Advanced optimization problems and solution methods for renewable energy integration - A bibliometric review

The worldwide shift to sustainable energy supply has led to extensive incorporation of renewable energy sources into modern power systems incorporating specifically with wind-turbine and solar-photovoltaic systems. The stochastic and intermittent nature of such renewable energy sources, however, poses significant challenges in their operation and planning, especially regarding optimization and system coordination. This paper provides a detailed overview of various advanced optimization problems and solution methods for the integration of renewable energy in today's power systems. The study divides important optimization problems into three categories: active and reactive power management, uncertainty modelling and real-time stochastic operation of power systems. Coordination of active and reactive power resources is a critical issue that needs to be addressed to ensure voltage stability and reliability of the grid with high penetrations of renewables. The review also explores the concept of stochastic energy and reactive power markets, which entails optimizing ancillary services like voltage support and reactive power dispatch together, considering interactions between transmission system operators and distribution system operators. Moreover, the traditional optimization techniques such as linear programming, nonlinear programming and mixed-integer programming are compared with the new ones such as the intelligent and hybrid techniques. The current review is a structured reference which combines technical analysis with bibliometric analysis and indicates future research directions to develop resilient, intelligent and market-oriented power system optimization frameworks.