Design and implementation of an electromechanical control system for micro-hydropower plants

Renewable energy resources are preferred as compared to conventional energy resource due to their environment friendly nature. Micro-hydropower plant is one of the best renewable energy sources that provides electricity to hilly and rural areas. Micro-hydropower plants are mostly installed at natural heads and runoff rivers. Lack of a reservoir at the headrace of micro-hydropower plant results in variable water flow to the turbine. Also, consumer load connected to the generator varies with time. The variation in water flow to the turbine and consumer load changes result in variation in generator output power and frequency. This paper presents a novel and innovative electromechanical control system that keeps generator frequency constant as the consumer load varies. The mechanical control part of this system controls water flow to the turbine using dc motor and sliding gate. The electric part of this controller keeps the generated power equal to ballast load power and consumer load power. The ballast loads are turned on and off at the zero crossing to the sinusoidal wave of the generator output that minimizes transients and power losses in switching. Electromechanical controller increases efficiency of micro-hydropower plant and also increases the reliability of power supply. The proposed system is simulated in MATLAB Simulink. An electronic model of the proposed system is implemented in Proteus software. Based on the Proteus model, a hardware model is designed and tested in the laboratory. The experimental model results are compared with Simulink model which are in close agreement.