Voltage regulator with high response to load fluctuation and reducing ripple of output current without noise filter, and power converter apparatus with the voltage regulator

A voltage regulator comprising:

• a plurality of chopper circuits connected in parallel between an input terminal and an output terminal, each of the plurality of chopper circuits being configured to switch an input voltage input to the input terminal and then output the input voltage from the output terminal via a first inductor of a primary winding of a transformer, the transformer including the primary winding and a secondary winding that are magnetically coupled with each other;
• and
• a second series circuit including a first series circuit and a third inductor that are connected in series, the first series circuit being configured by connecting respective second inductors of the secondary windings of the respective transformers of the plurality of chopper circuits in series, both ends of the second series circuit being connected to first and second connection points connected to each other,
• wherein the voltage regulator comprises:
• a first capacitor connected to be inserted between the first connection point and the output terminal;
• and
• a fourth inductor, which is configured to be one of the following:
• (1) the fourth inductor is connected to be inserted between the first connection point and one end of one of the second inductors that is connected closest to the first connection point,
• (2) the fourth inductor is connected to be inserted between the second connection point and one end of one of the second inductors that is connected closest to the second connection point, or
• (3) the fourth inductor is connected to be inserted between any pair of adjacent inductors of the plurality of second inductors.