Reconfiguration of 11KV Feeder

Reconfiguration of 11KV Feeder Introduction CE 2.1 I did this project as a graduate Electrical Engineering while pursuing my Bachelor of Engineering in the field of Electrical Engineering from Balochistan University of Engineering and Technology, Balochistan. I wanted to conduct a project that would be challenging and would involve how to improve the existing power grid by helping the current or load at a given time. I wanted to create a system by improving the power factor or changing the conductor size or substituting the cables with conductors. I was able to improve my written and oral presentation skills as well as my interpersonal skills by the successful completion of this project. Background CE 2.2 For this project as an undergraduate student in electrical engineering, I wanted to start working on a project that would be challenging. I wanted to learn about the different and commonly used electrical/electronic components, the working mechanism and the implementation in a common every-day system. Feeder configuration is a very important step to enhance the quality and reliability of a distribution system. During my studies, I had learned that traditionally, in Pakistan, the feeder configuration is done by opening/closing or tie sectionalizing the switches in order to alter network map and thus the flow of power from substation to customers. I had studied during my bachelors that the reason Feeder configuration is done is to reduce system power loss and also for load balancing. As the loading conditions change, it is important to reconfigure it to reduce power losses in the network. And it is due to this reason that I selected the Reconfiguration of 11KV Feeder for my project. CE 2.3 The objective of my project is to design a system to reconfigure the network for loss reduction for 11KV feeder. Or the reconfiguration of the distribution network under normal operation to reduce active losses and to balance loads in the system. CE 2.4 CE 2.5 I first had to conduct a detailed literature review to find the best applicable approach to this system for reconfiguration. I decided to use Branch exchange and Loop cutting methods along with a theoretical Heurestic approach to achieve my objectives. I used the computer software for ELR to analyse the feeder and to calculate the results. I initially, used an existing configuration based on actual data to calculate the current Energy Loss Reduction (ELR) I then tabulated all the results and obtained a schematic diagram to show my results. I completed the project within the time frame specified by the university. I presented my findings to my supervisor. Personal Engineering Activity CE 2.6 I approached a senior professor with an idea of conducting a project about the power grid. Along with my group members, I had a lot of brainstorming sessions and review meetings with my project supervisor to select a suitable topic. I suggested that I work on a project that was concerned with restructuring the power grid to minimize distribution losses and we suggested that we select a suitable location for this project to be carried out and thus the topic Reconfiguration of 11KV feeder came in to being and the supervisor agreed to this and asked us to begin working on this by first conducting a literature review on all the components we would require and the working of this project and to start working on this project. CE 2.7 I decided to select a Surab Town feeder of 11KV which starts from the 132KV Pakistan Railway Grid Station. I found that this grid has two transformers connected in parallel having a capacity of 10/13MVA each and 132/11KV. This particular feeder provided power of mixed loads to residential, commercial, agricultural and gas power plants. I carried out the Physical Survey of the existing 11KV Surab Town Feeder and plotted a Single line diagram of existing Surab town feeder. I calculated the energy losses and voltage drop of existing distribution system keeping in view the QESCO requirements. The length of feeder is 42.62km with annual energy loss 457898.1kWH and maximum percentage voltage drop is 6.5%, which is beyond the specified limit of QESCO i.e. 5.0% and is not acceptable as shown in the table below. Month Max Hour KWH Reading in Year-3 (KWH) Units Sent in Year-3 (KWH) Units Sold in Year-3 (KWH) Losses KWH % January 0920108 0922574 1954326 1020746 933580 47.8 February 1809123 1811499 1504110 785804 719490 47.8 March 2577218 2580502 1233398 1324005 -90607 -7.3 April 2944920 2946703 1695002 1472175 223911 13.2 May 4197868 4199507 1758256 1693000 65256 3.7 June 4483081 4485732 1472868 1392621 84892 5.8 July 5663010 5665217 1452128 1146852 303276 21.0 August 6179532 6174379 1272432 1263513 8919 0.7 September 72162 76150 1636414 5107276 129138 7.9 October 1747258 172496 2070467 1654039 418057 20.2 November 4868322 4873227 2704009 1584898 1119111 41.4 December 6046270 602780 3086286 1626763 1459523 47.3 I used the following simple algorithm for the algorithm: Start with an existing configuration. Read Input data..Run ELR program..Display results..Compare KWH losses, If KWH loss CE 2.8 My test system is a high loss, problematic distribution feeder of QESCO. In first, the existing Grid and feeder data are collected from Surab grid station. The data made run in ELR Software, which results high losses due to overloads. As the ampere load accedes then 300 amp on main Dog conductor , To overcome these overloads we recon figurate the feeder by using three different methods i.e. Branch Exchange Method, Loop Cutting Method and then we applied bifurcation method to isolate the existing feeder into two parts. I collected data from the Head office QESCO in Quetta, Pakistan and found that the monthly Peak Load is between 600-700 Amps and the off peak load between 5-90 Amps with the lowest being in November. I conducted a Load flow analysis was done using ELR Program with the following input Parameters at 5% annual Load growth rate Load in Amp.=395 Amp @ 5% for 5 years Bus Voltage=11KV Feeder load factor=6.29% Existing power factor=0.78% Proposed power factor=0.79% Capacitor installed=2Nos. I proposed the following one line diagram of QESCO feeder as prepared on the basis of field visits is shown below in figure. This figure clearly shows the difference between actual and proposed configuration of the feeder. In this figure 154 node are shifted. Also the route of power flow has been changed there by feeding all the consumers. This configuration has reduced the line losses too as evident from the load flow analysis. The details are feeder given below. Power T/F # ÃŽâ„ ¢ÃƒÅ½Ã¢â€ž ¢ Feeder code 020201 Power T/F capacity 10/13 MVA Number of node 92 Number of transformers 66 Number dog conductor 18 Number rabbit conductor 73 Total length of line 18.42 KM Total KVAS 5350 KVA I also proposed and conducted a Load flow analysis using ELR Program with the following input Parameters at 5% annual Load growth rate. Load in Amp= [emailprotected]%for 5 years Bus Voltage = 11KV Feeder load factor= 6.29% Existing power factor = 0.78% Proposed power factor = 0.95% (Improved Due to capacitor Placement) CE 2.9 I conducted this project successfully and found that the ELR program could be used sappropriately and properly to find the optimal configuration of 11KV feeder, demonstrating the feasibility of such an approach for the solution of this problem. However, refinements to the algorithm may be necessary in order to achieve satisfactory performance on large, real-world systems consisting of thousands of buses. The following were my results: Losses (KWH) minimized from 457898 to 332944 Voltage drop improved from 6.5% to 4.4% Power Factor improvement from 0.78% to 0.95% (Result of proposed configuration) B/C Ratio is 24.25 CE 2.10 My contribution during this project was: Gathering Exact Grid data on realistic approaches. Gathering feeder data, one line diagram preparation physically through field visits. Exact measures and distances of node-to-node and exact electrical parameters informations. Keeping in view different constraints, like Cost, Obstacles, Load. Losses, Environmental / social constraints, Betterment of WAPDA as well as general public. Re-notification of existing configuration and finding the optimal configuration by repetition the results obtained after execution of ELR Program. Removing haphazard road crossings and reducing the length of feeder. Load Balancing. Placement of Capacitor at best locations for obtaining best results. Summary CE 2.9 I successfully completed the project titled Reconfiguration of a 11KV Feeder along with my team members. I learned how to reconfigure a 11KV feeder and about the different approaches by execution of the ELR program I learned how to gather Grid data for realistic approaches to improve loading. By the successful completion of this project, I was able to improve my written, oral and interpersonal skills. I was also able to improve my team work. The main objective of this research is to develop methodology and guide lines for distribution engineers to show that by reducing the energy losses of distribution system, available capacity of the system may be conserved without putting up additional capacity. A generalized computer program is used to evaluate any given HT/LT system and propose capacitor banks at different points, different conductor sizes in different portions of system. This results in improving the stability as well as energy handling capacity of the system at minimum cost.