An improved electronic load controller for self-excited induction generator in micro-Hydel applications

This paper describes the mathematical modelling of self-excited induction generators (SEIGs) with are improved electronic load controller (IELC) for microhydel applications supplying variety of loads. In small hydro plants, governor unit of turbine can be eliminated using IELC, which is simple and cost effective. The improved electronic load controller is a combination of a three-phase insulated gate bipolar transistor (IGBT) based current controlled voltage source inverter (CC-VSI) and a high frequency DC chopper which keeps the generated voltage and frequency constant in spite of change of balanced/unbalanced loads. A dynamic model of the SEIG- IELC supplying different types of loads using stationary d-q axes reference frame is developed for predicting the behavior of the system under transient conditions. The simulation is carried out for compensation of balanced/unbalanced loading conditions. The simulated results show that generated frequency and voltage remain constant with change in load. The proposed IELC acts as reactive power compensator, harmonic eliminator, load balancer and load controller.