Electric motors are the majority of the industry prime movers. Induction motor is the most popular ones for their reliability and simplicity of construction .although induction motors are reliable they are subjected to some mode of failures. These failures may be inherent to the machine itself or due to operating conditions. The origins of inherent failures are due to mechanical or electrical forces acting in the machine enclosure. Researchers have studied a variety of machine faults. Unexpected faults and failures in these machines can lead to excessive downtime and generates large revenue losses in terms of maintenance and production.
Induction motors are used worldwide as the workhorse in industrial applications. Such motors…
Direct Current (DC) motors
A Direct Current (DC) motor is one of the broader classification of electric motors which operate from a direct current. Nearly all mechanical devices applied in daily life activities are powered by electric motors. Motors transform electrical energy to mechanical energy, hence they are essential for energy conversions in electrical machines.
All types of electrical motors are made up of a stationary field referred to a stator and…
resources in prison for those that are not hardened criminals. This would be a relevant program where people could find a job or a program that will help them make sure individuals are capable of supporting their children.
Hybrid-Electric Job Site Generator
Although world leaders have already taken many steps to reduce dependence on fossil fuels, there persists the need for continued use for the near future. One major technological advance, which allows modern consumers to curb gasoline…
Cost Moderate initial cost followed by a higher operating cost and maintenance. High purchasing price;
Lower operating cost and good energy saving which cut down operating cost.
Table 2 summary of comparison between PM and induction machines
losses in electric machines
To investigate the efficiency of the machine, an essential part is to evaluate the losses in the motor. Losses in the machine is determined by the structure and working condition. Losses in the machines can generally be…
Abstract:It is very important to control the speed of induction motors in industrial and engineering applications. Efficient control strategies are used for reducing operation cost too.This paper presents a direct flux and torque control of three phase induction motor drive using PI and Fuzzy logic controller. The Direct Flux and Torque Control (DTC) is one of the most excellent direct control strategies of stator flux and torque ripple of Induction Motor Drive(IMD). The conventional method of…
The proposed approach was implemented, tested and validated for SVPWM and DPWM2 techniques, including the over-modulation region. The proposed switching frequency variation strategy was able to reduce switching losses up to 20% over the conventional constant switching frequency SVPWM and DPWM2 techniques.
This strategy also spreads peaky harmonic spectrum of the output waveform which may help in reducing acoustic noise, however, consequent introduction of lower frequency harmonics in the…
How Electro-mechanical Actuator Works?
A Rotary Electromechanical Actuation system with an Electric Motor, a gear box & an elastic spring to absorb peak torque loads experienced during operational life. The Schematic below describes the system.
Fig. 1.1 Rotary Electro-mechanical Actuator
The Gear Box at the Motor Output is intended to amplify the torque output of the Motor with reduction in speed. The tentative ratio is set at 10:1.
Functional Requirements of…
Rotor and touchdown bearing models
Fig. 1 features the case study of the high-speed rotor. The photo was taken after manufacturing of the electric motor part, when the rotor was carried to the laboratory for an experimental modal analysis. During normal operation, the rotor is supported by AMBs. In the dropdown event, the rotor is in contact with touchdown bearings at both ends of the rotor.
Fig. 1. Rotor under investigation.
In this work, the finite element model of the rotor employs…
The joints had to be such that they can be loosened and tightened at any required configuration, this obstacle was overcome by the use of wing nut at the end of the screw instead of a normal nut, and the image below shows the wing nut and bolt.
This is the most cost effective yet strong way of locking the joints compared to knobs and other clamp mechanisms.
For the Robot Arm Construction our group members had a variety of materials to choose from, these materials…
they pass through the nozzle. Each nozzle converts heat and pressure energy into velocity energy by controlling the expansion of the gas. Each small nozzle has a convergent area.
Each stage of the turbine is larger than the preceding one. The pressure energy drops are quite rapid; consequently, each stage must be larger to use the energy of a lower pressure, lower temperature, and larger volume of gases. If more stages are used, the rate of divergence will be less.
The turbine motor area must…