PWM inverters for stand-alone single-phase high quality power generation

Nowadays, environmental issues are of most concern. Conventional solutions that use lead acid batteries and diesel engines as sources of energy for both uninterruptible power supply and isolated power generation systems are facing an increasing opposition due to environmental and economical concerns. To face these issues, alternative sources of electric energy have been studied in the last few years. Systems that use fuel cells as electric energy sources are environmentally safe and very efficient. This kind of systems can be used for a great number of applications such as in the power generation to feed isolated single-phase electric loads. In this work, a system for a stand-alone single-phase high quality power generation is presented. The system is based on a fuel cell system as a source of electrical energy. The output voltage of this system is a DC voltage, which is then applied to the input of a DC/AC power converter that uses a suitable PWM control technique, able to generate an AC output voltage. A step-up transformer increases the AC output voltage to an appropriate RMS value and a passive AC filter is used in order to supply the loads with high quality power. The presented results correspond to the system simulation in Matlab/Simulink platform, using the SimPowerSystems toolbox, for different kinds of loads with high quality energy standards.