Reliability analysis for hydrothermal generating systems including the effect of maintenance scheduling

Usually, power system reliability indicators are obtained for one year periods, and must take into account maintenance requirements for thermal generating units. This paper describes an efficient method for the calculation of the two most common power system reliability indicators: LOLE (loss of load expectation) and EENS (expected value of energy not served), in the case of electric systems including generation units with limits on energy generation (hydropower plants with a variable amount of available water). The method is based on transforming the initial load curve into a thermal load curve, which enables one to separate completely the hydrothermal and the thermal power systems, thereby facilitating both reliability evaluations and maintenance scheduling.