Towards optimized protection design and maintenance in electric power distribution systems

The fundamental goal of an electric utility is to serve its customers with safe, reliable and low cost power supply. This goal has led to a number of standard protection engineering practices that ensure adequate service; however, with deregulation of the utility industry and increased competitive pressures, there is a desire to further improve service reliability and reduce operation and maintenance costs. The number, type and location of the protective devices on a distribution feeder have a direct effect on the system reliability. This dissertation proposes a binary programming optimization to identify type and location of the protective devices on a distribution feeder in order to minimize the SAIFI or ASIFI reliability indices.;A given distribution circuit may have various types of customers with different reliability concerns. A goal programming approach is introduced to achieve compromise among engineering design objectives that addresses these concerns. The design goals can include: simultaneous minimization of the SAIFI and ASIFI indices by optimizing protective device effectiveness and location of fuse saving schemes to achieve a trade-off between permanent and temporary interruption rates. The protection design also influences maintenance and restoration considerations. The same binary programming approach is applied to optimize allocated maintenance resource to achieve maximum reliability. This technique identifies the quality of maintenance required for each circuit component.;Studies on a typical feeder from a major utility indicates significant reliability improvements as compared to traditional engineering design practices. Detailed computational analysis shows the feasibility of finding the global optimum quickly even for the largest circuits.