Over recent years the output power of microinverters (ΜIC Module Incorporated Inverter) is progressively pushed to higher levels, following the current PV modules market trends. The interleaved Flyback inverter - under Discontinuous Conduction Mode of operation (DCM) - is an appealing solution for PV applications which are based on MIC technology. This topology provides increased power level for distributed PV generation (DG-PV) exploitation with simple control configuration, high efficiency, and reduced filter size. In this paper the harmonic injection capability is incorporated into the interleaved Flyback inverter for the implementation of an active anti-islanding scheme. A suitable technical solution is proposed in order to bypass the unfolding H-bridge, without affecting the active power generation of the inverter and without requiring any hardware modification. In addition, a mathematical model based on the Instantaneous Power Balance (IPB) theory is presented, being a powerful analysis tool for inverters operating under complete magnetic discharge like the Flyback one (either conventional or interleaved) under DCM or BCM mode of operation. The proposed model predicts accurately the steady state operational behavior of Flyback inverter under current harmonic injection, either in grid-tied or islanding operation. The proposed technical implementation method and mathematical model are verified through simulation and experimental results. Finally, an anti-islanding set-up based on the proposed harmonic injection technique is presented and implemented into the Flyback micro-inverter. The proposed set-up is verified through experimental results on various QF values, as well as for weak grid conditions.

This work introduces a new cross-correlation anti-islanding detection scheme for Module Integrated Converters with Pseudo dc-link (Pdc-MICs). The proposed scheme periodically injects a second order harmonic current component of low magnitude (in open-loop mode) and evaluates grid response by means of correlation. The proposed scheme is highly reliable, providing Non-Detection-Zone (NDZ) free operation, fast detection, and compliance with the relevant power quality and anti-islanding standards. Additionally, it excels in lower computational cost, reduced Fault Detection Zone (FDZ), and higher output power quality, compared to the referenced anti-islanding schemes that are compatible with MICs. Last but not least, it can be implemented in MIC platforms without requiring an output current sensor, being an easily upgradable solution in software level. A firm theoretical framework that considers both high penetration levels of PV-systems and weak grid conditions is also included in this work. The theoretical framework as well as the effectiveness of the proposed scheme are verified through extensive experimental results for various electrical-network parameters and non-linear loading conditions. Finally, a comprehensive comparison between the proposed method and the most common anti-islanding techniques (compatible with MICs) is performed, leading to some valuable conclusions from MICs perspective.

This paper investigates the Wireless Power Transfer (WPT) system incorporation into DC microgrids applications. Emphasis is given on the mathematical analysis of the Series-Series (SS) WPT system for Constant Voltage Source (CVS) loading conditions that cannot be effectively described by the equivalent constant resistance model. For this reason, the complete harmonic analysis is considered in this work in order to study the real operational characteristics of SS-WPT systems that interface to a DC bus. The proposed system interconnects a DC bus with various distributed energy sources, whilst the ability of Constant Power Generation (CPG) behavior of the proposed system is revealed and examined for various SS-WPT system parameters values, highlighting its advantageous characteristics for distributed energy exploitation. Additionally, the incorporation of the SS-WPT system in distributed energy sources exploitation offers reduced wiring complexity and installation flexibility. Experimental and simulation results are presented, validating the theoretical analysis.

In the evolving landscape of precision agriculture, the integration of remote pest traps with deep learning technologies marks a critical step forward in remote pest detection, with the potential to substantially improve traditional pest monitoring methods. This article provides a comprehensive review of the developments, challenges, and innovative solutions in creating sensor-based electronic traps and applying deep learning for efficient and autonomous pest identification. By addressing the complexities of sensor integration, data collection, and the need for adaptive algorithms capable of classifying a wide range of insect pests, this review highlights the effective combination of electronic trap advancements with the precision offered by convolutional neural networks. An in-depth analysis of the technological advancements in electronic pest trap development is presented, highlighting improvements in design, efficiency, and sustainability while referring to ongoing and future challenges. Moreover, this article explores deep learning techniques, emphasizing on dataset enhancement and model optimization to overcome traditional challenges such as data scarcity and to improve the robustness of pest detection models. A thorough evaluation of various trap types against 85 unique pests is conducted, with the delta trap emerging as the most versatile, showcasing compatibility with multiple sensors and effectiveness against various pests. This review equips researchers, practitioners, and agricultural developers with critical insights and methodologies that can significantly enhance pest monitoring efficiency, reduce pesticide usage, and support sustainable agricultural practices.

This work studies the significant impact of Distributed-Energy-Resource (DER) inverters (which are connected to the same node) on anti-islanding protection of DER-installations. As it concerns the harmonic injection-based schemes, the induced harmonic voltage component that is provoked by each inverter is compromised, as synchronous injection (injection at the same time intervals) among the inverters cannot be reassured. Therefore, harmonic injection-based anti-islanding schemes will fail if the harmonic voltage component falls below a certain level. In this framework, a novel metric (i.e. the Upgrade-Factor, UF) is introduced, indicating the supplementary power (of DERs) that can be installed in the same point of common coupling without compromising the effectiveness of the harmonic injection scheme. As this metric enables the evaluation of harmonic injection schemes prior to the future integration of DERs, it could be a substantial addendum into the relevant standards that evaluates the anti-islanding features of grid-tied DER-inverters. Finally, this work proposes a technique (implemented in software level), which maximizes UF and reassures the effectiveness of the harmonic injection schemes under the power variations of installed inverters. Extensive simulations and experimental tests have been conducted that verify the effectiveness of the proposed strategy under various penetration-levels and islanding-network conditions.