Improvements of Reliability of Micro Hydro Power Plants in Sri Lanka

“Electricity” and “power” are two of the most common terms that are heard today due to the scarcity of resources available. Micro hydro power plants are basically small-scale hydroelectric installations which are particularly used as isolated power supply scheme for village electrification where utility power is well out of reach.


A group of final year  undergraduates namely, S S B Udugampala, V Vijayarajah, N T L W Vithanawasam, W M S C Weerasinghe, from the Department of Electrical Engineering of University of Moratuwa carried out a research on the “Improvements of Reliability of Micro Hydro Power Plants in Sri Lanka”The research  which was done in 2010 was supervised by Eng J Karunanayake, Dr. K T M U Hemapala.

After the several tests that had been done, current harmonics had been identified as the major cause for  capacitor bank failures.  By the analysis, it can be seen that the THD of this system exceeds the standards of limit of harmonic current in the system. So it is necessary to minimize the harmonic content in the system.   Introducing a detuned  filter to eliminate the selected harmonics would be a healthy solution. Since this solution incurs high cost we could not implement that also the consumers don’t care about the quality of the power. Therefore it is concerned that, only to protect the capacitor banks from the harmonic currents, not the full system.  If the system is producing current harmonics around  resonance frequency that would cause a very high undesirable voltage and that could affect capacitors badly. The suggestion for overcome this problem by adding inductors in series with the excitation capacitor bank to pull the resonance frequency to a value that is not present in the system. So it can make sure the capacitor banks are safe. 

Also a new design of Induction Generator Controller is implemented (IGC) based on microcontroller. It is a very simple circuit and easy to modify and maintain. It can most effectively replace the existing IGC. Also it is cheaper than the existing one. This project has given us an opportunity to explore the most of the areas of electrical engineering as well as other engineering disciplines such as software engineering. And this project gave us the chance to deal with the industry sector and to get some new the experience. Although there were some problems like acquiring the required information from the plants for the project development and funding problems for  implementing the proposed solution, the help from supervisors and plant owners were very helpful to us. As future improvements the IGC circuit can be modified with further protection features like overvoltage, over-current protection. The micro hydro power plant is one of the most suitable power generation methods for country like Sri Lanka which is a renewable energy. If these plants are developed with more innovative and efficient adoptions they can be utilized to fulfill majority of electricity demand requirement as green and cost effective power sources.


University of Moratuwa, a leading technological university in the region welcomes you to witness a truly unique experience!

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