Control method for inhibiting self-adaption waveform of inversion system low-frequency ripple

Abstract

The invention provides a control method for inhibiting a self-adaption waveform of an inversion system low-frequency ripple, wherein the same low-frequency ripple components are added into voltages of two capacitors at an output end of a differential inverter, the difference of the voltages is a sinusoidal waveform which is required by inversion, the current expression of a direct current side is calculated through a ripple transmission mechanism, the low-frequency ripple of the current of the direct current side is zero, accordingly, the amplitudes and phases of the low-frequency ripple components which are added into the voltages of the two capacitor are obtained, and the waveforms of the differential capacitor voltages are formed; and moreover, along with the load variation, the waveforms of the differential capacitor voltages are varied in a self-adaption manner, so powers which pass by the two capacitors include the ripple part of the output power, the direct current side only needs to provide the direct current average part of the output power, and accordingly, the influence of the low-frequency ripple on a direct current input power supply is inhibited.

Description

technical field [0001] The invention relates to an adaptive waveform control method of an inverter system based on the ability to suppress the low-frequency current ripple on the direct current side. Background technique [0002] In a DC-to-AC power supply system, outputting 50Hz / 60Hz AC will generate 100Hz / 120Hz ripple noise on the input DC terminal. These ripple noises will increase the equipment burden on the DC transmission line of the power system, resulting in power loss, and its electromagnetic radiation will also interfere with communication equipment; while the ripple noise in the DC power supply will interfere with useful signals in the load equipment, seriously affecting normal operation of the equipment; if the input side is a DC power source such as a fuel cell or a solar cell, the low-frequency ripple poses a serious threat to the life of the fuel cell and solar cell, and seriously reduces system efficiency; if the input side is a DC converter, the low-frequenc...

AI Technical Summary

Problems solved by technology

Although the low-frequency ripple current input by the two-stage conversion structure system is effectively suppressed, the voltage fluctuation on the input side of the inverter will increase the difficulty of controlling the output voltage harmonics of the subsequent inverter. Once the load changes suddenly, it will take several power frequency The cycle can achieve stability, and the dynamic performance of the system is poor

[0004] The above-mentioned methods of suppressing low-frequency current ripple need to be realized by adding peripheral circuits on the basis of single-stage inverters, and the cost is relatively high.

Moreover, the electrolytic capacitor in the system cannot be omitted, which limits the service life of the power supply system

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