Security considerations in composite power system reliability evaluation

The composite power system has been classified into different operating states in order to recognize security considerations in the system reliability assessment. Annualized indices obtained by considering the load to be constant throughout the year and the annual indices by considering a seven-step load model have been presented. A basic electric power utility objective should be to operate in the normal state with high probability. A system may be capable of operating within constraints but may not be able to withstand outages, even single level. A risk index designated as CSOSR (composite system operating state risk) has been defined and the utilization of this CSOSR for a simple system expansion plan has been demonstrated. It has been shown that composite reinforcement with both generation and transmission gives better results than simple addition of either generation or transmission facilities in the case of the MRBTS. This CSOSR is a new risk index which can be used in a wide variety of system studies