## 3 Detection of Cyber-Attacks with Supervised Machine Learning-Artificial Neural Networks  
### Cyber-Physical PV-Powered Energy Island Structure  
Cyber-physical EI infrastructures are intelligent and autonomous systems integrating cyber and physical components to control energy production, storage, and distribution. These systems deliver dynamic, efficient, and secure energy management using digital technologies, big data analytics, AI, IoT, and smart grid technology. In contrast to traditional energy infrastructures, these systems encompass physical and cyber elements. The physical layer comprises renewable energy sources (such as solar, wind, and biomass), energy storage systems (including batteries, super-capacitors, and green hydrogen storage), smart microgrids, and electric vehicles. The cyber layer involves IoT and sensor networks, AI-enhanced demand forecasting and system optimization, blockchain-based energy trading, and advanced cybersecurity measures. The framework of the PV-powered EI structure includes a PV converter, as depicted in Figure 2.  
Figure 1: A PV-powered EI has boost converter blocks to transfer the power through submarine DC cables to the onshore. This PV-powered EI can be connected to large-scale offshore wind farms [37]. Cyber-physical EIs present numerous advantages. Energy supply and demand are optimized through AI-supported systems, ensuring sustainable operation. With IoT and big data analytics, real-time data collection and analysis are possible, enabling rapid adjustments to weather conditions, energy prices, and shifts in demand. Additionally, these systems are fortified with blockchain-based energy management and advanced cybersecurity protocols, enhancing the security of energy infrastructures against cyber-attacks. These islands promote local energy independence by lessening reliance on the central grid and ensuring self-sufficiency in the event of a failure. Relying on renewable energy significantly contributes to environmental sustainability by reducing the use of fossil fuels and lowering carbon emissions. From an economic and commercial standpoint, cyber-physical EIs provide lower costs and stable energy prices due to local energy generation and storage. They also facilitate the creation of innovative solutions, such as peer-to-peer (P2P) energy sharing and micropayment systems, by digitizing energy trading. The future role of these systems will focus on optimizing green hydrogen production and storage, providing mobile energy solutions in conjunction with electric vehicle ecosystems, enhancing energy management speed and security with cutting-edge technologies, like 5G and quantum computing, and fostering the development of autonomous energy markets through smart contracts. Consequently, cyber-physical EIs hold significant promise as innovative, secure, and sustainable energy infrastructures for the future. This integration of AI, blockchain, IoT, and advanced energy management technologies will create a more efficient, flexible, and secure energy ecosystem. This transformation is set to redefine the energy sector and enhance both economic and environmental sustainability. The PV-powered EI has boost converter blocks to transfer the power to the DC bus and then through submarine DC cables to the onshore. As known, PV panels have solar irradiation and temperature variations that determine the input-output characteristics of the PV system. A power electronic converter with a maximum power point tracking (MPPT) algorithm facilitates the system's efficient operation. Equation (1) denotes that the MPPT algorithm aims to regulate PV-voltage-\(V_{PV}\) to hold on to the maximum power-\(P_{MPP}\) thanks to the point with the rate of change of PV-power \(P_{PV}\) concerning \(V_{PV}\). If the slope of this change (i.e., \(tana>0\)) is positive to the left of the maximum power point based on the solar panel's output P-V characteristic, the reference voltage is increased.