Method and device for adjusting boost ratio of power factor correction pfc circuit

Abstract

The invention discloses a method and a device for adjusting a step-up ratio of a PFC (power factor correction) circuit. The method comprises following steps: an input current instantaneous value and an input voltage instantaneous value of the PFC circuit are detected, and an input current average value and an input voltage average value are calculated respectively; a direct current bus voltage set value of an output end of the PFC circuit and a withstand voltage upper limit value of an electrolytic capacitor are acquired, an adjusting upper limit of the step-up ratio is acquired according to the withstand voltage upper limit value and the input voltage average value, and a first adjusting lower limit and a second adjusting lower limit of the step-up ratio are acquired according to the direct current bus voltage set value and the input voltage average value respectively; the change trend of the input current is judged according to the input current instantaneous value and the input current average value; when the input current is in a steady state or a rising process, an adjusting range of the step-up ratio is acquired according to the adjusting upper limit and the first adjusting lower limit; when the input current is in a falling process, an adjusting range of the step-up ratio is acquired according to the adjusting upper limit and the second adjusting lower limit. Therefore, more rapid and more accurate voltage control effect can be realized.

Description

technical field [0001] The invention relates to the technical field of power electronics, in particular to a method for adjusting a boost ratio of a power factor correction PFC circuit and a device for adjusting a boost ratio of a PFC circuit. Background technique [0002] In equipment such as household air conditioners, in order to improve the power factor of the power supply, a PFC circuit such as a Boost power factor correction circuit is usually connected after the uncontrolled full-bridge rectifier circuit, and a large-capacity electrolytic capacitor and a load (such as a switching power supply and Compressor, etc.), in this way, not only can a higher power factor be achieved through the PFC circuit, but also a stable DC voltage can be boosted and output to provide a stable DC power supply to the load. [0003] In related technologies, a single-cycle PFC control algorithm can be used to control the Boost power factor correction circuit. Specifically, the single-cycle PF...

AI Technical Summary

Problems solved by technology

However, the disadvantage of the related technology is that there will be hysteresis in the control process, which will lead to a large deviation of the calculated duty cycle, so that the voltage control effect of the PFC control algorithm is poor.

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