FIELD-ORIENTED CONTROL OF SELF-EXCITED INDUCTION GENERATOR

Abstract

Nowadays world is hungry for power. Every country develops more and more energy from its possible recourses for driving their economic and social growth towards new heights. India is no exception in that. For that so many scientist and engineers are working in finding more economic and viable power generating solutions which are also concerned with green and clean energy and also for reason of increasing cost of fuel. Renewable sources fits in this requirements. As of now India's most power is generated through thermal power plant which uses coal and we have huge unexplored potential of mini/micro hydro power in different parts of country. Power in every village is also a dream up to now because their geographic Iocations and other infrastructure problems. For this reason country like ours there are huge potential and demand for small isolated power generation systems. The squirrel cage induction generators are widely used for low power generation. These are ideally suited for non-conventional energy generation and have more advantages over synchronous generator in variable speed operation. In the stand alone operation, the three-phase induction generator operates in self excitation power generation mode when a capacitor bank connected in parallel/series with its stator terminals and driven by a prime mover. However, delivered power to the consumer must be within the acceptable quality in terms of voltage, frequency and waveform. Self-excited induction generator is suffered from change in voltage and frequency with change in loading at stator and speed of the prime mover. Self Excited Induction Generator requires suitable controller to be developed and crucial function of such controller would be to provide require variable capacitive reactive power to maintain voltage across the load at all time. A Field oriented controller of SEIG is analyzed in the dissertation for variable speed, constant. voltage operation of induction generator, in self-excited mode. Capacitor connected in the dc link of the Pulse Width Modulation inverter is used for the excitation of induction generator. The gating pulse of inverter controls the reactive power component of the current and hence voltage can be maintained constant.