Variable energy resource induced power system imbalances: A generalized assessment approach

The impact of variable energy resources (VER) on power system operations and planning has been a subject of extensive research in recent years. However, most of the results are based on specific case studies and do not allow generalization. This paper proposes a generalized approach to the assessment of power system imbalances. Penetration level, day-ahead and short-term forecast errors, and variability are identified as four main parameters of VER integration. The dependence of power system imbalances on VER integration parameters is studied, using steady-state simulations. The simulations use a power system enterprise model that consists of three layers: resource scheduling, balancing operations and the physical grid with integrated VER. Resource scheduling is modeled as a security-constrained unit-commitment (SCUC) problem. The balancing layer consists of three components: regulation service, real-time market and operator manual actions. The real-time market is implemented as a security-constrained economic dispatch (SCED) problem. The IEEE RTS96 test system with integrated wind generation is used as the physical grid in the case study.