Passivity Enhancement in Renewable Energy Source Based Power Plant With Paralleled Grid-Connected VSIs

Harmonic instability is threatening the operation of renewable energy based power plants where multiple grid connected voltage source inverters (VSIs) are connected in parallel. To analyze and improve the stability of the grid-connected VSIs, the real part of the output admittance of the VSIs is first investigated in this paper. It has been shown that the negative real part of the output admittanc...