Conversor CA-CC Push-Pull ZVS-PWM-PFC alimentado em corrente monofásico com ampla variação de tensão eficaz de entrada

Abstract

This work presents the study of a single-phase current-fed AC-DC Push-Pull converter with a wide rms input voltage range (88 V to 264 V) processing nominal power, where the duty cycle varies from 0 < D < 1. Other features presented include a high power factor (PF > 0.92), output voltage regulation (Vo = 400 V), soft switching of transistors (Zero Voltage Switching - ZVS), and a constant transistor switching frequency using pulse width modulation (Pulse Width Modulation - PWM). In the converter under study, soft-switching is achieved using the active clamping technique, which consists of two transistors and a film capacitor. By employing the active clamping technique, the converter can operate at nominal power when D < 0.5, a situation that does not occur when a similar converter uses a passive snubber, as it requires protection during the soft-start transition by coupling an auxiliary winding to the storage inductor for operation in Flyback mode. For the converter under study, studies are conducted in the non-overlapping mode (Non Overlapping Mode - NOM) of PWM signals, which occurs for 0 < D < 0.5, referred to as Region R1; and in the overlapping mode (Overlapping Mode - OM) of PWM signals, which occurs for 0.5 < D < 1, referred to as Region R2. To control the power flow from input to output, the Average Current Mode Control (ACMC) technique is used. Finally, for the specifications of an rms input voltage ranging from 88 V to 264 V at 60 Hz, an output active power of 2 kW, an output voltage of 400 V, and a switching frequency of 25 kHz, the design of the power and control circuits is carried out, along with the presentation of simulation results.