METHOD OF COMPENSATE FOR GRID CURRENT UNBALANCE AND DISTORTION FOR 3-PHASE BI-DIRECTIONAL INVERTER

摘要

The present invention relates to a method of compensating for grid current imbalance for a 3-phase bi-directional inverter and a method of compensating for harmonic distortion of the 3-phase bi-directional inverter and, more particularly, to a method of compensating for grid current imbalance by extracting a normal value in consideration of a zero phase value of an imbalance grid voltage to perform a phase locked loop(PLL), to a method of compensating for harmonic distortion by directly calculating a harmonic distortion component in an abc coordinate system and adding the calculated value to an inverter output voltage abc coordinate reference value to prevent collision against the method of compensating for grid current imbalance, and to a 3-phase bi-directional inverter using the same. According to the present invention, grid voltage imbalance and grid current distortion due to harmonic distortion of a 3-phase bi-directional DC-AC inverter can be compensated at the same time.