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A novel harmonics-reducing system of cascaded-induction generators has been proposed, and its effectiveness has been confirmed by the simulation results. Comparing the characteristics of the cascaded generators with those of the single generator, we see that the power efficiency decreases by 1-3%, and the input power factor decreases by around 20%, but the(More)
A novel six-phase voltage-fed inverter system is proposed. The system consists of two main three-phase inverters, coupling reactors, and an additional single-phase inverter. The ripple voltage injected into the DC link by the additional inverter results in 60-step load voltages with the help of the coupling reactors. The main inverters operate at the same(More)
A novel concept of asymmetrical nine-phase diode rectifiers with 18-pulse performance is extended to voltage step-up or -down rectifier circuits, in which each diode conduction interval in the main rectifier is 80/spl deg/ and one in the two auxiliary rectifiers is 20/spl deg/. The asymmetrical nine-phase diode rectifier requires differential(More)
A novel variable-speed cascaded induction generator system is proposed for small-scale hydroelectric power plants, in which the second induction generator has double three-phase stator windings (or six-phase windings). The proposed low-cost system can provide a brushless, robust structure and less distorted currents without using an expensive PWM rectifier(More)
  • K. Oguchi
  • 2008
Novel multiple boost rectifier systems coupled with an autotransformer having a capacity rating of 20% are presented. The autotransformer in the triple rectifier system synthesizes two three-phase voltage systems with a phase shift angle of 20deg and an amplitude of 1.064 times with respect to the line voltages. These asymmetrical voltage systems make the(More)
A novel control method for single-phase multilevel rectifiers is proposed to meet harmonic current limiting standards with minimum input filter inductance. Since the proposed rectifier consists of a main power circuit of a diode bridge and two auxiliary semiconductor switches in parallel with the main circuit, it provides several features; high(More)
In order to produce a comfortable luminous environment, 1/f fluctuation control of illuminance is proposed. It is shown that natural light which is comfortable to humans, such as sunlight streaming through leaves toward the ground, has 1/f fluctuation characteristics. On the other hand, artificial lights such as fluorescent lamps have near white-noise(More)
A new brushless speed control system is proposed which consists of a self-cascade induction motor and a brushless commutatorless motor. The slip power extracted from the stator terminals of the induction motor is converted to mechanical power by the commutatorless motor, which is coupled mechanically to the induction motor shaft. The field control method,(More)
Two systems for synthesizing three-phase sine waves with a combination of two units using multiple phase-shifted, single-phase resonant inverters are proposed. The first system has the advantages of a high-frequency resonant inverter and a high-frequency AC link. The second system has the advantage of a high-frequency resonant inverter. The structure and(More)
This paper propose a novel "inverse-problems" approach to control a three-level rectifier so that the harmonic standards such as IEC 1000-3-2 class A can be met at lower switching frequencies. A conventional programmed switching method eliminates some designated harmonics of converter voltages. This results in a considerable increase in the amplitude of the(More)