Segregation and analysis of distribution losses and mitigating techniques

Abstract

The operational efficiencies of a utility depend on the losses in the electrical distribution network. High losses contribute to inefficient electrical network resulting large tariff to utility consumers. Hence more attention should be paid to minimize and maintain system losses to an economical level. The situation reveals that the distribution losses of the CEB are higher than that of developed countries. Detailed energy audit should be carried out to identify the areas where the loss level is high. The study will help to localize the area suffering from high energy losses. Thus the measurement should be carried by installing energy meters for the said areas. This thesis presents a study about the electrical losses in low voltage distribution system of CEB. The nature of the distribution losses in low voltage power distribution system, their sources, measurement of technical and non-technical losses and their impact on the system are presented. The steps that can be taken to have an assessment of the distribution losses and steps to be taken to reduce technical losses and corrective actions to plug non-technical losses by proper administrative actions are detailed. A methodology to segregate distribution losses is also presented. Variation of low voltage distribution losses and voltage drop with consumer density per km were calculated. According to that results low voltage distribution line length in semi urban areas have to be limited in order to maintain the required voltage regulation and also to bring down LV losses. Unbalance voltages can results in adverse effects on equipment and the electric distribution system. Under unbalanced condition the distribution system will incur more losses as heating effects (I2R losses). More over, inaccuracy of metering power in three phase circuits due to unbalance current or voltage is discussed . Method for the selection of a distribution transformer of optimum capacity for given loading conditions is presented. In this regard economic evaluation is done based on initial transformer cost and operation and maintenance cost of transformer over its life.