Towards a strategy of optimization the maintenance activities of the MV/LV PDS transformers

In today's energy market in Morocco, a stable and reliable electric power supply system is an inevitable prerequisite for the technological and economic growth of the kingdom. Due to this, many public distribution companies are increasing their competitiveness by adopting new maintenance philosophies to reduce their Operation and Maintenance (O&M) costs. Indeed, being one of the most important parts of the medium voltage network, MV/LV public distribution substations transformer (PDS) play a key role in distribution of electricity, one of the main challenges for electricity distribution companies in Morocco is to manage the existing MV/LV PDS assets in the comprehensive and complex distribution system infrastructure. Moreover, the reliability of the electricity supply has become a subject of discussions at many different levels of society. There is an increasing awareness on developing preventive maintenance strategies which take into account the different aspects of risk which the companies are facing. One principal characteristic of preventive maintenance strategies is that the condition of the substation components is inspected on a regular basis. This paper describes a framework for criticality based maintenance management. The presented methodology shows how MV/LV PDS maintenance can be optimized on the basis of a multicriteria prioritization matrix. The proposed model has been demonstrated and tested by means of a case study of MV/LV PDS network, for the maintenance schedule and for the prioritizaton of maintenance activites. Obtained results have shown that the operational expenditure (OPEX) of MV/LV PDS asset maintenance and the key performance indicators (KPI's) of quality of electricity supply (SAIDI&SAIFI) can be both reduced and improved.