Tarek Selmi

Review of smart grid systems' requirements

Smart grid technology is a collection of existing and developing technologies all combined together. This technology is capable of enhancing the efficiency in production and consumption of electricity and improves the reliability and integration of renewable power into the grid. Current grids focus on centralized supply sources. However; the grids design can be modified and thus enhanced to receive fixed and predictable loads and to accept power from the renewable and distributed energy resources all through the grid. On the other hand, knowing that these resources are discontinuous and non-monotonic in nature, the grid requires an integration of monitoring and control technologies, as well as integration with automation processes in the aim of controlling divergent energy flows and planning for standby capacity to absorb the intermittent generation. The solar photovoltaic (PV) system consists of many stages with the conversion stage as one of the most crucial stage in the whole system. Accordingly, the characteristics and features of this stage control the behaviour of the solar PV system. Therefore; it is recommended that intelligent interfaces be linked and connected to the PV system to empower the grid the ability to handle two-way flows of power and communication. This implementation is required and will permit the seamless integration of solar technologies in high-penetration developments. In this paper, the authors aimed at reviewing the smart grid characteristics in the light of integrating renewable energy. In accordance, a wide research is conducted in the market to check the availability of different transformerless inverters that are compatible with solar PV applications. Following, a comparison between the features of selected inverters and those of smart grid is obtained. Consequently, a detailed description as well as the simulation of the designed transformerless inverter is demonstrated in this paper.

P&O MPPT implementation using MATLAB/Simulink

In this paper, a mathematical analysis of a photovoltaic cell is presented for the single diode and double diode cell configurations. The model of the double diode representation was implemented using a proprietary algorithm and MATLAB/Simulink. To track the point of maximum power, the perturb and observe (P&O) algorithm method was implemented. It was shown that the point of maximum power is always located at the expected position, is readily tracked, and maintained by minute increases and decreases in voltage. These encouraging results indicate opportunities for the utilization of this algorithm and its hardware implementation.

An approach to diagnose and remediate failures of Hall Effect sensors in BLDC motors

The paper deals with an approach to diagnose and remediate the faults affecting the Hall Effect sensors equipping brushless DC (BLDC) motors. The proposed approach is basically made up of an algorithm capable to detect, identify and remediate the fault in any of the three BLDC motor Hall Effect sensors. Following the detection of the fault, pointed out by a sensors binary word “000” or “111”, the algorithm allows the identification of the faulty sensor. A dedicated procedure is implemented for the sake of reconfiguration of the Hall Effect sensors-based control strategy. Simulation works, carried out under different faulty scenarios, have proven the performances of the proposed approach.

A novel single phase transformerless inverter topology for PV applications

A key stage of photovoltaic (PV) systems is the inverter connected at the chains end. Inverters dedicated to PV systems could be classified into two major topologies: (i) those equipped by a transformer and (ii) those without a transformer, the so-called: transformerless inverters (TIs). The latter were recognized to be more efficient in terms of energy efficiency and compactness. In spite of these performances, the integration of TIs in PV systems is compromised by some shortcomings, such as the circulation of a leakage current due to the absence of the galvanic isolation. This work considers a new single phase TI topology dedicated to PV systems. Beyond its energy efficiency capability and its null zero-crossing distortion, it has the merit to eradicate the leakage current. Following, the analysis of its operating sequences, the proposed TI topology is simulated in order to highlight its effectiveness.

Microcontroller-based inverter topology integrated in PV systems

Purpose – The purpose of this paper is to study the problem of the leakage currents in transformerless inverter topologies. It proposes a novel topology and how important the adopted control strategy on the power quality produced by the inverter. Design/methodology/approach – The paper presents an investigation of a novel transformerless inverter topology. It adopted a control strategy in which the DC source is disconnected from the inverter when the zero vectors of the control are applied. By using such control strategy, the electrical efficiency of the whole system was improved and the leakage current was significantly reduced. Findings – The paper provides a solution to minimize the leakage current in transformerless inverter topologies. Besides, the problem of zero-crossing distortions was totally eliminated. Research limitations/implications – Because of the high conversion ratio of the boost converter, the efficiency of the whole system needs to be enhanced. Practical implications – The paper includes the experimental results of the proposed topology which are in good match with the simulation results. Originality/value – This paper identifies a need to study the leakage current phenomena in transformerless inverter topologies.

Investigation and sizing of a solar power station at the Australian College of Kuwait

This paper deals with a review of solar power station installation requirements. It investigates then an approach to demonstrate a typical station at the Australian College of Kuwait based on Matlab/Simulink. The entire conversion system is supposed to feed a proposed transformerless inverter topology to minimize losses as much as possible. The simulated results have showed promising results and a test bench is under construction to validate the approach.