A new method for the computation of technical losses in electrical power distribution systems

This paper aims at presenting a new method for the evaluation of technical (demand and energy) losses in electrical power distribution systems. A computational tool was developed and implemented at Eletropaulo, the largest distribution company in Brazil. The methodology divides the distribution system into eight different segments, namely: energy meters, customer connections to the network, low voltage network, distribution transformers, medium voltage network, distribution substations, subtransmission system and other technical losses. The latter segment includes equipment losses in capacitors, voltage regulators, connectors, insulators and so forth. The computational tool comprises two modules. The first one determines technical losses in specific networks in a hierarchical way. From the evaluation of losses in a representative part of the distribution system, per unit loss indices for each segment are readily computed. Such indices are transferred to a second module, which is responsible for the assessment of a global energy balance for the overall distribution system.