Abstract:
Power electronic converters are commonly used to interface renewable energy
sources. There exist several topologies of these converters such as two level with
LCL filter, multilevel, matrix and interleaved. This thesis focuses on two level
LCL filter based topology which is commonly used in grid connected applications.
To meet national international standards, there is requirement of suitable control
strategy. It is an active area of research which has been investigated in this thesis.
Proportional Resonant Controller has been identified as a good candidate for
said application. Its performance has been tested under different conditions especially
system bandwidth. Moreover comparison with classical controller has
been presented as well. The classical PI controller is found to be robust and able
to provide high stability margins under varying load impedance however at the
same time it has high harmonic content in the output current. Proportional Resonant
controller is found to be adequate as it is able to provide low total harmonic
distortion in the output current as compared to PI controller. Simulation results
shows that proposed controller can provide better stability margins to the system,
ability to attenuate grid harmonics and good robustness by carefully selecting the
capacitor and inductor values in LCL filter as compared to PI controller.
