Reserve margin planning in a wind-hydro-thermal power system

A method for studying the effect of wind power on power system reserve margins, need of extra resources, etc. is presented. A conventional model for short-term operation planning for a hydrothermal power system is supplemented with a wind power model. The wind power model includes the forecast of total wind power generation and the uncertainty of the forecast. The conventional hydro-thermal model is extended to take into account load forecast uncertainty and reserve margins of the generation units. The requirements of instantaneous, fast, and slow reserves, depending on possible forced outages of thermal units and uncertain load and wind speed forecasts etc., are calculated together with the available capacities of the corresponding reserve type. The results include an estimation of whether there is a deficit or excess of instantaneous, fast, or slow reserves during each hour of the planning period. A numerical example shows an application of the method to the Swedish power system