High-power extremely low-frequency power supply and its sub-harmonic suppression device

Abstract

The invention discloses a large-power and extremely-low frequency power supply and a subharmonic suppression device thereof, and belongs to the field of a power supply. The device comprises an energystorage circuit and a control module, wherein the energy storage circuit comprises two capacitors, two switch tubes and an inductor, the two capacitors are connected in series, the two switch tubes are connected in series, one end of the inductor is connected between first ends of the two capacitors, the other end of the inductor is connected between first ends of the two switch tubes, second endsof the two capacitors are respectively connected with two output ends of an inversion module of the large-power and extremely-low frequency power supply, second ends of the two switch tubes are respectively connected between two output ends of a filtering module of the large-power and extremely-low frequency power supply and two input ends of the inversion module, the control module is used for controlling on / off of the two switch tubes according to current values and voltage values of output ends of the inversion module and voltage values of the output ends of the filtering modules and voltage values of the capacitors, so that the instantaneous powers of the capacitors in an energy storage circuit are equal to pulse powers of the output ends of the inversion modules.

Description

technical field [0001] The invention relates to the field of power supplies, in particular to a high-power extremely low-frequency power supply and a subharmonic suppression device thereof. Background technique [0002] The frequency range of Extremely Low-Frequency (ELF) radio waves is below 30 Hz. High-power ELF power supplies are devices that artificially generate ELF radio signals with a power of hundreds of kilowatts. [0003] The output of the inverter side of the high-power extremely low-frequency power supply is extremely low-frequency alternating current, and low-frequency harmonic components twice the operating frequency of the power supply will be generated at the input end of the inverter side, deteriorating the output harmonic characteristics of the extremely low-frequency power supply. At the same time, the low-frequency harmonic component is transmitted to the rectifier side and the grid side through the filter circuit, causing the inductance current to fluct...

AI Technical Summary

Problems solved by technology

At the same time, the low-frequency harmonic component is transmitted to the rectifier side and the grid side through the filter circuit, causing the inductance current to fluctuate at the output end of the rectifier, and in addition to the fundamental wave and characteristic sub-harmonics in the input current of the grid, waves at twice the low-frequency frequency are generated. low frequency sideband harmonics

Since the low-frequency sideband harmonics do not fall on the integer multiples of the grid operating frequency, they appear in the form of sub-harmonics, which will cause flickering of the light of the high-power extremely low-frequency power supply, increase the harmonic loss of the system, and affect the withstand voltage of the device and Insulation puts forward higher requirements, which adversely affects the reliability and life of the system

It may even resonate with the shaft frequency of the generator, causing synchronous oscillation of the power system

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