A Pattern for LCL Filter Design for Renewable Power Converters
In recent years, the use of renewable energy in power generation has increased, specifically in areas such as wind energy and solar energy. Simultaneously, there has been an increase in the development of power electronics switching devices targeting the renewable energy sector. The switching of power electronics devices in inverters produce harmonics in the AC load and have effects on the DC renewable generators like fuel cells as the harmonics decrease their lifetime. To cut the effects of those harmonics, filters are required. Several types of filters are used, and the simplest variant include filter inductor (L) connected to the inverter output, combinations with capacitors like LC and LCL. This paper deals with an LCL filter for the three-phase grid-connected inverter for renewable energy power systems applications. The goal is to model, simulate and analyze an LCL filter with a damping resistance connected in series with the capacitor. A DC renewable source of 1.4 kV with a nominal power of 60 kW is used in the system model. The inverter is expected to deliver a nominal power of 60 kW at 480 V with a reduced harmonics and pure sine-wave.
Index Terms— Inverter; LCL filter; renewable energy; passive damping.