Design a Digital Electronic Load Controller for Micro-Hydroelectric System Applications

Abstract

A micro-hydroelectric system is an important alternative for rural electrification, but its output voltage fluctuates over a small change of consumer loads. In order to protect the users and their appliances, the output voltage must be regulated to the nominal voltage of the appliances. For that purpose, this paper describes the concept of a simple and cost effective digital Electronic Load Controller (ELC). The formulation of proportional-integral-derivative (PID) control based ELC algorithm is presented, and the flow chart of the algorithm is derived. The hardware implementation of the ELC was established to verify the concept. By using a laboratory setup, the tuning effect of PID time interval on the voltage regulation was investigated and presented as there is no well documented information about the setting of that variable in literature. The experimental results showed that the ELC performed better with minimum value of time interval. The ELC was also tested with load variations, and the results showed that the output voltage was kept regulated at the nominal voltage despite the load variations. This has confirmed that the concept and methods used in the ELC design proposed in this paper can be considered for the voltage regulation of the micro-hydroelectric system.