Effect of Distributed Generation with a Hybrid Composition of Conventional and Green Sources on the Reliability of Power-System Operating Modes

Abstract

Hybrid schemes that combine green and conventional generation units create new opportunities for improving the efficiency of energy-resource utilization and reducing emissions; however, they also introduce additional challenges for ensuring reliable power-system operation. This paper analyzes the reliability of operating modes of an interconnected power system that incorporates distributed generation (DG) systems with a combined composition of sources, including conventional and green (renewable) units. The study considers the impact of mixed-type DG integration on power-system operating modes and analyzes the key reliability-related factors, including voltage stability, power balance, and power quality. Using a specific real power system as a case study, computational experiments of steady-state and transient modes were carried out for different power-generation scenarios of all DG sources. The calculations account for the stochastic nature of power output from wind installations and wind turbines, as well as random variations in nodal loads. Probabilistic characteristics of voltage variation at the point of common coupling between the DG system and the power system were obtained, confirming that the voltage magnitude tends to increase as the power output from DG sources grows. The results demonstrate that a rational combination of conventional and green sources, provided that they are properly regulated, can enhance power-system reliability while delivering environmental and economic benefits.