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

Abstract

The invention discloses a high-power extremely-low-frequency power supply and a secondary harmonic suppression device thereof, and belongs to the field of power supplies. The device comprises a directcurrent module and a control module, wherein the direct current module comprises two capacitors, two switch tubes and an inductor; the two capacitors and the two switch tubes are sequentially connected in series; one end of the inductor is connected between the two capacitors, and the other end of the inductor is connected between the two switch tubes; the input end and the output end of the direct current module are connected between the two output ends of a filter module of the high-power extremely-low-frequency power supply and the two input ends of an inverter module; and the control module is used for controlling the on and off of the two switch tubes according to the current value and the voltage value of the output end of the inverter module, the voltage value of the output end ofthe filter module and the voltage values of the capacitors, so that the instantaneous power of the capacitors in the direct current module is equal to the pulsation power of the output end of the inverter module.

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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