Power Systems & Energy Engineering

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    DISTRIBUTION NETWORK OPTIMIZATION BY OPTIMAL SIZING AND PLACEMENT OF D-STATCOM USING TEACHING AND LEARNING BASED OPTIMIZATION ALGORITHM (CASE STUDY: YIRGALEM SUBSTATION)
    (Hawassa University, 2021-10-18) AZMERAW ARGAW
    Distribution system is part of an electric power system which links the high voltage transmission networks with the end consumers. This work offers the way of improving the performance of the distribution network by improving voltage profile and reduction of power loss via injecting reactive power through the network. Optimal siting and sizing of custom power devices in power distribution networks maximizes voltage profile, compensates reactive power, minimizes power loss and enhances voltage profile. The search for optimal size and locations of these devices in radial distribution networks is challenging and requiring robust scheduling. This study is conducted with a focus on Aposto feeder of Yirgalem distribution network. The voltage profiles of most buses are not in an acceptable range, and the voltage stability index of the buses shows that network is prone to voltage stability problem. In this study, it is aimed to find the best optimal D-STATCOM sizing and placement by using Teaching and Learning Based Optimization (TLBO). Results obtained have been compared with those of the conventional optimization techniques reported in literature. For the Aposto feeder 62-bus network, the optimal location and size of D-STATCOM were determined at bus 38 with 1019.18 𝑘𝑉𝑎𝑟, at bus 28 with 942.96 𝑘𝑉𝑎𝑟, at bus 39 with 1074 𝑘𝑉𝑎𝑟 and at bus 25 with 1184 𝑘𝑉𝑎𝑟 by the GA, PSO, GREY WOLF and WHALE OPTIMIZATION method respectively. While the TLBO approach obtained the optimal site and size of the D-STATCOM in the network to be bus 51 and 871.4 𝐾𝑉𝑎𝑟 at normal load condition. As stated, the TLBO method performs better in terms of reducing both real and reactive power losses. The real power loss percentage reduction of the test system is 27.09%, 69.19% and 70.24% whereas the reactive power loss percentage reduction is 30.97%, 68.85% and 69.85% for light load, normal load, and heavy load respectively. Also, the minimum voltage level in the worst case is significantly enhanced from 0.93pu to 0.988pu. The model has been formulated to minimize the total cost of the network by determining the optima of the substation locations and power, the load transfers between the demand centers, the feeder routes and the load flow in the network subject to a set of constraints. As per the economic evaluations, the proposed solution is cost-effective. In this research D-STATCOM control is developed based on artificial intelligent (AI) using artificial neural network (ANN), which depends on optimum values obtained by TLBO. Generally, the simulation results show that the proposed technique is effective to maintain all buses voltage magnitude within the IEEE acceptable limit and to reduce power losses significantly
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    CUSTOMIZED INTERLINE POWER FLOW CONTROLLER FOR VOLTAGE PROFILE IMPROVEMENT AND POWER LOSS MINIMIZATION OF TRANSMISSION LINE (CASE STUDY: SOUTHERN REGION FROM SHASHEMENE TO BUKULUGUMA TRANSMISSION SYSTEM)
    (Hawassa University, 2024-10-22) ASRAT LEMMA
    An electrical system is a collection of components that are used to supply, transmit, and consume electricity. Transmission lines effectively transfer the electricity produced by different power plants. Nevertheless, the generated electricity is not entirely supplied to customers because of voltage drop and power loss. Uncontrolled bus voltage profile caused problems for industries that were developing quickly. Interline power flow controller (IPFC) is a type of flexible AC transmission system (FACTs) devices applicable to reduce power loss and enhance voltage profiles of the transmission networks from Shashemene to Bukuluguma transmission system. Load flow analysis on nine buses were performed by Newton Raphson load flow analysis technique using MATLAB R2016a. The analysis showed that out of nine buses four buses are out of voltage limit. On the system as a whole, there has been a loss of 8% real power and 10.42% MVAr reactive power, or 7.322MW and 4.530 MVAr, respectively. To minimize the loss problems, grey wolf optimization (GWO) techniques were proposed to search optimal place and size of interline power flow controller (IPFC), placed on bus 5, and sized 27MVAr. GWO techniques are compared with Antlion optimization, but GWO gives a good performance. After analysis data 4 buses bus number 4, 7, 8, and 9 are out of permissible values, the remaining buses are within acceptable limits. GWO techniques suggest implementing the lowest voltage stability index bus. After installing IPFC in optimal power flow place the network problem is improved by GWO 6.1% and ALO 3.9%, the lowest case voltage profile improved from 0.937pu to 0.978pu and 59.7% of active power and 40% of reactive power are saved. Finally, the reduction result suggest that the recommended approach is operative to regulate all buses voltage magnitudes within the NEC and IEEE permissible boundary and to minimize power loss considerably
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    CUSTOMIZED INTERLINE POWER FLOW CONTROLLER FOR VOLTAGE PROFILE IMPROVEMENT AND POWER LOSS MINIMIZATION OF TRANSMISSION LINE (CASE STUDY: SOUTHERN REGION FROM SHASHEMENE TO BUKULUGUMA TRANSMISSION SYSTEM)
    (Hawassa University, 2024-03-21) ASRAT LEMMA
    An electrical system is a collection of components that are used to supply, transmit, and consume electricity. Transmission lines effectively transfer the electricity produced by different power plants. Nevertheless, the generated electricity is not entirely supplied to customers because of voltage drop and power loss. Uncontrolled bus voltage profile caused problems for industries that were developing quickly. Interline power flow controller (IPFC) is a type of flexible AC transmission system (FACTs) devices applicable to reduce power loss and enhance voltage profiles of the transmission networks from Shashemene to Bukuluguma transmission system. Load flow analysis on nine buses were performed by Newton Raphson load flow analysis technique using MATLAB R2016a. The analysis showed that out of nine buses four buses are out of voltage limit. On the system as a whole, there has been a loss of 8% real power and 10.42% MVAr reactive power, or 7.322MW and 4.530 MVAr, respectively. To minimize the loss problems, grey wolf optimization (GWO) techniques were proposed to search optimal place and size of interline power flow controller (IPFC), placed on bus 5, and sized 27MVAr. GWO techniques are compared with Antlion optimization, but GWO gives a good performance. After analysis data 4 buses bus number 4, 7, 8, and 9 are out of permissible values, the remaining buses are within acceptable limits. GWO techniques suggest implementing the lowest voltage stability index bus. After installing IPFC in optimal power flow place the network problem is improved by GWO 6.1% and ALO 3.9%, the lowest case voltage profile improved from 0.937pu to 0.978pu and 59.7% of active power and 40% of reactive power are saved. Finally, the reduction result suggest that the recommended approach is operative to regulate all buses voltage magnitudes within the NEC and IEEE permissible boundary and to minimize power loss considerably
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    CUSTOMIZED INTERLINE POWER FLOW CONTROLLER FOR VOLTAGE PROFILE IMPROVEMENT AND POWER LOSS MINIMIZATION OF TRANSMISSION LINE (CASE STUDY: SOUTHERN REGION FROM SHASHEMENE TO BUKULUGUMA TRANSMISSION SYSTEM)
    (Hawassa University, 2024-10-03) ASRAT LEMMA
    An electrical system is a collection of components that are used to supply, transmit, and consume electricity. Transmission lines effectively transfer the electricity produced by different power plants. Nevertheless, the generated electricity is not entirely supplied to customers because of voltage drop and power loss. Uncontrolled bus voltage profile caused problems for industries that were developing quickly. Interline power flow controller (IPFC) is a type of flexible AC transmission system (FACTs) devices applicable to reduce power loss and enhance voltage profiles of the transmission networks from Shashemene to Bukuluguma transmission system. Load flow analysis on nine buses were performed by Newton Raphson load flow analysis technique using MATLAB R2016a. The analysis showed that out of nine buses four buses are out of voltage limit. On the system as a whole, there has been a loss of 8% real power and 10.42% MVAr reactive power, or 7.322MW and 4.530 MVAr, respectively. To minimize the loss problems, grey wolf optimization (GWO) techniques were proposed to search optimal place and size of interline power flow controller (IPFC), placed on bus 5, and sized 27MVAr. GWO techniques are compared with Antlion optimization, but GWO gives a good performance. After analysis data 4 buses bus number 4, 7, 8, and 9 are out of permissible values, the remaining buses are within acceptable limits. GWO techniques suggest implementing the lowest voltage stability index bus. After installing IPFC in optimal power flow place the network problem is improved by GWO 6.1% and ALO 3.9%, the lowest case voltage profile improved from 0.937pu to 0.978pu and 59.7% of active power and 40% of reactive power are saved. Finally, the reduction result suggest that the recommended approach is operative to regulate all buses voltage magnitudes within the NEC and IEEE permissible boundary and to minimize power loss considerably