Study on Smart Grid System for Improvement of Power Distribution System Reliability Case Study: Addis Ababa District

Gebreegziabher, Tesfay (2014) Study on Smart Grid System for Improvement of Power Distribution System Reliability Case Study: Addis Ababa District. Masters thesis, Addis Ababa University.

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Unreliable power distribution reduces user power consumption, affects daily activity and drags modern life style. It impacts societal development and individuals’ income. Basically, Power Distribution Reliability has been a major challenge in Addis Ababa city. It has incurred cost on customers and lowered product quality. In Addis, Customers have faced frequent interruption and utility has taken long time to alleviate it. Hence, it has to get amicable solution. Thus, the objective of the study is to assess the reliability of the current distribution system and suggest solutions of reliability improvement in smart grid environment. Bella substation of Addis Ababa district, which has high rate of interruption, is selected as case study area. Bella substation’s reliability is assessed based on data of two and half years from Ethiopian electric power corporation. To limit the scope of the study, feeder- 02 of Bella substation is chosen for reliability improvement measures. Feeder-02 has SAIDI of 163.3 Hr./cust./yr and SAIFI of 184.9 Int./cust./yr. The reliability index values of feeder-02 are not within the ranges of bench marks of best practices and Ethiopia’s reliability requirement. Bella substation also has SAIDI of 146.5 Hr./cust./yr. and SAIFI of 128.53 Int./cust./yr. Reliability indices of Bella substation show the substation is unreliable as compared to standard practices and Ethiopia’s reliability requirement. Distribution network reconfiguration capacity is enhanced by designing laterals using genetic algorithm optimization technique that can supply the feeder during contingencies. It’s simulated in Mat Lab 2012. The design has considered energy serving capability and maximum customer reconnection possibility. An optimized lateral design solution is obtained that can supply 14550kVA out of 16085kVA and reconnects 10440 customers out of 11235 after reconfiguration, i.e. 90.46 % of the supply capacity and 92.92% of the total customers. The same optimization algorithm is used to improve automation, reclosing and switching capacity of the feeder. A switch with automating equipment, a recloser, and three sectionalizing switches are integrated in the new design. SAIDI value of 98.33 hr. /cust./yr. and SAIFI of 56.025 int./cust./yr for the feeder-02 have been achieved. Reliability improvement by each new device is also calculated. Power restoration is boosted by integrating these devices. By integrating the sectionalizing /tie switches in the feeder, a minimum spanning tree (MST) for rapid restoration is attained using prim’s algorithm in Mat Lab. For different fault points in the feeder, optimized kVA capacity is achieved and power loss is minimized. In average, SAIDI of 11.452 Hr./cust./yr., SAIFI of 12.966 int./cust./yr. and ASAI of 0.9986 have been achieved for network reconfiguration at various fault points.

Item Type: Thesis (Masters)
Uncontrolled Keywords: Distribution Reliability, Smart Grid, Network Reconfiguration, GA optimization, Power Restoration, Prim’s Algorithm
Subjects: Q Science > Q Science (General)
Q Science > QA Mathematics > QA75 Electronic computers. Computer science
T Technology > T Technology (General)
T Technology > TK Electrical engineering. Electronics Nuclear engineering
Divisions: Africana
Depositing User: Andriamparany Edilbert RANOARIVONY
Date Deposited: 09 Aug 2018 13:30
Last Modified: 09 Aug 2018 13:30

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