Semi-bridge type PFC bus voltage eqaulation control method and device

Abstract

This invention discloses a control method for PFC bus bar voltage-sharing of half-bridge type and its device, in which the positive and negative bus bar differential voltage is underground a proportion-integral-differential transformation, then the signal is directly superinposed on the duty ratio signal not to be front end of current loop. Even if the current loop exists, its variation would notinfluence the gain of equalizer ring, since the adjuster parameters of the internal current loop are adjusted independently and the parameters of the equalizer ring need to be adjusted once, and the equalizer ring would not influence current loop to generate little distortion to current order and THD of the current would not become large because of the qualizer ring.

Description

Technical field: [0001] The invention relates to a half-bridge boost PFC (power factor correction circuit) bus voltage equalization control method and device. Background technique: [0002] The main circuit topology of the half-bridge PFC see figure 1 , this kind of circuit is simple and has few components and high efficiency. generally adopted figure 2 In the double-loop control shown, the outer loop is the voltage loop, and the output voltage feedback is compared with the output voltage command. After the error passes through the PID (proportional-integral-differential) regulator, the output value is used as the command value of the input inductor current amplitude, which is realized by the inner loop. The waveform of the input current tracks the waveform of the input mains, thereby realizing power factor correction. [0003] However, simply using figure 2 The control block diagram shown may have problems. In fact, the upper and lower bridge arms of the circuit and t...

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Problems solved by technology

[0005] However, in this scheme, the voltage equalizing ring will affect the input current command, thereby distorting the current command, and finally increasing the THD (distortion degree) of the input current; the change of the regulator parameters of the current inner loop will also affect the voltage equalizing ring. The parameters of the gain and equalizing ring should also be adjusted accordingly

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