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Goswami et al. [31] proposed the feeder reconfiguration of distribution system for loss minimization. This work reports a power flow based heuristic algorithm for determining the minimum loss configuration of radial distribution networks. The algorithm is based on the concept of the optimum flow pattern, which is determined by solving the KVL and KCL (Kirchhoff’s voltage and current laws) equations of the network. Niknam et al. [32] developed a hybrid evolutionary algorithm for distribution feeder reconfiguration. This algorithm presents a new method to reduce the distribution system loss by feeder reconfigurations. This new method combines the self-adaptive particle swarm optimization (SAPSO) with the shuffled frog-leaping algorithm (SFLA) in an attempt to find global optimal solutions for the distribution feeder reconfiguration (DFR).
Increasing requirements of urbanization, industrialization, and modernization demands further expansion and development of the national power grid and, nonetheless, with a better efficiency and an enhanced voltage stability. To satisfy the above objective, Nath et al. [33] have verified a network reconfiguration as an effective and suitable method. A fuzzy multiobjective approach for network reconfiguration of distribution systems has been proposed by Das [16]. This work presents an algorithm for network reconfiguration based on the heuristic rules and fuzzy multiobjective approach. Multiple objectives are considered for load balancing among the feeders and also to minimize the real power loss, deviation of node voltage, and branch current constraint violation, while being subject to a radial network structure in which all loads must be energized. Ahuja et al. [12] proposed an AIS-ACO hybrid approach for a multiobjective distribution system reconfiguration. This proposes a hybrid algorithm based on artificial immune systems and an ant colony optimization trick for distribution system reconfiguration, which is formulated as a multiobjective optimization problem. Kalambe et al. [34] presented loss minimization techniques in a distribution network, a bibliographical survey that describes the three main techniques of loss minimization that includes network reconfiguration. Karthikeyan et al. [35] has proposed a novel criterion for segregating the feeder with a proposal based on the slope of the curve between the feeder losses versus the receiving end voltage. Application of this criterion results in the most minimal loss configuration for any given loading condition. An existing switching indices criterion and a switching algorithm criterion have been considered and the results are compared with that of the proposed slope criterion, which results in the most minimal loss configuration.
2.4 Importance of Feeder Segregation in the Context of Current Status
The Indian agricultural sector is the third largest consumer of electricity after the industrial and domestic sectors but the revenue realization from this sector is very low [36]. The share of agriculture in total electricity consumption is significant, i.e. 23% in 2011–2012, 18.08% in 2017–2018, and 7.69% in 2018–2019, but the share of the agriculture sector in total revenue generation is very poor; it was only 7% in 2011–2012. This reason and the reasons explained in Section 2.1 shift the focus of the Indian Government to give the utmost urgent attention to the agriculture sector. As a result, the Indian Government has initiated the concept of agriculture feeder segregation.
The Government of India thought to bring up a national level scheme that will guide, monitor, finance, and promote the process of feeder segregation in different agricultural intensive states. Thus, the Ministry of Power requested the forum of regulators (FOR) to work upon a framework to draw up a scheme at national level for feeder segregation of rural and agricultural consumers and suggest measures for effective metering. The report recommended that a national level program for feeder segregation be implemented in a calibrated manner while allowing states to have the flexibility to design the project to suit their specific requirements, subject to adequate power being available at the national level.
Although various Indian states, as explained, have implemented the process of feeder segregation, their rate of implementation is very slow. Many Indian states have even not thought of the initiation of the segregation process to date. However, Indian utilities that have adopted the process of segregation are not able to harness all such benefits that they had envisaged through feeder segregation. The actual theft or the possibility of theft of line conductors, transformers, and other electrical elements fitted in to the agriculture feeder is one of the main hurdles behind all the above issues. None of the utilities have claimed that they have found the trick to handle this issue of theft, and no researcher has yet published any article proposing a solution to deal with the issue of theft. These facts are demotivating and weaken the confidence of Indian utilities to take part in the feeder segregation plan.
Hence the process of network reconfiguration can be used to address one of the biggest challenges in promoting a national level scheme. Apart from its basic objective, the inclusion of network reconfiguration will also help in reducing technical losses, improving voltage profile, minimizing outages, reducing device failures, minimizing overloading, smoothing peak demand, and increasing the network reliability. It will further contribute toward the national target of achieving AT&C loss minimization. The outcomes of this proposed chapter will give thrust to the implementation of the Feeder Segregation Plan (FSP) across different Indian states. It will enhance the confidence of various Indian utilities and provide motivation in implementing the FSP.
2.5 Threats with Feeder Segregation and Possible Solutions
The basic objective behind this chapter is to discuss a theft handling mechanism for protecting various power equipment/appliances fitted in agricultural feeders during off-feed hours. This theft handling mechanism is based on a network reconfiguration in which the normal topological structure of the distribution feeder is changed to a new objective-based structure through closing and opening of the sectionalizing and tie switches. If the agricultural feeder is included as part of the feeder reconfiguration, electricity will be made available during off-feed hours, and hence thieves will not take any risk. The following broad steps are required to be taken when developing the theft handling mechanism:
Step 1: To develop a method to decide the locations of different sectionalizing and tie switches in such a way that the inclusion of some of the section of the agricultural feeder in the network reconfiguration will not energize the connected pumps.
Step 2: To develop a method for the selection of tapping points for the agricultural pumps in such a way that the pumps do not draw power during off-feed hours.
Step 3: To deduce the best suitable method for network reconfiguration based on the contemporary situation and the demand for the Feeder Segregation Plan.
Step 4: To draw up a plan for distribution system automation (DSA) to manage the network reconfiguration.
Step 5: To determine the optimal switching frequency for the network reconfiguration while considering all its dynamics and impacts.
Step 6: To validate the above proposed methodologies using high-end tools like ETAP/MATLAB.
Wherever the distribution system in not automated and switching is done manually, the positions of the tie switches are provided based on the ease of reachability and in India where the same practice is being adopted. However, wherever the distribution system is automated and there is scope for implementing network reconfiguration, placing the switches randomly will not serve the purpose. Hence technical studies are being carried out in deciding their numbers and positions. Many research publications are available in this context. As far as steps 1 and 2 are concerned, they are totally new concepts and hence no research is available in this area.
Developing the automation features for the distribution system operation involving an agriculture feeder in a network reconfiguration will totally depend upon the methodologies used for achieving steps 1 and 2. Hence, unless and until some methodology has been developed for steps 1 and 2, it is worthless to design a method for distribution system automation (DSA) considering a feeder reconfiguration. A number of automation models are available for the distribution system. Adequate technologies have been developed in the area of distribution system automation. The main components used for distribution system automation (DSA) are remote terminal units (RTUs), pole top units (P-RTUs), distribution control center (DCC), distribution automation software, communication network,