Olorunfemi Ojo

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This paper presents analytical techniques for the determination of the expressions for the modulation signals used in the carrier-based sinusoidal and generalized discontinuous pulse-width modulation schemes for two-level, three-phase voltage source inverters. The proposed modulation schemes are applicable to inverters generating balanced or unbalanced(More)
This paper presents a new approach of optimizing the efficiency of induction-motor drives through minimizing the copper and core losses. The induction-machine model, which accounts for the varying core-loss resistance and saturation dependent magnetizing inductance, uses natural and reference frame independent quantities as state variables. Utilization of(More)
The advancement in power electronics has made the use of any number of phases in ac machines possible since with the inverter, any number of phase voltages can be realized as long as the corresponding inverter exists. To supply multiphase drives requires multiphase voltage source inverters (VSIs) whose output voltages depend very much on the methods of(More)
Using an expanded reference frame transformation expressed in the complex-variable form, the possibilities offered by multi-phase converters, using carrier-based, sine-triangle pulse-width modulation to generate voltages of different frequencies to actuate multi-phase electric machines are set forth. The generalized expressions for the modulation signals,(More)
High power, high reliability electric motor drives in such applications as electric ship propulsions, electric locomotives and hybrid electric vehicles require the use of high order phase electric machines run with multi-phase converters. Presently, five and asymmetrical six-phase machines with their associated converters are emerging industry standards.(More)
The air-gap flux linkage of a dual-stator-winding squirrel-cage induction machine comprises of four fundamental flux components due to the currents flowing in the two stator windings with P<sub>1</sub> and P<sub>2</sub> pole numbers and the currents that they induce in the squirrel cage. In view of the dissimilar pole numbers of the stator windings and(More)
Common-mode voltage (CMV) in voltage-source inverters (VSIs) has been well defined and is frequently referred to in the literature. While often referred to, there is no real consistency with respect to how the CMV properties of an individual modulation scheme are evaluated, lacking tools to assess the relative merits or disadvantages of a certain topology(More)
Home appliances and comfort conditioners are yet to benefit from the recent developments in power electronics because of cost constraints. In this paper, a speed-sensorless induction motor drive system using converters with reduced device counts (minimalist, sparse converters) and actuated from a single-phase system is proposed for such low-cost(More)