From the optimization algorithm, it has been found that for optimal setting of TCSC control parameter at 0.06278 pu, the congestion from the system is managed efficiently. For this setting of TCSC, the power flow in congested line is shown in Table 2 which reveals that the power flow in line-3 which was earlier congested is within its limit after placing TCSC in line-7. The performance of the proposed algorithm is also analyzed by placing TCSC to other potential locations i.e line-3 and line-6. It has been found that for control parameter setting of TCSC at 0.2866 pu and 0.0161pu respectively for these two locations of TCSC placement, the congestion is effectively alleviated from the system which can be observed from power flow results shown in Table 2. The percentage line loading for the considered potential locations of TCSC is illustrated in Fig. 5 which shows that placement of TCSC at these locations alleviates the system congestion.
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Fig. 5 Percentage line loading for IEEE 30-bus system
Although the placement of TCSC at all potential locations manages the congestion successfully, it is necessary to perform the cost-benefit analysis for FACTS device in order to analyse its cost effective location among various potential locations. Therefore, installation cost of TCSC and hence the system generation cost is calculated using equation (11).
Due to high cost involved with installation of FACTS devices, its investment cost should be analysed such that its placement gives the low installation cost. The installation cost of TCSC for different potential locations is calculated using equations 12-14 and is shown in Table 3 which reveals that placement of TCSC in line-2 is more economical as compared to other potential locations for TCSC placement. It can be also observed from Table 3 that placement of TCSC in line-3 gives minimum generation cost of the system as compared to other locations. Hence, the location found to place the TCSC with the proposed method gives minimum cost as well as system generation cost as compared to other locations.
The cost-benefit analysis for these potential locations of TCSC placement has been performed and the results are given in Table 6 from which it can be observed that placement of TCSC in line-2 gives its minimum installation cost as well as minimum generation cost of the system. Hence the proposed methodology gives optimal location for the placement of TCSC in order to manage congestion efficiently.
Table 3 Cost results for IEEE 30-bus system