it makes the experiment getting more convenient.
Key words： pressure test； PLC； power frequency series resonant； transformers； pressure regulator