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Currents due to shaft voltage causes deterioration of motor bearings, but can be prevented with a grounding brush on the shaft, grounding of the motor frame, insulation of the bearing supports, or shielding. Shaft voltage can be induced by non-symmetrical magnetic fields of the motor (or generator) itself.
These will absorb a part of the vibrations (and the noise) produced by the machines. To control the electromagnetic vibrations at the origin, skewing the electric motor or choosing a better slot/pole combination [3] will reduce electromagnetic force harmonics or avoid resonances between magnetic forces and structural modes of the electric motor.
The example locomotive is a simple, non-compound, type with two outside cylinders and valve gear, coupled driving wheels and a separate tender. Only basic balancing is covered with no mention of the effects of different cylinder arrangements, crank angles, etc. since balancing methods for three- and four-cylinder locomotives can be complicated ...
In an electric power system, automatic generation control (AGC) is a system for adjusting the power output of multiple generators at different power plants, in response to changes in the load. Since a power grid requires that generation and load closely balance moment by moment, frequent adjustments to the output of generators are necessary.
Capability curve of an electrical generator describes the limits of the active and reactive power that the generator can provide. The curve represents a boundary of all operating points in the MW/MVAr plane; it is typically drawn with the real power on the horizontal axis, and, for the synchronous generator , resembles a letter D in shape, thus ...
Torsional vibration is a concern in the crankshafts of internal combustion engines because it could break the crankshaft itself; shear-off the flywheel; or cause driven belts, gears and attached components to fail, especially when the frequency of the vibration matches the torsional resonant frequency of the crankshaft. Causes of the torsional ...
Now if the flow rate is reduced to ˙ by closing a control valve on the delivery pipe, the static pressure upstream of the valve is increased. This increased pressure ( p B {\displaystyle p_{B}} ) is then matched by the increased delivery pressure (at B) which is developed by the compressor.
The motor–generator set may contain a large flywheel to improve its ride-through; however, consideration must be taken in this application as the motor–generator will lose speed and may draw a large current when power returns or the circuit-breaker is re-closed. If the speed loss is excessive (the power outage is too long), the re-closure ...