Short-Term and Medium-Term Reliability Evaluation for Power Systems With High Penetration of Wind Power

The expanding share of the fluctuating and less predictable wind power generation can introduce complexities in power system reliability evaluation and management. This entails a need for the system operator to assess the system status more accurately for securing real-time balancing. The existing reliability evaluation techniques for power systems are well developed. These techniques are more focused on steady-state (time-independent) reliability evaluation and have been successfully applied in power system planning and expansion. In the operational phase, however, they may be too rough an approximation of the time-varying behavior of power systems with high penetration of wind power. This paper proposes a time-varying reliability assessment technique. Time-varying reliability models for wind farms, conventional generating units, and rapid start-up generating units are developed and represented as the corresponding universal generating functions (UGFs), respectively. A multistate model for a hybrid generation and reserve provider is also proposed based on the developed UGF representations of wind farms, conventional generating units, and rapid start-up generating units. The proposed technique provides a useful tool for the system operator to evaluate the reliability and arrange reserve for maintaining secure system operation in the short- as well as medium-terms.