SGMGV-03D3A61 Yaskawa Phase Electric Asynchronous Servo Motor

 

 

 

Magnets always have two poles: one called north; the other called south. Two north poles always repel each other, as do two south poles. However, north and south poles always attract each other. A magnetic field is defined as a physical field established between to poles. Its intensity and direction determine the forces of attraction or repulsion existing between the two magnets.

 

Figures 1.1 and 1.2 are typical representations of two interacting magnetic poles, and the magnetic field established between them.
Magnets are found in nature in all sorts of shapes and chemical constitution. Magnets used in industry are artificially made. Magnets that sustain their magnetism for long periods of time are denominated “permanent magnets.” These are widely used in several types of electric rotating machines, including synchronous machines. However, due to mechanical, as well as operational reasons, permanent
magnets in synchronous machines are restricted to those with ratings much lower than large turbine-driven generators, which is the subject of this book.

Turbine-driven generators (for short: turbogenerators) take advantage of the fact that magnetic fields can be created by the flow of electric currents in conductors. See Figure 1.3.