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Cogging torque is a critical dilemma in Permanent Magnet Brushless DC (PMBLDC) motors. In medium-low power PMBLDC motors, redundant vibrations and forbidding noises arise as a result of the harmonic magnetic forces created by cogging torque. This paper introduces a simple approach for minimizing cogging torque in PMBLDC motors by applying placement irregularities in rotor magnets. An angle shift in the rotor magnets in surface-mounted PMBLDC motors helps to attain magnet displacement. This displacement imparts an asymmetrical magnet structure to the rotor. Maintaining pole arc to pole pitch ratio (L/τ) of between 0.6 and 0.8, shifting angles from 1° to 8° were considered in order to analyze the effect of the angle shift on the rotor magnets. An analytical expression was also derived for finding the shifting angle with the minimum cogging torque in the PMBLDC motor by using the Virtual Work Method (VWM). The optimization of the shifting angle with minimum cogging torque was investigated using 3D Finite Element Analysis (FEA). A comparison of the simulation and analytical results of cogging torque was carried out. It was determined that the reduction of cogging torque in the analytical results showed good agreement with the FEA analysis.

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<span lang="EN-US">Multilevel Inverters are generally utilized for medium voltage and high power applications. Invented in 1975, MLIs have brought huge change in the field of Electrical and Electronics. It contains distinctive topologies. This paper proposes a photovoltaic aided multilevel inverter with Reverse Voltage topology with diminished number of switches. In comparison to other existing topologies this topology utilizes minimum number of switches and less number of carrier signals which in turns diminishes the complexity of the system as well as cost. The proposed framework contains five MOSFETs, five diodes to create eleven levels. In this topology the SPWM strategy has been utilized. This topology utilizes one sine wave and five triangular waves, which is half in comparison to the existing topologies. As sustainable power sources can be utilized for multilevel inverter, photovoltaic cell has been utilized. The MATLAB recreation for both solar powered module and Multilevel inverter has been appeared alongside the equipment approach.</span>

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A Permanent Magnet BLDC motor is designed for reduction in cogging torque and flux per pole. The cogging torque causes direct impact in permanent magnet BLDC motor performance by causing torque ripple problems. This paper proposes a new method for reducing cogging torque by adapting to U-clamped magnetic poles. Finite Element Analysis (FEA) is used to calculate the cogging torque and the flux per pole for different shapes of magnetic pole. It can be shown that the cogging torque could be greatly reduced by adapting to U-clamped magnetic poles. At the same time it is found that the flux per pole is also considerably reduced. The effectiveness of the proposed method is verified by comparing the cogging torque and flux per pole for various designs available in the literature.

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