This paper presents a new digital control scheme for a standalone photovoltaic (PV) system using fuzzy-logic and a dual maximum power point tracking (MPPT) controller. The first MPPT controller is an astronomical two-axis sun tracker, which is designed to track the sun over both the azimuth and elevation angles and obtain maximum solar radiation at all times. The second MPPT algorithm controls the power converter between the PV panel and the load and implements a new fuzzy-logic (FLC)-based perturb and observe (P&O) scheme to keep the system power operating point at its maximum. The FLC-MPPT is based on a voltage control approach of the power converter with a discrete PI controller to adapt the duty cycle. The input reference voltage is adaptively perturbed with variable steps until the maximum power is reached. The proposed control scheme achieves stable operation in the entire region of the PV panel and eliminates therefore the resulting oscillations around the maximum power operating point. A 150-Watt prototype system is used with two TMS320F28335 eZdsp boards to validate the proposed control scheme performance.Index Terms-Digital signal processor, fuzzy logic controller (FLC), maximum power point tracking (MPPT), physical tracking, standalone photovoltaic (PV) system.

As the Internet of Things (IoT) is gaining ground and becoming increasingly popular in smart city applications such as smart energy, smart buildings, smart factories, smart transportation, smart farming, and smart healthcare, the digital twin concept is evolving as complementary to its counter physical part. While an object is on the move, its operational and surrounding environmental parameters are collected by an edge computing device for local decision. A virtual replica of such object (digital twin) is based in the cloud computing platform and hosts the real-time physical object data, 2D and 3D models, historical data, and bill of materials (BOM) for further processing, analytics, and visualization. This paper proposes an end-to-end digital twin conceptual model that represents its complementary physical object from the ground to the cloud. The paper presents the proposed digital twin model’s multi-layers, namely, physical, communication, virtual space, data analytic and visualization, and application as well as the overlapping security layer. The hardware and software technologies that are used in building such a model will be explained in detail. A use case will be presented to show how the layers collect, exchange, and process the physical object data from the ground to the cloud.

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This paper presents the design and implementation of a two-axis stand alone rotary sun tracker. The objective is to analyze the effects of introducing both physical sun-tracking and maximum power point tracking (MPPT) on PV systems' efficiency in the gulf region. A two-axis rotation mechanism is implemented to track the sun over both the azimuth and elevation angles. The position of the sun is determined using the astronomical method. The sun's azimuth and elevation angles are continuously updated throughout the day using a Digital Signal Processor (DSP). The calculated angles are then used as set-points for two closed-loop control systems with PI controllers implemented in the DSP. The panel power is passed through a charger that implements perturb and observe MPPT algorithm to keep the system power operating point at its maximum value.