The demand of a three phase PWM inverter for the purpose of power control or grid-connecting is increasing. This inverter is
connected to a grid through an L-filter or LCL-filter to reduce the harmonics caused by switching. An LCL-filter can reduce the
harmonic of a low switching frequency and generate a satisfactory level of grid side current with a relatively low-inductance than an
L-filter. But the additional poles caused by the LC part affects a stability problem due to induced resonance of the system.
This paper presents a compensation method using a power theory to improve performance, the designed LCL-filter system and
to reduce the stability problems caused by resonance. The effectiveness of the proposed algorithm is verified by simulations.