Abstract:A photovoltaic system is highly susceptible to partial shading. Based on the functionality of a photovoltaic system that relies on solar irradiance to generate electrical power, it is tacitly assumed that the maximum power of a partially shaded photovoltaic system always decreases as the shading heaviness increases. However, the literature has reported that this might not be the case. The maximum power of a partially shaded photovoltaic system under a fixed configuration and partial shading pattern can be highly insusceptible to shading heaviness when a certain critical point is met. This paper presents an investigation of the impact of partial shading and the critical point that reduce the susceptibility of shading heaviness. Photovoltaic string formed by series-connected photovoltaic modules is used in this research. The investigation of the P-V characteristic curve under different numbers of shaded modules and shading heaviness suggests that the photovoltaic string becomes insusceptible to shading heaviness when the shaded modules irradiance reaches a certain critical point. The critical point can vary based on the number of the shaded modules. The formulated equation in this research contributes to determining the critical point for different photovoltaic string sizes and numbers of shaded modules in the photovoltaic string.

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This paper presents the investigation of partial shading characteristics of mono-crystalline and poly-crystalline photovoltaic module connected in series. Simulink models are developed to assist the investigation to determine the ideality factor for mono-crystalline and poly-crystalline photovoltaic module. Commercially available mono-crystalline and poly-crystalline photovoltaic module are used to extract measurable parameters for the model to study the behaviour of I-V curve. Measurements have been conducted for the investigation includingmono-crystalline only, poly-crystalline only, both unshaded, mono-crystalline shaded and poly-crystalline shaded. This paper contributes to the understanding of partial shading characteristics of different materials presence in photovoltaic string.

Effects of bypass diode configurations to the maximum power of photovoltaic module are presented. The impacts of one, two and three bypass diodes configurations to the photovoltaic module are investigated using simulation approach. Simulink models are developed to perform all the simulations in this investigation. In the investigation, various shading patterns are applied to one, two and three bypass diodes configurations to investigate the impact of bypass diode configuration to the maximum power of photovoltaic module. Simulation results show that the bypass diode configurations doesn't affect the maximum power of the photovoltaic module under certain shading conditions. The comparison study among one, two and three bypass diodes configurations show a greater quantity of bypass diode in a photovoltaic module doesn't guarantee better performance during partial shading condit

This study presents a resident-centric distributed community energy management system (CEMS). More specifically, the proposed resident-centric distributed CEMS allows residents to schedule their appliances autonomously, without the need to collaborate with the community and to consider whether their appliance scheduling is optimal from the perspective of the entire community. The central controller in the proposed CEMS will then determine a solution that is optimal for the entire community by dispatching the community's distributed energy sources according to the appliance scheduling of residents. In other words, the proposed distributed resident-centric CEMS allows residents to act autonomously while securing the collective goals of the community to a certain extent. In this paper, the collective goals of the community include participating in incentive-based demand response (IBDR) events at a specific time interval, and decreasing the total electricity cost of the community in response to time-varying electricity prices. The proposed distributed resident-centric CEMS is developed using the concept of distributed optimization and mixed-integer linear programming. Different types of public loads are incorporated into the proposed framework including stoppable and deferrable public loads. The simulation results show that the proposed framework dispatches power optimally.