A Novel Globally Optimized Instantaneous Torque Ripple Minimization Method in Switched Reluctance Motors with Matrix Converter Drives

The tangential component of electromagnetic force in switched reluctance motors (SRM) produces the desired torque which fluctuates with rotor position due to the doubly saliency in physical structure of SRM. The conventional methods are insufficient to completely compensate for the intrinsic behavior due to double saliency. This dissertation proposes a novel method of eliminating the torque ripple in the instantaneous torque profile of SRM and a method to generate the precise reference phase current waveforms for even open loop operational design through global optimization. For the purpose of implementation of the proposed method, a non-sinusoidal DC matrix converter is also proposed to generate such waveforms without using multiple source voltages and to be able to use the drive in electric vehicle applications where a battery system is available for DC voltage sources. The experimentally-obtained characteristics are used for finding the optimal solution for torque ripple reduction. FEA is used to investigate the accurate EM force and its radial and tangential components using volume integration method. The proposed global optimization method can give a precise solution for this non-linear problem. Therefore a modified fast-filled method is proposed to balance out the crests and troughs of the torque ripples throughout the operation of SRMs. A set of novel reference current waveforms are generated for feed-forward torque control. Comparative analyses with the torque and current profiles of conventional methods are performed to prove the elimination of ripple up to less than 1% by using the proposed method. Therefore, it is concluded that the advanced turn-on and delayed turn-off angles with gradual rise and fall significantly eliminate the ripple. Inverter topology requirement for SRM is geometry-dependent. A multi-level converter is more suitable to generate the required position-dependent phase current. Matrix converters can be used for finer control on flexible current profiling. Therefore, a non-sinusoidal DC matrix converter is proposed to generate the required phase current waveforms from a single DC source and to accommodate the changes if required accurately. Three reduced-switching states schemes were tested with matrix converter resulting in the ripple elimination between 0.9% - 2% where 0.45% reduction is possible

Analgesic and Anti-Inflammatory Effects of Phaseolus vulgaris L. Fixed Oil in Rodents

The seeds of Phaseolus vulgaris are known as common beans or kidney beans. The dry seeds are eaten as pulse and are enriched with protein, fiber, starch, B vitamins (B1, B6, B9), iron, potassium and selenium. Beans also contain about 1-2 % of fixed oil. Phaseolus vulgaris is linked with anticancer, antihyperlipidemic, hypoglycemic and antioxidant actions. The fixed oil of Phaseolus vulgaris (PVFO) seeds is extracted with hexane and used in this study to assess acute oral toxicity, analgesic (by acetic acid induced writhing, hot plate and tail flick tests in mice) and anti-inflammatory (by carrageenan induced paw edema in rats) actions. Four groups were made (n=6): Group-I: Normal Saline Control (2ml/kg), Group-II: PVFO (2ml/kg), Group-III: PVFO (4ml/kg) and Group-IV: Standard Acetyl salicylic acid (ASA 300 mg/kg). PVFO in 2ml/kg and 4ml/kg dose demonstrated analgesic and anti-inflammatory activities but in hot plate results were unreliable as here significant activity started after 90 minutes. For toxicity test 5ml/kg dose was administered orally in mice and no toxicity symptoms were observed. It is therefore concluded that PVFO is safe for oral use up to 5ml/kg and may possess analgesic and anti-inflammatory actions