A Review of Reliability in the Restructured Power System: Concepts, Classification and Challenges

Restructured power systems, have transformed traditional vertically integrated monopolies into dynamic, market-driven entities. However, it also introduces significant complexities in ensuring system reliability. Reliability assessment has accordingly evolved from traditional deterministic methods to more sophisticated probabilistic approaches capable of capturing these uncertainties. A particular concern in market-based systems is economic curtailment of variable renewable resources. Nevertheless, it creates indirect reliability risks by reducing the effective capacity credit of variable renewables to resource adequacy. Consequently, not all installed renewable capacity can be reliably counted upon during periods of highest system need. This review paper examines the critical role of reliability in restructured power systems. It covers: key concepts and definitions, commonly used reliability indicators, assessment methods and tools, principal challenges introduced by restructuring and impacts of market mechanisms on system reliability. While restructuring generally improves economic efficiency and has the potential to lower long-term costs, it simultaneously poses new threats to maintaining a reliable electricity supply. The advantages and disadvantages of restructured systems with respect to reliability are discussed, and the major challenges in reliability assessment within market-based environments are systematically classified. A comprehensive review of relevant studies is presented to highlight current approaches, gaps, and emerging trends. This article aims to provide a solid foundation for future research on achieving a reliable and resilient modern power grid. It also underscores the necessity of thoughtful market design, appropriate regulatory frameworks, and well-calibrated reliability mechanisms to safeguard continuous and secure electricity supply for consumers.

کلیدواژه ها:

Classification ، Evaluation Indicators ، improvement ، Reliability ، structured power system