Potentially Good Thesis Topic for Electrical Engineering Students: “Application Of Secondary Banking Method Of Distribution Transformers For Rural Distribution Systems”

This was one of the thesis topics that I was considering to undertake during my Electrical Engineering undergraduate college years. Unfortunately, my adviser did not accept it because for him, it might be too easy and might involve little research. However, I personally think that it is still a good topic and I am confident that the possible outcome of the research has a potential good contribution to the improvement of the rural electric distribution systems around the world. Here’s the abstract for this project;

Abstract- Rural distribution systems in the country (Philippines) are characterized by dispersed end-users, usually residential consumers, which are usually supplied by a single-phase power source. Because of long line distances (both on primary feeder and secondary main), the power supply suffer from severe voltage drop before it reached the consumers` service entrance. Voltage drop is due to the impedance of the line and line current both on the primary and secondary main. There is also a high percentage of power losses due to long lines and voltage drops.

To solve this problem, several methods are practiced to improve the voltage regulation. Some of these are; connecting shunt capacitors on the primary feeder, and changing the taps of the distribution transformers. However, it is not economical to use shunt capacitors to compensate the voltage drop in the secondary main. Moreover, the financial incapability of many Rural Electric Cooperatives hinders its technical ability to practice automatic tap changing on distribution transformers. It is also impractical to use tap changing on distribution transformers.

One efficient solution to this problem is to reconfigure the system and use secondary banking method of transformers. One of the main advantages of secondary banking is that it improves voltage regulation. Moreover, it also reduce voltage dip or light flicker due to motor starting, by providing parallel supply paths for motor starting currents, improves service continuity, reliability and flexibility in accommodating load growth at low cost.

However, secondary banking offers difficulty in performing transformer load management (TLM) to keep up with changing load conditions and difficulty in determining the load division among transformers, thereby, a difficulty in coordination of the secondary fuses, and transformer overloading.

This paper provides an assessment on voltage regulation at the secondary main up to the service entrance of the end-users using secondary banking method. In addition for the purpose of reconfiguration, this research will also propose a method of transformer load management (TLM) and load division of the transformer banks, and a method of determining the optimum transformer location for transformer banking, considering the constraints on changing load conditions, and load distributions.

The proposed method can be verified using manual calculations and computer load flow simulations.

Filed in: Distribution System
Local date: March, 2010

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