Security Constrained Economic Despatch – India: A Rolling Block Implementation Framework

Electric distribution utilities in India procure power through long term, medium term, as well as short term power purchase agreements (PPAs), most of which have been discovered through non-competitive route with regulatory approval. Optimisation of state/specific power procurement portfolio is undertaken by the Distribution Companies (DISCOMs) and utility implemented by the SLDCs on a dayahead basis. Security Constrained Economic Despatch (SCED) is the major initiative taken by Power System Operation Corporation Limited (POSOCO) to ensure the minimum generation cost over the interstate power procurement portfolio across all states. This paper reviews development leading to introduction of SCED. Energy Analytics Lab (EAL) developed a SCED modelling framework and implemented the same and suggested SCED implementation on a rolling block basis spread over blocks. The results show the effectiveness in minimising the cost of generation by introducing multi-period, rolling time block algorithms. These algorithms have the efficacy to harness the cheaper generation resources at inter as well as intra-state level.