The main components of the common frequency resonator device in the power sector are a frequency modulated voltage power supply, an isolation transformer, a reactor, an excitation transformer, and a capacitor voltage divider. The simultaneous series resonant connection method is composed of the reactor and capacitor of the test sample; The test sample is connected in parallel with a voltage divider, which is mainly used to measure the resonant voltage value on the test sample and provide an overvoltage protection signal

The power supply used in the pressure test of frequency series resonant inverters is the series resonant voltage test, which can provide more suitable voltage in the development process of testing equipment. A series of essential protection devices for resonant inverter power supplies have been developed through experimental research.

Variable frequency series resonance adopts the principle of series resonance. The main equipment consists of a variable frequency power supply control box (console), excitation transformer, reactor, and capacitor voltage divider. By connecting the rectifier silicon stack and microampere meter on the capacitor voltage divider, the DC withstand voltage test can be completed. Due to the fact that enterprise information management systems have an important filtering characteristic after resonance, the DC working voltage produced by them is superior to the DC voltage rectified by some other ordinary test transformers.

The resonant frequency of variable frequency series resonance, where L is the inductance value of the reactor. If several reactors are used in series or parallel, the influence of mutual inductance should be considered; C is the sum of the tested sample and the voltage divider capacitor, which can be measured using an electric bridge or dielectric loss High voltage current I=2 π fCU, electrical parameters and default values can be determined by the field pressure test voltage U of the pressure test sample; active power P=1.2 (P 0+PK), where P 0 is the load loss of the excitation transformer and PK is used for the rated power loss of the reactor.

As much as possible, in order to reduce the resonant frequency of the test series, the reduction ratio corresponding to the field should be changed. During the development process, the capacity of the active power P of the excitation transformer should be larger than that of the excitation transformer, and to meet the different requirements of field test design, the low output operating voltage of the input signal excitation current on the primary side should be changed slightly. Test power capacity S=P+P1, where P1 is the power loss of the frequency converter itself, and the available power supply current I1=from the power input voltage of 380V. The rated working voltage and current of the reactor in the experiment should also be greater than the voltage and high voltage current of the enterprise's research and test management system. When the reactor can meet the different experimental design development requirements of students by adopting series parallel connection, it is necessary to analyze the voltage and current borne by each reactor based on data calculation ability to ensure that they do not exceed the limit.