Electronic voltage regulator with switching control device and control method for stabilizing output voltage

A control method applied to an electronic voltage regulator which comprises input terminals electrically connected to a power source for providing an input voltage, output terminals for providing a stable output voltage, a power converter electrically connected to said power source for generating a DC voltage, and having an output switch assembly electrically connected to said DC voltage for converting said DC voltage to generate a compensation voltage to compensate said output voltage when said output voltage is different from a predetermined value, a switch with a first terminal electrical connected to said power source, a transformer electrically connected between said power converter, said switch, and output terminals, and a switching control device electrically connected to said power converter for controlling said power converter, wherein said transformer is a variable voltage source depending on a connection configuration of said switch and said switching control device obtains one group of voltages and one group of phrases by feedback of said input voltage, said output voltage, and said DC voltage and thereby a pulse width modulation (PWM) signal is generated through said output switch assembly, comprising the steps of:

• judging whether said output voltage is within a specific range;
• determining a connection configuration of said switch;
• generating said compensation voltage through said power converter and said transformer;
• controlling said compensation voltage having a phase difference with said input voltage and thereby causing a compensating power which is a product of said compensation voltage and an output current of said output terminals to be a positive value;
• utilizing said compensation voltage to stabilize said output voltage.

An electronic voltage regulator, comprising:

• input terminals electrically connected to a power source which provides an input voltage;
• output terminals for providing a stable output voltage;
• a power converter electrically connected to said power source for generating a DC voltage, and having an output switch assembly electrically connected to said DC voltage for converting said DC voltage to generate a compensation voltage to compensate said input voltage when said input voltage is different from a predetermined value;
• a switch with a first terminal electrically connected to said power source;
• a transformer with a primary winding and a secondary winding, wherein a first terminal of said primary winding electrically connected to an output terminal of said power converter, a second terminal of said primary winding electrically connected to a second terminal of said output terminals, a first terminal of said second winding electrically connected to a first terminal of said output terminals, a second terminal of said secondary winding electrically connected to a second terminal of said switch, and a third terminal of said switch electrically connected to said first terminal of said primary winding;
• and
• a switching control device electrically connected to said power converter for controlling said power converter to stabilize said output voltage;
• wherein said switching control device obtains one group of voltages and one group of phrases by feedback of said input voltage, said output voltage, and said DC voltage and thereby a pulse width modulation (PWM) signal is generated through said output switch assembly.