This paper delves into the transformative effort to realize electrical digital twin via Intelligent Substations (IS), as applied within the oil and gas industry. IS, is one of the PETRONAS cyber-physical solutions, harmoniously merges intelligent electrical equipment and systems into the electrical supply chain, targeting the revenue loss from sudden death or trip of electrical equipment, reduction of operating expenses (OPEX) by enhancing equipment reliability and efficiency. This paper presents a structured methodology for transitioning from traditional to digital substations. The symbiotic relationship between digital substations, intelligent devices, sensors, and Equipment Analytics applications is explored, emphasizing their crucial role in enhancing industrial maintenance strategies. Focusing on the Alternator Health Indicator (AHI), a pivotal IS equipment analytics application, AHI's real-time monitoring capabilities are demonstrated, showcasing its data collection methodology, analysis, and effectiveness in predicting equipment health to minimizing downtime before failure occurs. The study concludes with proposed enhancements including the incorporation of advanced machine learning algorithms, integration with Industrial Internet of Things (IIoT) sensors, and user-friendly interfaces, envisioning a more resilient and proactive approach to equipment maintenance strategies towards reaching higher level of Remote Autonomous Operation (RAO).