Filter capacitor current estimation and grid current control in LCL based grid connected inverter

摘要

The control of the grid side current in an LCL filter based grid connected converter is generally complex and involve multi loop structure. This paper presents a method to control the grid current indirectly by controlling the converter side current with compensation of the filter capacitor current. The proposed control algorithm uses only one current sensor to measure the converter side current. The filter capacitor current need to be estimated and an estimation method is presented to do the same. Simulation and experimental results are presented to confirm the feasibility of the proposed scheme.