Proportional resonant-controlled grid tied inverter with L-C resonant filter and its comparison with inverter with LCL filter

This paper presents series resonant L-C filter for the grid-tied inverter to remove harmonic injection into power grid. The controller for the inverter is based on proportional-resonant (P-R) method, which has been proved to be very effective to fulfil real power and reactive injection into the grid. It is found that such inverter-filter topology is most suitable for high power application in which harmonic components into the grid can be almost eliminited yet the demanded inductance is very small. Compared with LCL filter based inverter, series resonant filter based inverter can achieve better harmonic elimination in some operating conditions.