Parallel cross operation method of critical continuous conducting mode power factor corrector

Abstract

The parallel connection interleaving operational method of the power factor corrector in the critical and consecutive conducting mode belongs to the field of the control technology of the power converter. It chooses the method of digital dead beat control, adopts single DSP, confirms one of the several shunt-wound BCM Boost convertors as the master convertor, which is controlled in closed loop, and the rest as the appurtenant convertors, which are controlled in open loop. Under the condition of variable switch frequency and sampling frequency, make the inductive current of the appurtenant convertors follow the inductive current of the master convertors and realize the parallel connection interleaving operation of the BCM Boost APFC convertor. It only samples the input voltage and the output voltage, does not need to detect the peak value of the switched current in the hardware or to judge the crossover point of the inductive current, can get relatively high power and control it more simply.

Description

technical field [0001] The invention belongs to the research and application of a single-phase AC / DC power factor corrector (Active Power Factor Correction, APFC) in a switching power supply, and belongs to the technical field of power converter control. Background technique [0002] Boundary Continuous Conduction Mode (Boundary Conduction Mode, BCM) Boost APFC converter, referred to as BCM Boost APFC converter. Because it can realize the zero current and zero voltage (ZCS, ZVS) of the switching tube and eliminate the loss caused by the reverse recovery of the high-voltage fast recovery diode. Compared with the continuous (CCM) and discontinuous (DCM) BoostAPFC converter, It has high conversion efficiency. figure 1 and figure 2 The system structure and key working waveforms of BCM Boost APFC converter are given. image 3 The relationship curve between switching frequency and input voltage of BCM Boost APFC converter is given. [0003] figure 1 The control strategy of t...

AI Technical Summary

Problems solved by technology

In order to avoid problems in the logic circuit and improve the reliability of the parallel interleaved circuit, each converter needs an independent analog IC controller, which greatly increases the number of components in the circuit, especially when the number of parallel interleaved circuits is large. very complex to implement

Moreover, the difference between multi-controller PWM and the communication delay between controllers will affect the degree of uniform interleaving of inductor current and reduce the quality of input current.

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