Method for reducing capacitance in single-phase pulse load AC-DC power source

Abstract

The invention discloses a method for reducing capacitance in a single-phase pulse load AC-DC power source and belongs to the power electronic converter field. The single-phase pulse load AC-DC power source needs to implement a PFC function at an input AC side, which will introduce second harmonic current into a PFC busbar, and therefore, a large-capacitance capacitor is required to be arranged onthe PFC busbar so as to decouple the second harmonic current; the single-phase pulse load AC-DC power source also needs an output voltage under the condition of a pulse load to be stabilized within acertain range at an output side, the pulse current of the output side is transmitted to the PFC busbar, and as a result, a large-capacitance capacitor is required to decouple the pulse current; the large-capacitance capacitors for the above two purposes will reduce the power density of a converter; in order to improve the power density of the converter, a bidirectional converter is connected in parallel with the PFC output busbar so as to act as a controlled current source; the input current of the controlled current source is controlled according to a power conservation method, and at the same time, the second harmonic current and pulse current are decoupled; and therefore, the voltage ripples of a PFC busbar capacitor can be decreased, and the power density of the converter can be improved.

Description

technical field [0001] The invention relates to a method for reducing capacitance in a single-phase pulse load AC-DC power supply, which belongs to the field of power electronic converters. Background technique [0002] In recent years, with the development of power electronics technology, especially the development of power semiconductor devices and their control technology, the application of various power electronics equipment has become increasingly widespread. Rectifier, also known as AC-DC, as one of the main forms of switching power supply, not only brings convenience to industrial and agricultural production and people's life, but also injects a large amount of harmonic current into the power grid, becoming a major pollution source of the public power grid. In view of the impact of harmonics generated by electrical equipment on public power grids, many countries have formulated national standards for limiting harmonics. my country also promulgated "Power Quality-Publ...

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Problems solved by technology

However, due to the property that the liquid electrolyte is easy to volatilize over time, the electrolytic capacitor has a shorter lifespan than the capacitors with solid electrolytes such as ceramics and tantalum capacitors; at the same time, large-capacity electrolytic capacitors will result in low power density.

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