Influences of Control Parameters on Harmonic Characteristics of Current-controlled Inverters

Since a large number of inverters with LCL filters are widely used, harmonic disturbances of power systems are easily amplified by harmonic resonance. In order to study the influence of control parameters on the harmonic characteristics of current-type inverters, the Norton equivalent model of the current-controlled inverter with LCL filter is studied, where the influences of control parameters on two transfer functions, i.e., N
_i
and Y
_eq
, are investigated. It shows that the performance of harmonic suppressing of inverters could be improved by choosing appropriate parameters of proportional resonance controller of the inverter. The correctness of theoretical analysis is verified by the simulations in PSCAD/EMTDC.