LCL Filter Design Method for Grid-connected Inverters

Characterized with high harmonic current attenuating,low bulk and low cost,the LCL filter is suitable for middle and high power grid-connected inverters.Whereas,the optimization of filter parameters is complicated and difficult due to the multiplicity and coupling of elements.A design method was proposed considering the physical meaning and partial storage energy optimized,and the relationship between the filter parameters and active damping of the resonance was introduced in the parameters selection procedure.The harmonic characteristic,design specifications and calculating procedure were analyzed and listed.Finally,based on an example,the selection results of LCL filter parameters were advised under different active damping strategies.