Power conversion device

A power conversion device, comprising:

• first and second input capacitors which are connected in series between output terminals of a DC input power supply;
• first and second inverter circuits which include first and second inverters whose input terminals are respectively connected to both ends of the first and second input capacitors, and first and second transformers which have primary windings connected to the first and second inverters and secondary windings electro-magnetically coupled with the primary windings;
• first and second rectifying circuits which convert AC voltages across the secondary windings into DC voltages;
• a first error amplifier which generates a first error signal e1 based on a predetermined reference value and a signal corresponding to the detected value of either one of an output power, a DC output voltage, or a DC output current obtained by combining outputs of the first and second rectifying circuits;
• a second error amplifier which generates a second error signal e2 by comparing the voltage across the first input capacitor with the voltage across the second input capacitor;
• a first control circuit which controls the first inverter based on a signal obtained by subtracting the second error signal e2 from the first error signal e1;
• and
• a second control circuit which controls the second inverter based on a signal obtained by adding the second error signal e2 to the first error signal e1,
• wherein the DC voltages output from the rectifying circuits are combined with each other, and
• the voltage across the first input capacitor balances with the voltage across the second input capacitor by changing a control signal supplied to an inverter circuit in which the voltage across an input capacitor provided therein is higher so as to increase the output of an inverter provided in the inverter circuit, and by changing a control signal supplied to another inverter circuit in which the voltage across another input capacitor provided therein is lower so as to decrease the output of another inverter provided in another inverter circuit.