Decoupled solid state controller for asynchronous generator in pico-hydro power generation

Abstract

This paper deals with a decoupled solid state controller (DSSC) for an isolated asynchronous generator (IAG), used in constant power pico-hydro power generation for feeding three-phase four-wire loads. The proposed DSSC is used to control the voltage and frequency of the IAG in the decoupled manner. This DSSC is a combination of a voltage regulator (VR) for regulating the voltage and a conventional electronic load controller (ELC) for controlling the active power to regulate the frequency. The VR is realized using a zigzag/three-single-phase transformer and six-leg insulated gate bipolar transistors (IGBTs)-based current controlled voltage source converter (VSC) with a capacitor on its DC bus and an ELC is a combination of a three-phase diode bridge rectifier with a chopper switch and an auxiliary load. The proposed DSSC with an isolated generating system is modeled and simulated in MATLAB along with Simulink and power system blockset (PSB) toolboxes. The simulated results of the IAG-DSSC system are presented to demonstrate its performance for feeding three-phase four-wire linear/nonlinear (balanced/unbalanced) loads with the neutral current compensation.