Ramu Krishnan

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Linear switched reluctance motor (LSRM) drives are investigated and proved as an alternative actuator for vertical linear transportation applications such as a linear elevator. A onetenth scaled prototype elevator focused on a home elevator with LSRMs is designed and extensive experimental correlation is presented for the first time. The proposed LSRM has(More)
Vector control schemes are used in inverter-fed induction motor drives to obtain high performance. Crucial to the success of the vector control scheme is the knowledge of the instantaneous position of the rotor flux. The position of the rotor flux is measured in the direct scheme and estimated in the indirect schemes. Since the estimation of the flux(More)
A method of determining the motor losses under the operating conditions inclusive of saturation is described. General expressions for the flux frequencies in different parts of the core are derived. It is shown that the number of (fundamental) flux frequencies simultaneously present in the machine is a function of the number of phases and that the core(More)
The sensitivity of the pole-arc/pole-pitch ratio of the stator and rotor on the performance of a switched reluctance motor is investigated. An analytical method based on magnetic flux path and a two-dimensional finite-element analysis are used. The sensitivity study is performed by comparing the average torque developed for different stator as well as rotor(More)
Direct torque control (DTC) has drawn the attention of the motor drives designers because its implementation requires no position sensor. Crucial to the success of this scheme is the estimation of electromagnetic torque and stator flux linkages using the measured stator voltages and currents. The estimation is dependent only on one machine parameter, stator(More)
Linear switched reluctance motors (LSRMs) for the primary propulsion of a ship elevator is proposed and investigated for the first time in this paper. To achieve the stated objective, a new type of LSRM is proposed with twin stators and a translator between them with no back iron in the translator. The proposed configuration of the LSRM is designed,(More)
  • R. Krishnan
  • IEEE Transactions on Industry Applications
  • 1987
The power density and acceleration characteristics of the ac servo drive are being recognized as being superior to those of the dc counterpart. The ac servo family consists of permanent-magnet synchronous, dc brushless, induction, and switched reluctance motor drives. This ac servo family is comprised of radial (also known as the sausage type) and axial(More)
This paper presents the comparison of four linear switched reluctance machines (LSRMs) as possible candidates for application in vertical elevators. Linear induction and linear synchronous machines have been presented and experimentally tested in vertical elevators. In this paper, four longitudinal LSRM configurations are presented and designed to operate(More)
Increasing awareness of industrial noise pollution and emerging stricter standards have made noise an important topic of research in electric machines. This work is a state-of-the-art review on the identification of noise sources and techniques to mitigate noise. It points the reader to relevant research in the past on noise identification and mitigation(More)