Suresh Gopalakrishnan

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The objective of this paper is to present a sensorless position estimation technique for switched reluctance machines operating in dynamic modes over a wide speed range including zero speed. The technique combines two different methods to deliver high-resolution position information over the wide speed range. At zero and low speeds, a voltage pulse(More)
The switched reluctance (SR) drive is known to be fault tolerant, but it is not fault free. The goals of this study are the systematic classification of all electrical faults, for short and open circuits, in the SR drive (excluding the controller itself) and the investigation of fault patterns and possible remediation. Each situation is analyzed via(More)
Future automobiles will be equipped with x-by-wire systems to improve reliability, safety, and performance. The fault-tolerant capability of these systems is crucial due to their safety critical nature. Three fault-tolerant inverter topologies for permanent magnet brushless direct current motor drives suitable for automotive x-by-wire systems are analyzed.(More)
This article describes a semiintegrated permanent-magnet (PM) brushless drive for a 42-V electric compressor for automotive heating, ventilation, and air conditioning (HVAC). Electric compressors have the advantages of low refrigerant emissions, flexible packaging, and efficient variable-speed operation. These are intended for vehicles where the engine(More)
This paper presents a hybrid sensorless controller used with both the classical eight-switch converter and a reduced six-switch converter topology for switched reluctance motor (SRM) drives. The hybrid sensorless scheme consists of a sliding mode observer (SMO)-based position sensorless approach for high speeds along with a low-resolution discrete sensor(More)
Navy Shipboard Power Systems have different characteristics when compared with utility power systems. To conduct system studies on shipboard power systems, an effective simulation tool is required to model the Shipboard Electric Power Systems. This paper presents the results of the analysis of three popular simulation tools, ATP, PSpice and Saber for(More)
The switched reluctance drive is known to be fault tolerant, but it is not fault free. This paper takes an in-depth look at winding short circuits in this particular machine. Modeling and testing complement a theoretical analysis. Two cases need to be distinguished, one where a complete pole is shorted, and one where a few turns are shorted. Pole short(More)
We present the design, prototype implementation and initial evaluation of FedFS-a novel cluster file system architecture that provides a global file space by aggre-gating the local file systems of the cluster nodes into a loose federation. The federated file system (FedFS) is created ad-hoc for a distributed application that runs on the cluster, and its(More)
Electromechanical brake (EMB) systems offer the potential for enhanced vehicle control while simplifying the car assembly as well as recycling process. This article offers a comparison of two motor technologies, switched reluctance (SR) and permanent magnet (PM) brushless, motor in highly dynamic situations, in all four quadrants of their torque-speed(More)