Design of LCL filter for wind power inverter

An LCL filter is more and more widely used in wind power inverters. However, it may easily result in instability due to resonance, which makes it difficult for stability control without damping. A voltage oriented control strategy under the dq synchronization reference frame is adopted based on the mathematical model of the three-phase inverter for wind power, and then the characteristics and performance of an LCL filter compared with the L filter are investigated in detail. At the same time, the design of the LCL filter and the influence of system stability with different damping are given. Experimental results have effectively verified the design.