PhD ThesisThis research is concerned with the problem of network power quality when grid
connected systems are used to feed the network distribution grid. A parallel connection
of photovoltaic (PV) system is the main interest of study for this research. This type of
PV system uses power electronic components such as inverter and current controller that
produce harmonics which adversely affect the power quality of the distribution network.
Development and simulation of current controller using the proportional resonance (PR)
scheme is considered to overcome the harmonic problems in single and parallel PV
inverters. This scheme eliminates specific harmonic in the low order part. The control
parameter randomisation technique is added to the scheme to produce a more efficient
current controller system. Thus, the inverter harmonic performance (inverter output
current) is improved. This concept is extended to parallel inverter based systems, where
opportunities for harmonic cancellation improve the inverter harmonic performance
further. Experimental hardware setup using TMS320F2812 is also developed to verify
the promising simulation results