Experimental investigation on a Solar Photovoltaic system using reduced multilevel connections for power quality improvement

This research paper investigates the new multilevel connections with minimum number of components as a voltage source inverter (VSI) which is connected in parallel as shunt active power filter (SAPF) for the purpose of the improving power quality and reactive power compensation in power systems. The main contribution of this paper is the design & development of modular structure which is capable of producing a wide range of output levels (9,11,13,15,17,19,21,23,25,27,29 and 31) using Asymmetric PV sources. A comparative study is made with other (27-level) reduced multilevel connection (RMC) topologies suitable for asymmetric input sources from solar photovoltaics (SPV). In addition, the state space analysis and the loss calculations are performed in order to ensure that the inverter is superior to the conventional topologies. The switching angles are determined using Particle Swarm Optimization (PSO) method. The implementation part of RMC is carried out with the selective harmonic elimination (SHE) which mitigates harmonics in the system. MATLAB/Simulink software is used for modelling of the proposed system. An Experimental setup of the proposed multilevel connections is developed and then it is experimentally investigated. A capacity of 3 KWp Solar PV system which feeds the DC input to the developed prototype. On the basis of the research findings, it is possible to draw the conclusion that the proposed inverter topology minimizes the voltage harmonics by 2.56% and current harmonics by 2.33% which enhances power quality, compensates the reactive power, lessens the number of components used by 12 and more cost effective.