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Wound-rotor motors can be started with low inrush current, by inserting high resistance into the rotor circuit; as the motor accelerates, the resistance can be decreased. [ 1 ] Compared to a squirrel-cage rotor , the rotor of the slip ring motor has more winding turns; the induced voltage is then higher, and the current lower, than for a ...
In this example, the slip rings have a brush-lifting device and a sliding contact bar, allowing the slip-rings to be short-circuited when no longer required. This can be used in starting a slip-ring induction motor, for example. A slip ring is an electromechanical device that allows the transmission of power and electrical signals from a ...
The circle diagram can be drawn for alternators, synchronous motors, transformers, induction motors. The Heyland diagram is an approximate representation of a circle diagram applied to induction motors, which assumes that stator input voltage, rotor resistance and rotor reactance are constant and stator resistance and core loss are zero.
It is based on an induction generator with a multiphase wound rotor and a multiphase slip ring assembly with brushes for access to the rotor windings. It is possible to avoid the multiphase slip ring assembly, but there are problems with efficiency, cost and size. A better alternative is a brushless wound-rotor doubly fed electric machine. [12]
They are used in the rotor circuits of large slip ring induction motors to control starting current, torque and to limit large electrical fault currents (while other protection systems operate to clear or isolate the fault).
The National Packard Museum located in Warren, Ohio is the official museum of both the original Packard Motor Car Company and The Packard Electric Company. [68] Its purpose is to preserve the Packard legacy and recognize Packard's influence in transportation and industrial history through interaction with the community and outreach programs.
A blocked rotor test is conducted on an induction motor. It is also known as short-circuit test (because it is the mechanical analogy of a transformer short-circuit test), [1] locked rotor test or stalled torque test. [2] From this test, short-circuit current at normal voltage, power factor on short circuit, total leakage reactance, and ...
A unipolar motor (also called homopolar motor) is a direct current (DC) motor typically with slip-rings on each end of a cylindrical rotor and field magnets or a DC field winding generating a magnetic field on the stator. The rotor has typically not a winding but just straight connections in axial direction between the slip-rings (e.g. a copper ...