| 摘要 |
A power factor correction control device for dynamically sensing and boost regulation includes a rectifying unit, a transformer, a digital regulation controller, a driving element, a sensing resistor, an output diode and an output capacitor. The control device converts an AC input power into a DC output power so as to supply an external load. The transformer includes a primary coil and an auxiliary coil, the controller employs an auxiliary voltage from the auxiliary coil to calculate the current input voltage and the current output voltage to implement feedback control for the driving element. The driving element is thus turned on and off by the controller to achieve boost function such that the output voltage is greater than the input voltage. The present invention obtains the input voltage and the output voltage by calculation without any sensing resistor, thereby reducing power consumption and increasing power conversion efficiency. |
| 主权项 |
1. A power factor correction control device for dynamically sensing and boost regulation and for converting an alternative current (AC) power into a direct current (DC) output power with an output voltage to supply an external load, comprising:
a rectification unit for receiving and rectifying the AC power to generate an input voltage; a transformer comprising a primary coil and an auxiliary coil, each configured to have an opposite polarity to each other, an end of the primary coil receiving the input voltage from the rectification unit, a digital regulation controller being a digital electronic element for performing a voltage regulation control process, comprising an auxiliary terminal, a driving sensing terminal and a driving control terminal, the driving sensing terminal outputting a driving signal in a form of pulsed width modulation (PWM), the digital regulation controller generating the driving signal with a low level to turn off the driving element or the driving signal with a high level to turn on the driving element based on one operation mode selected from a discontinuous conduction mode (DCM), a boundary conduction mode (BCM) and a continuous conduction mode (CCM); a driving element implemented by a transistor having a drain terminal, a gate terminal and a source terminal; a sensing resistor; an output diode; and an output capacitor connected to the external load in parallel, wherein an another end of the primary coil is connected to a positive end of the output diode, an end of the auxiliary coil is connected to the auxiliary sensing terminal of the digital regulation controller, an another end of the auxiliary sensing terminal is grounded, the drain terminal of the driving element is connected to a connection point of the primary coil and the output diode, the gate terminal of the driving element is connected to the driving control terminal of the digital regulation controller, the source terminal of the driving element is connected to the driving sensing terminal and an end of the sensing resistor, an another end of the sensing resistor is grounded, an end of the output capacitor is connected to a negative end of the output diode, and an another end of the output capacitor is grounded, wherein the voltage regulation control process of the digital regulation controller comprises steps of: the driving control terminal outputting the driving signal with the high level to turn on the driving element, the digital regulation controller storing an auxiliary voltage of the auxiliary terminal as a turn-on auxiliary voltage expressed by VA1=|VIN|×NA/NP, VA1 being the turn-on auxiliary voltage, VIN being the input voltage, NA being a winding number of the auxiliary coil, NP being a winding number of the primary coil; calculating the input voltage based on |VIN|=VA1×NP/NA; the driving control terminal outputting the driving signal with the low level to turn off the driving element, the digital regulation controller calculating and storing the auxiliary voltage of the auxiliary terminal as a turn-off auxiliary voltage expressed by VA2=|(Vo−VIN)|×NA/NP, VA2 being the turn-off auxiliary voltage; calculating and storing a difference between the turn-on auxiliary voltage and the turn-off auxiliary voltage as a difference voltage expressed by VD=Vo×NA/NP, VD being the difference voltage, Vo being the output voltage; and obtaining the output voltage by calculation based on Vo=VD×NP/NA, wherein the digital regulation controller performs a feedback control on the driving element based on the input voltage and the output voltage through calculation so as to implement a boost follow function by fixing the difference voltage between the input voltage and the output voltage sensed by the auxiliary coil as the driving element being turned off, and the output voltage is greater than the input voltage by a fixed value. |
