Reconfiguration of Distribution Feeders for Minimization of Voltage Drop

Abstract—This article proposed a novel method for reconfiguration of electric energy distribution network underneath regular operating prerequisites to limit the lively losses on the community or to balance the load on the feeders. The notion at the back of reconfiguration is to understand recommended load transfers so that energy losses are minimized and the prescribed voltage limits are satisfied. The proposed method determines the acceptable gadget topology that reduces the energy loss according to a load pattern. The effectiveness of the proposed approach is tested on 11KV feeder which is bifurcated at the distribution give up (consumer end) to three phases 440V and 1 phase 230V. The evaluation of the proposed strategy is in phrases of improvement in voltage profile earlier than and after bifurcation, balancing in load earlier than and after bifurcation at the consumer end of the distribution network.

Keywords—Feeder,Voltage dropI.

Introduction

Distribution network system is an important part of power system which connects distribution lines with the consumers. Nowadays, distribution networks are rapidly growing; therefore an efficient operation method is essential for reducing cost and increasing effective operation. Between 30 and 40 % of total investments in the electrical sector goes to distribution systems, but nevertheless, they have not received the technological impact in the same manner as the generation and transmission systems. Many of the distribution networks work with minimum monitoring systems, mainly with local and manual control of capacitors, sectionalizing switches and voltage regulators, and without adequate computation support for the system's operators. There are many losses in distribution system such as voltage drop, poor power factor, theft of energy, failure of distribution system, poor reliability of the supply etc. Merlin et al. [1] using a discrete branch & bound technique in order to increase the efficiency of the distribution electrical network considering feeder reconfiguration. In this method all the network switches are closed to form a meshed system, &then the switches are opened successively to restore to the radial configuration.

However, this method involves approximations. Shirmohammadi et al. [2] proposed an algorithm to overcome these approximations. In this method switches are opened one by one, based on an optimal flow pattern. Peponis et al. [3] have developed a methodology for the optimal operation of distribution network. In this method loss minimization is obtained by installation of shunt capacitors & reconfiguration of network. Schmidt et al. [4] have formulated the problem as the mixed integer nonlinear optimization problem. The integer variables represent the status of the switches, & continue variables represent current flowing through the branches. Broadwater et al. [5] have considered the time varying load demand, obtained through load estimation, to reduce the loss. Mortom et al. [6] have proposed method based on an exhaustive search algorithm for obtaining a minimum loss radial configuration of distribution system.

How we can reduce these types of losses:-

· Reconfiguration of the network. ·

HVDS The network is reconfigured to reduce the.

Under conditions of permanent failure, the network is reconfigured to restore the service, minimizing the zones without interruption of supply. This can be achieved by networks reconfiguration. Several approaches are used to find the optimal configuration with the following subjects:-Reducing power system losses. -Improving service restoring for the isolated portion of a distribution system.

-Enhancing system reliability by introducing an analytical mathematical model.

-Improving load factors to facilitate load aggregation in distribution networks. Benefits of reconfiguration of distribution network

1) Excellent voltage profile.

2) System power factor improves causing easy reactive power control.

3) Considerable reduction in line losses and consequents a vings in power purchase cost.

Bifurcation & its need

Bifurcation suggest two, when a fully over loaded 11KV distribution feeder is divided into two parts, or when one feeder is obtained from two or more fully overloaded feeder. The system come to be a new feeder under light load from the heavy load feeder is referred to as bifurcation of the feeder. In figure 1 show bifurcation of two 11KV overloaded network. Some part of the load these overload network put on the new feeder & improve the voltage profile. [image: ]Fig. I Bifurcation of Network Previous behaviour of feeder existingAt earlier stages when the feeder start feeding load to consumers there was no information how larger feeder feeds the load to the consumers. As population increases the load will increases abruptly. At that stage there was no any knowledge that how much rating of the feeder to be extended depending upon load. This factor comes into Knowledge when it was seen that feeder feeding the system begins to overload. At this stage various problems like at the end of feeder poor voltage profile, larger losses in the feeder, large fault frequency, difficult fault location, difficult feeder maintenance etc. At beginning stage the route of the feeder feeding to consumer was zigzag. The population was less and feeder feeds the small consumer but cover large area.

II. Problem DescriptionIn case of ordinary system, the feeder runs according to the load and mostly the feeders run along the roads. In this case length of the feeder sometimes increase to large extends. Therefore, the system gets complex and level of voltage at the end point of feeder is reduced to permissible level, so the quality of voltage is decreased. With the help of reconfiguration of network technique, the quality of voltage level can be improved. The paper further presents the case study for three villages which are reconfigured to improve the voltage profile of distribution line. III. HistoryUnder Nakodar Division Punjab Sub-Station installed at Noormahal is feeding the following villages:

1. Cheema village

2. Pharwala village

3. Ghumtala Village Before bifurcation the load on the Cheema & Pharwala village feeder 3165. 1 kVA and 2279. 7KVA & maximum demand was 165A & 119A. Voltage regulation of the Cheema & Pharwala feeder before bifurcation was 7. 29% & 6. 69% which was calculated.

After bifurcation the voltage regulation of the Cheema & Pharwala feeder was estimated at 4. 5% & 5. 30% which was 7. 29 % & 6. 69%. Cheema & Pharwala village load after bifurcation was 2051. 6 kVA & 1836 kVA and Maximum Demand was 107A & 96A. This is also leads to advantage as it will decrease number of transformer. Also Ghumtala village load before bifurcation was 2111 kVA and its maximum demand was 110 ampere. Voltage regulation of the Ghumtala village before bifurcation was 11. 73% which was calculated. After bifurcation the voltage regulation of the Ghumtala village was estimated at 5. 56% which was 11. 73% earlier and Ghumtala village load after bifurcation was 1775 kVA and Maximum Demand was 93A. This is also lead to advantage as it will decrease number of transformer. After bifurcation Cheema, Pharwala & Ghumtala village feeder then new 11 kV feeder install & putt on the load 1893 KVA & the voltage regulation of the new feeder was found to be 6. 12%. The total money expenditure on new 11 kV feeder is Rs3001571.