A SELF-CASCADED INDUCTION GENERATOR COMBINED WITH A SEPARATELY CONTROLLED INVERTER AND A SYNCHRONOUS CONDENSER

Since the oil shock of the 1970's, induction generators have been regarded as energy-saving, small-scale, energy-producing devices. The cage rotor-type induction generator is unique in that its construction is simple yet sturdy. A major problem in the induction generator system, however, is this source of the reactive power to the induction generator. One solution to this problem is to use a synchronous condenser, as noted in the work of Ooi et al., but the Ooi induction generator system has brushes, thus requiring frequent maintenance. This paper examines the Ooi induction generator system and substitutes a self-cascaded induction machine for the wound rotor induction machine in addressing the problem of the absence of brushes in the Ooi system. The frequency converter of the induction generator system is comprised of a rectifier and a separately controlled inverter. It was found that the theoretical value obtained by the quantitative analysis coincided with the experimental results. Thus, the Ooi induction generator system can be improved by including a brushless synchronous condenser and a self-cascaded induction machine.