Reliability Assessment at Day-Ahead Operating Stage in Power Systems with Wind Generation

Abstract

This paper proposes to evaluate reliability performances at operating stage for power systems with variable wind generation. This is a first step towards recognizing the stronger coupling of power system decision making across different timescales. In the day-ahead energy-reserve co-optimization unit commitment model, the validity of using operating reserve as an approximation of long-term reliability requirement is tested with realistic wind generation profile. Reliability indices such as Loss of Load Probability (LOLP) and Loss of Expected Energy (LOEE) are computed at each hour of the day at the conclusion of the day-ahead unit commitment decision. Numerical experiments conducted in the IEEE Reliability Test System suggest that while operating reserve requirement does not change within a day, the actual reliability performance of the system varies significantly depending on (i) system loading conditions , (ii) wind power variation, and (iii) operating rules. Also, the operating reserve requirement is shown to either overapproximate or under-approximate the reliability requirement of power system. It indicates that operating reserve could be a very coarse deterministic approximation of system reliability requirement especially with high wind penetration. A much more integrated approach for modeling, analysis, and decision making is envisaged for provision of reliable and cost-effective electricity services.

Estado del Arte de conmutación de líneas de transmisión con análisis de contingencias

“…Donde L es la carga promedio conectada y la U es la indisponibilidad promedio anual del servicio. LOEE; se utiliza en la etapa de generación y transmisión, representa la energía que no se suministra por la falta de capacidad de la infraestructura [45] [46].…”

“…EIU (Energy Index Unreliability); tasa de la energía del sistema que no se toma en cuenta cuando existe un inconveniente en el sistema, es energía no disponible [46].…”

“…Los últimos índices no son aplicables cuando existe una reducción o un incremento de la demanda, se utiliza en la etapa de transmisión y a la etapa de generación, aunque, principalmente se utiliza en mantenimientos programados [46] [47].…”

Planning of a hybrid energy system connected to a distribution system

“…The second scenario is transmission line failure which results in a total loss of wind farm utilization. The outage probability of wind turbine is found to be related to wind speed [68]. The relationship between wind speed and wind turbine outage probability is shown in Equation 4.…”

Risk assessment of power system with high penetration of wind power considering negative peak shaving and extreme weather conditions

“…Some researches have focused on the reserve decision methods considering the outage of conventional units and the uncertainty of wind and load prediction based on PJM method [2]- [5]. Moreover, many studies focus on how to get the optimal reserve capacity in different time frames [6]- [8] based on risk-constrained dynamic economic dispatching or unit commitment. The concepts of VaR (Value at Risk) and CvaR (Conditional Value at Risk) are introduced into the dynamic economic dispatching to make the reserve decision [9]- [12].…”