INVERTER AND PHOTOVOLTAIC POWER GENERATION SYSTEM EMPLOYING IT

摘要

PROBLEM TO BE SOLVED: To protect a circuit element surely in an inverter 21 employed in a photovoltaic power generation system for housing and arranged to link a primary circuit on a solar cell 22 side with a secondary circuit on a commercial power supply system 23 side while insulating the cell and the system electrically by converting an input DC current through a high frequency inverter bridge 24 into a high frequency current of a specified carrier frequency having a commercial AC amplitude level, inputting the converted high frequency current into a high frequency insulation transformer 25, removing a ripple component from the high frequency current thus obtained through a diode bridge 26 and a low-pass filter 28 and then delivering the high frequency currents to respective phases through a low frequency inverter bridge 29.;SOLUTION: In parallel with a DC capacitor C0 for suppressing a variation in a DC input voltage, a surge absorber 41 for short-circuiting a DC input line is provided. Its protective operation voltage is set lower than a breakdown voltage of a circulation diode D0 provided contiguously to the full-wave rectification diode bridge 26 for rectifying a high frequency current from the high frequency insulation transformer 25.;COPYRIGHT: (C)2004,JPO&NCIPI