| Abstract |
Voltage-controlled inverters with an LC filter are widely used in uninterruptable power supplies anddroop-controlled inverters. However, as inverters usually have an operational lifetime of several years,important plant parameters such as the inductance and capacitance of the LC filter may diminish due to aging. In this paper, deviations in the LC filter parameters and their effect on the stability and robustness of the control are analyzed. An internal model control is designed for the inverter and a robust stability analysis is carried out. Furthermore, different controller designs for increased robustness are discussed and validated by simulations. Finally, the robust internal model control developed, is implemented in an FPGA-based system and used in an experimental setup to investigate the controller performance. |
