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Neodymium Permanent Eddy Current Magnet, Laminated Type Eddy Current Loss Permanent Magnets, Germany Surplus Neodymium Block Magnets, Industrial Electronics Laminated Magnet, China supplier the strongest magnets for USA European UK motor motion customers
Neodymium Permanent Eddy Current Magnet Laminated Type
• Grades: N35–N52, N35M–N50M, N35H–N48H, N35SH–N45SH, N28UH–N42UH, N28EH–N40EH For all Neodymium Permanent Magnet and Neodymium Permanent Magnet assemblies.
• Coating: Ni-Cu-Ni, Black Nickel, Zn, Sn, Au, Ag, Black Epoxy, Phosphated. For all Neodymium Permanent Magnet and Neodymium Permanent Magnet assemblies.
• Magnetization Direction: For all Neodymium Permanent Magnet and Neodymium Permanent Magnet assemblies.
• Demagnetization Curves & Outgoing Inspection Report for each Neodymium Permanent Magnet and Neodymium Permanent Magnet assembly.
Eddy currents (also called Foucault’s currents) are loops of electrical current induced within conductors by a changing magnetic field in the conductor according to Faraday’s law of induction. Eddy currents flow in closed loops within conductors, in planes perpendicular to the magnetic field.
In most cases, the eddy current loss of permanent magnets is much lower than iron loss and copper loss of the motor, but it will generate a large temperature rise in the high-speed motor and the high power density motor.
Ideally, stator magnetic field and rotor magnetic field of PMSM are rotating synchronously, or relatively static, thus permanent magnets without eddy current loss in such case. In fact, there are a series of space and time harmonics are existing in the air gap magnetic field, and these harmonic components are stemming from cogging effect, non-sinusoidal distribution of magnetomotive force and phase current. The harmonic magnetic field will link with rotor magnetic field and hence generated eddy current and caused relevant eddy current loss. It should be also noted that the harmonic magnetic field and eddy current loss will rise with increasing motor speed.
In an electrical machine, the magnetic losses or core losses are due to the soft magnetic material operating in a time-varying magnetic field. Core losses are made up of eddy current losses that arise from circulating electrical currents induced in conducting materials (the electrical steel used in the stator and copper used in the motor windings) and magnetic hysteresis losses which are proportional to the enclosed area of the B–H loop of the particular material. The characteristics required of the soft magnetic material are:
• high saturation induction to minimize weight and volume of the iron parts;
• high permeability for design of a low reluctance magnetic circuit;
• low coercivity to minimize hysteresis losses; and
• high resistivity to minimize eddy current losses (minimization of eddy currents is also achieved by using thin laminations that are covered by a thin insulating layer to provide interlaminar insulation).
Eddy currents are currents which circulate in conductors like swirling eddies in a stream. They are induced by changing magnetic fields and flow in closed loops, perpendicular to the plane of the magnetic field. They can be created when a conductor is moving through a magnetic field, or when the magnetic field surrounding a stationary conductor is varying i.e. anything which results in the conductor experiencing a change in the intensity or direction of a magnetic field can produce eddy currents. The size of the eddy current is proportional to the size of the magnetic field, the area of the loop and the rate of change of magnetic flux, and inversely proportional to the resistivity of the conductor. Segment Samarium Cobalt Laminated Magnets