Power Generation Using Photovoltaic Induction Generator in an Isolated Power Network

Owing to increased emphasis on renewable resources, the development of suitable isolated power generators driven by energy sources such as photovoltaic, wind, small hydro-electric, biogas and etc. has recently assumed greater significance. A single phase capacitor self-excited induction generator (SEIG) has emerged as a suitable candidate of isolated power sources. This paper presents performance analysis of a single phase self-excited induction generator driven by photovoltaic (PV) system for low power isolated stand-alone applications. A single phase induction machine can work as a self-excited induction generator when its rotor is driven at suitable speed by an photovoltaic powered dc motor. Its excitation is provided by connecting a single phase capacitor bank at a stator terminals. Either to augment grid power or to get uninterrupted power during grid failure stand-alone low capacity ac generators are used. These are driven by photovoltaic, wind power or IC engines using kerosene, diesel, petrol or biogas as fuel. Self-excitation with capacitors at the stator terminals of the induction machines is well demonstrated experimentally on a PV powered dc motor-induction machine set. The parameters and the excitation requirements of the induction machine run in self-excited induction generator mode are determined. The effects of variations in prime mover speed, terminal capacitance and load power factor on the machine terminal voltage are studied.

Keywords:

Photovoltaic generators , portable induction generators and integrated renewable energy systems