一种基于新能源并网的LCL型逆变器有源阻尼控制策略OA

[Purposes]Grid-tied inverters with LCL-type filters play a crucial role in offshore wind power systems.They can eliminate high-frequency current harmonics,thus ensuring that the power quality complies with grid-connection standards.Considering it is difficult to eliminate harmon-ic current distortions introduced by complex grid completely,effective strategies are necessary for their suppression.In this paper,an active damping(AD)method that replaces the PI controller with a proportional resonant(PR)and harmonic compensation controller to suppress background harmon-ics in the power grid,which not only enhances the suppression effect,but also reduces the reliance on sensors.[Methods]First,the transfer functions and equivalent circuits under the proposed AD con-trol strategy were analyzed,which combines inverter-side inductance current feedback with harmonic compensation.Second,the parameter design method for this strategy was derived and verified.Final-ly,the effectiveness of the proposed strategy was validated through Matlab/Simulink simulations and by constructing an experimental platform.[Results]Simulation and experimental results demonstrate that this method can effectively realize good performances of harmonic elimination and active damping resonance suppression with both stiff and weak grid conditions,while reducing the number of sensors used.