Diseño y control de un sistema de generación eléctrica, basado en máquina de inducción, para la alimentación de cargas aisladas mediante distribución trifásica de cuatro conductores

Abstract

Although the self-excited induction generator (SEIG) offers poor voltage regulation, as well has many advantages over the classical three-phase synchronous generator: brushless (squirrel cage rotor), reduced size (because its good power-volume ratio), rugged and low cost. So the induction generator is a suitable candidate for energy supply in rural communities and remote areas, where these machines can be driven using some renewable energy resources like wind energy or micro-hydropower. Usually, in this last application, the SEIG operates at constant load power This thesis proposes a three-phase four-wire power supply system, based on a standalone SEIG with a shunt electronic converter, to feed three-phase and single-phase linear or nonlinear loads. The electronic converter is composed by a three-phase four-wire voltage source inverter (VSI) and, connected to its dc side, two DC-DC converters. The VSI compensates the current harmonics, the reactive power and the load unbalances. The first of the DC-DC converters is a battery charger/discharger and the other converter dissipates the active power excess, through a chopper. So these converters keep the active power balance of the complete system. The control strategy of the VSI is based in a fundamental positive-sequence detector of load current. For the battery converter the control strategy is based in a relay control with compensation. The designed control architecture assures that, in steady state and under different loading conditions, the voltage and the frequency of the standalone SEIG remain at their nominal values.