Analysis of Smart Photovoltaic Module for Effective Use of Solar Energy

The main objective of this thesis is to present a comprehensive investigation of residential PV grid-connected inverters and propose novel, practical topologies to address the unbalanced power generation between PV modules. This thesis proposed a modular inverter (MI) derived from a power electronic converter topology. The suggested single-stage modular Cuk inverter (MCI) in this thesis is designed by connecting multiple low voltage (LV) MIs in series and linking the output terminals to the distribution network. The recommended topology does not require a large DC-link decoupling capacitor, which iscommon in conventional central inverters. The decentralized features of the proposed MCI enhance the controllability of the residential PV system. The suggested MCI topology is designed based on the Cuk converter. Therefore, it offers continuous input and output current features, which enable the use of small-sized filter components. MCI topology operates over a broad range of voltages, which makes it suitable for supplying local loads or charging battery storage. The control system of the proposed topology consists of two control systems. In PV-to-grid mode, the input control loop at the PV side is designed to mitigate ripples in the input current, which commonly reduces the efficiency of the MPPT algorithm. On the other hand, the outer control system at the grid side is responsible for maintaining a sinusoidal waveform matched with the grid current. The Simulink simulation results illustrate the effectiveness of the proposed MI in mitigating the unbalanced power production of residential PV systems. Also, a scaled-down prototype experiment has been developed to validate mathematical and simulation analysis. The thesis presents another distributed MPPT approach for mitigating unbalanced power production in residential PV applications. The proposed strategy aims to replace the conventional bypass diodes inside the PV module with an effective power converter to utilize the full power of the PV module under the partial shading (PS) effect. The suggested cascaded boost-based design is recommended to increase the power generation of the PV module and effectively tackle the unbalanced power production in PV residential systems. The design employs a boost converter to extract power from the three submodules (SM) of the PV model, and the outputs of the three boost converters are cascaded to step up the voltage to meet the grid side requirements. The voltage source inverter (VSI) is used at the grid side to effectively invert the DC power from the PV model side to alternating power. The proposed cascaded topology provides extra protection for the PV module by integrating a one-directional diode to prevent the reverse current from harming the PV module in faulty system scenarios. A practical experiment has been conducted to examine the effectiveness of the proposed topology. In the last part of the thesis, a module predictive control (MPC) strategy for a two-stage single-phase inverter using a single-ended primary-inductor converter (SEPIC) converter has been developed for residential PV applications. This control approach predicts the input inductor current, the DC link capacitor voltage, and the AC grid current of the double-stage inverter, comparing them with the reference values to perform the control actions. It consists of two parts: the DC MPC controller, which regulates the PV input current and decouples the double-line frequency ripples in the DC link capacitor, and the AC MPC controller, which optimally operates the single-phase VSI while synchronizing with the grid current. The cost function of the MPC approach maintains a smooth input current, which enables the efficient operation of the MPPT. The system-level PR controller ensures that the proposed cascaded output current operates at grid frequency to maintain a stable operation of the PV system. The validity of the proposed MPC method is examined through both experimental and simulation studies. The findings of this research project demonstrate that the proposed structure enhances the understanding of unbalanced irradiation levels in PV systems and their adverse impact on power production. Robust evidence is provided through the evaluation of the proposed solutions using both a simulation platform and experimental validation. The results indicate a significant improvement in power output after mitigating irregular irradiance levelsbetween PV components.