PFC jitter frequency control method and system, and electric appliance

Abstract

The invention provides a PFC jitter frequency control method, a PFC jitter frequency control system and an electric appliance. The PFC jitter frequency control method comprises steps of controlling aPFC frequency jitter module to generate a PFC carrier frequency periodically changing with the time through a PFC carrier jitter frequency function; obtaining the phase of a mains supply voltage signal, and controlling the PFC carrier frequency corresponding to each frequency point of the PFC carrier jitter frequency function to periodically change along with the phase of the mains supply voltagesignal; wherein the minimum frequency point and the maximum frequency point of the PFC carrier frequency function correspond to a zero crossing point phase of the mains supply voltage signal, and thezero crossing point phase of the PFC carrier frequency function corresponds to the minimum frequency point and the maximum frequency point of the mains supply voltage signal. The method is advantagedin that the electric stress of power devices such as an IGBT or an MOS in the PFC circuit can be effectively reduced, switching loss is reduced; electromagnetic noise of household appliances or powersupplies and other products can be effectively suppressed, and electromagnetic interference to the outside is reduced.

Description

technical field [0001] The invention relates to the field of home appliance control, in particular to a PFC frequency shaking control method, system and electrical appliances. Background technique [0002] In the existing digital PFC (Power Factor Correction, power factor correction) control technology, the digital PFC adopts fixed carrier frequency control, and the high-power semiconductor devices (IGBT, MOS, fast diode, etc.) in the PFC control circuit work at a fixed frequency point In general, such devices generate a large amount of electromagnetic noise during the switching process, which may be conducted from the line or radiated from the space, and it is difficult to effectively suppress it through filter circuits or structural shielding. Statistics show that the electromagnetic interference of PFC carrier frequency or carrier frequency multiplier is particularly prominent. [0003] The Chinese invention patent with the patent number CN201610412431.8 provides a varia...

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Problems solved by technology

This method can effectively suppress the output of even-order harmonic components, but there are still problems such as large electrical stress of switching devices such as IGBT or MOS, large switching losses, and ineffective suppression of electromagnetic interference.

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