Design and control of a standalone photovoltaic system with energy storage for household applications

The integration of renewable energy sources (RES) with the electrical grid or directly with alternating current (AC) loads has gained importance in the context of global decarbonization initiatives. However, the inherent variability of RES, particularly solar energy, poses significant challenges for maintaining a stable and continuous power supply. This thesis investigates the design and control of a standalone photovoltaic (PV) system optimized for residential applications at the Shawinigan site, in Quebec. It specifically addresses critical issues such as frequency instability, voltage fluctuations, and harmonic distortion that derive from the stochastic nature of solar energy generation. The analysis includes the complexity associated with integrating energy storage systems, such as batteries, into standalone PV configurations, necessitating careful management of power flow between components and the assurance of stable voltage regulation. A notable contribution of this research is the development of a novel dual-loop current-voltage control algorithm for a single-phase inverter, utilizing the capacitor current of the LCL filter as a reference input. This method enhances system stability, power quality, and dynamic response. The efficacy of the control algorithm is evaluated through MATLAB/Simulink simulations, confirming the optimal performance of the overall system. This research illustrates the proposed solution's effectiveness in maintaining stable operation of the PV system under varying environmental conditions and offers valuable insights for improving the integration and control of RES in standalone applications.