ADEQUACY WORTH EVALUATION IN ELECTRIC POWER SYSTEMS

Load interruption and poor quality of electricity supply have severe economic and social consequences in a modem society and therefore electric power utilities try to provide an adequate supply of electrical energy to all their customers. Adequacy evaluation of a complete electric power system relates to the examination of the composite generation and transmission facilities required to satisfy the demand at the bulk customer supply points and also the distribution facilities required to satisfy the actual consumer load point requirements. This thesis is concerned with the probabilistic adequacy evaluation of overall electric power systems consisting of generation, transmission and distribution facilities. It extends the available techniques and illustrates procedures for performing adequacy evaluation of overall power systems. One of the major objectives of the research work was to design suitable distribution networks for selected load buses of a test system. Distribution facilities for two load buses of a test system were designed and the reliability performance of the designed distribution networks evaluated for different operating procedures, protection schemes, modes of restoration, etc. The impacts on the overall customer load point adequacies of the pertinent factors associated with generation, transmission and distribution systems are examined in this thesis by application to two moderately sized electric power systems. Evaluation of the costs associated with different system configurations and the corresponding reliability worth at the customer end is generally termed as reliability cost/worth assessment The actual or perceived costs of customer interruptions can be used to determine the worth of electric service reliability. This thesis illustrates the development of a procedure for evaluating an Interrupted Energy Assessment Rate (TEAR) at each system customer load point considering the influence of outages in all parts of the electric power system. The developed TEAR can be used with the available adequacy indices in order to assess the severity associated with unsupplied energy due to supply interruptions. The customer TEAR are estimated using three basic methods and the results obtained from these methods compared using the test systems. The TEAR are also estimated for the distribution system segments. The individual customer load point WAR values and/or the sector LEAR values at the bulk system supply points can be used in basic reliability cost/worth assessments or in specific applications such as selecting preferred load curtailment strategies./This thesis briefly illustrates how system planners and operators can incorporate interruption cost evaluation into quantitative reliability assessment of a complete electric power system