The mixture of normals approximation technique for equivalent load duration curves

A novel approximation technique based on mixture-of-normals distributions is presented. The mixtures of normal approximation (MONA) for equivalent load duration curves (ELDCs) proceeds in three steps. First, the system load random variable is approximated by a mixture-of-normals distribution. Next, the approximation of the outage random variable of a group of one or more units by the distribution is obtained. These two approximations are combined to derive the MONA of each ELDC. The construction of the MONA for the system load random variable can be interpreted in terms of partitioning the load into various categories based on the load magnitudes. A salient feature of the MONA technique is a simple recursive formula for convolving (rolling in) and deconvolving (rolling out) the contribution of each generating block. The performance of the MONA technique is analyzed in terms of its ability to fit the original load duration curve, its ability to fit the ELDCs, its accuracy, and its robustness