POWER CONVERSION APPARATUS, GRID CONNECTION APPARATUS, AND GRID CONNECTION SYSTEM

A power converting apparatus is provided with a step-up chopper circuit (2) that steps-up an input voltage (Vi) from a distributed power supply, an inverter circuit (3) that converts the output voltage (Vd) of the step-up chopper circuit (2) into alternating current, a first control circuit (voltage detector (PT), error calculator (21), and output voltage controller (22)) for controlling the output voltage (Vd), and a second control circuit (current detector (DCT), error calculator (31), input current controller (32), and PWM comparator (33)) for controlling the chopper input current (Ii). The first control circuit generates a target current value (Ir) so as to make the output voltage (Vd) become a target output voltage value (Vr). The second control circuit controls the step-up chopper circuit (2) so as to make the chopper input current (Ii) become the target current value (Ir). The first control circuit also has a low-pass filter (23a) that removes ripple components included in the output voltage (Vd).